vfs_real: Remove redundant copying of std::vector instances in GetFiles() and GetSubdirectories()

We already return by value, so we don't explicitly need to make the
copy.

externals/glad/include/KHR/khrplatform.h

@@ -2,7 +2,7 @@
 #define __khrplatform_h_
 
 /*
-** Copyright (c) 2008-2009 The Khronos Group Inc.
+** Copyright (c) 2008-2018 The Khronos Group Inc.
 **
 ** Permission is hereby granted, free of charge, to any person obtaining a
 ** copy of this software and/or associated documentation files (the
@@ -26,18 +26,16 @@
 
 /* Khronos platform-specific types and definitions.
  *
- * $Revision: 32517 $ on $Date: 2016-03-11 02:41:19 -0800 (Fri, 11 Mar 2016) $
+ * The master copy of khrplatform.h is maintained in the Khronos EGL
+ * Registry repository at https://github.com/KhronosGroup/EGL-Registry
+ * The last semantic modification to khrplatform.h was at commit ID:
+ *      67a3e0864c2d75ea5287b9f3d2eb74a745936692
  *
  * Adopters may modify this file to suit their platform. Adopters are
  * encouraged to submit platform specific modifications to the Khronos
  * group so that they can be included in future versions of this file.
- * Please submit changes by sending them to the public Khronos Bugzilla
- * (http://khronos.org/bugzilla) by filing a bug against product
- * "Khronos (general)" component "Registry".
- *
- * A predefined template which fills in some of the bug fields can be
- * reached using http://tinyurl.com/khrplatform-h-bugreport, but you
- * must create a Bugzilla login first.
+ * Please submit changes by filing pull requests or issues on
+ * the EGL Registry repository linked above.
  *
  *
  * See the Implementer's Guidelines for information about where this file

src/common/common_funcs.h

@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <string>
+
 #if !defined(ARCHITECTURE_x86_64) && !defined(ARCHITECTURE_ARM)
 #include <cstdlib> // for exit
 #endif
@@ -36,40 +38,6 @@
 #define Crash() exit(1)
 #endif
 
-// GCC 4.8 defines all the rotate functions now
-// Small issue with GCC's lrotl/lrotr intrinsics is they are still 32bit while we require 64bit
-#ifdef _rotl
-#define rotl _rotl
-#else
-inline u32 rotl(u32 x, int shift) {
-    shift &= 31;
-    if (!shift)
-        return x;
-    return (x << shift) | (x >> (32 - shift));
-}
-#endif
-
-#ifdef _rotr
-#define rotr _rotr
-#else
-inline u32 rotr(u32 x, int shift) {
-    shift &= 31;
-    if (!shift)
-        return x;
-    return (x >> shift) | (x << (32 - shift));
-}
-#endif
-
-inline u64 _rotl64(u64 x, unsigned int shift) {
-    unsigned int n = shift % 64;
-    return (x << n) | (x >> (64 - n));
-}
-
-inline u64 _rotr64(u64 x, unsigned int shift) {
-    unsigned int n = shift % 64;
-    return (x >> n) | (x << (64 - n));
-}
-
 #else // _MSC_VER
 
 // Locale Cross-Compatibility
@@ -80,17 +48,13 @@ __declspec(dllimport) void __stdcall DebugBreak(void);
 }
 #define Crash() DebugBreak()
 
-// cstdlib provides these on MSVC
-#define rotr _rotr
-#define rotl _rotl
-
 #endif // _MSC_VER ndef
 
 // Generic function to get last error message.
 // Call directly after the command or use the error num.
 // This function might change the error code.
 // Defined in Misc.cpp.
-const char* GetLastErrorMsg();
+std::string GetLastErrorMsg();
 
 namespace Common {
 

src/common/file_util.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <sstream>
 #include "common/assert.h"
 #include "common/common_funcs.h"
 #include "common/common_paths.h"
@@ -386,7 +387,7 @@ u64 GetSize(FILE* f) {
 bool CreateEmptyFile(const std::string& filename) {
     LOG_TRACE(Common_Filesystem, "{}", filename);
 
-    if (!FileUtil::IOFile(filename, "wb")) {
+    if (!FileUtil::IOFile(filename, "wb").IsOpen()) {
         LOG_ERROR(Common_Filesystem, "failed {}: {}", filename, GetLastErrorMsg());
         return false;
     }
@@ -591,7 +592,7 @@ std::string GetBundleDirectory() {
 #endif
 
 #ifdef _WIN32
-std::string& GetExeDirectory() {
+const std::string& GetExeDirectory() {
     static std::string exe_path;
     if (exe_path.empty()) {
         wchar_t wchar_exe_path[2048];
@@ -750,7 +751,7 @@ size_t WriteStringToFile(bool text_file, const std::string& str, const char* fil
 size_t ReadFileToString(bool text_file, const char* filename, std::string& str) {
     IOFile file(filename, text_file ? "r" : "rb");
 
-    if (!file)
+    if (!file.IsOpen())
         return false;
 
     str.resize(static_cast<u32>(file.GetSize()));
@@ -799,6 +800,71 @@ void SplitFilename83(const std::string& filename, std::array<char, 9>& short_nam
     }
 }
 
+std::vector<std::string> SplitPathComponents(const std::string& filename) {
+    auto copy(filename);
+    std::replace(copy.begin(), copy.end(), '\\', '/');
+    std::vector<std::string> out;
+
+    std::stringstream stream(filename);
+    std::string item;
+    while (std::getline(stream, item, '/'))
+        out.push_back(std::move(item));
+
+    return out;
+}
+
+std::string GetParentPath(const std::string& path) {
+    auto out = path;
+    const auto name_bck_index = out.find_last_of('\\');
+    const auto name_fwd_index = out.find_last_of('/');
+    size_t name_index;
+    if (name_bck_index == std::string::npos || name_fwd_index == std::string::npos)
+        name_index = std::min<size_t>(name_bck_index, name_fwd_index);
+    else
+        name_index = std::max<size_t>(name_bck_index, name_fwd_index);
+
+    return out.erase(name_index);
+}
+
+std::string GetPathWithoutTop(std::string path) {
+    if (path.empty())
+        return "";
+    while (path[0] == '\\' || path[0] == '/') {
+        path = path.substr(1);
+        if (path.empty())
+            return "";
+    }
+    const auto name_bck_index = path.find_first_of('\\');
+    const auto name_fwd_index = path.find_first_of('/');
+    return path.substr(std::min<size_t>(name_bck_index, name_fwd_index) + 1);
+    return path.substr(std::min<size_t>(name_bck_index, name_fwd_index) + 1);
+}
+
+std::string GetFilename(std::string path) {
+    std::replace(path.begin(), path.end(), '\\', '/');
+    auto name_index = path.find_last_of('/');
+    if (name_index == std::string::npos)
+        return "";
+    return path.substr(name_index + 1);
+}
+
+std::string GetExtensionFromFilename(const std::string& name) {
+    size_t index = name.find_last_of('.');
+    if (index == std::string::npos)
+        return "";
+
+    return name.substr(index + 1);
+}
+
+std::string RemoveTrailingSlash(const std::string& path) {
+    if (path.empty())
+        return path;
+    if (path.back() == '\\' || path.back() == '/')
+        return path.substr(0, path.size() - 1);
+
+    return path;
+}
+
 IOFile::IOFile() {}
 
 IOFile::IOFile(const std::string& filename, const char openmode[], int flags) {
@@ -820,7 +886,6 @@ IOFile& IOFile::operator=(IOFile&& other) noexcept {
 
 void IOFile::Swap(IOFile& other) noexcept {
     std::swap(m_file, other.m_file);
-    std::swap(m_good, other.m_good);
 }
 
 bool IOFile::Open(const std::string& filename, const char openmode[], int flags) {
@@ -837,16 +902,15 @@ bool IOFile::Open(const std::string& filename, const char openmode[], int flags)
     m_file = fopen(filename.c_str(), openmode);
 #endif
 
-    m_good = IsOpen();
-    return m_good;
+    return IsOpen();
 }
 
 bool IOFile::Close() {
     if (!IsOpen() || 0 != std::fclose(m_file))
-        m_good = false;
+        return false;
 
     m_file = nullptr;
-    return m_good;
+    return true;
 }
 
 u64 IOFile::GetSize() const {
@@ -856,11 +920,8 @@ u64 IOFile::GetSize() const {
     return 0;
 }
 
-bool IOFile::Seek(s64 off, int origin) {
-    if (!IsOpen() || 0 != fseeko(m_file, off, origin))
-        m_good = false;
-
-    return m_good;
+bool IOFile::Seek(s64 off, int origin) const {
+    return IsOpen() && 0 == fseeko(m_file, off, origin);
 }
 
 u64 IOFile::Tell() const {
@@ -871,26 +932,20 @@ u64 IOFile::Tell() const {
 }
 
 bool IOFile::Flush() {
-    if (!IsOpen() || 0 != std::fflush(m_file))
-        m_good = false;
-
-    return m_good;
+    return IsOpen() && 0 == std::fflush(m_file);
 }
 
 bool IOFile::Resize(u64 size) {
-    if (!IsOpen() || 0 !=
+    return IsOpen() && 0 ==
 #ifdef _WIN32
-                         // ector: _chsize sucks, not 64-bit safe
-                         // F|RES: changed to _chsize_s. i think it is 64-bit safe
-                         _chsize_s(_fileno(m_file), size)
+                           // ector: _chsize sucks, not 64-bit safe
+                           // F|RES: changed to _chsize_s. i think it is 64-bit safe
+                           _chsize_s(_fileno(m_file), size)
 #else
-                         // TODO: handle 64bit and growing
-                         ftruncate(fileno(m_file), size)
+                           // TODO: handle 64bit and growing
+                           ftruncate(fileno(m_file), size)
 #endif
-    )
-        m_good = false;
-
-    return m_good;
+        ;
 }
 
 } // namespace FileUtil

src/common/file_util.h

@@ -133,7 +133,7 @@ std::string GetBundleDirectory();
 #endif
 
 #ifdef _WIN32
-std::string& GetExeDirectory();
+const std::string& GetExeDirectory();
 std::string AppDataRoamingDirectory();
 #endif
 
@@ -150,6 +150,34 @@ size_t ReadFileToString(bool text_file, const char* filename, std::string& str);
 void SplitFilename83(const std::string& filename, std::array<char, 9>& short_name,
                      std::array<char, 4>& extension);
 
+// Splits the path on '/' or '\' and put the components into a vector
+// i.e. "C:\Users\Yuzu\Documents\save.bin" becomes {"C:", "Users", "Yuzu", "Documents", "save.bin" }
+std::vector<std::string> SplitPathComponents(const std::string& filename);
+
+// Gets all of the text up to the last '/' or '\' in the path.
+std::string GetParentPath(const std::string& path);
+
+// Gets all of the text after the first '/' or '\' in the path.
+std::string GetPathWithoutTop(std::string path);
+
+// Gets the filename of the path
+std::string GetFilename(std::string path);
+
+// Gets the extension of the filename
+std::string GetExtensionFromFilename(const std::string& name);
+
+// Removes the final '/' or '\' if one exists
+std::string RemoveTrailingSlash(const std::string& path);
+
+// Creates a new vector containing indices [first, last) from the original.
+template <typename T>
+std::vector<T> SliceVector(const std::vector<T>& vector, size_t first, size_t last) {
+    if (first >= last)
+        return {};
+    last = std::min<size_t>(last, vector.size());
+    return std::vector<T>(vector.begin() + first, vector.begin() + first + last);
+}
+
 // simple wrapper for cstdlib file functions to
 // hopefully will make error checking easier
 // and make forgetting an fclose() harder
@@ -172,41 +200,27 @@ public:
     bool Close();
 
     template <typename T>
-    size_t ReadArray(T* data, size_t length) {
+    size_t ReadArray(T* data, size_t length) const {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
 
-        if (!IsOpen()) {
-            m_good = false;
+        if (!IsOpen())
             return -1;
-        }
 
-        size_t items_read = std::fread(data, sizeof(T), length, m_file);
-        if (items_read != length)
-            m_good = false;
-
-        return items_read;
+        return std::fread(data, sizeof(T), length, m_file);
     }
 
     template <typename T>
     size_t WriteArray(const T* data, size_t length) {
         static_assert(std::is_trivially_copyable<T>(),
                       "Given array does not consist of trivially copyable objects");
-
-        if (!IsOpen()) {
-            m_good = false;
+        if (!IsOpen())
             return -1;
-        }
-
-        size_t items_written = std::fwrite(data, sizeof(T), length, m_file);
-        if (items_written != length)
-            m_good = false;
-
-        return items_written;
+        return std::fwrite(data, sizeof(T), length, m_file);
     }
 
     template <typename T>
-    size_t ReadBytes(T* data, size_t length) {
+    size_t ReadBytes(T* data, size_t length) const {
         static_assert(std::is_trivially_copyable<T>(), "T must be trivially copyable");
         return ReadArray(reinterpret_cast<char*>(data), length);
     }
@@ -231,15 +245,7 @@ public:
         return nullptr != m_file;
     }
 
-    // m_good is set to false when a read, write or other function fails
-    bool IsGood() const {
-        return m_good;
-    }
-    explicit operator bool() const {
-        return IsGood();
-    }
-
-    bool Seek(s64 off, int origin);
+    bool Seek(s64 off, int origin) const;
     u64 Tell() const;
     u64 GetSize() const;
     bool Resize(u64 size);
@@ -247,13 +253,11 @@ public:
 
     // clear error state
     void Clear() {
-        m_good = true;
         std::clearerr(m_file);
     }
 
 private:
     std::FILE* m_file = nullptr;
-    bool m_good = true;
 };
 
 } // namespace FileUtil

src/common/logging/backend.cpp

@@ -3,19 +3,20 @@
 // Refer to the license.txt file included.
 
 #include <algorithm>
-#include <array>
+#include <atomic>
 #include <chrono>
 #include <climits>
 #include <condition_variable>
 #include <memory>
+#include <mutex>
 #include <thread>
+#include <vector>
 #ifdef _WIN32
 #include <share.h> // For _SH_DENYWR
 #else
 #define _SH_DENYWR 0
 #endif
 #include "common/assert.h"
-#include "common/common_funcs.h" // snprintf compatibility define
 #include "common/logging/backend.h"
 #include "common/logging/log.h"
 #include "common/logging/text_formatter.h"
@@ -48,11 +49,11 @@ public:
         backends.push_back(std::move(backend));
     }
 
-    void RemoveBackend(const std::string& backend_name) {
+    void RemoveBackend(std::string_view backend_name) {
         std::lock_guard<std::mutex> lock(writing_mutex);
-        auto it = std::remove_if(backends.begin(), backends.end(), [&backend_name](const auto& i) {
-            return !strcmp(i->GetName(), backend_name.c_str());
-        });
+        const auto it =
+            std::remove_if(backends.begin(), backends.end(),
+                           [&backend_name](const auto& i) { return backend_name == i->GetName(); });
         backends.erase(it, backends.end());
     }
 
@@ -64,10 +65,10 @@ public:
         filter = f;
     }
 
-    Backend* GetBackend(const std::string& backend_name) {
-        auto it = std::find_if(backends.begin(), backends.end(), [&backend_name](const auto& i) {
-            return !strcmp(i->GetName(), backend_name.c_str());
-        });
+    Backend* GetBackend(std::string_view backend_name) {
+        const auto it =
+            std::find_if(backends.begin(), backends.end(),
+                         [&backend_name](const auto& i) { return backend_name == i->GetName(); });
         if (it == backends.end())
             return nullptr;
         return it->get();
@@ -265,11 +266,11 @@ void AddBackend(std::unique_ptr<Backend> backend) {
     Impl::Instance().AddBackend(std::move(backend));
 }
 
-void RemoveBackend(const std::string& backend_name) {
+void RemoveBackend(std::string_view backend_name) {
     Impl::Instance().RemoveBackend(backend_name);
 }
 
-Backend* GetBackend(const std::string& backend_name) {
+Backend* GetBackend(std::string_view backend_name) {
     return Impl::Instance().GetBackend(backend_name);
 }
 

src/common/logging/backend.h

@@ -4,10 +4,9 @@
 #pragma once
 
 #include <chrono>
-#include <cstdarg>
 #include <memory>
 #include <string>
-#include <utility>
+#include <string_view>
 #include "common/file_util.h"
 #include "common/logging/filter.h"
 #include "common/logging/log.h"
@@ -106,9 +105,9 @@ private:
 
 void AddBackend(std::unique_ptr<Backend> backend);
 
-void RemoveBackend(const std::string& backend_name);
+void RemoveBackend(std::string_view backend_name);
 
-Backend* GetBackend(const std::string& backend_name);
+Backend* GetBackend(std::string_view backend_name);
 
 /**
  * Returns the name of the passed log class as a C-string. Subclasses are separated by periods

src/common/logging/filter.cpp

@@ -8,39 +8,9 @@
 #include "common/string_util.h"
 
 namespace Log {
-
-Filter::Filter(Level default_level) {
-    ResetAll(default_level);
-}
-
-void Filter::ResetAll(Level level) {
-    class_levels.fill(level);
-}
-
-void Filter::SetClassLevel(Class log_class, Level level) {
-    class_levels[static_cast<size_t>(log_class)] = level;
-}
-
-void Filter::ParseFilterString(const std::string& filter_str) {
-    auto clause_begin = filter_str.cbegin();
-    while (clause_begin != filter_str.cend()) {
-        auto clause_end = std::find(clause_begin, filter_str.cend(), ' ');
-
-        // If clause isn't empty
-        if (clause_end != clause_begin) {
-            ParseFilterRule(clause_begin, clause_end);
-        }
-
-        if (clause_end != filter_str.cend()) {
-            // Skip over the whitespace
-            ++clause_end;
-        }
-        clause_begin = clause_end;
-    }
-}
-
+namespace {
 template <typename It>
-static Level GetLevelByName(const It begin, const It end) {
+Level GetLevelByName(const It begin, const It end) {
     for (u8 i = 0; i < static_cast<u8>(Level::Count); ++i) {
         const char* level_name = GetLevelName(static_cast<Level>(i));
         if (Common::ComparePartialString(begin, end, level_name)) {
@@ -51,7 +21,7 @@ static Level GetLevelByName(const It begin, const It end) {
 }
 
 template <typename It>
-static Class GetClassByName(const It begin, const It end) {
+Class GetClassByName(const It begin, const It end) {
     for (ClassType i = 0; i < static_cast<ClassType>(Class::Count); ++i) {
         const char* level_name = GetLogClassName(static_cast<Class>(i));
         if (Common::ComparePartialString(begin, end, level_name)) {
@@ -61,8 +31,8 @@ static Class GetClassByName(const It begin, const It end) {
     return Class::Count;
 }
 
-bool Filter::ParseFilterRule(const std::string::const_iterator begin,
-                             const std::string::const_iterator end) {
+template <typename Iterator>
+bool ParseFilterRule(Filter& instance, Iterator begin, Iterator end) {
     auto level_separator = std::find(begin, end, ':');
     if (level_separator == end) {
         LOG_ERROR(Log, "Invalid log filter. Must specify a log level after `:`: {}",
@@ -77,7 +47,7 @@ bool Filter::ParseFilterRule(const std::string::const_iterator begin,
     }
 
     if (Common::ComparePartialString(begin, level_separator, "*")) {
-        ResetAll(level);
+        instance.ResetAll(level);
         return true;
     }
 
@@ -87,9 +57,40 @@ bool Filter::ParseFilterRule(const std::string::const_iterator begin,
         return false;
     }
 
-    SetClassLevel(log_class, level);
+    instance.SetClassLevel(log_class, level);
     return true;
 }
+} // Anonymous namespace
+
+Filter::Filter(Level default_level) {
+    ResetAll(default_level);
+}
+
+void Filter::ResetAll(Level level) {
+    class_levels.fill(level);
+}
+
+void Filter::SetClassLevel(Class log_class, Level level) {
+    class_levels[static_cast<size_t>(log_class)] = level;
+}
+
+void Filter::ParseFilterString(std::string_view filter_view) {
+    auto clause_begin = filter_view.cbegin();
+    while (clause_begin != filter_view.cend()) {
+        auto clause_end = std::find(clause_begin, filter_view.cend(), ' ');
+
+        // If clause isn't empty
+        if (clause_end != clause_begin) {
+            ParseFilterRule(*this, clause_begin, clause_end);
+        }
+
+        if (clause_end != filter_view.cend()) {
+            // Skip over the whitespace
+            ++clause_end;
+        }
+        clause_begin = clause_end;
+    }
+}
 
 bool Filter::CheckMessage(Class log_class, Level level) const {
     return static_cast<u8>(level) >= static_cast<u8>(class_levels[static_cast<size_t>(log_class)]);

src/common/logging/filter.h

@@ -6,7 +6,7 @@
 
 #include <array>
 #include <cstddef>
-#include <string>
+#include <string_view>
 #include "common/logging/log.h"
 
 namespace Log {
@@ -40,9 +40,7 @@ public:
      *  - `Service:Info` -- Sets the level of Service to Info.
      *  - `Service.FS:Trace` -- Sets the level of the Service.FS class to Trace.
      */
-    void ParseFilterString(const std::string& filter_str);
-    bool ParseFilterRule(const std::string::const_iterator start,
-                         const std::string::const_iterator end);
+    void ParseFilterString(std::string_view filter_view);
 
     /// Matches class/level combination against the filter, returning true if it passed.
     bool CheckMessage(Class log_class, Level level) const;

src/common/logging/log.h

@@ -103,7 +103,7 @@ template <typename... Args>
 void FmtLogMessage(Class log_class, Level log_level, const char* filename, unsigned int line_num,
                    const char* function, const char* format, const Args&... args) {
     FmtLogMessageImpl(log_class, log_level, filename, line_num, function, format,
-                      fmt::make_args(args...));
+                      fmt::make_format_args(args...));
 }
 
 } // namespace Log

src/common/misc.cpp

@@ -4,34 +4,28 @@
 
 #include <cstddef>
 #ifdef _WIN32
-#include <windows.h>
+#include <Windows.h>
 #else
 #include <cerrno>
 #include <cstring>
 #endif
 
-// Neither Android nor OS X support TLS
-#if defined(__APPLE__) || (ANDROID && __clang__)
-#define __thread
-#endif
+#include "common/common_funcs.h"
 
 // Generic function to get last error message.
 // Call directly after the command or use the error num.
 // This function might change the error code.
-const char* GetLastErrorMsg() {
+std::string GetLastErrorMsg() {
     static const size_t buff_size = 255;
+    char err_str[buff_size];
 
 #ifdef _WIN32
-    static __declspec(thread) char err_str[buff_size] = {};
-
     FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM, nullptr, GetLastError(),
                    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), err_str, buff_size, nullptr);
 #else
-    static __thread char err_str[buff_size] = {};
-
     // Thread safe (XSI-compliant)
     strerror_r(errno, err_str, buff_size);
 #endif
 
-    return err_str;
+    return std::string(err_str, buff_size);
 }

src/common/param_package.cpp

@@ -3,7 +3,9 @@
 // Refer to the license.txt file included.
 
 #include <array>
+#include <utility>
 #include <vector>
+
 #include "common/logging/log.h"
 #include "common/param_package.h"
 #include "common/string_util.h"
@@ -12,10 +14,11 @@ namespace Common {
 
 constexpr char KEY_VALUE_SEPARATOR = ':';
 constexpr char PARAM_SEPARATOR = ',';
+
 constexpr char ESCAPE_CHARACTER = '$';
-const std::string KEY_VALUE_SEPARATOR_ESCAPE{ESCAPE_CHARACTER, '0'};
-const std::string PARAM_SEPARATOR_ESCAPE{ESCAPE_CHARACTER, '1'};
-const std::string ESCAPE_CHARACTER_ESCAPE{ESCAPE_CHARACTER, '2'};
+constexpr char KEY_VALUE_SEPARATOR_ESCAPE[] = "$0";
+constexpr char PARAM_SEPARATOR_ESCAPE[] = "$1";
+constexpr char ESCAPE_CHARACTER_ESCAPE[] = "$2";
 
 ParamPackage::ParamPackage(const std::string& serialized) {
     std::vector<std::string> pairs;
@@ -35,7 +38,7 @@ ParamPackage::ParamPackage(const std::string& serialized) {
             part = Common::ReplaceAll(part, ESCAPE_CHARACTER_ESCAPE, {ESCAPE_CHARACTER});
         }
 
-        Set(key_value[0], key_value[1]);
+        Set(key_value[0], std::move(key_value[1]));
     }
 }
 
@@ -101,16 +104,16 @@ float ParamPackage::Get(const std::string& key, float default_value) const {
     }
 }
 
-void ParamPackage::Set(const std::string& key, const std::string& value) {
-    data[key] = value;
+void ParamPackage::Set(const std::string& key, std::string value) {
+    data.insert_or_assign(key, std::move(value));
 }
 
 void ParamPackage::Set(const std::string& key, int value) {
-    data[key] = std::to_string(value);
+    data.insert_or_assign(key, std::to_string(value));
 }
 
 void ParamPackage::Set(const std::string& key, float value) {
-    data[key] = std::to_string(value);
+    data.insert_or_assign(key, std::to_string(value));
 }
 
 bool ParamPackage::Has(const std::string& key) const {

src/common/param_package.h

@@ -28,7 +28,7 @@ public:
     std::string Get(const std::string& key, const std::string& default_value) const;
     int Get(const std::string& key, int default_value) const;
     float Get(const std::string& key, float default_value) const;
-    void Set(const std::string& key, const std::string& value);
+    void Set(const std::string& key, std::string value);
     void Set(const std::string& key, int value);
     void Set(const std::string& key, float value);
     bool Has(const std::string& key) const;

src/common/string_util.cpp

@@ -34,18 +34,6 @@ std::string ToUpper(std::string str) {
     return str;
 }
 
-// faster than sscanf
-bool AsciiToHex(const char* _szValue, u32& result) {
-    char* endptr = nullptr;
-    const u32 value = strtoul(_szValue, &endptr, 16);
-
-    if (!endptr || *endptr)
-        return false;
-
-    result = value;
-    return true;
-}
-
 // For Debugging. Read out an u8 array.
 std::string ArrayToString(const u8* data, size_t size, int line_len, bool spaces) {
     std::ostringstream oss;

src/common/string_util.h

@@ -57,9 +57,6 @@ static bool TryParse(const std::string& str, N* const output) {
         return false;
 }
 
-// TODO: kill this
-bool AsciiToHex(const char* _szValue, u32& result);
-
 std::string TabsToSpaces(int tab_size, const std::string& in);
 
 void SplitString(const std::string& str, char delim, std::vector<std::string>& output);

src/common/swap.h

@@ -167,7 +167,7 @@ inline double swapd(double f) {
 
 template <typename T, typename F>
 struct swap_struct_t {
-    typedef swap_struct_t<T, F> swapped_t;
+    using swapped_t = swap_struct_t;
 
 protected:
     T value = T();
@@ -177,7 +177,7 @@ protected:
     }
 
 public:
-    T const swap() const {
+    T swap() const {
         return swap(value);
     }
     swap_struct_t() = default;
@@ -185,39 +185,39 @@ public:
 
     template <typename S>
     swapped_t& operator=(const S& source) {
-        value = swap((T)source);
+        value = swap(static_cast<T>(source));
         return *this;
     }
 
     operator s8() const {
-        return (s8)swap();
+        return static_cast<s8>(swap());
     }
     operator u8() const {
-        return (u8)swap();
+        return static_cast<u8>(swap());
     }
     operator s16() const {
-        return (s16)swap();
+        return static_cast<s16>(swap());
     }
     operator u16() const {
-        return (u16)swap();
+        return static_cast<u16>(swap());
     }
     operator s32() const {
-        return (s32)swap();
+        return static_cast<s32>(swap());
     }
     operator u32() const {
-        return (u32)swap();
+        return static_cast<u32>(swap());
     }
     operator s64() const {
-        return (s64)swap();
+        return static_cast<s64>(swap());
     }
     operator u64() const {
-        return (u64)swap();
+        return static_cast<u64>(swap());
     }
     operator float() const {
-        return (float)swap();
+        return static_cast<float>(swap());
     }
     operator double() const {
-        return (double)swap();
+        return static_cast<double>(swap());
     }
 
     // +v
@@ -253,7 +253,7 @@ public:
     }
     template <typename S>
     swapped_t operator+(const S& i) const {
-        return swap() + (T)i;
+        return swap() + static_cast<T>(i);
     }
     // v - 5
     swapped_t operator-(const swapped_t& i) const {
@@ -261,7 +261,7 @@ public:
     }
     template <typename S>
     swapped_t operator-(const S& i) const {
-        return swap() - (T)i;
+        return swap() - static_cast<T>(i);
     }
 
     // v += 5
@@ -271,7 +271,7 @@ public:
     }
     template <typename S>
     swapped_t& operator+=(const S& i) {
-        value = swap(swap() + (T)i);
+        value = swap(swap() + static_cast<T>(i));
         return *this;
     }
     // v -= 5
@@ -281,7 +281,7 @@ public:
     }
     template <typename S>
     swapped_t& operator-=(const S& i) {
-        value = swap(swap() - (T)i);
+        value = swap(swap() - static_cast<T>(i));
         return *this;
     }
 
@@ -541,7 +541,7 @@ S operator&(const S& i, const swap_struct_t<T, F> v) {
 
 template <typename S, typename T, typename F>
 S operator&(const swap_struct_t<T, F> v, const S& i) {
-    return (S)(v.swap() & i);
+    return static_cast<S>(v.swap() & i);
 }
 
 // Comparaison
@@ -606,51 +606,51 @@ struct swap_double_t {
 };
 
 #if COMMON_LITTLE_ENDIAN
-typedef u32 u32_le;
-typedef u16 u16_le;
-typedef u64 u64_le;
+using u16_le = u16;
+using u32_le = u32;
+using u64_le = u64;
 
-typedef s32 s32_le;
-typedef s16 s16_le;
-typedef s64 s64_le;
+using s16_le = s16;
+using s32_le = s32;
+using s64_le = s64;
 
-typedef float float_le;
-typedef double double_le;
+using float_le = float;
+using double_le = double;
 
-typedef swap_struct_t<u64, swap_64_t<u64>> u64_be;
-typedef swap_struct_t<s64, swap_64_t<s64>> s64_be;
+using u64_be = swap_struct_t<u64, swap_64_t<u64>>;
+using s64_be = swap_struct_t<s64, swap_64_t<s64>>;
 
-typedef swap_struct_t<u32, swap_32_t<u32>> u32_be;
-typedef swap_struct_t<s32, swap_32_t<s32>> s32_be;
+using u32_be = swap_struct_t<u32, swap_32_t<u32>>;
+using s32_be = swap_struct_t<s32, swap_32_t<s32>>;
 
-typedef swap_struct_t<u16, swap_16_t<u16>> u16_be;
-typedef swap_struct_t<s16, swap_16_t<s16>> s16_be;
+using u16_be = swap_struct_t<u16, swap_16_t<u16>>;
+using s16_be = swap_struct_t<s16, swap_16_t<s16>>;
 
-typedef swap_struct_t<float, swap_float_t<float>> float_be;
-typedef swap_struct_t<double, swap_double_t<double>> double_be;
+using float_be = swap_struct_t<float, swap_float_t<float>>;
+using double_be = swap_struct_t<double, swap_double_t<double>>;
 #else
 
-typedef swap_struct_t<u64, swap_64_t<u64>> u64_le;
-typedef swap_struct_t<s64, swap_64_t<s64>> s64_le;
+using u64_le = swap_struct_t<u64, swap_64_t<u64>>;
+using s64_le = swap_struct_t<s64, swap_64_t<s64>>;
 
-typedef swap_struct_t<u32, swap_32_t<u32>> u32_le;
-typedef swap_struct_t<s32, swap_32_t<s32>> s32_le;
+using u32_le = swap_struct_t<u32, swap_32_t<u32>>;
+using s32_le = swap_struct_t<s32, swap_32_t<s32>>;
 
-typedef swap_struct_t<u16, swap_16_t<u16>> u16_le;
-typedef swap_struct_t<s16, swap_16_t<s16>> s16_le;
+using u16_le = swap_struct_t<u16, swap_16_t<u16>>;
+using s16_le = swap_struct_t<s16, swap_16_t<s16>>;
 
-typedef swap_struct_t<float, swap_float_t<float>> float_le;
-typedef swap_struct_t<double, swap_double_t<double>> double_le;
+using float_le = swap_struct_t<float, swap_float_t<float>>;
+using double_le = swap_struct_t<double, swap_double_t<double>>;
 
-typedef u32 u32_be;
-typedef u16 u16_be;
-typedef u64 u64_be;
+using u16_be = u16;
+using u32_be = u32;
+using u64_be = u64;
 
-typedef s32 s32_be;
-typedef s16 s16_be;
-typedef s64 s64_be;
+using s16_be = s16;
+using s32_be = s32;
+using s64_be = s64;
 
-typedef float float_be;
-typedef double double_be;
+using float_be = float;
+using double_be = double;
 
 #endif

src/common/telemetry.h

@@ -52,27 +52,14 @@ public:
 template <typename T>
 class Field : public FieldInterface {
 public:
-    Field(FieldType type, std::string name, const T& value)
-        : name(std::move(name)), type(type), value(value) {}
-
-    Field(FieldType type, std::string name, T&& value)
+    Field(FieldType type, std::string name, T value)
         : name(std::move(name)), type(type), value(std::move(value)) {}
 
-    Field(const Field& other) : Field(other.type, other.name, other.value) {}
+    Field(const Field&) = default;
+    Field& operator=(const Field&) = default;
 
-    Field& operator=(const Field& other) {
-        type = other.type;
-        name = other.name;
-        value = other.value;
-        return *this;
-    }
-
-    Field& operator=(Field&& other) {
-        type = other.type;
-        name = std::move(other.name);
-        value = std::move(other.value);
-        return *this;
-    }
+    Field(Field&&) = default;
+    Field& operator=(Field&& other) = default;
 
     void Accept(VisitorInterface& visitor) const override;
 
@@ -94,11 +81,11 @@ public:
         return value;
     }
 
-    inline bool operator==(const Field<T>& other) {
+    bool operator==(const Field& other) const {
         return (type == other.type) && (name == other.name) && (value == other.value);
     }
 
-    inline bool operator!=(const Field<T>& other) {
+    bool operator!=(const Field& other) const {
         return !(*this == other);
     }
 

src/core/CMakeLists.txt

@@ -8,27 +8,27 @@ add_library(core STATIC
     core_cpu.h
     core_timing.cpp
     core_timing.h
+    file_sys/content_archive.cpp
+    file_sys/content_archive.h
     file_sys/directory.h
-    file_sys/disk_filesystem.cpp
-    file_sys/disk_filesystem.h
     file_sys/errors.h
-    file_sys/filesystem.cpp
-    file_sys/filesystem.h
+    file_sys/mode.h
     file_sys/partition_filesystem.cpp
     file_sys/partition_filesystem.h
-    file_sys/path_parser.cpp
-    file_sys/path_parser.h
     file_sys/program_metadata.cpp
     file_sys/program_metadata.h
     file_sys/romfs_factory.cpp
     file_sys/romfs_factory.h
-    file_sys/romfs_filesystem.cpp
-    file_sys/romfs_filesystem.h
     file_sys/savedata_factory.cpp
     file_sys/savedata_factory.h
     file_sys/sdmc_factory.cpp
     file_sys/sdmc_factory.h
-    file_sys/storage.h
+    file_sys/vfs.cpp
+    file_sys/vfs.h
+    file_sys/vfs_offset.cpp
+    file_sys/vfs_offset.h
+    file_sys/vfs_real.cpp
+    file_sys/vfs_real.h
     frontend/emu_window.cpp
     frontend/emu_window.h
     frontend/framebuffer_layout.cpp

src/core/core.cpp

@@ -19,17 +19,20 @@
 #include "core/loader/loader.h"
 #include "core/memory_setup.h"
 #include "core/settings.h"
+#include "file_sys/vfs_real.h"
 #include "video_core/video_core.h"
 
 namespace Core {
 
 /*static*/ System System::s_instance;
 
+System::System() = default;
+
 System::~System() = default;
 
 /// Runs a CPU core while the system is powered on
 static void RunCpuCore(std::shared_ptr<Cpu> cpu_state) {
-    while (Core::System().GetInstance().IsPoweredOn()) {
+    while (Core::System::GetInstance().IsPoweredOn()) {
         cpu_state->RunLoop(true);
     }
 }
@@ -84,7 +87,7 @@ System::ResultStatus System::SingleStep() {
 }
 
 System::ResultStatus System::Load(EmuWindow* emu_window, const std::string& filepath) {
-    app_loader = Loader::GetLoader(filepath);
+    app_loader = Loader::GetLoader(std::make_shared<FileSys::RealVfsFile>(filepath));
 
     if (!app_loader) {
         LOG_CRITICAL(Core, "Failed to obtain loader for {}!", filepath);

src/core/core.h

@@ -168,6 +168,8 @@ public:
     }
 
 private:
+    System();
+
     /// Returns the currently running CPU core
     Cpu& CurrentCpuCore();
 

src/core/file_sys/content_archive.cpp

@@ -0,0 +1,170 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <utility>
+
+#include "common/logging/log.h"
+#include "core/file_sys/content_archive.h"
+#include "core/file_sys/vfs_offset.h"
+#include "core/loader/loader.h"
+
+namespace FileSys {
+
+// Media offsets in headers are stored divided by 512. Mult. by this to get real offset.
+constexpr u64 MEDIA_OFFSET_MULTIPLIER = 0x200;
+
+constexpr u64 SECTION_HEADER_SIZE = 0x200;
+constexpr u64 SECTION_HEADER_OFFSET = 0x400;
+
+constexpr u32 IVFC_MAX_LEVEL = 6;
+
+enum class NCASectionFilesystemType : u8 {
+    PFS0 = 0x2,
+    ROMFS = 0x3,
+};
+
+struct NCASectionHeaderBlock {
+    INSERT_PADDING_BYTES(3);
+    NCASectionFilesystemType filesystem_type;
+    u8 crypto_type;
+    INSERT_PADDING_BYTES(3);
+};
+static_assert(sizeof(NCASectionHeaderBlock) == 0x8, "NCASectionHeaderBlock has incorrect size.");
+
+struct PFS0Superblock {
+    NCASectionHeaderBlock header_block;
+    std::array<u8, 0x20> hash;
+    u32_le size;
+    INSERT_PADDING_BYTES(4);
+    u64_le hash_table_offset;
+    u64_le hash_table_size;
+    u64_le pfs0_header_offset;
+    u64_le pfs0_size;
+    INSERT_PADDING_BYTES(432);
+};
+static_assert(sizeof(PFS0Superblock) == 0x200, "PFS0Superblock has incorrect size.");
+
+struct IVFCLevel {
+    u64_le offset;
+    u64_le size;
+    u32_le block_size;
+    u32_le reserved;
+};
+static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
+
+struct RomFSSuperblock {
+    NCASectionHeaderBlock header_block;
+    u32_le magic;
+    u32_le magic_number;
+    INSERT_PADDING_BYTES(8);
+    std::array<IVFCLevel, 6> levels;
+    INSERT_PADDING_BYTES(64);
+};
+static_assert(sizeof(RomFSSuperblock) == 0xE8, "RomFSSuperblock has incorrect size.");
+
+NCA::NCA(VirtualFile file_) : file(std::move(file_)) {
+    if (sizeof(NCAHeader) != file->ReadObject(&header))
+        LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+    if (!IsValidNCA(header)) {
+        status = Loader::ResultStatus::ErrorInvalidFormat;
+        return;
+    }
+
+    std::ptrdiff_t number_sections =
+        std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
+                      [](NCASectionTableEntry entry) { return entry.media_offset > 0; });
+
+    for (std::ptrdiff_t i = 0; i < number_sections; ++i) {
+        // Seek to beginning of this section.
+        NCASectionHeaderBlock block{};
+        if (sizeof(NCASectionHeaderBlock) !=
+            file->ReadObject(&block, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
+            LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+        if (block.filesystem_type == NCASectionFilesystemType::ROMFS) {
+            RomFSSuperblock sb{};
+            if (sizeof(RomFSSuperblock) !=
+                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
+                LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+            const size_t romfs_offset =
+                header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER +
+                sb.levels[IVFC_MAX_LEVEL - 1].offset;
+            const size_t romfs_size = sb.levels[IVFC_MAX_LEVEL - 1].size;
+            files.emplace_back(std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset));
+            romfs = files.back();
+        } else if (block.filesystem_type == NCASectionFilesystemType::PFS0) {
+            PFS0Superblock sb{};
+            // Seek back to beginning of this section.
+            if (sizeof(PFS0Superblock) !=
+                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
+                LOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+            u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
+                          MEDIA_OFFSET_MULTIPLIER) +
+                         sb.pfs0_header_offset;
+            u64 size = MEDIA_OFFSET_MULTIPLIER * (header.section_tables[i].media_end_offset -
+                                                  header.section_tables[i].media_offset);
+            auto npfs = std::make_shared<PartitionFilesystem>(
+                std::make_shared<OffsetVfsFile>(file, size, offset));
+
+            if (npfs->GetStatus() == Loader::ResultStatus::Success) {
+                dirs.emplace_back(npfs);
+                if (IsDirectoryExeFS(dirs.back()))
+                    exefs = dirs.back();
+            }
+        }
+    }
+
+    status = Loader::ResultStatus::Success;
+}
+
+Loader::ResultStatus NCA::GetStatus() const {
+    return status;
+}
+
+std::vector<std::shared_ptr<VfsFile>> NCA::GetFiles() const {
+    if (status != Loader::ResultStatus::Success)
+        return {};
+    return files;
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> NCA::GetSubdirectories() const {
+    if (status != Loader::ResultStatus::Success)
+        return {};
+    return dirs;
+}
+
+std::string NCA::GetName() const {
+    return file->GetName();
+}
+
+std::shared_ptr<VfsDirectory> NCA::GetParentDirectory() const {
+    return file->GetContainingDirectory();
+}
+
+NCAContentType NCA::GetType() const {
+    return header.content_type;
+}
+
+u64 NCA::GetTitleId() const {
+    if (status != Loader::ResultStatus::Success)
+        return {};
+    return header.title_id;
+}
+
+VirtualFile NCA::GetRomFS() const {
+    return romfs;
+}
+
+VirtualDir NCA::GetExeFS() const {
+    return exefs;
+}
+
+bool NCA::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    return false;
+}
+} // namespace FileSys

src/core/file_sys/content_archive.h

@@ -0,0 +1,100 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "common/common_funcs.h"
+#include "common/common_types.h"
+#include "common/swap.h"
+#include "core/file_sys/partition_filesystem.h"
+
+namespace FileSys {
+
+enum class NCAContentType : u8 {
+    Program = 0,
+    Meta = 1,
+    Control = 2,
+    Manual = 3,
+    Data = 4,
+};
+
+struct NCASectionTableEntry {
+    u32_le media_offset;
+    u32_le media_end_offset;
+    INSERT_PADDING_BYTES(0x8);
+};
+static_assert(sizeof(NCASectionTableEntry) == 0x10, "NCASectionTableEntry has incorrect size.");
+
+struct NCAHeader {
+    std::array<u8, 0x100> rsa_signature_1;
+    std::array<u8, 0x100> rsa_signature_2;
+    u32_le magic;
+    u8 is_system;
+    NCAContentType content_type;
+    u8 crypto_type;
+    u8 key_index;
+    u64_le size;
+    u64_le title_id;
+    INSERT_PADDING_BYTES(0x4);
+    u32_le sdk_version;
+    u8 crypto_type_2;
+    INSERT_PADDING_BYTES(15);
+    std::array<u8, 0x10> rights_id;
+    std::array<NCASectionTableEntry, 0x4> section_tables;
+    std::array<std::array<u8, 0x20>, 0x4> hash_tables;
+    std::array<std::array<u8, 0x10>, 0x4> key_area;
+    INSERT_PADDING_BYTES(0xC0);
+};
+static_assert(sizeof(NCAHeader) == 0x400, "NCAHeader has incorrect size.");
+
+inline bool IsDirectoryExeFS(const std::shared_ptr<VfsDirectory>& pfs) {
+    // According to switchbrew, an exefs must only contain these two files:
+    return pfs->GetFile("main") != nullptr && pfs->GetFile("main.npdm") != nullptr;
+}
+
+inline bool IsValidNCA(const NCAHeader& header) {
+    return header.magic == Common::MakeMagic('N', 'C', 'A', '2') ||
+           header.magic == Common::MakeMagic('N', 'C', 'A', '3');
+}
+
+// An implementation of VfsDirectory that represents a Nintendo Content Archive (NCA) conatiner.
+// After construction, use GetStatus to determine if the file is valid and ready to be used.
+class NCA : public ReadOnlyVfsDirectory {
+public:
+    explicit NCA(VirtualFile file);
+    Loader::ResultStatus GetStatus() const;
+
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+    std::string GetName() const override;
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+
+    NCAContentType GetType() const;
+    u64 GetTitleId() const;
+
+    VirtualFile GetRomFS() const;
+    VirtualDir GetExeFS() const;
+
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+
+private:
+    std::vector<VirtualDir> dirs;
+    std::vector<VirtualFile> files;
+
+    VirtualFile romfs = nullptr;
+    VirtualDir exefs = nullptr;
+    VirtualFile file;
+
+    NCAHeader header{};
+
+    Loader::ResultStatus status{};
+};
+
+} // namespace FileSys

src/core/file_sys/directory.h

@@ -8,13 +8,17 @@
 #include <cstddef>
 #include "common/common_funcs.h"
 #include "common/common_types.h"
-#include "core/file_sys/filesystem.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // FileSys namespace
 
 namespace FileSys {
 
+enum EntryType : u8 {
+    Directory = 0,
+    File = 1,
+};
+
 // Structure of a directory entry, from
 // http://switchbrew.org/index.php?title=Filesystem_services#DirectoryEntry
 const size_t FILENAME_LENGTH = 0x300;

src/core/file_sys/disk_filesystem.cpp

@@ -1,239 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <cstring>
-#include <memory>
-#include "common/common_types.h"
-#include "common/logging/log.h"
-#include "core/file_sys/disk_filesystem.h"
-#include "core/file_sys/errors.h"
-
-namespace FileSys {
-
-static std::string ModeFlagsToString(Mode mode) {
-    std::string mode_str;
-    u32 mode_flags = static_cast<u32>(mode);
-
-    // Calculate the correct open mode for the file.
-    if ((mode_flags & static_cast<u32>(Mode::Read)) &&
-        (mode_flags & static_cast<u32>(Mode::Write))) {
-        if (mode_flags & static_cast<u32>(Mode::Append))
-            mode_str = "a+";
-        else
-            mode_str = "r+";
-    } else {
-        if (mode_flags & static_cast<u32>(Mode::Read))
-            mode_str = "r";
-        else if (mode_flags & static_cast<u32>(Mode::Append))
-            mode_str = "a";
-        else if (mode_flags & static_cast<u32>(Mode::Write))
-            mode_str = "w";
-    }
-
-    mode_str += "b";
-
-    return mode_str;
-}
-
-std::string Disk_FileSystem::GetName() const {
-    return "Disk";
-}
-
-ResultVal<std::unique_ptr<StorageBackend>> Disk_FileSystem::OpenFile(const std::string& path,
-                                                                     Mode mode) const {
-
-    // Calculate the correct open mode for the file.
-    std::string mode_str = ModeFlagsToString(mode);
-
-    std::string full_path = base_directory + path;
-    auto file = std::make_shared<FileUtil::IOFile>(full_path, mode_str.c_str());
-
-    if (!file->IsOpen()) {
-        return ERROR_PATH_NOT_FOUND;
-    }
-
-    return MakeResult<std::unique_ptr<StorageBackend>>(
-        std::make_unique<Disk_Storage>(std::move(file)));
-}
-
-ResultCode Disk_FileSystem::DeleteFile(const std::string& path) const {
-    std::string full_path = base_directory + path;
-
-    if (!FileUtil::Exists(full_path)) {
-        return ERROR_PATH_NOT_FOUND;
-    }
-
-    FileUtil::Delete(full_path);
-
-    return RESULT_SUCCESS;
-}
-
-ResultCode Disk_FileSystem::RenameFile(const std::string& src_path,
-                                       const std::string& dest_path) const {
-    const std::string full_src_path = base_directory + src_path;
-    const std::string full_dest_path = base_directory + dest_path;
-
-    if (!FileUtil::Exists(full_src_path)) {
-        return ERROR_PATH_NOT_FOUND;
-    }
-    // TODO(wwylele): Use correct error code
-    return FileUtil::Rename(full_src_path, full_dest_path) ? RESULT_SUCCESS : ResultCode(-1);
-}
-
-ResultCode Disk_FileSystem::DeleteDirectory(const Path& path) const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode Disk_FileSystem::DeleteDirectoryRecursively(const Path& path) const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode Disk_FileSystem::CreateFile(const std::string& path, u64 size) const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-
-    std::string full_path = base_directory + path;
-    if (size == 0) {
-        FileUtil::CreateEmptyFile(full_path);
-        return RESULT_SUCCESS;
-    }
-
-    FileUtil::IOFile file(full_path, "wb");
-    // Creates a sparse file (or a normal file on filesystems without the concept of sparse files)
-    // We do this by seeking to the right size, then writing a single null byte.
-    if (file.Seek(size - 1, SEEK_SET) && file.WriteBytes("", 1) == 1) {
-        return RESULT_SUCCESS;
-    }
-
-    LOG_ERROR(Service_FS, "Too large file");
-    // TODO(Subv): Find out the correct error code
-    return ResultCode(-1);
-}
-
-ResultCode Disk_FileSystem::CreateDirectory(const std::string& path) const {
-    // TODO(Subv): Perform path validation to prevent escaping the emulator sandbox.
-    std::string full_path = base_directory + path;
-
-    if (FileUtil::CreateDir(full_path)) {
-        return RESULT_SUCCESS;
-    }
-
-    LOG_CRITICAL(Service_FS, "(unreachable) Unknown error creating {}", full_path);
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode Disk_FileSystem::RenameDirectory(const Path& src_path, const Path& dest_path) const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultVal<std::unique_ptr<DirectoryBackend>> Disk_FileSystem::OpenDirectory(
-    const std::string& path) const {
-
-    std::string full_path = base_directory + path;
-
-    if (!FileUtil::IsDirectory(full_path)) {
-        // TODO(Subv): Find the correct error code for this.
-        return ResultCode(-1);
-    }
-
-    auto directory = std::make_unique<Disk_Directory>(full_path);
-    return MakeResult<std::unique_ptr<DirectoryBackend>>(std::move(directory));
-}
-
-u64 Disk_FileSystem::GetFreeSpaceSize() const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-    return 0;
-}
-
-ResultVal<FileSys::EntryType> Disk_FileSystem::GetEntryType(const std::string& path) const {
-    std::string full_path = base_directory + path;
-    if (!FileUtil::Exists(full_path)) {
-        return ERROR_PATH_NOT_FOUND;
-    }
-
-    if (FileUtil::IsDirectory(full_path))
-        return MakeResult(EntryType::Directory);
-
-    return MakeResult(EntryType::File);
-}
-
-ResultVal<size_t> Disk_Storage::Read(const u64 offset, const size_t length, u8* buffer) const {
-    LOG_TRACE(Service_FS, "called offset={}, length={}", offset, length);
-    file->Seek(offset, SEEK_SET);
-    return MakeResult<size_t>(file->ReadBytes(buffer, length));
-}
-
-ResultVal<size_t> Disk_Storage::Write(const u64 offset, const size_t length, const bool flush,
-                                      const u8* buffer) const {
-    LOG_WARNING(Service_FS, "(STUBBED) called");
-    file->Seek(offset, SEEK_SET);
-    size_t written = file->WriteBytes(buffer, length);
-    if (flush) {
-        file->Flush();
-    }
-    return MakeResult<size_t>(written);
-}
-
-u64 Disk_Storage::GetSize() const {
-    return file->GetSize();
-}
-
-bool Disk_Storage::SetSize(const u64 size) const {
-    file->Resize(size);
-    file->Flush();
-    return true;
-}
-
-Disk_Directory::Disk_Directory(const std::string& path) {
-    unsigned size = FileUtil::ScanDirectoryTree(path, directory);
-    directory.size = size;
-    directory.isDirectory = true;
-    children_iterator = directory.children.begin();
-}
-
-u64 Disk_Directory::Read(const u64 count, Entry* entries) {
-    u64 entries_read = 0;
-
-    while (entries_read < count && children_iterator != directory.children.cend()) {
-        const FileUtil::FSTEntry& file = *children_iterator;
-        const std::string& filename = file.virtualName;
-        Entry& entry = entries[entries_read];
-
-        LOG_TRACE(Service_FS, "File {}: size={} dir={}", filename, file.size, file.isDirectory);
-
-        // TODO(Link Mauve): use a proper conversion to UTF-16.
-        for (size_t j = 0; j < FILENAME_LENGTH; ++j) {
-            entry.filename[j] = filename[j];
-            if (!filename[j])
-                break;
-        }
-
-        if (file.isDirectory) {
-            entry.file_size = 0;
-            entry.type = EntryType::Directory;
-        } else {
-            entry.file_size = file.size;
-            entry.type = EntryType::File;
-        }
-
-        ++entries_read;
-        ++children_iterator;
-    }
-    return entries_read;
-}
-
-u64 Disk_Directory::GetEntryCount() const {
-    // We convert the children iterator into a const_iterator to allow template argument deduction
-    // in std::distance.
-    std::vector<FileUtil::FSTEntry>::const_iterator current = children_iterator;
-    return std::distance(current, directory.children.end());
-}
-
-} // namespace FileSys

src/core/file_sys/disk_filesystem.h

@@ -1,84 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <cstddef>
-#include <memory>
-#include <string>
-#include "common/common_types.h"
-#include "common/file_util.h"
-#include "core/file_sys/directory.h"
-#include "core/file_sys/filesystem.h"
-#include "core/file_sys/storage.h"
-#include "core/hle/result.h"
-
-namespace FileSys {
-
-class Disk_FileSystem : public FileSystemBackend {
-public:
-    explicit Disk_FileSystem(std::string base_directory)
-        : base_directory(std::move(base_directory)) {}
-
-    std::string GetName() const override;
-
-    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
-                                                        Mode mode) const override;
-    ResultCode DeleteFile(const std::string& path) const override;
-    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const override;
-    ResultCode DeleteDirectory(const Path& path) const override;
-    ResultCode DeleteDirectoryRecursively(const Path& path) const override;
-    ResultCode CreateFile(const std::string& path, u64 size) const override;
-    ResultCode CreateDirectory(const std::string& path) const override;
-    ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const override;
-    ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
-        const std::string& path) const override;
-    u64 GetFreeSpaceSize() const override;
-    ResultVal<EntryType> GetEntryType(const std::string& path) const override;
-
-protected:
-    std::string base_directory;
-};
-
-class Disk_Storage : public StorageBackend {
-public:
-    explicit Disk_Storage(std::shared_ptr<FileUtil::IOFile> file) : file(std::move(file)) {}
-
-    ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const override;
-    ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
-    u64 GetSize() const override;
-    bool SetSize(u64 size) const override;
-    bool Close() const override {
-        return false;
-    }
-    void Flush() const override {}
-
-private:
-    std::shared_ptr<FileUtil::IOFile> file;
-};
-
-class Disk_Directory : public DirectoryBackend {
-public:
-    explicit Disk_Directory(const std::string& path);
-
-    ~Disk_Directory() override {
-        Close();
-    }
-
-    u64 Read(const u64 count, Entry* entries) override;
-    u64 GetEntryCount() const override;
-
-    bool Close() const override {
-        return true;
-    }
-
-protected:
-    FileUtil::FSTEntry directory;
-
-    // We need to remember the last entry we returned, so a subsequent call to Read will continue
-    // from the next one. This iterator will always point to the next unread entry.
-    std::vector<FileUtil::FSTEntry>::iterator children_iterator;
-};
-
-} // namespace FileSys

src/core/file_sys/errors.h

@@ -11,7 +11,7 @@ namespace FileSys {
 namespace ErrCodes {
 enum {
     NotFound = 1,
-    SaveDataNotFound = 1002,
+    TitleNotFound = 1002,
     SdCardNotFound = 2001,
     RomFSNotFound = 2520,
 };

src/core/file_sys/filesystem.cpp

@@ -1,122 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <cstddef>
-#include <iomanip>
-#include <sstream>
-#include "common/logging/log.h"
-#include "common/string_util.h"
-#include "core/file_sys/filesystem.h"
-#include "core/memory.h"
-
-namespace FileSys {
-
-Path::Path(LowPathType type, u32 size, u32 pointer) : type(type) {
-    switch (type) {
-    case Binary: {
-        binary.resize(size);
-        Memory::ReadBlock(pointer, binary.data(), binary.size());
-        break;
-    }
-
-    case Char: {
-        string.resize(size - 1); // Data is always null-terminated.
-        Memory::ReadBlock(pointer, &string[0], string.size());
-        break;
-    }
-
-    case Wchar: {
-        u16str.resize(size / 2 - 1); // Data is always null-terminated.
-        Memory::ReadBlock(pointer, &u16str[0], u16str.size() * sizeof(char16_t));
-        break;
-    }
-
-    default:
-        break;
-    }
-}
-
-std::string Path::DebugStr() const {
-    switch (GetType()) {
-    case Invalid:
-    default:
-        return "[Invalid]";
-    case Empty:
-        return "[Empty]";
-    case Binary: {
-        std::stringstream res;
-        res << "[Binary: ";
-        for (unsigned byte : binary)
-            res << std::hex << std::setw(2) << std::setfill('0') << byte;
-        res << ']';
-        return res.str();
-    }
-    case Char:
-        return "[Char: " + AsString() + ']';
-    case Wchar:
-        return "[Wchar: " + AsString() + ']';
-    }
-}
-
-std::string Path::AsString() const {
-    switch (GetType()) {
-    case Char:
-        return string;
-    case Wchar:
-        return Common::UTF16ToUTF8(u16str);
-    case Empty:
-        return {};
-    case Invalid:
-    case Binary:
-    default:
-        // TODO(yuriks): Add assert
-        LOG_ERROR(Service_FS, "LowPathType cannot be converted to string!");
-        return {};
-    }
-}
-
-std::u16string Path::AsU16Str() const {
-    switch (GetType()) {
-    case Char:
-        return Common::UTF8ToUTF16(string);
-    case Wchar:
-        return u16str;
-    case Empty:
-        return {};
-    case Invalid:
-    case Binary:
-        // TODO(yuriks): Add assert
-        LOG_ERROR(Service_FS, "LowPathType cannot be converted to u16string!");
-        return {};
-    }
-
-    UNREACHABLE();
-}
-
-std::vector<u8> Path::AsBinary() const {
-    switch (GetType()) {
-    case Binary:
-        return binary;
-    case Char:
-        return std::vector<u8>(string.begin(), string.end());
-    case Wchar: {
-        // use two u8 for each character of u16str
-        std::vector<u8> to_return(u16str.size() * 2);
-        for (size_t i = 0; i < u16str.size(); ++i) {
-            u16 tmp_char = u16str.at(i);
-            to_return[i * 2] = (tmp_char & 0xFF00) >> 8;
-            to_return[i * 2 + 1] = (tmp_char & 0x00FF);
-        }
-        return to_return;
-    }
-    case Empty:
-        return {};
-    case Invalid:
-    default:
-        // TODO(yuriks): Add assert
-        LOG_ERROR(Service_FS, "LowPathType cannot be converted to binary!");
-        return {};
-    }
-}
-} // namespace FileSys

src/core/file_sys/filesystem.h

@@ -1,170 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <memory>
-#include <string>
-#include <utility>
-#include <vector>
-#include "common/bit_field.h"
-#include "common/common_types.h"
-#include "common/swap.h"
-#include "core/hle/result.h"
-
-namespace FileSys {
-
-class StorageBackend;
-class DirectoryBackend;
-
-// Path string type
-enum LowPathType : u32 {
-    Invalid = 0,
-    Empty = 1,
-    Binary = 2,
-    Char = 3,
-    Wchar = 4,
-};
-
-enum EntryType : u8 {
-    Directory = 0,
-    File = 1,
-};
-
-enum class Mode : u32 {
-    Read = 1,
-    Write = 2,
-    Append = 4,
-};
-
-class Path {
-public:
-    Path() : type(Invalid) {}
-    Path(const char* path) : type(Char), string(path) {}
-    Path(std::vector<u8> binary_data) : type(Binary), binary(std::move(binary_data)) {}
-    Path(LowPathType type, u32 size, u32 pointer);
-
-    LowPathType GetType() const {
-        return type;
-    }
-
-    /**
-     * Gets the string representation of the path for debugging
-     * @return String representation of the path for debugging
-     */
-    std::string DebugStr() const;
-
-    std::string AsString() const;
-    std::u16string AsU16Str() const;
-    std::vector<u8> AsBinary() const;
-
-private:
-    LowPathType type;
-    std::vector<u8> binary;
-    std::string string;
-    std::u16string u16str;
-};
-
-/// Parameters of the archive, as specified in the Create or Format call.
-struct ArchiveFormatInfo {
-    u32_le total_size;         ///< The pre-defined size of the archive.
-    u32_le number_directories; ///< The pre-defined number of directories in the archive.
-    u32_le number_files;       ///< The pre-defined number of files in the archive.
-    u8 duplicate_data;         ///< Whether the archive should duplicate the data.
-};
-static_assert(std::is_pod<ArchiveFormatInfo>::value, "ArchiveFormatInfo is not POD");
-
-class FileSystemBackend : NonCopyable {
-public:
-    virtual ~FileSystemBackend() {}
-
-    /**
-     * Get a descriptive name for the archive (e.g. "RomFS", "SaveData", etc.)
-     */
-    virtual std::string GetName() const = 0;
-
-    /**
-     * Create a file specified by its path
-     * @param path Path relative to the Archive
-     * @param size The size of the new file, filled with zeroes
-     * @return Result of the operation
-     */
-    virtual ResultCode CreateFile(const std::string& path, u64 size) const = 0;
-
-    /**
-     * Delete a file specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode DeleteFile(const std::string& path) const = 0;
-
-    /**
-     * Create a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode CreateDirectory(const std::string& path) const = 0;
-
-    /**
-     * Delete a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode DeleteDirectory(const Path& path) const = 0;
-
-    /**
-     * Delete a directory specified by its path and anything under it
-     * @param path Path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode DeleteDirectoryRecursively(const Path& path) const = 0;
-
-    /**
-     * Rename a File specified by its path
-     * @param src_path Source path relative to the archive
-     * @param dest_path Destination path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode RenameFile(const std::string& src_path,
-                                  const std::string& dest_path) const = 0;
-
-    /**
-     * Rename a Directory specified by its path
-     * @param src_path Source path relative to the archive
-     * @param dest_path Destination path relative to the archive
-     * @return Result of the operation
-     */
-    virtual ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const = 0;
-
-    /**
-     * Open a file specified by its path, using the specified mode
-     * @param path Path relative to the archive
-     * @param mode Mode to open the file with
-     * @return Opened file, or error code
-     */
-    virtual ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
-                                                                Mode mode) const = 0;
-
-    /**
-     * Open a directory specified by its path
-     * @param path Path relative to the archive
-     * @return Opened directory, or error code
-     */
-    virtual ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
-        const std::string& path) const = 0;
-
-    /**
-     * Get the free space
-     * @return The number of free bytes in the archive
-     */
-    virtual u64 GetFreeSpaceSize() const = 0;
-
-    /**
-     * Get the type of the specified path
-     * @return The type of the specified path or error code
-     */
-    virtual ResultVal<EntryType> GetEntryType(const std::string& path) const = 0;
-};
-
-} // namespace FileSys

src/core/file_sys/mode.h

@@ -0,0 +1,17 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+namespace FileSys {
+
+enum class Mode : u32 {
+    Read = 1,
+    Write = 2,
+    Append = 4,
+};
+
+} // namespace FileSys

src/core/file_sys/partition_filesystem.cpp

@@ -2,135 +2,118 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <algorithm>
+#include <cstddef>
+#include <cstring>
+#include <iterator>
 #include <utility>
+
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "core/file_sys/partition_filesystem.h"
+#include "core/file_sys/vfs_offset.h"
 #include "core/loader/loader.h"
 
 namespace FileSys {
 
-Loader::ResultStatus PartitionFilesystem::Load(const std::string& file_path, size_t offset) {
-    FileUtil::IOFile file(file_path, "rb");
-    if (!file.IsOpen())
-        return Loader::ResultStatus::Error;
+bool PartitionFilesystem::Header::HasValidMagicValue() const {
+    return magic == Common::MakeMagic('H', 'F', 'S', '0') ||
+           magic == Common::MakeMagic('P', 'F', 'S', '0');
+}
 
+PartitionFilesystem::PartitionFilesystem(std::shared_ptr<VfsFile> file) {
     // At least be as large as the header
-    if (file.GetSize() < sizeof(Header))
-        return Loader::ResultStatus::Error;
-
-    file.Seek(offset, SEEK_SET);
-    // For cartridges, HFSs can get very large, so we need to calculate the size up to
-    // the actual content itself instead of just blindly reading in the entire file.
-    Header pfs_header;
-    if (!file.ReadBytes(&pfs_header, sizeof(Header)))
-        return Loader::ResultStatus::Error;
-
-    if (pfs_header.magic != Common::MakeMagic('H', 'F', 'S', '0') &&
-        pfs_header.magic != Common::MakeMagic('P', 'F', 'S', '0')) {
-        return Loader::ResultStatus::ErrorInvalidFormat;
+    if (file->GetSize() < sizeof(Header)) {
+        status = Loader::ResultStatus::Error;
+        return;
     }
 
-    bool is_hfs = pfs_header.magic == Common::MakeMagic('H', 'F', 'S', '0');
+    // For cartridges, HFSs can get very large, so we need to calculate the size up to
+    // the actual content itself instead of just blindly reading in the entire file.
+    if (sizeof(Header) != file->ReadObject(&pfs_header)) {
+        status = Loader::ResultStatus::Error;
+        return;
+    }
+
+    if (!pfs_header.HasValidMagicValue()) {
+        status = Loader::ResultStatus::ErrorInvalidFormat;
+        return;
+    }
+
+    is_hfs = pfs_header.magic == Common::MakeMagic('H', 'F', 'S', '0');
 
     size_t entry_size = is_hfs ? sizeof(HFSEntry) : sizeof(PFSEntry);
     size_t metadata_size =
         sizeof(Header) + (pfs_header.num_entries * entry_size) + pfs_header.strtab_size;
 
     // Actually read in now...
-    file.Seek(offset, SEEK_SET);
-    std::vector<u8> file_data(metadata_size);
+    std::vector<u8> file_data = file->ReadBytes(metadata_size);
+    const size_t total_size = file_data.size();
 
-    if (!file.ReadBytes(file_data.data(), metadata_size))
-        return Loader::ResultStatus::Error;
-
-    Loader::ResultStatus result = Load(file_data);
-    if (result != Loader::ResultStatus::Success)
-        LOG_ERROR(Service_FS, "Failed to load PFS from file {}!", file_path);
-
-    return result;
-}
-
-Loader::ResultStatus PartitionFilesystem::Load(const std::vector<u8>& file_data, size_t offset) {
-    size_t total_size = file_data.size() - offset;
-    if (total_size < sizeof(Header))
-        return Loader::ResultStatus::Error;
-
-    memcpy(&pfs_header, &file_data[offset], sizeof(Header));
-    if (pfs_header.magic != Common::MakeMagic('H', 'F', 'S', '0') &&
-        pfs_header.magic != Common::MakeMagic('P', 'F', 'S', '0')) {
-        return Loader::ResultStatus::ErrorInvalidFormat;
+    if (total_size != metadata_size) {
+        status = Loader::ResultStatus::Error;
+        return;
     }
 
-    is_hfs = pfs_header.magic == Common::MakeMagic('H', 'F', 'S', '0');
-
-    size_t entries_offset = offset + sizeof(Header);
-    size_t entry_size = is_hfs ? sizeof(HFSEntry) : sizeof(PFSEntry);
+    size_t entries_offset = sizeof(Header);
     size_t strtab_offset = entries_offset + (pfs_header.num_entries * entry_size);
-    for (u16 i = 0; i < pfs_header.num_entries; i++) {
-        FileEntry entry;
-
-        memcpy(&entry.fs_entry, &file_data[entries_offset + (i * entry_size)], sizeof(FSEntry));
-        entry.name = std::string(reinterpret_cast<const char*>(
-            &file_data[strtab_offset + entry.fs_entry.strtab_offset]));
-        pfs_entries.push_back(std::move(entry));
-    }
-
     content_offset = strtab_offset + pfs_header.strtab_size;
+    for (u16 i = 0; i < pfs_header.num_entries; i++) {
+        FSEntry entry;
 
-    return Loader::ResultStatus::Success;
-}
+        memcpy(&entry, &file_data[entries_offset + (i * entry_size)], sizeof(FSEntry));
+        std::string name(
+            reinterpret_cast<const char*>(&file_data[strtab_offset + entry.strtab_offset]));
 
-u32 PartitionFilesystem::GetNumEntries() const {
-    return pfs_header.num_entries;
-}
-
-u64 PartitionFilesystem::GetEntryOffset(u32 index) const {
-    if (index > GetNumEntries())
-        return 0;
-
-    return content_offset + pfs_entries[index].fs_entry.offset;
-}
-
-u64 PartitionFilesystem::GetEntrySize(u32 index) const {
-    if (index > GetNumEntries())
-        return 0;
-
-    return pfs_entries[index].fs_entry.size;
-}
-
-std::string PartitionFilesystem::GetEntryName(u32 index) const {
-    if (index > GetNumEntries())
-        return "";
-
-    return pfs_entries[index].name;
-}
-
-u64 PartitionFilesystem::GetFileOffset(const std::string& name) const {
-    for (u32 i = 0; i < pfs_header.num_entries; i++) {
-        if (pfs_entries[i].name == name)
-            return content_offset + pfs_entries[i].fs_entry.offset;
+        pfs_files.emplace_back(
+            std::make_shared<OffsetVfsFile>(file, entry.size, content_offset + entry.offset, name));
     }
 
-    return 0;
+    status = Loader::ResultStatus::Success;
 }
 
-u64 PartitionFilesystem::GetFileSize(const std::string& name) const {
-    for (u32 i = 0; i < pfs_header.num_entries; i++) {
-        if (pfs_entries[i].name == name)
-            return pfs_entries[i].fs_entry.size;
-    }
-
-    return 0;
+Loader::ResultStatus PartitionFilesystem::GetStatus() const {
+    return status;
 }
 
-void PartitionFilesystem::Print() const {
-    LOG_DEBUG(Service_FS, "Magic:                  {}", pfs_header.magic);
+std::vector<std::shared_ptr<VfsFile>> PartitionFilesystem::GetFiles() const {
+    return pfs_files;
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> PartitionFilesystem::GetSubdirectories() const {
+    return pfs_dirs;
+}
+
+std::string PartitionFilesystem::GetName() const {
+    return is_hfs ? "HFS0" : "PFS0";
+}
+
+std::shared_ptr<VfsDirectory> PartitionFilesystem::GetParentDirectory() const {
+    // TODO(DarkLordZach): Add support for nested containers.
+    return nullptr;
+}
+
+void PartitionFilesystem::PrintDebugInfo() const {
+    LOG_DEBUG(Service_FS, "Magic:                  {:.4}", pfs_header.magic);
     LOG_DEBUG(Service_FS, "Files:                  {}", pfs_header.num_entries);
     for (u32 i = 0; i < pfs_header.num_entries; i++) {
         LOG_DEBUG(Service_FS, " > File {}:              {} (0x{:X} bytes, at 0x{:X})", i,
-                  pfs_entries[i].name.c_str(), pfs_entries[i].fs_entry.size,
-                  GetFileOffset(pfs_entries[i].name));
+                  pfs_files[i]->GetName(), pfs_files[i]->GetSize(),
+                  dynamic_cast<OffsetVfsFile*>(pfs_files[i].get())->GetOffset());
     }
 }
+
+bool PartitionFilesystem::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    const auto iter = std::find(pfs_files.begin(), pfs_files.end(), file);
+    if (iter == pfs_files.end())
+        return false;
+
+    const std::ptrdiff_t offset = std::distance(pfs_files.begin(), iter);
+    pfs_files[offset] = pfs_files.back();
+    pfs_files.pop_back();
+
+    pfs_dirs.emplace_back(std::move(dir));
+
+    return true;
+}
 } // namespace FileSys

src/core/file_sys/partition_filesystem.h

@@ -10,6 +10,7 @@
 #include "common/common_funcs.h"
 #include "common/common_types.h"
 #include "common/swap.h"
+#include "core/file_sys/vfs.h"
 
 namespace Loader {
 enum class ResultStatus;
@@ -21,19 +22,19 @@ namespace FileSys {
  * Helper which implements an interface to parse PFS/HFS filesystems.
  * Data can either be loaded from a file path or data with an offset into it.
  */
-class PartitionFilesystem {
+class PartitionFilesystem : public ReadOnlyVfsDirectory {
 public:
-    Loader::ResultStatus Load(const std::string& file_path, size_t offset = 0);
-    Loader::ResultStatus Load(const std::vector<u8>& file_data, size_t offset = 0);
+    explicit PartitionFilesystem(std::shared_ptr<VfsFile> file);
+    Loader::ResultStatus GetStatus() const;
 
-    u32 GetNumEntries() const;
-    u64 GetEntryOffset(u32 index) const;
-    u64 GetEntrySize(u32 index) const;
-    std::string GetEntryName(u32 index) const;
-    u64 GetFileOffset(const std::string& name) const;
-    u64 GetFileSize(const std::string& name) const;
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+    std::string GetName() const override;
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+    void PrintDebugInfo() const;
 
-    void Print() const;
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
 
 private:
     struct Header {
@@ -41,6 +42,8 @@ private:
         u32_le num_entries;
         u32_le strtab_size;
         INSERT_PADDING_BYTES(0x4);
+
+        bool HasValidMagicValue() const;
     };
 
     static_assert(sizeof(Header) == 0x10, "PFS/HFS header structure size is wrong");
@@ -72,16 +75,14 @@ private:
 
 #pragma pack(pop)
 
-    struct FileEntry {
-        FSEntry fs_entry;
-        std::string name;
-    };
+    Loader::ResultStatus status{};
 
-    Header pfs_header;
-    bool is_hfs;
-    size_t content_offset;
+    Header pfs_header{};
+    bool is_hfs = false;
+    size_t content_offset = 0;
 
-    std::vector<FileEntry> pfs_entries;
+    std::vector<VirtualFile> pfs_files;
+    std::vector<VirtualDir> pfs_dirs;
 };
 
 } // namespace FileSys

src/core/file_sys/path_parser.cpp

@@ -1,98 +0,0 @@
-// Copyright 2016 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <algorithm>
-#include <set>
-#include "common/file_util.h"
-#include "common/string_util.h"
-#include "core/file_sys/path_parser.h"
-
-namespace FileSys {
-
-PathParser::PathParser(const Path& path) {
-    if (path.GetType() != LowPathType::Char && path.GetType() != LowPathType::Wchar) {
-        is_valid = false;
-        return;
-    }
-
-    auto path_string = path.AsString();
-    if (path_string.size() == 0 || path_string[0] != '/') {
-        is_valid = false;
-        return;
-    }
-
-    // Filter out invalid characters for the host system.
-    // Although some of these characters are valid on 3DS, they are unlikely to be used by games.
-    if (std::find_if(path_string.begin(), path_string.end(), [](char c) {
-            static const std::set<char> invalid_chars{'<', '>', '\\', '|', ':', '\"', '*', '?'};
-            return invalid_chars.find(c) != invalid_chars.end();
-        }) != path_string.end()) {
-        is_valid = false;
-        return;
-    }
-
-    Common::SplitString(path_string, '/', path_sequence);
-
-    auto begin = path_sequence.begin();
-    auto end = path_sequence.end();
-    end = std::remove_if(begin, end, [](std::string& str) { return str == "" || str == "."; });
-    path_sequence = std::vector<std::string>(begin, end);
-
-    // checks if the path is out of bounds.
-    int level = 0;
-    for (auto& node : path_sequence) {
-        if (node == "..") {
-            --level;
-            if (level < 0) {
-                is_valid = false;
-                return;
-            }
-        } else {
-            ++level;
-        }
-    }
-
-    is_valid = true;
-    is_root = level == 0;
-}
-
-PathParser::HostStatus PathParser::GetHostStatus(const std::string& mount_point) const {
-    auto path = mount_point;
-    if (!FileUtil::IsDirectory(path))
-        return InvalidMountPoint;
-    if (path_sequence.empty()) {
-        return DirectoryFound;
-    }
-
-    for (auto iter = path_sequence.begin(); iter != path_sequence.end() - 1; iter++) {
-        if (path.back() != '/')
-            path += '/';
-        path += *iter;
-
-        if (!FileUtil::Exists(path))
-            return PathNotFound;
-        if (FileUtil::IsDirectory(path))
-            continue;
-        return FileInPath;
-    }
-
-    path += "/" + path_sequence.back();
-    if (!FileUtil::Exists(path))
-        return NotFound;
-    if (FileUtil::IsDirectory(path))
-        return DirectoryFound;
-    return FileFound;
-}
-
-std::string PathParser::BuildHostPath(const std::string& mount_point) const {
-    std::string path = mount_point;
-    for (auto& node : path_sequence) {
-        if (path.back() != '/')
-            path += '/';
-        path += node;
-    }
-    return path;
-}
-
-} // namespace FileSys

src/core/file_sys/path_parser.h

@@ -1,61 +0,0 @@
-// Copyright 2016 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <string>
-#include <vector>
-#include "core/file_sys/filesystem.h"
-
-namespace FileSys {
-
-/**
- * A helper class parsing and verifying a string-type Path.
- * Every archives with a sub file system should use this class to parse the path argument and check
- * the status of the file / directory in question on the host file system.
- */
-class PathParser {
-public:
-    explicit PathParser(const Path& path);
-
-    /**
-     * Checks if the Path is valid.
-     * This function should be called once a PathParser is constructed.
-     * A Path is valid if:
-     *  - it is a string path (with type LowPathType::Char or LowPathType::Wchar),
-     *  - it starts with "/" (this seems a hard requirement in real 3DS),
-     *  - it doesn't contain invalid characters, and
-     *  - it doesn't go out of the root directory using "..".
-     */
-    bool IsValid() const {
-        return is_valid;
-    }
-
-    /// Checks if the Path represents the root directory.
-    bool IsRootDirectory() const {
-        return is_root;
-    }
-
-    enum HostStatus {
-        InvalidMountPoint,
-        PathNotFound,   // "/a/b/c" when "a" doesn't exist
-        FileInPath,     // "/a/b/c" when "a" is a file
-        FileFound,      // "/a/b/c" when "c" is a file
-        DirectoryFound, // "/a/b/c" when "c" is a directory
-        NotFound        // "/a/b/c" when "a/b/" exists but "c" doesn't exist
-    };
-
-    /// Checks the status of the specified file / directory by the Path on the host file system.
-    HostStatus GetHostStatus(const std::string& mount_point) const;
-
-    /// Builds a full path on the host file system.
-    std::string BuildHostPath(const std::string& mount_point) const;
-
-private:
-    std::vector<std::string> path_sequence;
-    bool is_valid{};
-    bool is_root{};
-};
-
-} // namespace FileSys

src/core/file_sys/program_metadata.cpp

@@ -9,40 +9,29 @@
 
 namespace FileSys {
 
-Loader::ResultStatus ProgramMetadata::Load(const std::string& file_path) {
-    FileUtil::IOFile file(file_path, "rb");
-    if (!file.IsOpen())
-        return Loader::ResultStatus::Error;
-
-    std::vector<u8> file_data(file.GetSize());
-
-    if (!file.ReadBytes(file_data.data(), file_data.size()))
-        return Loader::ResultStatus::Error;
-
-    Loader::ResultStatus result = Load(file_data);
-    if (result != Loader::ResultStatus::Success)
-        LOG_ERROR(Service_FS, "Failed to load NPDM from file {}!", file_path);
-
-    return result;
-}
-
-Loader::ResultStatus ProgramMetadata::Load(const std::vector<u8> file_data, size_t offset) {
-    size_t total_size = static_cast<size_t>(file_data.size() - offset);
+Loader::ResultStatus ProgramMetadata::Load(VirtualFile file) {
+    size_t total_size = static_cast<size_t>(file->GetSize());
     if (total_size < sizeof(Header))
         return Loader::ResultStatus::Error;
 
-    size_t header_offset = offset;
-    memcpy(&npdm_header, &file_data[offset], sizeof(Header));
+    // TODO(DarkLordZach): Use ReadObject when Header/AcidHeader becomes trivially copyable.
+    std::vector<u8> npdm_header_data = file->ReadBytes(sizeof(Header));
+    if (sizeof(Header) != npdm_header_data.size())
+        return Loader::ResultStatus::Error;
+    std::memcpy(&npdm_header, npdm_header_data.data(), sizeof(Header));
 
-    size_t aci_offset = header_offset + npdm_header.aci_offset;
-    size_t acid_offset = header_offset + npdm_header.acid_offset;
-    memcpy(&aci_header, &file_data[aci_offset], sizeof(AciHeader));
-    memcpy(&acid_header, &file_data[acid_offset], sizeof(AcidHeader));
+    std::vector<u8> acid_header_data = file->ReadBytes(sizeof(AcidHeader), npdm_header.acid_offset);
+    if (sizeof(AcidHeader) != acid_header_data.size())
+        return Loader::ResultStatus::Error;
+    std::memcpy(&acid_header, acid_header_data.data(), sizeof(AcidHeader));
 
-    size_t fac_offset = acid_offset + acid_header.fac_offset;
-    size_t fah_offset = aci_offset + aci_header.fah_offset;
-    memcpy(&acid_file_access, &file_data[fac_offset], sizeof(FileAccessControl));
-    memcpy(&aci_file_access, &file_data[fah_offset], sizeof(FileAccessHeader));
+    if (sizeof(AciHeader) != file->ReadObject(&aci_header, npdm_header.aci_offset))
+        return Loader::ResultStatus::Error;
+
+    if (sizeof(FileAccessControl) != file->ReadObject(&acid_file_access, acid_header.fac_offset))
+        return Loader::ResultStatus::Error;
+    if (sizeof(FileAccessHeader) != file->ReadObject(&aci_file_access, aci_header.fah_offset))
+        return Loader::ResultStatus::Error;
 
     return Loader::ResultStatus::Success;
 }

src/core/file_sys/program_metadata.h

@@ -10,6 +10,7 @@
 #include "common/bit_field.h"
 #include "common/common_types.h"
 #include "common/swap.h"
+#include "partition_filesystem.h"
 
 namespace Loader {
 enum class ResultStatus;
@@ -37,8 +38,7 @@ enum class ProgramFilePermission : u64 {
  */
 class ProgramMetadata {
 public:
-    Loader::ResultStatus Load(const std::string& file_path);
-    Loader::ResultStatus Load(const std::vector<u8> file_data, size_t offset = 0);
+    Loader::ResultStatus Load(VirtualFile file);
 
     bool Is64BitProgram() const;
     ProgramAddressSpaceType GetAddressSpaceType() const;
@@ -51,6 +51,7 @@ public:
     void Print() const;
 
 private:
+    // TODO(DarkLordZach): BitField is not trivially copyable.
     struct Header {
         std::array<char, 4> magic;
         std::array<u8, 8> reserved;
@@ -77,6 +78,7 @@ private:
 
     static_assert(sizeof(Header) == 0x80, "NPDM header structure size is wrong");
 
+    // TODO(DarkLordZach): BitField is not trivially copyable.
     struct AcidHeader {
         std::array<u8, 0x100> signature;
         std::array<u8, 0x100> nca_modulus;

src/core/file_sys/romfs_factory.cpp

@@ -7,21 +7,19 @@
 #include "common/common_types.h"
 #include "common/logging/log.h"
 #include "core/file_sys/romfs_factory.h"
-#include "core/file_sys/romfs_filesystem.h"
 
 namespace FileSys {
 
 RomFSFactory::RomFSFactory(Loader::AppLoader& app_loader) {
     // Load the RomFS from the app
-    if (Loader::ResultStatus::Success != app_loader.ReadRomFS(romfs_file, data_offset, data_size)) {
+    if (Loader::ResultStatus::Success != app_loader.ReadRomFS(file)) {
         LOG_ERROR(Service_FS, "Unable to read RomFS!");
     }
 }
 
-ResultVal<std::unique_ptr<FileSystemBackend>> RomFSFactory::Open(u64 title_id) {
+ResultVal<VirtualFile> RomFSFactory::Open(u64 title_id) {
     // TODO(DarkLordZach): Use title id.
-    auto archive = std::make_unique<RomFS_FileSystem>(romfs_file, data_offset, data_size);
-    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+    return MakeResult<VirtualFile>(file);
 }
 
 } // namespace FileSys

src/core/file_sys/romfs_factory.h

@@ -5,10 +5,7 @@
 #pragma once
 
 #include <memory>
-#include <string>
-#include <vector>
 #include "common/common_types.h"
-#include "core/file_sys/filesystem.h"
 #include "core/hle/result.h"
 #include "core/loader/loader.h"
 
@@ -19,12 +16,10 @@ class RomFSFactory {
 public:
     explicit RomFSFactory(Loader::AppLoader& app_loader);
 
-    ResultVal<std::unique_ptr<FileSystemBackend>> Open(u64 title_id);
+    ResultVal<VirtualFile> Open(u64 title_id);
 
 private:
-    std::shared_ptr<FileUtil::IOFile> romfs_file;
-    u64 data_offset;
-    u64 data_size;
+    VirtualFile file;
 };
 
 } // namespace FileSys

src/core/file_sys/romfs_filesystem.cpp

@@ -1,110 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#include <cstring>
-#include <memory>
-#include "common/common_types.h"
-#include "common/logging/log.h"
-#include "core/file_sys/romfs_filesystem.h"
-
-namespace FileSys {
-
-std::string RomFS_FileSystem::GetName() const {
-    return "RomFS";
-}
-
-ResultVal<std::unique_ptr<StorageBackend>> RomFS_FileSystem::OpenFile(const std::string& path,
-                                                                      Mode mode) const {
-    return MakeResult<std::unique_ptr<StorageBackend>>(
-        std::make_unique<RomFS_Storage>(romfs_file, data_offset, data_size));
-}
-
-ResultCode RomFS_FileSystem::DeleteFile(const std::string& path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to delete a file from an ROMFS archive ({}).", GetName());
-    // TODO(bunnei): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::RenameFile(const std::string& src_path,
-                                        const std::string& dest_path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to rename a file within an ROMFS archive ({}).", GetName());
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::DeleteDirectory(const Path& path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to delete a directory from an ROMFS archive ({}).",
-                 GetName());
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::DeleteDirectoryRecursively(const Path& path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to delete a directory from an ROMFS archive ({}).",
-                 GetName());
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::CreateFile(const std::string& path, u64 size) const {
-    LOG_CRITICAL(Service_FS, "Attempted to create a file in an ROMFS archive ({}).", GetName());
-    // TODO(bunnei): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::CreateDirectory(const std::string& path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to create a directory in an ROMFS archive ({}).",
-                 GetName());
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultCode RomFS_FileSystem::RenameDirectory(const Path& src_path, const Path& dest_path) const {
-    LOG_CRITICAL(Service_FS, "Attempted to rename a file within an ROMFS archive ({}).", GetName());
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultVal<std::unique_ptr<DirectoryBackend>> RomFS_FileSystem::OpenDirectory(
-    const std::string& path) const {
-    LOG_WARNING(Service_FS, "Opening Directory in a ROMFS archive");
-    return MakeResult<std::unique_ptr<DirectoryBackend>>(std::make_unique<ROMFSDirectory>());
-}
-
-u64 RomFS_FileSystem::GetFreeSpaceSize() const {
-    LOG_WARNING(Service_FS, "Attempted to get the free space in an ROMFS archive");
-    return 0;
-}
-
-ResultVal<FileSys::EntryType> RomFS_FileSystem::GetEntryType(const std::string& path) const {
-    LOG_CRITICAL(Service_FS, "Called within an ROMFS archive (path {}).", path);
-    // TODO(wwylele): Use correct error code
-    return ResultCode(-1);
-}
-
-ResultVal<size_t> RomFS_Storage::Read(const u64 offset, const size_t length, u8* buffer) const {
-    LOG_TRACE(Service_FS, "called offset={}, length={}", offset, length);
-    romfs_file->Seek(data_offset + offset, SEEK_SET);
-    size_t read_length = (size_t)std::min((u64)length, data_size - offset);
-
-    return MakeResult<size_t>(romfs_file->ReadBytes(buffer, read_length));
-}
-
-ResultVal<size_t> RomFS_Storage::Write(const u64 offset, const size_t length, const bool flush,
-                                       const u8* buffer) const {
-    LOG_ERROR(Service_FS, "Attempted to write to ROMFS file");
-    // TODO(Subv): Find error code
-    return MakeResult<size_t>(0);
-}
-
-u64 RomFS_Storage::GetSize() const {
-    return data_size;
-}
-
-bool RomFS_Storage::SetSize(const u64 size) const {
-    LOG_ERROR(Service_FS, "Attempted to set the size of an ROMFS file");
-    return false;
-}
-
-} // namespace FileSys

src/core/file_sys/romfs_filesystem.h

@@ -1,85 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <cstddef>
-#include <memory>
-#include <string>
-#include <vector>
-#include "common/common_types.h"
-#include "common/file_util.h"
-#include "core/file_sys/directory.h"
-#include "core/file_sys/filesystem.h"
-#include "core/file_sys/storage.h"
-#include "core/hle/result.h"
-
-namespace FileSys {
-
-/**
- * Helper which implements an interface to deal with Switch .istorage ROMFS images used in some
- * archives This should be subclassed by concrete archive types, which will provide the input data
- * (load the raw ROMFS archive) and override any required methods
- */
-class RomFS_FileSystem : public FileSystemBackend {
-public:
-    RomFS_FileSystem(std::shared_ptr<FileUtil::IOFile> file, u64 offset, u64 size)
-        : romfs_file(file), data_offset(offset), data_size(size) {}
-
-    std::string GetName() const override;
-
-    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
-                                                        Mode mode) const override;
-    ResultCode DeleteFile(const std::string& path) const override;
-    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const override;
-    ResultCode DeleteDirectory(const Path& path) const override;
-    ResultCode DeleteDirectoryRecursively(const Path& path) const override;
-    ResultCode CreateFile(const std::string& path, u64 size) const override;
-    ResultCode CreateDirectory(const std::string& path) const override;
-    ResultCode RenameDirectory(const Path& src_path, const Path& dest_path) const override;
-    ResultVal<std::unique_ptr<DirectoryBackend>> OpenDirectory(
-        const std::string& path) const override;
-    u64 GetFreeSpaceSize() const override;
-    ResultVal<EntryType> GetEntryType(const std::string& path) const override;
-
-protected:
-    std::shared_ptr<FileUtil::IOFile> romfs_file;
-    u64 data_offset;
-    u64 data_size;
-};
-
-class RomFS_Storage : public StorageBackend {
-public:
-    RomFS_Storage(std::shared_ptr<FileUtil::IOFile> file, u64 offset, u64 size)
-        : romfs_file(file), data_offset(offset), data_size(size) {}
-
-    ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const override;
-    ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
-    u64 GetSize() const override;
-    bool SetSize(u64 size) const override;
-    bool Close() const override {
-        return false;
-    }
-    void Flush() const override {}
-
-private:
-    std::shared_ptr<FileUtil::IOFile> romfs_file;
-    u64 data_offset;
-    u64 data_size;
-};
-
-class ROMFSDirectory : public DirectoryBackend {
-public:
-    u64 Read(const u64 count, Entry* entries) override {
-        return 0;
-    }
-    u64 GetEntryCount() const override {
-        return 0;
-    }
-    bool Close() const override {
-        return false;
-    }
-};
-
-} // namespace FileSys

src/core/file_sys/savedata_factory.cpp

@@ -6,22 +6,19 @@
 #include "common/common_types.h"
 #include "common/logging/log.h"
 #include "core/core.h"
-#include "core/file_sys/disk_filesystem.h"
 #include "core/file_sys/savedata_factory.h"
 #include "core/hle/kernel/process.h"
 
 namespace FileSys {
 
-std::string SaveDataDescriptor::DebugInfo() {
+std::string SaveDataDescriptor::DebugInfo() const {
     return fmt::format("[type={:02X}, title_id={:016X}, user_id={:016X}{:016X}, save_id={:016X}]",
                        static_cast<u8>(type), title_id, user_id[1], user_id[0], save_id);
 }
 
-SaveDataFactory::SaveDataFactory(std::string nand_directory)
-    : nand_directory(std::move(nand_directory)) {}
+SaveDataFactory::SaveDataFactory(VirtualDir save_directory) : dir(std::move(save_directory)) {}
 
-ResultVal<std::unique_ptr<FileSystemBackend>> SaveDataFactory::Open(SaveDataSpaceId space,
-                                                                    SaveDataDescriptor meta) {
+ResultVal<VirtualDir> SaveDataFactory::Open(SaveDataSpaceId space, SaveDataDescriptor meta) {
     if (meta.type == SaveDataType::SystemSaveData || meta.type == SaveDataType::SaveData) {
         if (meta.zero_1 != 0) {
             LOG_WARNING(Service_FS,
@@ -56,28 +53,23 @@ ResultVal<std::unique_ptr<FileSystemBackend>> SaveDataFactory::Open(SaveDataSpac
     // TODO(DarkLordZach): Try to not create when opening, there are dedicated create save methods.
     // But, user_ids don't match so this works for now.
 
-    if (!FileUtil::Exists(save_directory)) {
+    auto out = dir->GetDirectoryRelative(save_directory);
+
+    if (out == nullptr) {
         // TODO(bunnei): This is a work-around to always create a save data directory if it does not
         // already exist. This is a hack, as we do not understand yet how this works on hardware.
         // Without a save data directory, many games will assert on boot. This should not have any
         // bad side-effects.
-        FileUtil::CreateFullPath(save_directory);
-    }
-
-    // TODO(DarkLordZach): For some reason, CreateFullPath doesn't create the last bit. Should be
-    // fixed with VFS.
-    if (!FileUtil::IsDirectory(save_directory)) {
-        FileUtil::CreateDir(save_directory);
+        out = dir->CreateDirectoryRelative(save_directory);
     }
 
     // Return an error if the save data doesn't actually exist.
-    if (!FileUtil::IsDirectory(save_directory)) {
+    if (out == nullptr) {
         // TODO(Subv): Find out correct error code.
         return ResultCode(-1);
     }
 
-    auto archive = std::make_unique<Disk_FileSystem>(save_directory);
-    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+    return MakeResult<VirtualDir>(std::move(out));
 }
 
 std::string SaveDataFactory::GetFullPath(SaveDataSpaceId space, SaveDataType type, u64 title_id,
@@ -87,14 +79,14 @@ std::string SaveDataFactory::GetFullPath(SaveDataSpaceId space, SaveDataType typ
     if (type == SaveDataType::SaveData && title_id == 0)
         title_id = Core::CurrentProcess()->program_id;
 
-    std::string prefix;
+    std::string out;
 
     switch (space) {
     case SaveDataSpaceId::NandSystem:
-        prefix = nand_directory + "system/save/";
+        out = "/system/save/";
         break;
     case SaveDataSpaceId::NandUser:
-        prefix = nand_directory + "user/save/";
+        out = "/user/save/";
         break;
     default:
         ASSERT_MSG(false, "Unrecognized SaveDataSpaceId: {:02X}", static_cast<u8>(space));
@@ -102,9 +94,9 @@ std::string SaveDataFactory::GetFullPath(SaveDataSpaceId space, SaveDataType typ
 
     switch (type) {
     case SaveDataType::SystemSaveData:
-        return fmt::format("{}{:016X}/{:016X}{:016X}", prefix, save_id, user_id[1], user_id[0]);
+        return fmt::format("{}{:016X}/{:016X}{:016X}", out, save_id, user_id[1], user_id[0]);
     case SaveDataType::SaveData:
-        return fmt::format("{}{:016X}/{:016X}{:016X}/{:016X}", prefix, 0, user_id[1], user_id[0],
+        return fmt::format("{}{:016X}/{:016X}{:016X}/{:016X}", out, 0, user_id[1], user_id[0],
                            title_id);
     default:
         ASSERT_MSG(false, "Unrecognized SaveDataType: {:02X}", static_cast<u8>(type));

src/core/file_sys/savedata_factory.h

@@ -7,7 +7,6 @@
 #include <memory>
 #include <string>
 #include "common/common_types.h"
-#include "core/file_sys/filesystem.h"
 #include "core/hle/result.h"
 
 namespace FileSys {
@@ -38,21 +37,19 @@ struct SaveDataDescriptor {
     u64_le zero_2;
     u64_le zero_3;
 
-    std::string DebugInfo();
+    std::string DebugInfo() const;
 };
 static_assert(sizeof(SaveDataDescriptor) == 0x40, "SaveDataDescriptor has incorrect size.");
 
 /// File system interface to the SaveData archive
 class SaveDataFactory {
 public:
-    explicit SaveDataFactory(std::string nand_directory);
+    explicit SaveDataFactory(VirtualDir dir);
 
-    ResultVal<std::unique_ptr<FileSystemBackend>> Open(SaveDataSpaceId space,
-                                                       SaveDataDescriptor meta);
+    ResultVal<VirtualDir> Open(SaveDataSpaceId space, SaveDataDescriptor meta);
 
 private:
-    std::string nand_directory;
-    std::string sd_directory;
+    VirtualDir dir;
 
     std::string GetFullPath(SaveDataSpaceId space, SaveDataType type, u64 title_id, u128 user_id,
                             u64 save_id) const;

src/core/file_sys/sdmc_factory.cpp

@@ -3,25 +3,15 @@
 // Refer to the license.txt file included.
 
 #include <memory>
-#include "common/common_types.h"
-#include "common/logging/log.h"
-#include "common/string_util.h"
 #include "core/core.h"
-#include "core/file_sys/disk_filesystem.h"
 #include "core/file_sys/sdmc_factory.h"
 
 namespace FileSys {
 
-SDMCFactory::SDMCFactory(std::string sd_directory) : sd_directory(std::move(sd_directory)) {}
+SDMCFactory::SDMCFactory(VirtualDir dir) : dir(std::move(dir)) {}
 
-ResultVal<std::unique_ptr<FileSystemBackend>> SDMCFactory::Open() {
-    // Create the SD Card directory if it doesn't already exist.
-    if (!FileUtil::IsDirectory(sd_directory)) {
-        FileUtil::CreateFullPath(sd_directory);
-    }
-
-    auto archive = std::make_unique<Disk_FileSystem>(sd_directory);
-    return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
+ResultVal<VirtualDir> SDMCFactory::Open() {
+    return MakeResult<VirtualDir>(dir);
 }
 
 } // namespace FileSys

src/core/file_sys/sdmc_factory.h

@@ -4,10 +4,6 @@
 
 #pragma once
 
-#include <memory>
-#include <string>
-#include "common/common_types.h"
-#include "core/file_sys/filesystem.h"
 #include "core/hle/result.h"
 
 namespace FileSys {
@@ -15,12 +11,12 @@ namespace FileSys {
 /// File system interface to the SDCard archive
 class SDMCFactory {
 public:
-    explicit SDMCFactory(std::string sd_directory);
+    explicit SDMCFactory(VirtualDir dir);
 
-    ResultVal<std::unique_ptr<FileSystemBackend>> Open();
+    ResultVal<VirtualDir> Open();
 
 private:
-    std::string sd_directory;
+    VirtualDir dir;
 };
 
 } // namespace FileSys

src/core/file_sys/storage.h

@@ -1,63 +0,0 @@
-// Copyright 2018 yuzu emulator team
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-#pragma once
-
-#include <cstddef>
-#include "common/common_types.h"
-#include "core/hle/result.h"
-
-namespace FileSys {
-
-class StorageBackend : NonCopyable {
-public:
-    StorageBackend() {}
-    virtual ~StorageBackend() {}
-
-    /**
-     * Read data from the file
-     * @param offset Offset in bytes to start reading data from
-     * @param length Length in bytes of data to read from file
-     * @param buffer Buffer to read data into
-     * @return Number of bytes read, or error code
-     */
-    virtual ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const = 0;
-
-    /**
-     * Write data to the file
-     * @param offset Offset in bytes to start writing data to
-     * @param length Length in bytes of data to write to file
-     * @param flush The flush parameters (0 == do not flush)
-     * @param buffer Buffer to read data from
-     * @return Number of bytes written, or error code
-     */
-    virtual ResultVal<size_t> Write(u64 offset, size_t length, bool flush,
-                                    const u8* buffer) const = 0;
-
-    /**
-     * Flushes the file
-     */
-    virtual void Flush() const = 0;
-
-    /**
-     * Set the size of the file in bytes
-     * @param size New size of the file
-     * @return true if successful
-     */
-    virtual bool SetSize(u64 size) const = 0;
-
-    /**
-     * Get the size of the file in bytes
-     * @return Size of the file in bytes
-     */
-    virtual u64 GetSize() const = 0;
-
-    /**
-     * Close the file
-     * @return true if the file closed correctly
-     */
-    virtual bool Close() const = 0;
-};
-
-} // namespace FileSys

src/core/file_sys/vfs.cpp

@@ -0,0 +1,238 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <numeric>
+#include "common/file_util.h"
+#include "common/logging/backend.h"
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+VfsFile::~VfsFile() = default;
+
+std::string VfsFile::GetExtension() const {
+    return FileUtil::GetExtensionFromFilename(GetName());
+}
+
+VfsDirectory::~VfsDirectory() = default;
+
+boost::optional<u8> VfsFile::ReadByte(size_t offset) const {
+    u8 out{};
+    size_t size = Read(&out, 1, offset);
+    if (size == 1)
+        return out;
+
+    return boost::none;
+}
+
+std::vector<u8> VfsFile::ReadBytes(size_t size, size_t offset) const {
+    std::vector<u8> out(size);
+    size_t read_size = Read(out.data(), size, offset);
+    out.resize(read_size);
+    return out;
+}
+
+std::vector<u8> VfsFile::ReadAllBytes() const {
+    return ReadBytes(GetSize());
+}
+
+bool VfsFile::WriteByte(u8 data, size_t offset) {
+    return Write(&data, 1, offset) == 1;
+}
+
+size_t VfsFile::WriteBytes(std::vector<u8> data, size_t offset) {
+    return Write(data.data(), data.size(), offset);
+}
+
+std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(const std::string& path) const {
+    auto vec = FileUtil::SplitPathComponents(path);
+    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
+              vec.end());
+    if (vec.empty())
+        return nullptr;
+    if (vec.size() == 1)
+        return GetFile(vec[0]);
+    auto dir = GetSubdirectory(vec[0]);
+    for (size_t component = 1; component < vec.size() - 1; ++component) {
+        if (dir == nullptr)
+            return nullptr;
+        dir = dir->GetSubdirectory(vec[component]);
+    }
+    if (dir == nullptr)
+        return nullptr;
+    return dir->GetFile(vec.back());
+}
+
+std::shared_ptr<VfsFile> VfsDirectory::GetFileAbsolute(const std::string& path) const {
+    if (IsRoot())
+        return GetFileRelative(path);
+
+    return GetParentDirectory()->GetFileAbsolute(path);
+}
+
+std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryRelative(const std::string& path) const {
+    auto vec = FileUtil::SplitPathComponents(path);
+    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
+              vec.end());
+    if (vec.empty())
+        // TODO(DarkLordZach): Return this directory if path is '/' or similar. Can't currently
+        // because of const-ness
+        return nullptr;
+    auto dir = GetSubdirectory(vec[0]);
+    for (size_t component = 1; component < vec.size(); ++component) {
+        if (dir == nullptr)
+            return nullptr;
+        dir = dir->GetSubdirectory(vec[component]);
+    }
+    return dir;
+}
+
+std::shared_ptr<VfsDirectory> VfsDirectory::GetDirectoryAbsolute(const std::string& path) const {
+    if (IsRoot())
+        return GetDirectoryRelative(path);
+
+    return GetParentDirectory()->GetDirectoryAbsolute(path);
+}
+
+std::shared_ptr<VfsFile> VfsDirectory::GetFile(const std::string& name) const {
+    const auto& files = GetFiles();
+    const auto iter = std::find_if(files.begin(), files.end(),
+                                   [&name](const auto& file1) { return name == file1->GetName(); });
+    return iter == files.end() ? nullptr : *iter;
+}
+
+std::shared_ptr<VfsDirectory> VfsDirectory::GetSubdirectory(const std::string& name) const {
+    const auto& subs = GetSubdirectories();
+    const auto iter = std::find_if(subs.begin(), subs.end(),
+                                   [&name](const auto& file1) { return name == file1->GetName(); });
+    return iter == subs.end() ? nullptr : *iter;
+}
+
+bool VfsDirectory::IsRoot() const {
+    return GetParentDirectory() == nullptr;
+}
+
+size_t VfsDirectory::GetSize() const {
+    const auto& files = GetFiles();
+    const auto sum_sizes = [](const auto& range) {
+        return std::accumulate(range.begin(), range.end(), 0ULL,
+                               [](const auto& f1, const auto& f2) { return f1 + f2->GetSize(); });
+    };
+
+    const auto file_total = sum_sizes(files);
+    const auto& sub_dir = GetSubdirectories();
+    const auto subdir_total = sum_sizes(sub_dir);
+
+    return file_total + subdir_total;
+}
+
+std::shared_ptr<VfsFile> VfsDirectory::CreateFileRelative(const std::string& path) {
+    auto vec = FileUtil::SplitPathComponents(path);
+    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
+              vec.end());
+    if (vec.empty())
+        return nullptr;
+    if (vec.size() == 1)
+        return CreateFile(vec[0]);
+    auto dir = GetSubdirectory(vec[0]);
+    if (dir == nullptr) {
+        dir = CreateSubdirectory(vec[0]);
+        if (dir == nullptr)
+            return nullptr;
+    }
+
+    return dir->CreateFileRelative(FileUtil::GetPathWithoutTop(path));
+}
+
+std::shared_ptr<VfsFile> VfsDirectory::CreateFileAbsolute(const std::string& path) {
+    if (IsRoot())
+        return CreateFileRelative(path);
+    return GetParentDirectory()->CreateFileAbsolute(path);
+}
+
+std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryRelative(const std::string& path) {
+    auto vec = FileUtil::SplitPathComponents(path);
+    vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
+              vec.end());
+    if (vec.empty())
+        return nullptr;
+    if (vec.size() == 1)
+        return CreateSubdirectory(vec[0]);
+    auto dir = GetSubdirectory(vec[0]);
+    if (dir == nullptr) {
+        dir = CreateSubdirectory(vec[0]);
+        if (dir == nullptr)
+            return nullptr;
+    }
+    return dir->CreateDirectoryRelative(FileUtil::GetPathWithoutTop(path));
+}
+
+std::shared_ptr<VfsDirectory> VfsDirectory::CreateDirectoryAbsolute(const std::string& path) {
+    if (IsRoot())
+        return CreateDirectoryRelative(path);
+    return GetParentDirectory()->CreateDirectoryAbsolute(path);
+}
+
+bool VfsDirectory::DeleteSubdirectoryRecursive(const std::string& name) {
+    auto dir = GetSubdirectory(name);
+    if (dir == nullptr)
+        return false;
+
+    bool success = true;
+    for (const auto& file : dir->GetFiles()) {
+        if (!DeleteFile(file->GetName()))
+            success = false;
+    }
+
+    for (const auto& sdir : dir->GetSubdirectories()) {
+        if (!dir->DeleteSubdirectoryRecursive(sdir->GetName()))
+            success = false;
+    }
+
+    return success;
+}
+
+bool VfsDirectory::Copy(const std::string& src, const std::string& dest) {
+    const auto f1 = GetFile(src);
+    auto f2 = CreateFile(dest);
+    if (f1 == nullptr || f2 == nullptr)
+        return false;
+
+    if (!f2->Resize(f1->GetSize())) {
+        DeleteFile(dest);
+        return false;
+    }
+
+    return f2->WriteBytes(f1->ReadAllBytes()) == f1->GetSize();
+}
+
+bool ReadOnlyVfsDirectory::IsWritable() const {
+    return false;
+}
+
+bool ReadOnlyVfsDirectory::IsReadable() const {
+    return true;
+}
+
+std::shared_ptr<VfsDirectory> ReadOnlyVfsDirectory::CreateSubdirectory(const std::string& name) {
+    return nullptr;
+}
+
+std::shared_ptr<VfsFile> ReadOnlyVfsDirectory::CreateFile(const std::string& name) {
+    return nullptr;
+}
+
+bool ReadOnlyVfsDirectory::DeleteSubdirectory(const std::string& name) {
+    return false;
+}
+
+bool ReadOnlyVfsDirectory::DeleteFile(const std::string& name) {
+    return false;
+}
+
+bool ReadOnlyVfsDirectory::Rename(const std::string& name) {
+    return false;
+}
+} // namespace FileSys

src/core/file_sys/vfs.h

@@ -0,0 +1,237 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <vector>
+#include "boost/optional.hpp"
+#include "common/common_types.h"
+#include "common/file_util.h"
+
+namespace FileSys {
+struct VfsFile;
+struct VfsDirectory;
+
+// Convenience typedefs to use VfsDirectory and VfsFile
+using VirtualDir = std::shared_ptr<FileSys::VfsDirectory>;
+using VirtualFile = std::shared_ptr<FileSys::VfsFile>;
+
+// A class representing a file in an abstract filesystem.
+struct VfsFile : NonCopyable {
+    virtual ~VfsFile();
+
+    // Retrieves the file name.
+    virtual std::string GetName() const = 0;
+    // Retrieves the extension of the file name.
+    virtual std::string GetExtension() const;
+    // Retrieves the size of the file.
+    virtual size_t GetSize() const = 0;
+    // Resizes the file to new_size. Returns whether or not the operation was successful.
+    virtual bool Resize(size_t new_size) = 0;
+    // Gets a pointer to the directory containing this file, returning nullptr if there is none.
+    virtual std::shared_ptr<VfsDirectory> GetContainingDirectory() const = 0;
+
+    // Returns whether or not the file can be written to.
+    virtual bool IsWritable() const = 0;
+    // Returns whether or not the file can be read from.
+    virtual bool IsReadable() const = 0;
+
+    // The primary method of reading from the file. Reads length bytes into data starting at offset
+    // into file. Returns number of bytes successfully read.
+    virtual size_t Read(u8* data, size_t length, size_t offset = 0) const = 0;
+    // The primary method of writing to the file. Writes length bytes from data starting at offset
+    // into file. Returns number of bytes successfully written.
+    virtual size_t Write(const u8* data, size_t length, size_t offset = 0) = 0;
+
+    // Reads exactly one byte at the offset provided, returning boost::none on error.
+    virtual boost::optional<u8> ReadByte(size_t offset = 0) const;
+    // Reads size bytes starting at offset in file into a vector.
+    virtual std::vector<u8> ReadBytes(size_t size, size_t offset = 0) const;
+    // Reads all the bytes from the file into a vector. Equivalent to 'file->Read(file->GetSize(),
+    // 0)'
+    virtual std::vector<u8> ReadAllBytes() const;
+
+    // Reads an array of type T, size number_elements starting at offset.
+    // Returns the number of bytes (sizeof(T)*number_elements) read successfully.
+    template <typename T>
+    size_t ReadArray(T* data, size_t number_elements, size_t offset = 0) const {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+
+        return Read(reinterpret_cast<u8*>(data), number_elements * sizeof(T), offset);
+    }
+
+    // Reads size bytes into the memory starting at data starting at offset into the file.
+    // Returns the number of bytes read successfully.
+    template <typename T>
+    size_t ReadBytes(T* data, size_t size, size_t offset = 0) const {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+        return Read(reinterpret_cast<u8*>(data), size, offset);
+    }
+
+    // Reads one object of type T starting at offset in file.
+    // Returns the number of bytes read successfully (sizeof(T)).
+    template <typename T>
+    size_t ReadObject(T* data, size_t offset = 0) const {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+        return Read(reinterpret_cast<u8*>(data), sizeof(T), offset);
+    }
+
+    // Writes exactly one byte to offset in file and retuns whether or not the byte was written
+    // successfully.
+    virtual bool WriteByte(u8 data, size_t offset = 0);
+    // Writes a vector of bytes to offset in file and returns the number of bytes successfully
+    // written.
+    virtual size_t WriteBytes(std::vector<u8> data, size_t offset = 0);
+
+    // Writes an array of type T, size number_elements to offset in file.
+    // Returns the number of bytes (sizeof(T)*number_elements) written successfully.
+    template <typename T>
+    size_t WriteArray(T* data, size_t number_elements, size_t offset = 0) {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+
+        return Write(data, number_elements * sizeof(T), offset);
+    }
+
+    // Writes size bytes starting at memory location data to offset in file.
+    // Returns the number of bytes written successfully.
+    template <typename T>
+    size_t WriteBytes(T* data, size_t size, size_t offset = 0) {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+        return Write(reinterpret_cast<u8*>(data), size, offset);
+    }
+
+    // Writes one object of type T to offset in file.
+    // Returns the number of bytes written successfully (sizeof(T)).
+    template <typename T>
+    size_t WriteObject(const T& data, size_t offset = 0) {
+        static_assert(std::is_trivially_copyable<T>::value,
+                      "Data type must be trivially copyable.");
+        return Write(&data, sizeof(T), offset);
+    }
+
+    // Renames the file to name. Returns whether or not the operation was successsful.
+    virtual bool Rename(const std::string& name) = 0;
+};
+
+// A class representing a directory in an abstract filesystem.
+struct VfsDirectory : NonCopyable {
+    virtual ~VfsDirectory();
+
+    // Retrives the file located at path as if the current directory was root. Returns nullptr if
+    // not found.
+    virtual std::shared_ptr<VfsFile> GetFileRelative(const std::string& path) const;
+    // Calls GetFileRelative(path) on the root of the current directory.
+    virtual std::shared_ptr<VfsFile> GetFileAbsolute(const std::string& path) const;
+
+    // Retrives the directory located at path as if the current directory was root. Returns nullptr
+    // if not found.
+    virtual std::shared_ptr<VfsDirectory> GetDirectoryRelative(const std::string& path) const;
+    // Calls GetDirectoryRelative(path) on the root of the current directory.
+    virtual std::shared_ptr<VfsDirectory> GetDirectoryAbsolute(const std::string& path) const;
+
+    // Returns a vector containing all of the files in this directory.
+    virtual std::vector<std::shared_ptr<VfsFile>> GetFiles() const = 0;
+    // Returns the file with filename matching name. Returns nullptr if directory dosen't have a
+    // file with name.
+    virtual std::shared_ptr<VfsFile> GetFile(const std::string& name) const;
+
+    // Returns a vector containing all of the subdirectories in this directory.
+    virtual std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const = 0;
+    // Returns the directory with name matching name. Returns nullptr if directory dosen't have a
+    // directory with name.
+    virtual std::shared_ptr<VfsDirectory> GetSubdirectory(const std::string& name) const;
+
+    // Returns whether or not the directory can be written to.
+    virtual bool IsWritable() const = 0;
+    // Returns whether of not the directory can be read from.
+    virtual bool IsReadable() const = 0;
+
+    // Returns whether or not the directory is the root of the current file tree.
+    virtual bool IsRoot() const;
+
+    // Returns the name of the directory.
+    virtual std::string GetName() const = 0;
+    // Returns the total size of all files and subdirectories in this directory.
+    virtual size_t GetSize() const;
+    // Returns the parent directory of this directory. Returns nullptr if this directory is root or
+    // has no parent.
+    virtual std::shared_ptr<VfsDirectory> GetParentDirectory() const = 0;
+
+    // Creates a new subdirectory with name name. Returns a pointer to the new directory or nullptr
+    // if the operation failed.
+    virtual std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) = 0;
+    // Creates a new file with name name. Returns a pointer to the new file or nullptr if the
+    // operation failed.
+    virtual std::shared_ptr<VfsFile> CreateFile(const std::string& name) = 0;
+
+    // Creates a new file at the path relative to this directory. Also creates directories if
+    // they do not exist and is supported by this implementation. Returns nullptr on any failure.
+    virtual std::shared_ptr<VfsFile> CreateFileRelative(const std::string& path);
+
+    // Creates a new file at the path relative to root of this directory. Also creates directories
+    // if they do not exist and is supported by this implementation. Returns nullptr on any failure.
+    virtual std::shared_ptr<VfsFile> CreateFileAbsolute(const std::string& path);
+
+    // Creates a new directory at the path relative to this directory. Also creates directories if
+    // they do not exist and is supported by this implementation. Returns nullptr on any failure.
+    virtual std::shared_ptr<VfsDirectory> CreateDirectoryRelative(const std::string& path);
+
+    // Creates a new directory at the path relative to root of this directory. Also creates
+    // directories if they do not exist and is supported by this implementation. Returns nullptr on
+    // any failure.
+    virtual std::shared_ptr<VfsDirectory> CreateDirectoryAbsolute(const std::string& path);
+
+    // Deletes the subdirectory with name and returns true on success.
+    virtual bool DeleteSubdirectory(const std::string& name) = 0;
+    // Deletes all subdirectories and files of subdirectory with name recirsively and then deletes
+    // the subdirectory. Returns true on success.
+    virtual bool DeleteSubdirectoryRecursive(const std::string& name);
+    // Returnes whether or not the file with name name was deleted successfully.
+    virtual bool DeleteFile(const std::string& name) = 0;
+
+    // Returns whether or not this directory was renamed to name.
+    virtual bool Rename(const std::string& name) = 0;
+
+    // Returns whether or not the file with name src was successfully copied to a new file with name
+    // dest.
+    virtual bool Copy(const std::string& src, const std::string& dest);
+
+    // Interprets the file with name file instead as a directory of type directory.
+    // The directory must have a constructor that takes a single argument of type
+    // std::shared_ptr<VfsFile>. Allows to reinterpret container files (i.e NCA, zip, XCI, etc) as a
+    // subdirectory in one call.
+    template <typename Directory>
+    bool InterpretAsDirectory(const std::string& file) {
+        auto file_p = GetFile(file);
+        if (file_p == nullptr)
+            return false;
+        return ReplaceFileWithSubdirectory(file, std::make_shared<Directory>(file_p));
+    }
+
+protected:
+    // Backend for InterpretAsDirectory.
+    // Removes all references to file and adds a reference to dir in the directory's implementation.
+    virtual bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) = 0;
+};
+
+// A convenience partial-implementation of VfsDirectory that stubs out methods that should only work
+// if writable. This is to avoid redundant empty methods everywhere.
+struct ReadOnlyVfsDirectory : public VfsDirectory {
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
+    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
+    bool DeleteSubdirectory(const std::string& name) override;
+    bool DeleteFile(const std::string& name) override;
+    bool Rename(const std::string& name) override;
+};
+} // namespace FileSys

src/core/file_sys/vfs_offset.cpp

@@ -0,0 +1,94 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <utility>
+
+#include "core/file_sys/vfs_offset.h"
+
+namespace FileSys {
+
+OffsetVfsFile::OffsetVfsFile(std::shared_ptr<VfsFile> file_, size_t size_, size_t offset_,
+                             std::string name_)
+    : file(std::move(file_)), offset(offset_), size(size_), name(std::move(name_)) {}
+
+std::string OffsetVfsFile::GetName() const {
+    return name.empty() ? file->GetName() : name;
+}
+
+size_t OffsetVfsFile::GetSize() const {
+    return size;
+}
+
+bool OffsetVfsFile::Resize(size_t new_size) {
+    if (offset + new_size < file->GetSize()) {
+        size = new_size;
+    } else {
+        auto res = file->Resize(offset + new_size);
+        if (!res)
+            return false;
+        size = new_size;
+    }
+
+    return true;
+}
+
+std::shared_ptr<VfsDirectory> OffsetVfsFile::GetContainingDirectory() const {
+    return file->GetContainingDirectory();
+}
+
+bool OffsetVfsFile::IsWritable() const {
+    return file->IsWritable();
+}
+
+bool OffsetVfsFile::IsReadable() const {
+    return file->IsReadable();
+}
+
+size_t OffsetVfsFile::Read(u8* data, size_t length, size_t r_offset) const {
+    return file->Read(data, TrimToFit(length, r_offset), offset + r_offset);
+}
+
+size_t OffsetVfsFile::Write(const u8* data, size_t length, size_t r_offset) {
+    return file->Write(data, TrimToFit(length, r_offset), offset + r_offset);
+}
+
+boost::optional<u8> OffsetVfsFile::ReadByte(size_t r_offset) const {
+    if (r_offset < size)
+        return file->ReadByte(offset + r_offset);
+
+    return boost::none;
+}
+
+std::vector<u8> OffsetVfsFile::ReadBytes(size_t r_size, size_t r_offset) const {
+    return file->ReadBytes(TrimToFit(r_size, r_offset), offset + r_offset);
+}
+
+std::vector<u8> OffsetVfsFile::ReadAllBytes() const {
+    return file->ReadBytes(size, offset);
+}
+
+bool OffsetVfsFile::WriteByte(u8 data, size_t r_offset) {
+    if (r_offset < size)
+        return file->WriteByte(data, offset + r_offset);
+
+    return false;
+}
+
+size_t OffsetVfsFile::WriteBytes(std::vector<u8> data, size_t r_offset) {
+    return file->Write(data.data(), TrimToFit(data.size(), r_offset), offset + r_offset);
+}
+
+bool OffsetVfsFile::Rename(const std::string& name) {
+    return file->Rename(name);
+}
+
+size_t OffsetVfsFile::GetOffset() const {
+    return offset;
+}
+
+size_t OffsetVfsFile::TrimToFit(size_t r_size, size_t r_offset) const {
+    return std::max<size_t>(std::min<size_t>(size - r_offset, r_size), 0);
+}
+
+} // namespace FileSys

src/core/file_sys/vfs_offset.h

@@ -0,0 +1,46 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+// An implementation of VfsFile that wraps around another VfsFile at a certain offset.
+// Similar to seeking to an offset.
+// If the file is writable, operations that would write past the end of the offset file will expand
+// the size of this wrapper.
+struct OffsetVfsFile : public VfsFile {
+    OffsetVfsFile(std::shared_ptr<VfsFile> file, size_t size, size_t offset = 0,
+                  std::string new_name = "");
+
+    std::string GetName() const override;
+    size_t GetSize() const override;
+    bool Resize(size_t new_size) override;
+    std::shared_ptr<VfsDirectory> GetContainingDirectory() const override;
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    size_t Read(u8* data, size_t length, size_t offset) const override;
+    size_t Write(const u8* data, size_t length, size_t offset) override;
+    boost::optional<u8> ReadByte(size_t offset) const override;
+    std::vector<u8> ReadBytes(size_t size, size_t offset) const override;
+    std::vector<u8> ReadAllBytes() const override;
+    bool WriteByte(u8 data, size_t offset) override;
+    size_t WriteBytes(std::vector<u8> data, size_t offset) override;
+
+    bool Rename(const std::string& name) override;
+
+    size_t GetOffset() const;
+
+private:
+    size_t TrimToFit(size_t r_size, size_t r_offset) const;
+
+    std::shared_ptr<VfsFile> file;
+    size_t offset;
+    size_t size;
+    std::string name;
+};
+
+} // namespace FileSys

src/core/file_sys/vfs_real.cpp

@@ -0,0 +1,183 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstddef>
+#include <iterator>
+#include <utility>
+
+#include "common/common_paths.h"
+#include "common/logging/log.h"
+#include "core/file_sys/vfs_real.h"
+
+namespace FileSys {
+
+static std::string PermissionsToCharArray(Mode perms) {
+    std::string out;
+    switch (perms) {
+    case Mode::Read:
+        out += "r";
+        break;
+    case Mode::Write:
+        out += "r+";
+        break;
+    case Mode::Append:
+        out += "a";
+        break;
+    }
+    return out + "b";
+}
+
+RealVfsFile::RealVfsFile(const std::string& path_, Mode perms_)
+    : backing(path_, PermissionsToCharArray(perms_).c_str()), path(path_),
+      parent_path(FileUtil::GetParentPath(path_)),
+      path_components(FileUtil::SplitPathComponents(path_)),
+      parent_components(FileUtil::SliceVector(path_components, 0, path_components.size() - 1)),
+      perms(perms_) {}
+
+std::string RealVfsFile::GetName() const {
+    return path_components.back();
+}
+
+size_t RealVfsFile::GetSize() const {
+    return backing.GetSize();
+}
+
+bool RealVfsFile::Resize(size_t new_size) {
+    return backing.Resize(new_size);
+}
+
+std::shared_ptr<VfsDirectory> RealVfsFile::GetContainingDirectory() const {
+    return std::make_shared<RealVfsDirectory>(parent_path, perms);
+}
+
+bool RealVfsFile::IsWritable() const {
+    return perms == Mode::Append || perms == Mode::Write;
+}
+
+bool RealVfsFile::IsReadable() const {
+    return perms == Mode::Read || perms == Mode::Write;
+}
+
+size_t RealVfsFile::Read(u8* data, size_t length, size_t offset) const {
+    if (!backing.Seek(offset, SEEK_SET))
+        return 0;
+    return backing.ReadBytes(data, length);
+}
+
+size_t RealVfsFile::Write(const u8* data, size_t length, size_t offset) {
+    if (!backing.Seek(offset, SEEK_SET))
+        return 0;
+    return backing.WriteBytes(data, length);
+}
+
+bool RealVfsFile::Rename(const std::string& name) {
+    const auto out = FileUtil::Rename(GetName(), name);
+    path = parent_path + DIR_SEP + name;
+    path_components = parent_components;
+    path_components.push_back(name);
+    backing = FileUtil::IOFile(path, PermissionsToCharArray(perms).c_str());
+    return out;
+}
+
+bool RealVfsFile::Close() {
+    return backing.Close();
+}
+
+RealVfsDirectory::RealVfsDirectory(const std::string& path_, Mode perms_)
+    : path(FileUtil::RemoveTrailingSlash(path_)), parent_path(FileUtil::GetParentPath(path)),
+      path_components(FileUtil::SplitPathComponents(path)),
+      parent_components(FileUtil::SliceVector(path_components, 0, path_components.size() - 1)),
+      perms(perms_) {
+    if (!FileUtil::Exists(path) && (perms == Mode::Write || perms == Mode::Append))
+        FileUtil::CreateDir(path);
+    unsigned size;
+    if (perms == Mode::Append)
+        return;
+
+    FileUtil::ForeachDirectoryEntry(
+        &size, path,
+        [this](unsigned* entries_out, const std::string& directory, const std::string& filename) {
+            std::string full_path = directory + DIR_SEP + filename;
+            if (FileUtil::IsDirectory(full_path))
+                subdirectories.emplace_back(std::make_shared<RealVfsDirectory>(full_path, perms));
+            else
+                files.emplace_back(std::make_shared<RealVfsFile>(full_path, perms));
+            return true;
+        });
+}
+
+std::vector<std::shared_ptr<VfsFile>> RealVfsDirectory::GetFiles() const {
+    return files;
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> RealVfsDirectory::GetSubdirectories() const {
+    return subdirectories;
+}
+
+bool RealVfsDirectory::IsWritable() const {
+    return perms == Mode::Write || perms == Mode::Append;
+}
+
+bool RealVfsDirectory::IsReadable() const {
+    return perms == Mode::Read || perms == Mode::Write;
+}
+
+std::string RealVfsDirectory::GetName() const {
+    return path_components.back();
+}
+
+std::shared_ptr<VfsDirectory> RealVfsDirectory::GetParentDirectory() const {
+    if (path_components.size() <= 1)
+        return nullptr;
+
+    return std::make_shared<RealVfsDirectory>(parent_path, perms);
+}
+
+std::shared_ptr<VfsDirectory> RealVfsDirectory::CreateSubdirectory(const std::string& name) {
+    if (!FileUtil::CreateDir(path + DIR_SEP + name))
+        return nullptr;
+    subdirectories.emplace_back(std::make_shared<RealVfsDirectory>(path + DIR_SEP + name, perms));
+    return subdirectories.back();
+}
+
+std::shared_ptr<VfsFile> RealVfsDirectory::CreateFile(const std::string& name) {
+    if (!FileUtil::CreateEmptyFile(path + DIR_SEP + name))
+        return nullptr;
+    files.emplace_back(std::make_shared<RealVfsFile>(path + DIR_SEP + name, perms));
+    return files.back();
+}
+
+bool RealVfsDirectory::DeleteSubdirectory(const std::string& name) {
+    return FileUtil::DeleteDirRecursively(path + DIR_SEP + name);
+}
+
+bool RealVfsDirectory::DeleteFile(const std::string& name) {
+    auto file = GetFile(name);
+    if (file == nullptr)
+        return false;
+    files.erase(std::find(files.begin(), files.end(), file));
+    auto real_file = std::static_pointer_cast<RealVfsFile>(file);
+    real_file->Close();
+    return FileUtil::Delete(path + DIR_SEP + name);
+}
+
+bool RealVfsDirectory::Rename(const std::string& name) {
+    return FileUtil::Rename(path, parent_path + DIR_SEP + name);
+}
+
+bool RealVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    const auto iter = std::find(files.begin(), files.end(), file);
+    if (iter == files.end())
+        return false;
+
+    const std::ptrdiff_t offset = std::distance(files.begin(), iter);
+    files[offset] = files.back();
+    files.pop_back();
+
+    subdirectories.emplace_back(std::move(dir));
+
+    return true;
+}
+} // namespace FileSys

src/core/file_sys/vfs_real.h

@@ -0,0 +1,69 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/file_util.h"
+#include "core/file_sys/mode.h"
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+// An implmentation of VfsFile that represents a file on the user's computer.
+struct RealVfsFile : public VfsFile {
+    friend struct RealVfsDirectory;
+
+    RealVfsFile(const std::string& name, Mode perms = Mode::Read);
+
+    std::string GetName() const override;
+    size_t GetSize() const override;
+    bool Resize(size_t new_size) override;
+    std::shared_ptr<VfsDirectory> GetContainingDirectory() const override;
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    size_t Read(u8* data, size_t length, size_t offset) const override;
+    size_t Write(const u8* data, size_t length, size_t offset) override;
+    bool Rename(const std::string& name) override;
+
+private:
+    bool Close();
+
+    FileUtil::IOFile backing;
+    std::string path;
+    std::string parent_path;
+    std::vector<std::string> path_components;
+    std::vector<std::string> parent_components;
+    Mode perms;
+};
+
+// An implementation of VfsDirectory that represents a directory on the user's computer.
+struct RealVfsDirectory : public VfsDirectory {
+    RealVfsDirectory(const std::string& path, Mode perms);
+
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    std::string GetName() const override;
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(const std::string& name) override;
+    std::shared_ptr<VfsFile> CreateFile(const std::string& name) override;
+    bool DeleteSubdirectory(const std::string& name) override;
+    bool DeleteFile(const std::string& name) override;
+    bool Rename(const std::string& name) override;
+
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+
+private:
+    std::string path;
+    std::string parent_path;
+    std::vector<std::string> path_components;
+    std::vector<std::string> parent_components;
+    Mode perms;
+    std::vector<std::shared_ptr<VfsFile>> files;
+    std::vector<std::shared_ptr<VfsDirectory>> subdirectories;
+};
+
+} // namespace FileSys

src/core/gdbstub/gdbstub.cpp

@@ -205,7 +205,7 @@ static Kernel::Thread* FindThreadById(int id) {
     for (u32 core = 0; core < Core::NUM_CPU_CORES; core++) {
         const auto& threads = Core::System::GetInstance().Scheduler(core)->GetThreadList();
         for (auto& thread : threads) {
-            if (thread->GetThreadId() == id) {
+            if (thread->GetThreadId() == static_cast<u32>(id)) {
                 current_core = core;
                 return thread.get();
             }
@@ -214,7 +214,7 @@ static Kernel::Thread* FindThreadById(int id) {
     return nullptr;
 }
 
-static u64 RegRead(int id, Kernel::Thread* thread = nullptr) {
+static u64 RegRead(std::size_t id, Kernel::Thread* thread = nullptr) {
     if (!thread) {
         return 0;
     }
@@ -234,7 +234,7 @@ static u64 RegRead(int id, Kernel::Thread* thread = nullptr) {
     }
 }
 
-static void RegWrite(int id, u64 val, Kernel::Thread* thread = nullptr) {
+static void RegWrite(std::size_t id, u64 val, Kernel::Thread* thread = nullptr) {
     if (!thread) {
         return;
     }
@@ -744,7 +744,7 @@ static bool IsDataAvailable() {
     fd_set fd_socket;
 
     FD_ZERO(&fd_socket);
-    FD_SET(gdbserver_socket, &fd_socket);
+    FD_SET(static_cast<u32>(gdbserver_socket), &fd_socket);
 
     struct timeval t;
     t.tv_sec = 0;
@@ -793,7 +793,7 @@ static void ReadRegisters() {
 
     u8* bufptr = buffer;
 
-    for (int reg = 0; reg <= SP_REGISTER; reg++) {
+    for (u32 reg = 0; reg <= SP_REGISTER; reg++) {
         LongToGdbHex(bufptr + reg * 16, RegRead(reg, current_thread));
     }
 
@@ -807,7 +807,7 @@ static void ReadRegisters() {
 
     bufptr += 8;
 
-    for (int reg = UC_ARM64_REG_Q0; reg <= UC_ARM64_REG_Q0 + 31; reg++) {
+    for (u32 reg = UC_ARM64_REG_Q0; reg <= UC_ARM64_REG_Q0 + 31; reg++) {
         LongToGdbHex(bufptr + reg * 16, RegRead(reg, current_thread));
     }
 
@@ -858,7 +858,7 @@ static void WriteRegisters() {
     if (command_buffer[0] != 'G')
         return SendReply("E01");
 
-    for (int i = 0, reg = 0; reg <= FPSCR_REGISTER; i++, reg++) {
+    for (u32 i = 0, reg = 0; reg <= FPSCR_REGISTER; i++, reg++) {
         if (reg <= SP_REGISTER) {
             RegWrite(reg, GdbHexToLong(buffer_ptr + i * 16), current_thread);
         } else if (reg == PC_REGISTER) {

src/core/hle/ipc_helpers.h

@@ -174,6 +174,25 @@ public:
     template <typename First, typename... Other>
     void Push(const First& first_value, const Other&... other_values);
 
+    /**
+     * Helper function for pushing strongly-typed enumeration values.
+     *
+     * @tparam Enum The enumeration type to be pushed
+     *
+     * @param value The value to push.
+     *
+     * @note The underlying size of the enumeration type is the size of the
+     *       data that gets pushed. e.g. "enum class SomeEnum : u16" will
+     *       push a u16-sized amount of data.
+     */
+    template <typename Enum>
+    void PushEnum(Enum value) {
+        static_assert(std::is_enum_v<Enum>, "T must be an enum type within a PushEnum call.");
+        static_assert(!std::is_convertible_v<Enum, int>,
+                      "enum type in PushEnum must be a strongly typed enum.");
+        Push(static_cast<std::underlying_type_t<Enum>>(value));
+    }
+
     /**
      * @brief Copies the content of the given trivially copyable class to the buffer as a normal
      * param

src/core/hle/kernel/address_arbiter.cpp

@@ -20,7 +20,7 @@ namespace AddressArbiter {
 static ResultCode WaitForAddress(VAddr address, s64 timeout) {
     SharedPtr<Thread> current_thread = GetCurrentThread();
     current_thread->arb_wait_address = address;
-    current_thread->status = THREADSTATUS_WAIT_ARB;
+    current_thread->status = ThreadStatus::WaitArb;
     current_thread->wakeup_callback = nullptr;
 
     current_thread->WakeAfterDelay(timeout);
@@ -65,7 +65,7 @@ static void WakeThreads(std::vector<SharedPtr<Thread>>& waiting_threads, s32 num
 
     // Signal the waiting threads.
     for (size_t i = 0; i < last; i++) {
-        ASSERT(waiting_threads[i]->status = THREADSTATUS_WAIT_ARB);
+        ASSERT(waiting_threads[i]->status == ThreadStatus::WaitArb);
         waiting_threads[i]->SetWaitSynchronizationResult(RESULT_SUCCESS);
         waiting_threads[i]->arb_wait_address = 0;
         waiting_threads[i]->ResumeFromWait();

src/core/hle/kernel/hle_ipc.cpp

@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <utility>
+
 #include <boost/range/algorithm_ext/erase.hpp>
 #include "common/assert.h"
 #include "common/common_funcs.h"
@@ -19,10 +21,10 @@ namespace Kernel {
 
 void SessionRequestHandler::ClientConnected(SharedPtr<ServerSession> server_session) {
     server_session->SetHleHandler(shared_from_this());
-    connected_sessions.push_back(server_session);
+    connected_sessions.push_back(std::move(server_session));
 }
 
-void SessionRequestHandler::ClientDisconnected(SharedPtr<ServerSession> server_session) {
+void SessionRequestHandler::ClientDisconnected(const SharedPtr<ServerSession>& server_session) {
     server_session->SetHleHandler(nullptr);
     boost::range::remove_erase(connected_sessions, server_session);
 }
@@ -36,7 +38,7 @@ SharedPtr<Event> HLERequestContext::SleepClientThread(SharedPtr<Thread> thread,
     thread->wakeup_callback =
         [context = *this, callback](ThreadWakeupReason reason, SharedPtr<Thread> thread,
                                     SharedPtr<WaitObject> object, size_t index) mutable -> bool {
-        ASSERT(thread->status == THREADSTATUS_WAIT_HLE_EVENT);
+        ASSERT(thread->status == ThreadStatus::WaitHLEEvent);
         callback(thread, context, reason);
         context.WriteToOutgoingCommandBuffer(*thread);
         return true;
@@ -48,7 +50,7 @@ SharedPtr<Event> HLERequestContext::SleepClientThread(SharedPtr<Thread> thread,
     }
 
     event->Clear();
-    thread->status = THREADSTATUS_WAIT_HLE_EVENT;
+    thread->status = ThreadStatus::WaitHLEEvent;
     thread->wait_objects = {event};
     event->AddWaitingThread(thread);
 
@@ -299,10 +301,6 @@ size_t HLERequestContext::WriteBuffer(const void* buffer, size_t size, int buffe
     return size;
 }
 
-size_t HLERequestContext::WriteBuffer(const std::vector<u8>& buffer, int buffer_index) const {
-    return WriteBuffer(buffer.data(), buffer.size());
-}
-
 size_t HLERequestContext::GetReadBufferSize(int buffer_index) const {
     const bool is_buffer_a{BufferDescriptorA().size() && BufferDescriptorA()[buffer_index].Size()};
     return is_buffer_a ? BufferDescriptorA()[buffer_index].Size()

src/core/hle/kernel/hle_ipc.h

@@ -5,8 +5,10 @@
 #pragma once
 
 #include <array>
+#include <iterator>
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <vector>
 #include <boost/container/small_vector.hpp>
 #include "common/common_types.h"
@@ -59,12 +61,12 @@ public:
      * associated ServerSession.
      * @param server_session ServerSession associated with the connection.
      */
-    void ClientDisconnected(SharedPtr<ServerSession> server_session);
+    void ClientDisconnected(const SharedPtr<ServerSession>& server_session);
 
 protected:
     /// List of sessions that are connected to this handler.
     /// A ServerSession whose server endpoint is an HLE implementation is kept alive by this list
-    // for the duration of the connection.
+    /// for the duration of the connection.
     std::vector<SharedPtr<ServerSession>> connected_sessions;
 };
 
@@ -171,8 +173,25 @@ public:
     /// Helper function to write a buffer using the appropriate buffer descriptor
     size_t WriteBuffer(const void* buffer, size_t size, int buffer_index = 0) const;
 
-    /// Helper function to write a buffer using the appropriate buffer descriptor
-    size_t WriteBuffer(const std::vector<u8>& buffer, int buffer_index = 0) const;
+    /* Helper function to write a buffer using the appropriate buffer descriptor
+     *
+     * @tparam ContiguousContainer an arbitrary container that satisfies the
+     *         ContiguousContainer concept in the C++ standard library.
+     *
+     * @param container    The container to write the data of into a buffer.
+     * @param buffer_index The buffer in particular to write to.
+     */
+    template <typename ContiguousContainer,
+              typename = std::enable_if_t<!std::is_pointer_v<ContiguousContainer>>>
+    size_t WriteBuffer(const ContiguousContainer& container, int buffer_index = 0) const {
+        using ContiguousType = typename ContiguousContainer::value_type;
+
+        static_assert(std::is_trivially_copyable_v<ContiguousType>,
+                      "Container to WriteBuffer must contain trivially copyable objects");
+
+        return WriteBuffer(std::data(container), std::size(container) * sizeof(ContiguousType),
+                           buffer_index);
+    }
 
     /// Helper function to get the size of the input buffer
     size_t GetReadBufferSize(int buffer_index = 0) const;

src/core/hle/kernel/mutex.cpp

@@ -28,7 +28,7 @@ static std::pair<SharedPtr<Thread>, u32> GetHighestPriorityMutexWaitingThread(
         if (thread->mutex_wait_address != mutex_addr)
             continue;
 
-        ASSERT(thread->status == THREADSTATUS_WAIT_MUTEX);
+        ASSERT(thread->status == ThreadStatus::WaitMutex);
 
         ++num_waiters;
         if (highest_priority_thread == nullptr ||
@@ -83,7 +83,7 @@ ResultCode Mutex::TryAcquire(VAddr address, Handle holding_thread_handle,
     GetCurrentThread()->mutex_wait_address = address;
     GetCurrentThread()->wait_handle = requesting_thread_handle;
 
-    GetCurrentThread()->status = THREADSTATUS_WAIT_MUTEX;
+    GetCurrentThread()->status = ThreadStatus::WaitMutex;
     GetCurrentThread()->wakeup_callback = nullptr;
 
     // Update the lock holder thread's priority to prevent priority inversion.
@@ -121,7 +121,7 @@ ResultCode Mutex::Release(VAddr address) {
     // Grant the mutex to the next waiting thread and resume it.
     Memory::Write32(address, mutex_value);
 
-    ASSERT(thread->status == THREADSTATUS_WAIT_MUTEX);
+    ASSERT(thread->status == ThreadStatus::WaitMutex);
     thread->ResumeFromWait();
 
     thread->lock_owner = nullptr;

src/core/hle/kernel/object_address_table.cpp

@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <utility>
+
 #include "common/assert.h"
 #include "core/hle/kernel/object_address_table.h"
 
@@ -11,7 +13,7 @@ ObjectAddressTable g_object_address_table;
 
 void ObjectAddressTable::Insert(VAddr addr, SharedPtr<Object> obj) {
     ASSERT_MSG(objects.find(addr) == objects.end(), "Object already exists with addr=0x{:X}", addr);
-    objects[addr] = obj;
+    objects[addr] = std::move(obj);
 }
 
 void ObjectAddressTable::Close(VAddr addr) {

src/core/hle/kernel/scheduler.cpp

@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <utility>
+
 #include "core/core.h"
 #include "core/core_timing.h"
 #include "core/hle/kernel/process.h"
@@ -32,7 +34,7 @@ Thread* Scheduler::PopNextReadyThread() {
     Thread* next = nullptr;
     Thread* thread = GetCurrentThread();
 
-    if (thread && thread->status == THREADSTATUS_RUNNING) {
+    if (thread && thread->status == ThreadStatus::Running) {
         // We have to do better than the current thread.
         // This call returns null when that's not possible.
         next = ready_queue.pop_first_better(thread->current_priority);
@@ -55,17 +57,17 @@ void Scheduler::SwitchContext(Thread* new_thread) {
         previous_thread->last_running_ticks = CoreTiming::GetTicks();
         cpu_core->SaveContext(previous_thread->context);
 
-        if (previous_thread->status == THREADSTATUS_RUNNING) {
+        if (previous_thread->status == ThreadStatus::Running) {
             // This is only the case when a reschedule is triggered without the current thread
             // yielding execution (i.e. an event triggered, system core time-sliced, etc)
             ready_queue.push_front(previous_thread->current_priority, previous_thread);
-            previous_thread->status = THREADSTATUS_READY;
+            previous_thread->status = ThreadStatus::Ready;
         }
     }
 
     // Load context of new thread
     if (new_thread) {
-        ASSERT_MSG(new_thread->status == THREADSTATUS_READY,
+        ASSERT_MSG(new_thread->status == ThreadStatus::Ready,
                    "Thread must be ready to become running.");
 
         // Cancel any outstanding wakeup events for this thread
@@ -76,7 +78,7 @@ void Scheduler::SwitchContext(Thread* new_thread) {
         current_thread = new_thread;
 
         ready_queue.remove(new_thread->current_priority, new_thread);
-        new_thread->status = THREADSTATUS_RUNNING;
+        new_thread->status = ThreadStatus::Running;
 
         if (previous_process != current_thread->owner_process) {
             Core::CurrentProcess() = current_thread->owner_process;
@@ -113,7 +115,7 @@ void Scheduler::Reschedule() {
 void Scheduler::AddThread(SharedPtr<Thread> thread, u32 priority) {
     std::lock_guard<std::mutex> lock(scheduler_mutex);
 
-    thread_list.push_back(thread);
+    thread_list.push_back(std::move(thread));
     ready_queue.prepare(priority);
 }
 
@@ -127,14 +129,14 @@ void Scheduler::RemoveThread(Thread* thread) {
 void Scheduler::ScheduleThread(Thread* thread, u32 priority) {
     std::lock_guard<std::mutex> lock(scheduler_mutex);
 
-    ASSERT(thread->status == THREADSTATUS_READY);
+    ASSERT(thread->status == ThreadStatus::Ready);
     ready_queue.push_back(priority, thread);
 }
 
 void Scheduler::UnscheduleThread(Thread* thread, u32 priority) {
     std::lock_guard<std::mutex> lock(scheduler_mutex);
 
-    ASSERT(thread->status == THREADSTATUS_READY);
+    ASSERT(thread->status == ThreadStatus::Ready);
     ready_queue.remove(priority, thread);
 }
 
@@ -142,7 +144,7 @@ void Scheduler::SetThreadPriority(Thread* thread, u32 priority) {
     std::lock_guard<std::mutex> lock(scheduler_mutex);
 
     // If thread was ready, adjust queues
-    if (thread->status == THREADSTATUS_READY)
+    if (thread->status == ThreadStatus::Ready)
         ready_queue.move(thread, thread->current_priority, priority);
     else
         ready_queue.prepare(priority);

src/core/hle/kernel/server_session.cpp

@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <tuple>
+#include <utility>
 
 #include "core/core.h"
 #include "core/hle/ipc_helpers.h"
@@ -109,10 +110,10 @@ ResultCode ServerSession::HandleSyncRequest(SharedPtr<Thread> thread) {
         result = hle_handler->HandleSyncRequest(context);
     }
 
-    if (thread->status == THREADSTATUS_RUNNING) {
+    if (thread->status == ThreadStatus::Running) {
         // Put the thread to sleep until the server replies, it will be awoken in
         // svcReplyAndReceive for LLE servers.
-        thread->status = THREADSTATUS_WAIT_IPC;
+        thread->status = ThreadStatus::WaitIPC;
 
         if (hle_handler != nullptr) {
             // For HLE services, we put the request threads to sleep for a short duration to
@@ -158,7 +159,7 @@ ServerSession::SessionPair ServerSession::CreateSessionPair(const std::string& n
     std::shared_ptr<Session> parent(new Session);
     parent->client = client_session.get();
     parent->server = server_session.get();
-    parent->port = port;
+    parent->port = std::move(port);
 
     client_session->parent = parent;
     server_session->parent = parent;

src/core/hle/kernel/shared_memory.cpp

@@ -2,7 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <cstring>
+#include <utility>
 #include "common/logging/log.h"
 #include "core/core.h"
 #include "core/hle/kernel/errors.h"
@@ -21,7 +21,7 @@ SharedPtr<SharedMemory> SharedMemory::Create(SharedPtr<Process> owner_process, u
                                              MemoryRegion region, std::string name) {
     SharedPtr<SharedMemory> shared_memory(new SharedMemory);
 
-    shared_memory->owner_process = owner_process;
+    shared_memory->owner_process = std::move(owner_process);
     shared_memory->name = std::move(name);
     shared_memory->size = size;
     shared_memory->permissions = permissions;
@@ -87,7 +87,7 @@ SharedPtr<SharedMemory> SharedMemory::CreateForApplet(std::shared_ptr<std::vecto
     shared_memory->size = size;
     shared_memory->permissions = permissions;
     shared_memory->other_permissions = other_permissions;
-    shared_memory->backing_block = heap_block;
+    shared_memory->backing_block = std::move(heap_block);
     shared_memory->backing_block_offset = offset;
     shared_memory->base_address = Memory::HEAP_VADDR + offset;
 

src/core/hle/kernel/svc.cpp

@@ -133,7 +133,7 @@ static ResultCode GetProcessId(u32* process_id, Handle process_handle) {
 /// Default thread wakeup callback for WaitSynchronization
 static bool DefaultThreadWakeupCallback(ThreadWakeupReason reason, SharedPtr<Thread> thread,
                                         SharedPtr<WaitObject> object, size_t index) {
-    ASSERT(thread->status == THREADSTATUS_WAIT_SYNCH_ANY);
+    ASSERT(thread->status == ThreadStatus::WaitSynchAny);
 
     if (reason == ThreadWakeupReason::Timeout) {
         thread->SetWaitSynchronizationResult(RESULT_TIMEOUT);
@@ -197,7 +197,7 @@ static ResultCode WaitSynchronization(Handle* index, VAddr handles_address, u64
         object->AddWaitingThread(thread);
 
     thread->wait_objects = std::move(objects);
-    thread->status = THREADSTATUS_WAIT_SYNCH_ANY;
+    thread->status = ThreadStatus::WaitSynchAny;
 
     // Create an event to wake the thread up after the specified nanosecond delay has passed
     thread->WakeAfterDelay(nano_seconds);
@@ -217,7 +217,7 @@ static ResultCode CancelSynchronization(Handle thread_handle) {
         return ERR_INVALID_HANDLE;
     }
 
-    ASSERT(thread->status == THREADSTATUS_WAIT_SYNCH_ANY);
+    ASSERT(thread->status == ThreadStatus::WaitSynchAny);
     thread->SetWaitSynchronizationResult(
         ResultCode(ErrorModule::Kernel, ErrCodes::SynchronizationCanceled));
     thread->ResumeFromWait();
@@ -468,8 +468,8 @@ static void ExitProcess() {
                 continue;
 
             // TODO(Subv): When are the other running/ready threads terminated?
-            ASSERT_MSG(thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
-                           thread->status == THREADSTATUS_WAIT_SYNCH_ALL,
+            ASSERT_MSG(thread->status == ThreadStatus::WaitSynchAny ||
+                           thread->status == ThreadStatus::WaitSynchAll,
                        "Exiting processes with non-waiting threads is currently unimplemented");
 
             thread->Stop();
@@ -545,7 +545,7 @@ static ResultCode StartThread(Handle thread_handle) {
         return ERR_INVALID_HANDLE;
     }
 
-    ASSERT(thread->status == THREADSTATUS_DORMANT);
+    ASSERT(thread->status == ThreadStatus::Dormant);
 
     thread->ResumeFromWait();
     Core::System::GetInstance().CpuCore(thread->processor_id).PrepareReschedule();
@@ -596,7 +596,7 @@ static ResultCode WaitProcessWideKeyAtomic(VAddr mutex_addr, VAddr condition_var
     current_thread->condvar_wait_address = condition_variable_addr;
     current_thread->mutex_wait_address = mutex_addr;
     current_thread->wait_handle = thread_handle;
-    current_thread->status = THREADSTATUS_WAIT_MUTEX;
+    current_thread->status = ThreadStatus::WaitMutex;
     current_thread->wakeup_callback = nullptr;
 
     current_thread->WakeAfterDelay(nano_seconds);
@@ -656,7 +656,7 @@ static ResultCode SignalProcessWideKey(VAddr condition_variable_addr, s32 target
         if (mutex_val == 0) {
             // We were able to acquire the mutex, resume this thread.
             Memory::Write32(thread->mutex_wait_address, thread->wait_handle);
-            ASSERT(thread->status == THREADSTATUS_WAIT_MUTEX);
+            ASSERT(thread->status == ThreadStatus::WaitMutex);
             thread->ResumeFromWait();
 
             auto lock_owner = thread->lock_owner;
@@ -672,8 +672,8 @@ static ResultCode SignalProcessWideKey(VAddr condition_variable_addr, s32 target
             Handle owner_handle = static_cast<Handle>(mutex_val & Mutex::MutexOwnerMask);
             auto owner = g_handle_table.Get<Thread>(owner_handle);
             ASSERT(owner);
-            ASSERT(thread->status != THREADSTATUS_RUNNING);
-            thread->status = THREADSTATUS_WAIT_MUTEX;
+            ASSERT(thread->status != ThreadStatus::Running);
+            thread->status = ThreadStatus::WaitMutex;
             thread->wakeup_callback = nullptr;
 
             // Signal that the mutex now has a waiting thread.
@@ -795,8 +795,9 @@ static ResultCode SetThreadCoreMask(Handle thread_handle, u32 core, u64 mask) {
         return ERR_INVALID_HANDLE;
     }
 
-    if (core == THREADPROCESSORID_DEFAULT) {
-        ASSERT(thread->owner_process->ideal_processor != THREADPROCESSORID_DEFAULT);
+    if (core == static_cast<u32>(THREADPROCESSORID_DEFAULT)) {
+        ASSERT(thread->owner_process->ideal_processor !=
+               static_cast<u8>(THREADPROCESSORID_DEFAULT));
         // Set the target CPU to the one specified in the process' exheader.
         core = thread->owner_process->ideal_processor;
         mask = 1ull << core;
@@ -811,7 +812,7 @@ static ResultCode SetThreadCoreMask(Handle thread_handle, u32 core, u64 mask) {
 
     if (core == OnlyChangeMask) {
         core = thread->ideal_core;
-    } else if (core >= Core::NUM_CPU_CORES && core != -1) {
+    } else if (core >= Core::NUM_CPU_CORES && core != static_cast<u32>(-1)) {
         return ResultCode(ErrorModule::Kernel, ErrCodes::InvalidProcessorId);
     }
 

src/core/hle/kernel/thread.cpp

@@ -30,7 +30,7 @@ namespace Kernel {
 static CoreTiming::EventType* ThreadWakeupEventType = nullptr;
 
 bool Thread::ShouldWait(Thread* thread) const {
-    return status != THREADSTATUS_DEAD;
+    return status != ThreadStatus::Dead;
 }
 
 void Thread::Acquire(Thread* thread) {
@@ -63,11 +63,11 @@ void Thread::Stop() {
 
     // Clean up thread from ready queue
     // This is only needed when the thread is termintated forcefully (SVC TerminateProcess)
-    if (status == THREADSTATUS_READY) {
+    if (status == ThreadStatus::Ready) {
         scheduler->UnscheduleThread(this, current_priority);
     }
 
-    status = THREADSTATUS_DEAD;
+    status = ThreadStatus::Dead;
 
     WakeupAllWaitingThreads();
 
@@ -86,7 +86,7 @@ void Thread::Stop() {
 
 void WaitCurrentThread_Sleep() {
     Thread* thread = GetCurrentThread();
-    thread->status = THREADSTATUS_WAIT_SLEEP;
+    thread->status = ThreadStatus::WaitSleep;
 }
 
 void ExitCurrentThread() {
@@ -110,10 +110,9 @@ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
 
     bool resume = true;
 
-    if (thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
-        thread->status == THREADSTATUS_WAIT_SYNCH_ALL ||
-        thread->status == THREADSTATUS_WAIT_HLE_EVENT) {
-
+    if (thread->status == ThreadStatus::WaitSynchAny ||
+        thread->status == ThreadStatus::WaitSynchAll ||
+        thread->status == ThreadStatus::WaitHLEEvent) {
         // Remove the thread from each of its waiting objects' waitlists
         for (auto& object : thread->wait_objects)
             object->RemoveWaitingThread(thread.get());
@@ -126,7 +125,7 @@ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
 
     if (thread->mutex_wait_address != 0 || thread->condvar_wait_address != 0 ||
         thread->wait_handle) {
-        ASSERT(thread->status == THREADSTATUS_WAIT_MUTEX);
+        ASSERT(thread->status == ThreadStatus::WaitMutex);
         thread->mutex_wait_address = 0;
         thread->condvar_wait_address = 0;
         thread->wait_handle = 0;
@@ -141,7 +140,7 @@ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
     }
 
     if (thread->arb_wait_address != 0) {
-        ASSERT(thread->status == THREADSTATUS_WAIT_ARB);
+        ASSERT(thread->status == ThreadStatus::WaitArb);
         thread->arb_wait_address = 0;
     }
 
@@ -165,7 +164,7 @@ void Thread::CancelWakeupTimer() {
 static boost::optional<s32> GetNextProcessorId(u64 mask) {
     for (s32 index = 0; index < Core::NUM_CPU_CORES; ++index) {
         if (mask & (1ULL << index)) {
-            if (!Core::System().GetInstance().Scheduler(index)->GetCurrentThread()) {
+            if (!Core::System::GetInstance().Scheduler(index)->GetCurrentThread()) {
                 // Core is enabled and not running any threads, use this one
                 return index;
             }
@@ -178,28 +177,28 @@ void Thread::ResumeFromWait() {
     ASSERT_MSG(wait_objects.empty(), "Thread is waking up while waiting for objects");
 
     switch (status) {
-    case THREADSTATUS_WAIT_SYNCH_ALL:
-    case THREADSTATUS_WAIT_SYNCH_ANY:
-    case THREADSTATUS_WAIT_HLE_EVENT:
-    case THREADSTATUS_WAIT_SLEEP:
-    case THREADSTATUS_WAIT_IPC:
-    case THREADSTATUS_WAIT_MUTEX:
-    case THREADSTATUS_WAIT_ARB:
+    case ThreadStatus::WaitSynchAll:
+    case ThreadStatus::WaitSynchAny:
+    case ThreadStatus::WaitHLEEvent:
+    case ThreadStatus::WaitSleep:
+    case ThreadStatus::WaitIPC:
+    case ThreadStatus::WaitMutex:
+    case ThreadStatus::WaitArb:
         break;
 
-    case THREADSTATUS_READY:
+    case ThreadStatus::Ready:
         // The thread's wakeup callback must have already been cleared when the thread was first
         // awoken.
         ASSERT(wakeup_callback == nullptr);
         // If the thread is waiting on multiple wait objects, it might be awoken more than once
         // before actually resuming. We can ignore subsequent wakeups if the thread status has
-        // already been set to THREADSTATUS_READY.
+        // already been set to ThreadStatus::Ready.
         return;
 
-    case THREADSTATUS_RUNNING:
+    case ThreadStatus::Running:
         DEBUG_ASSERT_MSG(false, "Thread with object id {} has already resumed.", GetObjectId());
         return;
-    case THREADSTATUS_DEAD:
+    case ThreadStatus::Dead:
         // This should never happen, as threads must complete before being stopped.
         DEBUG_ASSERT_MSG(false, "Thread with object id {} cannot be resumed because it's DEAD.",
                          GetObjectId());
@@ -208,21 +207,21 @@ void Thread::ResumeFromWait() {
 
     wakeup_callback = nullptr;
 
-    status = THREADSTATUS_READY;
+    status = ThreadStatus::Ready;
 
     boost::optional<s32> new_processor_id = GetNextProcessorId(affinity_mask);
     if (!new_processor_id) {
         new_processor_id = processor_id;
     }
     if (ideal_core != -1 &&
-        Core::System().GetInstance().Scheduler(ideal_core)->GetCurrentThread() == nullptr) {
+        Core::System::GetInstance().Scheduler(ideal_core)->GetCurrentThread() == nullptr) {
         new_processor_id = ideal_core;
     }
 
     ASSERT(*new_processor_id < 4);
 
     // Add thread to new core's scheduler
-    auto& next_scheduler = Core::System().GetInstance().Scheduler(*new_processor_id);
+    auto& next_scheduler = Core::System::GetInstance().Scheduler(*new_processor_id);
 
     if (*new_processor_id != processor_id) {
         // Remove thread from previous core's scheduler
@@ -310,7 +309,7 @@ ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point,
     SharedPtr<Thread> thread(new Thread);
 
     thread->thread_id = NewThreadId();
-    thread->status = THREADSTATUS_DORMANT;
+    thread->status = ThreadStatus::Dormant;
     thread->entry_point = entry_point;
     thread->stack_top = stack_top;
     thread->nominal_priority = thread->current_priority = priority;
@@ -325,7 +324,7 @@ ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point,
     thread->name = std::move(name);
     thread->callback_handle = wakeup_callback_handle_table.Create(thread).Unwrap();
     thread->owner_process = owner_process;
-    thread->scheduler = Core::System().GetInstance().Scheduler(processor_id);
+    thread->scheduler = Core::System::GetInstance().Scheduler(processor_id);
     thread->scheduler->AddThread(thread, priority);
 
     // Find the next available TLS index, and mark it as used
@@ -400,7 +399,7 @@ SharedPtr<Thread> SetupMainThread(VAddr entry_point, u32 priority,
 
     // Initialize new "main" thread
     auto thread_res = Thread::Create("main", entry_point, priority, 0, THREADPROCESSORID_0,
-                                     Memory::STACK_AREA_VADDR_END, owner_process);
+                                     Memory::STACK_AREA_VADDR_END, std::move(owner_process));
 
     SharedPtr<Thread> thread = std::move(thread_res).Unwrap();
 
@@ -471,7 +470,7 @@ void Thread::ChangeCore(u32 core, u64 mask) {
     ideal_core = core;
     affinity_mask = mask;
 
-    if (status != THREADSTATUS_READY) {
+    if (status != ThreadStatus::Ready) {
         return;
     }
 
@@ -481,14 +480,14 @@ void Thread::ChangeCore(u32 core, u64 mask) {
         new_processor_id = processor_id;
     }
     if (ideal_core != -1 &&
-        Core::System().GetInstance().Scheduler(ideal_core)->GetCurrentThread() == nullptr) {
+        Core::System::GetInstance().Scheduler(ideal_core)->GetCurrentThread() == nullptr) {
         new_processor_id = ideal_core;
     }
 
     ASSERT(*new_processor_id < 4);
 
     // Add thread to new core's scheduler
-    auto& next_scheduler = Core::System().GetInstance().Scheduler(*new_processor_id);
+    auto& next_scheduler = Core::System::GetInstance().Scheduler(*new_processor_id);
 
     if (*new_processor_id != processor_id) {
         // Remove thread from previous core's scheduler

src/core/hle/kernel/thread.h

@@ -36,18 +36,18 @@ enum ThreadProcessorId : s32 {
                                      (1 << THREADPROCESSORID_2) | (1 << THREADPROCESSORID_3)
 };
 
-enum ThreadStatus {
-    THREADSTATUS_RUNNING,        ///< Currently running
-    THREADSTATUS_READY,          ///< Ready to run
-    THREADSTATUS_WAIT_HLE_EVENT, ///< Waiting for hle event to finish
-    THREADSTATUS_WAIT_SLEEP,     ///< Waiting due to a SleepThread SVC
-    THREADSTATUS_WAIT_IPC,       ///< Waiting for the reply from an IPC request
-    THREADSTATUS_WAIT_SYNCH_ANY, ///< Waiting due to WaitSynch1 or WaitSynchN with wait_all = false
-    THREADSTATUS_WAIT_SYNCH_ALL, ///< Waiting due to WaitSynchronizationN with wait_all = true
-    THREADSTATUS_WAIT_MUTEX,     ///< Waiting due to an ArbitrateLock/WaitProcessWideKey svc
-    THREADSTATUS_WAIT_ARB,       ///< Waiting due to a SignalToAddress/WaitForAddress svc
-    THREADSTATUS_DORMANT,        ///< Created but not yet made ready
-    THREADSTATUS_DEAD            ///< Run to completion, or forcefully terminated
+enum class ThreadStatus {
+    Running,      ///< Currently running
+    Ready,        ///< Ready to run
+    WaitHLEEvent, ///< Waiting for hle event to finish
+    WaitSleep,    ///< Waiting due to a SleepThread SVC
+    WaitIPC,      ///< Waiting for the reply from an IPC request
+    WaitSynchAny, ///< Waiting due to WaitSynch1 or WaitSynchN with wait_all = false
+    WaitSynchAll, ///< Waiting due to WaitSynchronizationN with wait_all = true
+    WaitMutex,    ///< Waiting due to an ArbitrateLock/WaitProcessWideKey svc
+    WaitArb,      ///< Waiting due to a SignalToAddress/WaitForAddress svc
+    Dormant,      ///< Created but not yet made ready
+    Dead          ///< Run to completion, or forcefully terminated
 };
 
 enum class ThreadWakeupReason {
@@ -194,14 +194,14 @@ public:
      * with wait_all = true.
      */
     bool IsSleepingOnWaitAll() const {
-        return status == THREADSTATUS_WAIT_SYNCH_ALL;
+        return status == ThreadStatus::WaitSynchAll;
     }
 
     ARM_Interface::ThreadContext context;
 
     u32 thread_id;
 
-    u32 status;
+    ThreadStatus status;
     VAddr entry_point;
     VAddr stack_top;
 

src/core/hle/kernel/vm_manager.cpp

@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <iterator>
+#include <utility>
 #include "common/assert.h"
 #include "common/logging/log.h"
 #include "core/arm/arm_interface.h"
@@ -16,30 +17,20 @@
 namespace Kernel {
 
 static const char* GetMemoryStateName(MemoryState state) {
-    static const char* names[] = {
-        "Unmapped",
-        "Io",
-        "Normal",
-        "CodeStatic",
-        "CodeMutable",
-        "Heap",
-        "Shared",
-        "Unknown1"
-        "ModuleCodeStatic",
-        "ModuleCodeMutable",
-        "IpcBuffer0",
-        "Mapped",
-        "ThreadLocal",
-        "TransferMemoryIsolated",
-        "TransferMemory",
-        "ProcessMemory",
-        "Unknown2"
-        "IpcBuffer1",
-        "IpcBuffer3",
-        "KernelStack",
+    static constexpr const char* names[] = {
+        "Unmapped",         "Io",
+        "Normal",           "CodeStatic",
+        "CodeMutable",      "Heap",
+        "Shared",           "Unknown1",
+        "ModuleCodeStatic", "ModuleCodeMutable",
+        "IpcBuffer0",       "Mapped",
+        "ThreadLocal",      "TransferMemoryIsolated",
+        "TransferMemory",   "ProcessMemory",
+        "Unknown2",         "IpcBuffer1",
+        "IpcBuffer3",       "KernelStack",
     };
 
-    return names[(int)state];
+    return names[static_cast<int>(state)];
 }
 
 bool VirtualMemoryArea::CanBeMergedWith(const VirtualMemoryArea& next) const {
@@ -117,7 +108,7 @@ ResultVal<VMManager::VMAHandle> VMManager::MapMemoryBlock(VAddr target,
     final_vma.type = VMAType::AllocatedMemoryBlock;
     final_vma.permissions = VMAPermission::ReadWrite;
     final_vma.meminfo_state = state;
-    final_vma.backing_block = block;
+    final_vma.backing_block = std::move(block);
     final_vma.offset = offset;
     UpdatePageTableForVMA(final_vma);
 
@@ -160,7 +151,7 @@ ResultVal<VMManager::VMAHandle> VMManager::MapMMIO(VAddr target, PAddr paddr, u6
     final_vma.permissions = VMAPermission::ReadWrite;
     final_vma.meminfo_state = state;
     final_vma.paddr = paddr;
-    final_vma.mmio_handler = mmio_handler;
+    final_vma.mmio_handler = std::move(mmio_handler);
     UpdatePageTableForVMA(final_vma);
 
     return MakeResult<VMAHandle>(MergeAdjacent(vma_handle));

src/core/hle/kernel/wait_object.cpp

@@ -38,9 +38,9 @@ SharedPtr<Thread> WaitObject::GetHighestPriorityReadyThread() {
 
     for (const auto& thread : waiting_threads) {
         // The list of waiting threads must not contain threads that are not waiting to be awakened.
-        ASSERT_MSG(thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
-                       thread->status == THREADSTATUS_WAIT_SYNCH_ALL ||
-                       thread->status == THREADSTATUS_WAIT_HLE_EVENT,
+        ASSERT_MSG(thread->status == ThreadStatus::WaitSynchAny ||
+                       thread->status == ThreadStatus::WaitSynchAll ||
+                       thread->status == ThreadStatus::WaitHLEEvent,
                    "Inconsistent thread statuses in waiting_threads");
 
         if (thread->current_priority >= candidate_priority)
@@ -49,10 +49,10 @@ SharedPtr<Thread> WaitObject::GetHighestPriorityReadyThread() {
         if (ShouldWait(thread.get()))
             continue;
 
-        // A thread is ready to run if it's either in THREADSTATUS_WAIT_SYNCH_ANY or
-        // in THREADSTATUS_WAIT_SYNCH_ALL and the rest of the objects it is waiting on are ready.
+        // A thread is ready to run if it's either in ThreadStatus::WaitSynchAny or
+        // in ThreadStatus::WaitSynchAll and the rest of the objects it is waiting on are ready.
         bool ready_to_run = true;
-        if (thread->status == THREADSTATUS_WAIT_SYNCH_ALL) {
+        if (thread->status == ThreadStatus::WaitSynchAll) {
             ready_to_run = std::none_of(thread->wait_objects.begin(), thread->wait_objects.end(),
                                         [&thread](const SharedPtr<WaitObject>& object) {
                                             return object->ShouldWait(thread.get());

src/core/hle/service/acc/acc.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <array>
 #include "common/logging/log.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/service/acc/acc.h"
@@ -24,18 +25,17 @@ struct UserData {
 static_assert(sizeof(UserData) == 0x80, "UserData structure has incorrect size");
 
 struct ProfileBase {
-    u8 user_id[0x10];
+    u128 user_id;
     u64 timestamp;
-    u8 username[0x20];
+    std::array<u8, 0x20> username;
 };
 static_assert(sizeof(ProfileBase) == 0x38, "ProfileBase structure has incorrect size");
 
-using Uid = std::array<u64, 2>;
-static constexpr Uid DEFAULT_USER_ID{0x10ull, 0x20ull};
+static constexpr u128 DEFAULT_USER_ID{1ull, 0ull};
 
 class IProfile final : public ServiceFramework<IProfile> {
 public:
-    IProfile() : ServiceFramework("IProfile") {
+    IProfile(u128 user_id) : ServiceFramework("IProfile"), user_id(user_id) {
         static const FunctionInfo functions[] = {
             {0, nullptr, "Get"},
             {1, &IProfile::GetBase, "GetBase"},
@@ -48,11 +48,18 @@ public:
 private:
     void GetBase(Kernel::HLERequestContext& ctx) {
         LOG_WARNING(Service_ACC, "(STUBBED) called");
+
+        // TODO(Subv): Retrieve this information from somewhere.
         ProfileBase profile_base{};
+        profile_base.user_id = user_id;
+        profile_base.username = {'y', 'u', 'z', 'u'};
+
         IPC::ResponseBuilder rb{ctx, 16};
         rb.Push(RESULT_SUCCESS);
         rb.PushRaw(profile_base);
     }
+
+    u128 user_id; ///< The user id this profile refers to.
 };
 
 class IManagerForApplication final : public ServiceFramework<IManagerForApplication> {
@@ -75,14 +82,16 @@ private:
         LOG_WARNING(Service_ACC, "(STUBBED) called");
         IPC::ResponseBuilder rb{ctx, 3};
         rb.Push(RESULT_SUCCESS);
-        rb.Push(true); // TODO: Check when this is supposed to return true and when not
+        rb.Push(false); // TODO: Check when this is supposed to return true and when not
     }
 
     void GetAccountId(Kernel::HLERequestContext& ctx) {
         LOG_WARNING(Service_ACC, "(STUBBED) called");
-        IPC::ResponseBuilder rb{ctx, 4};
-        rb.Push(RESULT_SUCCESS);
-        rb.Push<u64>(0x12345678ABCDEF);
+        // TODO(Subv): Find out what this actually does and implement it. Stub it as an error for
+        // now since we do not implement NNID. Returning a bogus id here will cause games to send
+        // invalid IPC requests after ListOpenUsers is called.
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultCode(-1));
     }
 };
 
@@ -95,25 +104,29 @@ void Module::Interface::GetUserExistence(Kernel::HLERequestContext& ctx) {
 
 void Module::Interface::ListAllUsers(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_ACC, "(STUBBED) called");
-    constexpr std::array<u128, 10> user_ids{DEFAULT_USER_ID};
-    ctx.WriteBuffer(user_ids.data(), user_ids.size());
+    // TODO(Subv): There is only one user for now.
+    const std::vector<u128> user_ids = {DEFAULT_USER_ID};
+    ctx.WriteBuffer(user_ids);
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
 }
 
 void Module::Interface::ListOpenUsers(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_ACC, "(STUBBED) called");
-    constexpr std::array<u128, 10> user_ids{DEFAULT_USER_ID};
-    ctx.WriteBuffer(user_ids.data(), user_ids.size());
+    // TODO(Subv): There is only one user for now.
+    const std::vector<u128> user_ids = {DEFAULT_USER_ID};
+    ctx.WriteBuffer(user_ids);
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
 }
 
 void Module::Interface::GetProfile(Kernel::HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    u128 user_id = rp.PopRaw<u128>();
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<IProfile>();
-    LOG_DEBUG(Service_ACC, "called");
+    rb.PushIpcInterface<IProfile>(user_id);
+    LOG_DEBUG(Service_ACC, "called user_id=0x{:016X}{:016X}", user_id[1], user_id[0]);
 }
 
 void Module::Interface::InitializeApplicationInfo(Kernel::HLERequestContext& ctx) {

src/core/hle/service/acc/acc.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void GetUserExistence(Kernel::HLERequestContext& ctx);
         void ListAllUsers(Kernel::HLERequestContext& ctx);

src/core/hle/service/am/am.cpp

@@ -5,7 +5,6 @@
 #include <cinttypes>
 #include <stack>
 #include "core/core.h"
-#include "core/file_sys/filesystem.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/kernel/event.h"
 #include "core/hle/kernel/process.h"

src/core/hle/service/am/am.h

@@ -72,7 +72,7 @@ public:
 
 class ISelfController final : public ServiceFramework<ISelfController> {
 public:
-    ISelfController(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
+    explicit ISelfController(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
 
 private:
     void SetFocusHandlingMode(Kernel::HLERequestContext& ctx);

src/core/hle/service/am/applet_ae.cpp

@@ -12,7 +12,7 @@ namespace Service::AM {
 
 class ILibraryAppletProxy final : public ServiceFramework<ILibraryAppletProxy> {
 public:
-    ILibraryAppletProxy(std::shared_ptr<NVFlinger::NVFlinger> nvflinger)
+    explicit ILibraryAppletProxy(std::shared_ptr<NVFlinger::NVFlinger> nvflinger)
         : ServiceFramework("ILibraryAppletProxy"), nvflinger(std::move(nvflinger)) {
         static const FunctionInfo functions[] = {
             {0, &ILibraryAppletProxy::GetCommonStateGetter, "GetCommonStateGetter"},

src/core/hle/service/am/applet_ae.h

@@ -17,7 +17,7 @@ namespace AM {
 
 class AppletAE final : public ServiceFramework<AppletAE> {
 public:
-    AppletAE(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
+    explicit AppletAE(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
     ~AppletAE() = default;
 
 private:

src/core/hle/service/am/applet_oe.cpp

@@ -12,7 +12,7 @@ namespace Service::AM {
 
 class IApplicationProxy final : public ServiceFramework<IApplicationProxy> {
 public:
-    IApplicationProxy(std::shared_ptr<NVFlinger::NVFlinger> nvflinger)
+    explicit IApplicationProxy(std::shared_ptr<NVFlinger::NVFlinger> nvflinger)
         : ServiceFramework("IApplicationProxy"), nvflinger(std::move(nvflinger)) {
         static const FunctionInfo functions[] = {
             {0, &IApplicationProxy::GetCommonStateGetter, "GetCommonStateGetter"},

src/core/hle/service/am/applet_oe.h

@@ -17,7 +17,7 @@ namespace AM {
 
 class AppletOE final : public ServiceFramework<AppletOE> {
 public:
-    AppletOE(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
+    explicit AppletOE(std::shared_ptr<NVFlinger::NVFlinger> nvflinger);
     ~AppletOE() = default;
 
 private:

src/core/hle/service/apm/interface.cpp

@@ -20,6 +20,21 @@ public:
     }
 
 private:
+    enum class PerformanceConfiguration : u32 {
+        Config1 = 0x00010000,
+        Config2 = 0x00010001,
+        Config3 = 0x00010002,
+        Config4 = 0x00020000,
+        Config5 = 0x00020001,
+        Config6 = 0x00020002,
+        Config7 = 0x00020003,
+        Config8 = 0x00020004,
+        Config9 = 0x00020005,
+        Config10 = 0x00020006,
+        Config11 = 0x92220007,
+        Config12 = 0x92220008,
+    };
+
     void SetPerformanceConfiguration(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
 
@@ -40,7 +55,7 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 3};
         rb.Push(RESULT_SUCCESS);
-        rb.Push<u32>(0); // Performance configuration
+        rb.Push<u32>(static_cast<u32>(PerformanceConfiguration::Config1));
 
         LOG_WARNING(Service_APM, "(STUBBED) called mode={}", static_cast<u32>(mode));
     }

src/core/hle/service/apm/interface.h

@@ -10,7 +10,7 @@ namespace Service::APM {
 
 class APM final : public ServiceFramework<APM> {
 public:
-    APM(std::shared_ptr<Module> apm, const char* name);
+    explicit APM(std::shared_ptr<Module> apm, const char* name);
     ~APM() = default;
 
 private:

src/core/hle/service/audio/audout_u.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <array>
 #include <vector>
 #include "common/logging/log.h"
 #include "core/core_timing.h"
@@ -167,8 +168,8 @@ void AudOutU::ListAudioOutsImpl(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_Audio, "(STUBBED) called");
     IPC::RequestParser rp{ctx};
 
-    const std::string audio_interface = "AudioInterface";
-    ctx.WriteBuffer(audio_interface.c_str(), audio_interface.size());
+    constexpr std::array<char, 15> audio_interface{{"AudioInterface"}};
+    ctx.WriteBuffer(audio_interface);
 
     IPC::ResponseBuilder rb = rp.MakeBuilder(3, 0, 0);
 

src/core/hle/service/audio/audren_u.cpp

@@ -2,6 +2,8 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <array>
+
 #include "common/alignment.h"
 #include "common/logging/log.h"
 #include "core/core_timing.h"
@@ -17,7 +19,7 @@ constexpr u64 audio_ticks{static_cast<u64>(CoreTiming::BASE_CLOCK_RATE / 200)};
 
 class IAudioRenderer final : public ServiceFramework<IAudioRenderer> {
 public:
-    IAudioRenderer(AudioRendererParameter audren_params)
+    explicit IAudioRenderer(AudioRendererParameter audren_params)
         : ServiceFramework("IAudioRenderer"), worker_params(audren_params) {
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetAudioRendererSampleRate"},
@@ -176,7 +178,7 @@ private:
     struct UpdateDataHeader {
         UpdateDataHeader() {}
 
-        UpdateDataHeader(const AudioRendererParameter& config) {
+        explicit UpdateDataHeader(const AudioRendererParameter& config) {
             revision = Common::MakeMagic('R', 'E', 'V', '4'); // 5.1.0 Revision
             behavior_size = 0xb0;
             memory_pools_size = (config.effect_count + (config.voice_count * 4)) * 0x10;
@@ -298,8 +300,8 @@ private:
         LOG_WARNING(Service_Audio, "(STUBBED) called");
         IPC::RequestParser rp{ctx};
 
-        const std::string audio_interface = "AudioInterface";
-        ctx.WriteBuffer(audio_interface.c_str(), audio_interface.size());
+        constexpr std::array<char, 15> audio_interface{{"AudioInterface"}};
+        ctx.WriteBuffer(audio_interface);
 
         IPC::ResponseBuilder rb = rp.MakeBuilder(3, 0, 0);
         rb.Push(RESULT_SUCCESS);
@@ -323,8 +325,8 @@ private:
         LOG_WARNING(Service_Audio, "(STUBBED) called");
         IPC::RequestParser rp{ctx};
 
-        const std::string audio_interface = "AudioDevice";
-        ctx.WriteBuffer(audio_interface.c_str(), audio_interface.size());
+        constexpr std::array<char, 12> audio_interface{{"AudioDevice"}};
+        ctx.WriteBuffer(audio_interface);
 
         IPC::ResponseBuilder rb = rp.MakeBuilder(3, 0, 0);
         rb.Push(RESULT_SUCCESS);

src/core/hle/service/bcat/module.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void CreateBcatService(Kernel::HLERequestContext& ctx);
 

src/core/hle/service/fatal/fatal.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void ThrowFatalWithPolicy(Kernel::HLERequestContext& ctx);
         void ThrowFatalWithCpuContext(Kernel::HLERequestContext& ctx);

src/core/hle/service/filesystem/filesystem.cpp

@@ -2,17 +2,208 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <boost/container/flat_map.hpp>
+#include <utility>
+
+#include "common/assert.h"
 #include "common/file_util.h"
+#include "core/core.h"
 #include "core/file_sys/errors.h"
-#include "core/file_sys/filesystem.h"
 #include "core/file_sys/savedata_factory.h"
 #include "core/file_sys/sdmc_factory.h"
+#include "core/file_sys/vfs.h"
+#include "core/file_sys/vfs_offset.h"
+#include "core/file_sys/vfs_real.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
 
 namespace Service::FileSystem {
 
+// Size of emulated sd card free space, reported in bytes.
+// Just using 32GB because thats reasonable
+// TODO(DarkLordZach): Eventually make this configurable in settings.
+constexpr u64 EMULATED_SD_REPORTED_SIZE = 32000000000;
+
+static FileSys::VirtualDir GetDirectoryRelativeWrapped(FileSys::VirtualDir base,
+                                                       const std::string& dir_name) {
+    if (dir_name.empty() || dir_name == "." || dir_name == "/" || dir_name == "\\")
+        return base;
+
+    return base->GetDirectoryRelative(dir_name);
+}
+
+VfsDirectoryServiceWrapper::VfsDirectoryServiceWrapper(FileSys::VirtualDir backing_)
+    : backing(std::move(backing_)) {}
+
+std::string VfsDirectoryServiceWrapper::GetName() const {
+    return backing->GetName();
+}
+
+ResultCode VfsDirectoryServiceWrapper::CreateFile(const std::string& path, u64 size) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    auto file = dir->CreateFile(FileUtil::GetFilename(path));
+    if (file == nullptr) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    if (!file->Resize(size)) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::DeleteFile(const std::string& path) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    if (path == "/" || path == "\\") {
+        // TODO(DarkLordZach): Why do games call this and what should it do? Works as is but...
+        return RESULT_SUCCESS;
+    }
+    if (dir->GetFile(FileUtil::GetFilename(path)) == nullptr)
+        return FileSys::ERROR_PATH_NOT_FOUND;
+    if (!backing->DeleteFile(FileUtil::GetFilename(path))) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::CreateDirectory(const std::string& path) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    if (dir == nullptr && FileUtil::GetFilename(FileUtil::GetParentPath(path)).empty())
+        dir = backing;
+    auto new_dir = dir->CreateSubdirectory(FileUtil::GetFilename(path));
+    if (new_dir == nullptr) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::DeleteDirectory(const std::string& path) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    if (!dir->DeleteSubdirectory(FileUtil::GetFilename(path))) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::DeleteDirectoryRecursively(const std::string& path) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    if (!dir->DeleteSubdirectoryRecursive(FileUtil::GetFilename(path))) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::RenameFile(const std::string& src_path,
+                                                  const std::string& dest_path) const {
+    auto src = backing->GetFileRelative(src_path);
+    if (FileUtil::GetParentPath(src_path) == FileUtil::GetParentPath(dest_path)) {
+        // Use more-optimized vfs implementation rename.
+        if (src == nullptr)
+            return FileSys::ERROR_PATH_NOT_FOUND;
+        if (!src->Rename(FileUtil::GetFilename(dest_path))) {
+            // TODO(DarkLordZach): Find a better error code for this
+            return ResultCode(-1);
+        }
+        return RESULT_SUCCESS;
+    }
+
+    // Move by hand -- TODO(DarkLordZach): Optimize
+    auto c_res = CreateFile(dest_path, src->GetSize());
+    if (c_res != RESULT_SUCCESS)
+        return c_res;
+
+    auto dest = backing->GetFileRelative(dest_path);
+    ASSERT_MSG(dest != nullptr, "Newly created file with success cannot be found.");
+
+    ASSERT_MSG(dest->WriteBytes(src->ReadAllBytes()) == src->GetSize(),
+               "Could not write all of the bytes but everything else has succeded.");
+
+    if (!src->GetContainingDirectory()->DeleteFile(FileUtil::GetFilename(src_path))) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+
+    return RESULT_SUCCESS;
+}
+
+ResultCode VfsDirectoryServiceWrapper::RenameDirectory(const std::string& src_path,
+                                                       const std::string& dest_path) const {
+    auto src = GetDirectoryRelativeWrapped(backing, src_path);
+    if (FileUtil::GetParentPath(src_path) == FileUtil::GetParentPath(dest_path)) {
+        // Use more-optimized vfs implementation rename.
+        if (src == nullptr)
+            return FileSys::ERROR_PATH_NOT_FOUND;
+        if (!src->Rename(FileUtil::GetFilename(dest_path))) {
+            // TODO(DarkLordZach): Find a better error code for this
+            return ResultCode(-1);
+        }
+        return RESULT_SUCCESS;
+    }
+
+    // TODO(DarkLordZach): Implement renaming across the tree (move).
+    ASSERT_MSG(false,
+               "Could not rename directory with path \"{}\" to new path \"{}\" because parent dirs "
+               "don't match -- UNIMPLEMENTED",
+               src_path, dest_path);
+
+    // TODO(DarkLordZach): Find a better error code for this
+    return ResultCode(-1);
+}
+
+ResultVal<FileSys::VirtualFile> VfsDirectoryServiceWrapper::OpenFile(const std::string& path,
+                                                                     FileSys::Mode mode) const {
+    auto npath = path;
+    while (npath.size() > 0 && (npath[0] == '/' || npath[0] == '\\'))
+        npath = npath.substr(1);
+    auto file = backing->GetFileRelative(npath);
+    if (file == nullptr)
+        return FileSys::ERROR_PATH_NOT_FOUND;
+
+    if (mode == FileSys::Mode::Append) {
+        return MakeResult<FileSys::VirtualFile>(
+            std::make_shared<FileSys::OffsetVfsFile>(file, 0, file->GetSize()));
+    }
+
+    return MakeResult<FileSys::VirtualFile>(file);
+}
+
+ResultVal<FileSys::VirtualDir> VfsDirectoryServiceWrapper::OpenDirectory(const std::string& path) {
+    auto dir = GetDirectoryRelativeWrapped(backing, path);
+    if (dir == nullptr) {
+        // TODO(DarkLordZach): Find a better error code for this
+        return ResultCode(-1);
+    }
+    return MakeResult(dir);
+}
+
+u64 VfsDirectoryServiceWrapper::GetFreeSpaceSize() const {
+    if (backing->IsWritable())
+        return EMULATED_SD_REPORTED_SIZE;
+
+    return 0;
+}
+
+ResultVal<FileSys::EntryType> VfsDirectoryServiceWrapper::GetEntryType(
+    const std::string& path) const {
+    auto dir = GetDirectoryRelativeWrapped(backing, FileUtil::GetParentPath(path));
+    if (dir == nullptr)
+        return FileSys::ERROR_PATH_NOT_FOUND;
+    auto filename = FileUtil::GetFilename(path);
+    // TODO(Subv): Some games use the '/' path, find out what this means.
+    if (filename.empty())
+        return MakeResult(FileSys::EntryType::Directory);
+
+    if (dir->GetFile(filename) != nullptr)
+        return MakeResult(FileSys::EntryType::File);
+    if (dir->GetSubdirectory(filename) != nullptr)
+        return MakeResult(FileSys::EntryType::Directory);
+    return FileSys::ERROR_PATH_NOT_FOUND;
+}
+
 /**
  * Map of registered file systems, identified by type. Once an file system is registered here, it
  * is never removed until UnregisterFileSystems is called.
@@ -42,7 +233,7 @@ ResultCode RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory) {
     return RESULT_SUCCESS;
 }
 
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenRomFS(u64 title_id) {
+ResultVal<FileSys::VirtualFile> OpenRomFS(u64 title_id) {
     LOG_TRACE(Service_FS, "Opening RomFS for title_id={:016X}", title_id);
 
     if (romfs_factory == nullptr) {
@@ -53,19 +244,19 @@ ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenRomFS(u64 title_id) {
     return romfs_factory->Open(title_id);
 }
 
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenSaveData(
-    FileSys::SaveDataSpaceId space, FileSys::SaveDataDescriptor save_struct) {
+ResultVal<FileSys::VirtualDir> OpenSaveData(FileSys::SaveDataSpaceId space,
+                                            FileSys::SaveDataDescriptor save_struct) {
     LOG_TRACE(Service_FS, "Opening Save Data for space_id={:01X}, save_struct={}",
-              static_cast<u8>(space), SaveStructDebugInfo(save_struct));
+              static_cast<u8>(space), save_struct.DebugInfo());
 
     if (save_data_factory == nullptr) {
-        return ResultCode(ErrorModule::FS, FileSys::ErrCodes::SaveDataNotFound);
+        return ResultCode(ErrorModule::FS, FileSys::ErrCodes::TitleNotFound);
     }
 
     return save_data_factory->Open(space, save_struct);
 }
 
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenSDMC() {
+ResultVal<FileSys::VirtualDir> OpenSDMC() {
     LOG_TRACE(Service_FS, "Opening SDMC");
 
     if (sdmc_factory == nullptr) {
@@ -80,8 +271,10 @@ void RegisterFileSystems() {
     save_data_factory = nullptr;
     sdmc_factory = nullptr;
 
-    std::string nand_directory = FileUtil::GetUserPath(D_NAND_IDX);
-    std::string sd_directory = FileUtil::GetUserPath(D_SDMC_IDX);
+    auto nand_directory = std::make_shared<FileSys::RealVfsDirectory>(
+        FileUtil::GetUserPath(D_NAND_IDX), FileSys::Mode::Write);
+    auto sd_directory = std::make_shared<FileSys::RealVfsDirectory>(
+        FileUtil::GetUserPath(D_SDMC_IDX), FileSys::Mode::Write);
 
     auto savedata = std::make_unique<FileSys::SaveDataFactory>(std::move(nand_directory));
     save_data_factory = std::move(savedata);

src/core/hle/service/filesystem/filesystem.h

@@ -6,15 +6,13 @@
 
 #include <memory>
 #include "common/common_types.h"
+#include "core/file_sys/directory.h"
+#include "core/file_sys/mode.h"
 #include "core/file_sys/romfs_factory.h"
 #include "core/file_sys/savedata_factory.h"
 #include "core/file_sys/sdmc_factory.h"
 #include "core/hle/result.h"
 
-namespace FileSys {
-class FileSystemBackend;
-} // namespace FileSys
-
 namespace Service {
 
 namespace SM {
@@ -29,11 +27,10 @@ ResultCode RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory);
 
 // TODO(DarkLordZach): BIS Filesystem
 // ResultCode RegisterBIS(std::unique_ptr<FileSys::BISFactory>&& factory);
-
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenRomFS(u64 title_id);
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenSaveData(
-    FileSys::SaveDataSpaceId space, FileSys::SaveDataDescriptor save_struct);
-ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenSDMC();
+ResultVal<FileSys::VirtualFile> OpenRomFS(u64 title_id);
+ResultVal<FileSys::VirtualDir> OpenSaveData(FileSys::SaveDataSpaceId space,
+                                            FileSys::SaveDataDescriptor save_struct);
+ResultVal<FileSys::VirtualDir> OpenSDMC();
 
 // TODO(DarkLordZach): BIS Filesystem
 // ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenBIS();
@@ -41,5 +38,100 @@ ResultVal<std::unique_ptr<FileSys::FileSystemBackend>> OpenSDMC();
 /// Registers all Filesystem services with the specified service manager.
 void InstallInterfaces(SM::ServiceManager& service_manager);
 
+// A class that wraps a VfsDirectory with methods that return ResultVal and ResultCode instead of
+// pointers and booleans. This makes using a VfsDirectory with switch services much easier and
+// avoids repetitive code.
+class VfsDirectoryServiceWrapper {
+public:
+    explicit VfsDirectoryServiceWrapper(FileSys::VirtualDir backing);
+
+    /**
+     * Get a descriptive name for the archive (e.g. "RomFS", "SaveData", etc.)
+     */
+    std::string GetName() const;
+
+    /**
+     * Create a file specified by its path
+     * @param path Path relative to the Archive
+     * @param size The size of the new file, filled with zeroes
+     * @return Result of the operation
+     */
+    ResultCode CreateFile(const std::string& path, u64 size) const;
+
+    /**
+     * Delete a file specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode DeleteFile(const std::string& path) const;
+
+    /**
+     * Create a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode CreateDirectory(const std::string& path) const;
+
+    /**
+     * Delete a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode DeleteDirectory(const std::string& path) const;
+
+    /**
+     * Delete a directory specified by its path and anything under it
+     * @param path Path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode DeleteDirectoryRecursively(const std::string& path) const;
+
+    /**
+     * Rename a File specified by its path
+     * @param src_path Source path relative to the archive
+     * @param dest_path Destination path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode RenameFile(const std::string& src_path, const std::string& dest_path) const;
+
+    /**
+     * Rename a Directory specified by its path
+     * @param src_path Source path relative to the archive
+     * @param dest_path Destination path relative to the archive
+     * @return Result of the operation
+     */
+    ResultCode RenameDirectory(const std::string& src_path, const std::string& dest_path) const;
+
+    /**
+     * Open a file specified by its path, using the specified mode
+     * @param path Path relative to the archive
+     * @param mode Mode to open the file with
+     * @return Opened file, or error code
+     */
+    ResultVal<FileSys::VirtualFile> OpenFile(const std::string& path, FileSys::Mode mode) const;
+
+    /**
+     * Open a directory specified by its path
+     * @param path Path relative to the archive
+     * @return Opened directory, or error code
+     */
+    ResultVal<FileSys::VirtualDir> OpenDirectory(const std::string& path);
+
+    /**
+     * Get the free space
+     * @return The number of free bytes in the archive
+     */
+    u64 GetFreeSpaceSize() const;
+
+    /**
+     * Get the type of the specified path
+     * @return The type of the specified path or error code
+     */
+    ResultVal<FileSys::EntryType> GetEntryType(const std::string& path) const;
+
+private:
+    FileSys::VirtualDir backing;
+};
+
 } // namespace FileSystem
 } // namespace Service

src/core/hle/service/filesystem/fsp_srv.cpp

@@ -3,16 +3,20 @@
 // Refer to the license.txt file included.
 
 #include <cinttypes>
+#include <cstring>
+#include <iterator>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "common/assert.h"
+#include "common/common_types.h"
 #include "common/logging/log.h"
 #include "common/string_util.h"
 #include "core/core.h"
 #include "core/file_sys/directory.h"
 #include "core/file_sys/errors.h"
-#include "core/file_sys/filesystem.h"
-#include "core/file_sys/storage.h"
 #include "core/hle/ipc_helpers.h"
-#include "core/hle/kernel/client_port.h"
-#include "core/hle/kernel/client_session.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
@@ -25,13 +29,13 @@ enum class StorageId : u8 {
     GameCard = 2,
     NandSystem = 3,
     NandUser = 4,
-    SdCard = 5
+    SdCard = 5,
 };
 
 class IStorage final : public ServiceFramework<IStorage> {
 public:
-    IStorage(std::unique_ptr<FileSys::StorageBackend>&& backend)
-        : ServiceFramework("IStorage"), backend(std::move(backend)) {
+    explicit IStorage(FileSys::VirtualFile backend_)
+        : ServiceFramework("IStorage"), backend(std::move(backend_)) {
         static const FunctionInfo functions[] = {
             {0, &IStorage::Read, "Read"}, {1, nullptr, "Write"},   {2, nullptr, "Flush"},
             {3, nullptr, "SetSize"},      {4, nullptr, "GetSize"}, {5, nullptr, "OperateRange"},
@@ -40,7 +44,7 @@ public:
     }
 
 private:
-    std::unique_ptr<FileSys::StorageBackend> backend;
+    FileSys::VirtualFile backend;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -62,14 +66,7 @@ private:
         }
 
         // Read the data from the Storage backend
-        std::vector<u8> output(length);
-        ResultVal<size_t> res = backend->Read(offset, length, output.data());
-        if (res.Failed()) {
-            IPC::ResponseBuilder rb{ctx, 2};
-            rb.Push(res.Code());
-            return;
-        }
-
+        std::vector<u8> output = backend->ReadBytes(length, offset);
         // Write the data to memory
         ctx.WriteBuffer(output);
 
@@ -80,8 +77,8 @@ private:
 
 class IFile final : public ServiceFramework<IFile> {
 public:
-    explicit IFile(std::unique_ptr<FileSys::StorageBackend>&& backend)
-        : ServiceFramework("IFile"), backend(std::move(backend)) {
+    explicit IFile(FileSys::VirtualFile backend_)
+        : ServiceFramework("IFile"), backend(std::move(backend_)) {
         static const FunctionInfo functions[] = {
             {0, &IFile::Read, "Read"},       {1, &IFile::Write, "Write"},
             {2, &IFile::Flush, "Flush"},     {3, &IFile::SetSize, "SetSize"},
@@ -91,7 +88,7 @@ public:
     }
 
 private:
-    std::unique_ptr<FileSys::StorageBackend> backend;
+    FileSys::VirtualFile backend;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -114,20 +111,14 @@ private:
         }
 
         // Read the data from the Storage backend
-        std::vector<u8> output(length);
-        ResultVal<size_t> res = backend->Read(offset, length, output.data());
-        if (res.Failed()) {
-            IPC::ResponseBuilder rb{ctx, 2};
-            rb.Push(res.Code());
-            return;
-        }
+        std::vector<u8> output = backend->ReadBytes(length, offset);
 
         // Write the data to memory
         ctx.WriteBuffer(output);
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(RESULT_SUCCESS);
-        rb.Push(static_cast<u64>(*res));
+        rb.Push(static_cast<u64>(output.size()));
     }
 
     void Write(Kernel::HLERequestContext& ctx) {
@@ -150,14 +141,21 @@ private:
             return;
         }
 
+        const std::vector<u8> data = ctx.ReadBuffer();
+
+        ASSERT_MSG(
+            static_cast<s64>(data.size()) <= length,
+            "Attempting to write more data than requested (requested={:016X}, actual={:016X}).",
+            length, data.size());
+
         // Write the data to the Storage backend
-        std::vector<u8> data = ctx.ReadBuffer();
-        ResultVal<size_t> res = backend->Write(offset, length, true, data.data());
-        if (res.Failed()) {
-            IPC::ResponseBuilder rb{ctx, 2};
-            rb.Push(res.Code());
-            return;
-        }
+        const auto write_size =
+            static_cast<std::size_t>(std::distance(data.begin(), data.begin() + length));
+        const std::size_t written = backend->Write(data.data(), write_size, offset);
+
+        ASSERT_MSG(static_cast<s64>(written) == length,
+                   "Could not write all bytes to file (requested={:016X}, actual={:016X}).", length,
+                   written);
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(RESULT_SUCCESS);
@@ -165,7 +163,8 @@ private:
 
     void Flush(Kernel::HLERequestContext& ctx) {
         LOG_DEBUG(Service_FS, "called");
-        backend->Flush();
+
+        // Exists for SDK compatibiltity -- No need to flush file.
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(RESULT_SUCCESS);
@@ -174,7 +173,7 @@ private:
     void SetSize(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
         const u64 size = rp.Pop<u64>();
-        backend->SetSize(size);
+        backend->Resize(size);
         LOG_DEBUG(Service_FS, "called, size={}", size);
 
         IPC::ResponseBuilder rb{ctx, 2};
@@ -191,19 +190,39 @@ private:
     }
 };
 
+template <typename T>
+static void BuildEntryIndex(std::vector<FileSys::Entry>& entries, const std::vector<T>& new_data,
+                            FileSys::EntryType type) {
+    for (const auto& new_entry : new_data) {
+        FileSys::Entry entry;
+        entry.filename[0] = '\0';
+        std::strncat(entry.filename, new_entry->GetName().c_str(), FileSys::FILENAME_LENGTH - 1);
+        entry.type = type;
+        entry.file_size = new_entry->GetSize();
+        entries.emplace_back(std::move(entry));
+    }
+}
+
 class IDirectory final : public ServiceFramework<IDirectory> {
 public:
-    explicit IDirectory(std::unique_ptr<FileSys::DirectoryBackend>&& backend)
-        : ServiceFramework("IDirectory"), backend(std::move(backend)) {
+    explicit IDirectory(FileSys::VirtualDir backend_)
+        : ServiceFramework("IDirectory"), backend(std::move(backend_)) {
         static const FunctionInfo functions[] = {
             {0, &IDirectory::Read, "Read"},
             {1, &IDirectory::GetEntryCount, "GetEntryCount"},
         };
         RegisterHandlers(functions);
+
+        // TODO(DarkLordZach): Verify that this is the correct behavior.
+        // Build entry index now to save time later.
+        BuildEntryIndex(entries, backend->GetFiles(), FileSys::File);
+        BuildEntryIndex(entries, backend->GetSubdirectories(), FileSys::Directory);
     }
 
 private:
-    std::unique_ptr<FileSys::DirectoryBackend> backend;
+    FileSys::VirtualDir backend;
+    std::vector<FileSys::Entry> entries;
+    u64 next_entry_index = 0;
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
@@ -212,28 +231,30 @@ private:
         LOG_DEBUG(Service_FS, "called, unk=0x{:X}", unk);
 
         // Calculate how many entries we can fit in the output buffer
-        u64 count_entries = ctx.GetWriteBufferSize() / sizeof(FileSys::Entry);
+        const u64 count_entries = ctx.GetWriteBufferSize() / sizeof(FileSys::Entry);
 
-        // Read the data from the Directory backend
-        std::vector<FileSys::Entry> entries(count_entries);
-        u64 read_entries = backend->Read(count_entries, entries.data());
+        // Cap at total number of entries.
+        const u64 actual_entries = std::min(count_entries, entries.size() - next_entry_index);
 
-        // Convert the data into a byte array
-        std::vector<u8> output(entries.size() * sizeof(FileSys::Entry));
-        std::memcpy(output.data(), entries.data(), output.size());
+        // Determine data start and end
+        const auto* begin = reinterpret_cast<u8*>(entries.data() + next_entry_index);
+        const auto* end = reinterpret_cast<u8*>(entries.data() + next_entry_index + actual_entries);
+        const auto range_size = static_cast<std::size_t>(std::distance(begin, end));
+
+        next_entry_index += actual_entries;
 
         // Write the data to memory
-        ctx.WriteBuffer(output);
+        ctx.WriteBuffer(begin, range_size);
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(RESULT_SUCCESS);
-        rb.Push(read_entries);
+        rb.Push(actual_entries);
     }
 
     void GetEntryCount(Kernel::HLERequestContext& ctx) {
         LOG_DEBUG(Service_FS, "called");
 
-        u64 count = backend->GetEntryCount();
+        u64 count = entries.size() - next_entry_index;
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(RESULT_SUCCESS);
@@ -243,7 +264,7 @@ private:
 
 class IFileSystem final : public ServiceFramework<IFileSystem> {
 public:
-    explicit IFileSystem(std::unique_ptr<FileSys::FileSystemBackend>&& backend)
+    explicit IFileSystem(FileSys::VirtualDir backend)
         : ServiceFramework("IFileSystem"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
             {0, &IFileSystem::CreateFile, "CreateFile"},
@@ -278,7 +299,7 @@ public:
         LOG_DEBUG(Service_FS, "called file {} mode 0x{:X} size 0x{:08X}", name, mode, size);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend->CreateFile(name, size));
+        rb.Push(backend.CreateFile(name, size));
     }
 
     void DeleteFile(Kernel::HLERequestContext& ctx) {
@@ -290,7 +311,7 @@ public:
         LOG_DEBUG(Service_FS, "called file {}", name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend->DeleteFile(name));
+        rb.Push(backend.DeleteFile(name));
     }
 
     void CreateDirectory(Kernel::HLERequestContext& ctx) {
@@ -302,7 +323,7 @@ public:
         LOG_DEBUG(Service_FS, "called directory {}", name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend->CreateDirectory(name));
+        rb.Push(backend.CreateDirectory(name));
     }
 
     void RenameFile(Kernel::HLERequestContext& ctx) {
@@ -320,7 +341,7 @@ public:
         LOG_DEBUG(Service_FS, "called file '{}' to file '{}'", src_name, dst_name);
 
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(backend->RenameFile(src_name, dst_name));
+        rb.Push(backend.RenameFile(src_name, dst_name));
     }
 
     void OpenFile(Kernel::HLERequestContext& ctx) {
@@ -333,14 +354,14 @@ public:
 
         LOG_DEBUG(Service_FS, "called file {} mode {}", name, static_cast<u32>(mode));
 
-        auto result = backend->OpenFile(name, mode);
+        auto result = backend.OpenFile(name, mode);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
             return;
         }
 
-        auto file = std::move(result.Unwrap());
+        IFile file(result.Unwrap());
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(RESULT_SUCCESS);
@@ -358,14 +379,14 @@ public:
 
         LOG_DEBUG(Service_FS, "called directory {} filter {}", name, filter_flags);
 
-        auto result = backend->OpenDirectory(name);
+        auto result = backend.OpenDirectory(name);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
             return;
         }
 
-        auto directory = std::move(result.Unwrap());
+        IDirectory directory(result.Unwrap());
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(RESULT_SUCCESS);
@@ -380,7 +401,7 @@ public:
 
         LOG_DEBUG(Service_FS, "called file {}", name);
 
-        auto result = backend->GetEntryType(name);
+        auto result = backend.GetEntryType(name);
         if (result.Failed()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(result.Code());
@@ -400,7 +421,7 @@ public:
     }
 
 private:
-    std::unique_ptr<FileSys::FileSystemBackend> backend;
+    VfsDirectoryServiceWrapper backend;
 };
 
 FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
@@ -536,17 +557,19 @@ void FSP_SRV::MountSaveData(Kernel::HLERequestContext& ctx) {
     LOG_INFO(Service_FS, "called with unknown={:08X}", unk);
     auto save_struct = rp.PopRaw<FileSys::SaveDataDescriptor>();
 
-    auto filesystem = OpenSaveData(space_id, save_struct);
+    auto dir = OpenSaveData(space_id, save_struct);
 
-    if (filesystem.Failed()) {
+    if (dir.Failed()) {
         IPC::ResponseBuilder rb{ctx, 2, 0, 0};
-        rb.Push(ResultCode(ErrorModule::FS, FileSys::ErrCodes::SaveDataNotFound));
+        rb.Push(ResultCode(ErrorModule::FS, FileSys::ErrCodes::TitleNotFound));
         return;
     }
 
+    IFileSystem filesystem(std::move(dir.Unwrap()));
+
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<IFileSystem>(std::move(filesystem.Unwrap()));
+    rb.PushIpcInterface<IFileSystem>(std::move(filesystem));
 }
 
 void FSP_SRV::GetGlobalAccessLogMode(Kernel::HLERequestContext& ctx) {
@@ -569,18 +592,11 @@ void FSP_SRV::OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx) {
         return;
     }
 
-    auto storage = romfs.Unwrap()->OpenFile({}, {});
-
-    if (storage.Failed()) {
-        LOG_CRITICAL(Service_FS, "no storage interface available!");
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(storage.Code());
-        return;
-    }
+    IStorage storage(std::move(romfs.Unwrap()));
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<IStorage>(std::move(storage.Unwrap()));
+    rb.PushIpcInterface<IStorage>(std::move(storage));
 }
 
 void FSP_SRV::OpenRomStorage(Kernel::HLERequestContext& ctx) {
@@ -591,33 +607,9 @@ void FSP_SRV::OpenRomStorage(Kernel::HLERequestContext& ctx) {
 
     LOG_DEBUG(Service_FS, "called with storage_id={:02X}, title_id={:016X}",
               static_cast<u8>(storage_id), title_id);
-    if (title_id != Core::System::GetInstance().CurrentProcess()->program_id) {
-        LOG_CRITICAL(
-            Service_FS,
-            "Attempting to access RomFS of another title id (current={:016X}, requested={:016X}).",
-            Core::System::GetInstance().CurrentProcess()->program_id, title_id);
-    }
 
-    auto romfs = OpenRomFS(title_id);
-    if (romfs.Failed()) {
-        LOG_CRITICAL(Service_FS, "no file system interface available!");
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(ResultCode(ErrorModule::FS, FileSys::ErrCodes::RomFSNotFound));
-        return;
-    }
-
-    auto storage = romfs.Unwrap()->OpenFile({}, {});
-
-    if (storage.Failed()) {
-        LOG_CRITICAL(Service_FS, "no storage interface available!");
-        IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(storage.Code());
-        return;
-    }
-
-    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
-    rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<IStorage>(std::move(storage.Unwrap()));
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultCode(ErrorModule::FS, FileSys::ErrCodes::TitleNotFound));
 }
 
 } // namespace Service::FileSystem

src/core/hle/service/filesystem/fsp_srv.h

@@ -27,7 +27,7 @@ private:
     void OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx);
     void OpenRomStorage(Kernel::HLERequestContext& ctx);
 
-    std::unique_ptr<FileSys::FileSystemBackend> romfs;
+    FileSys::VirtualFile romfs;
 };
 
 } // namespace Service::FileSystem

src/core/hle/service/friend/friend.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void CreateFriendService(Kernel::HLERequestContext& ctx);
 

src/core/hle/service/hid/hid.cpp

@@ -5,6 +5,7 @@
 #include <atomic>
 #include "common/logging/log.h"
 #include "core/core_timing.h"
+#include "core/frontend/emu_window.h"
 #include "core/frontend/input.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/kernel/client_port.h"
@@ -63,7 +64,8 @@ private:
         std::transform(Settings::values.analogs.begin() + Settings::NativeAnalog::STICK_HID_BEGIN,
                        Settings::values.analogs.begin() + Settings::NativeAnalog::STICK_HID_END,
                        sticks.begin(), Input::CreateDevice<Input::AnalogDevice>);
-        // TODO(shinyquagsire23): gyro, touch, mouse, keyboard
+        touch_device = Input::CreateDevice<Input::TouchDevice>(Settings::values.touch_device);
+        // TODO(shinyquagsire23): gyro, mouse, keyboard
     }
 
     void UpdatePadCallback(u64 userdata, int cycles_late) {
@@ -83,8 +85,7 @@ private:
         controller_header.left_color_buttons = JOYCON_BUTTONS_NEON_BLUE;
 
         for (size_t controller = 0; controller < mem.controllers.size(); controller++) {
-            for (int index = 0; index < HID_NUM_LAYOUTS; index++) {
-                ControllerLayout& layout = mem.controllers[controller].layouts[index];
+            for (auto& layout : mem.controllers[controller].layouts) {
                 layout.header.num_entries = HID_NUM_ENTRIES;
                 layout.header.max_entry_index = HID_NUM_ENTRIES - 1;
 
@@ -151,8 +152,6 @@ private:
             }
         }
 
-        // TODO(bunnei): Properly implement the touch screen, the below will just write empty data
-
         TouchScreen& touchscreen = mem.touchscreen;
         const u64 last_entry = touchscreen.header.latest_entry;
         const u64 curr_entry = (last_entry + 1) % touchscreen.entries.size();
@@ -164,7 +163,26 @@ private:
         touchscreen.header.max_entry_index = touchscreen.entries.size();
         touchscreen.header.timestamp = timestamp;
         touchscreen.entries[curr_entry].header.timestamp = sample_counter;
-        touchscreen.entries[curr_entry].header.num_touches = 0;
+
+        TouchScreenEntryTouch touch_entry{};
+        auto [x, y, pressed] = touch_device->GetStatus();
+        touch_entry.timestamp = timestamp;
+        touch_entry.x = static_cast<u16>(x * Layout::ScreenUndocked::Width);
+        touch_entry.y = static_cast<u16>(y * Layout::ScreenUndocked::Height);
+        touch_entry.touch_index = 0;
+
+        // TODO(DarkLordZach): Maybe try to derive these from EmuWindow?
+        touch_entry.diameter_x = 15;
+        touch_entry.diameter_y = 15;
+        touch_entry.angle = 0;
+
+        // TODO(DarkLordZach): Implement multi-touch support
+        if (pressed) {
+            touchscreen.entries[curr_entry].header.num_touches = 1;
+            touchscreen.entries[curr_entry].touches[0] = touch_entry;
+        } else {
+            touchscreen.entries[curr_entry].header.num_touches = 0;
+        }
 
         // TODO(shinyquagsire23): Properly implement mouse
         Mouse& mouse = mem.mouse;
@@ -194,8 +212,7 @@ private:
         keyboard.entries[curr_keyboard_entry].timestamp_2 = keyboard_sample_counter;
 
         // TODO(shinyquagsire23): Figure out what any of these are
-        for (size_t i = 0; i < mem.unk_input_1.size(); i++) {
-            UnkInput1& input = mem.unk_input_1[i];
+        for (auto& input : mem.unk_input_1) {
             const u64 last_input_entry = input.header.latest_entry;
             const u64 curr_input_entry = (input.header.latest_entry + 1) % input.entries.size();
             const u64 input_sample_counter = input.entries[last_input_entry].timestamp + 1;
@@ -209,9 +226,7 @@ private:
             input.entries[curr_input_entry].timestamp_2 = input_sample_counter;
         }
 
-        for (size_t i = 0; i < mem.unk_input_2.size(); i++) {
-            UnkInput2& input = mem.unk_input_2[i];
-
+        for (auto& input : mem.unk_input_2) {
             input.header.timestamp_ticks = timestamp;
             input.header.num_entries = 17;
             input.header.latest_entry = 0;
@@ -250,6 +265,7 @@ private:
     std::array<std::unique_ptr<Input::ButtonDevice>, Settings::NativeButton::NUM_BUTTONS_HID>
         buttons;
     std::array<std::unique_ptr<Input::AnalogDevice>, Settings::NativeAnalog::NUM_STICKS_HID> sticks;
+    std::unique_ptr<Input::TouchDevice> touch_device;
 };
 
 class IActiveVibrationDeviceList final : public ServiceFramework<IActiveVibrationDeviceList> {

src/core/hle/service/hid/hid.h

@@ -380,7 +380,7 @@ static_assert(sizeof(ControllerLayout) == 0x350,
 
 struct Controller {
     ControllerHeader header;
-    std::array<ControllerLayout, 7> layouts;
+    std::array<ControllerLayout, HID_NUM_LAYOUTS> layouts;
     std::array<u8, 0x2a70> unk_1;
     ControllerMAC mac_left;
     ControllerMAC mac_right;

src/core/hle/service/nfp/nfp.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void CreateUserInterface(Kernel::HLERequestContext& ctx);
 

src/core/hle/service/nifm/nifm.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void CreateGeneralServiceOld(Kernel::HLERequestContext& ctx);
         void CreateGeneralService(Kernel::HLERequestContext& ctx);

src/core/hle/service/ns/pl_u.cpp

@@ -119,7 +119,7 @@ void PL_U::GetSharedMemoryNativeHandle(Kernel::HLERequestContext& ctx) {
 void PL_U::GetSharedFontInOrderOfPriority(Kernel::HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
     const u64 language_code{rp.Pop<u64>()}; // TODO(ogniK): Find out what this is used for
-    LOG_DEBUG(Service_NS, "called, language_code=%lx", language_code);
+    LOG_DEBUG(Service_NS, "called, language_code={:X}", language_code);
     IPC::ResponseBuilder rb{ctx, 4};
     std::vector<u32> font_codes;
     std::vector<u32> font_offsets;
@@ -132,9 +132,9 @@ void PL_U::GetSharedFontInOrderOfPriority(Kernel::HLERequestContext& ctx) {
         font_sizes.push_back(SHARED_FONT_REGIONS[i].size);
     }
 
-    ctx.WriteBuffer(font_codes.data(), font_codes.size(), 0);
-    ctx.WriteBuffer(font_offsets.data(), font_offsets.size(), 1);
-    ctx.WriteBuffer(font_sizes.data(), font_sizes.size(), 2);
+    ctx.WriteBuffer(font_codes, 0);
+    ctx.WriteBuffer(font_offsets, 1);
+    ctx.WriteBuffer(font_sizes, 2);
 
     rb.Push(RESULT_SUCCESS);
     rb.Push<u8>(static_cast<u8>(LoadState::Done)); // Fonts Loaded

src/core/hle/service/nvdrv/devices/nvdisp_disp0.h

@@ -17,7 +17,7 @@ class nvmap;
 
 class nvdisp_disp0 final : public nvdevice {
 public:
-    nvdisp_disp0(std::shared_ptr<nvmap> nvmap_dev) : nvdevice(), nvmap_dev(std::move(nvmap_dev)) {}
+    explicit nvdisp_disp0(std::shared_ptr<nvmap> nvmap_dev) : nvmap_dev(std::move(nvmap_dev)) {}
     ~nvdisp_disp0() = default;
 
     u32 ioctl(Ioctl command, const std::vector<u8>& input, std::vector<u8>& output) override;

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.h

@@ -18,7 +18,7 @@ class nvmap;
 
 class nvhost_as_gpu final : public nvdevice {
 public:
-    nvhost_as_gpu(std::shared_ptr<nvmap> nvmap_dev) : nvmap_dev(std::move(nvmap_dev)) {}
+    explicit nvhost_as_gpu(std::shared_ptr<nvmap> nvmap_dev) : nvmap_dev(std::move(nvmap_dev)) {}
     ~nvhost_as_gpu() override = default;
 
     u32 ioctl(Ioctl command, const std::vector<u8>& input, std::vector<u8>& output) override;

src/core/hle/service/nvdrv/devices/nvhost_gpu.h

@@ -18,7 +18,7 @@ constexpr u32 NVGPU_IOCTL_CHANNEL_SUBMIT_GPFIFO(0x8);
 
 class nvhost_gpu final : public nvdevice {
 public:
-    nvhost_gpu(std::shared_ptr<nvmap> nvmap_dev) : nvmap_dev(std::move(nvmap_dev)) {}
+    explicit nvhost_gpu(std::shared_ptr<nvmap> nvmap_dev) : nvmap_dev(std::move(nvmap_dev)) {}
     ~nvhost_gpu() override = default;
 
     u32 ioctl(Ioctl command, const std::vector<u8>& input, std::vector<u8>& output) override;

src/core/hle/service/nvdrv/nvdrv.h

@@ -30,7 +30,7 @@ public:
 
     /// Returns a pointer to one of the available devices, identified by its name.
     template <typename T>
-    std::shared_ptr<T> GetDevice(std::string name) {
+    std::shared_ptr<T> GetDevice(const std::string& name) {
         auto itr = devices.find(name);
         if (itr == devices.end())
             return nullptr;

src/core/hle/service/nvflinger/nvflinger.cpp

@@ -23,15 +23,10 @@ constexpr u64 frame_ticks = static_cast<u64>(CoreTiming::BASE_CLOCK_RATE / SCREE
 
 NVFlinger::NVFlinger() {
     // Add the different displays to the list of displays.
-    Display default_{0, "Default"};
-    Display external{1, "External"};
-    Display edid{2, "Edid"};
-    Display internal{3, "Internal"};
-
-    displays.emplace_back(default_);
-    displays.emplace_back(external);
-    displays.emplace_back(edid);
-    displays.emplace_back(internal);
+    displays.emplace_back(0, "Default");
+    displays.emplace_back(1, "External");
+    displays.emplace_back(2, "Edid");
+    displays.emplace_back(3, "Internal");
 
     // Schedule the screen composition events
     composition_event =

src/core/hle/service/pctl/module.h

@@ -12,7 +12,7 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        Interface(std::shared_ptr<Module> module, const char* name);
+        explicit Interface(std::shared_ptr<Module> module, const char* name);
 
         void CreateService(Kernel::HLERequestContext& ctx);
         void CreateServiceWithoutInitialize(Kernel::HLERequestContext& ctx);