13 files changed, 541 insertions, 67 deletions
diff --git a/src/core/file_sys/directory.h b/src/core/file_sys/directory.h
index 5a40bf472..c7639795e 100644
--- a/src/core/file_sys/directory.h
+++ b/src/core/file_sys/directory.h
@@ -6,34 +6,28 @@
 
 #include <array>
 #include <cstddef>
+#include "common/common_funcs.h"
 #include "common/common_types.h"
+#include "core/file_sys/filesystem.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // FileSys namespace
 
 namespace FileSys {
 
-// Structure of a directory entry, from http://3dbrew.org/wiki/FSDir:Read#Entry_format
-const size_t FILENAME_LENGTH = 0x20C / 2;
+// Structure of a directory entry, from
+// http://switchbrew.org/index.php?title=Filesystem_services#DirectoryEntry
+const size_t FILENAME_LENGTH = 0x300;
 struct Entry {
-    char16_t filename[FILENAME_LENGTH]; // Entry name (UTF-16, null-terminated)
-    std::array<char, 9> short_name; // 8.3 file name ('longfilename' -> 'LONGFI~1', null-terminated)
-    char unknown1;                  // unknown (observed values: 0x0A, 0x70, 0xFD)
-    std::array<char, 4>
-        extension;     // 8.3 file extension (set to spaces for directories, null-terminated)
-    char unknown2;     // unknown (always 0x01)
-    char unknown3;     // unknown (0x00 or 0x08)
-    char is_directory; // directory flag
-    char is_hidden;    // hidden flag
-    char is_archive;   // archive flag
-    char is_read_only; // read-only flag
-    u64 file_size;     // file size (for files only)
+    char filename[FILENAME_LENGTH];
+    INSERT_PADDING_BYTES(4);
+    EntryType type;
+    INSERT_PADDING_BYTES(3);
+    u64 file_size;
 };
-static_assert(sizeof(Entry) == 0x228, "Directory Entry struct isn't exactly 0x228 bytes long!");
-static_assert(offsetof(Entry, short_name) == 0x20C, "Wrong offset for short_name in Entry.");
-static_assert(offsetof(Entry, extension) == 0x216, "Wrong offset for extension in Entry.");
-static_assert(offsetof(Entry, is_archive) == 0x21E, "Wrong offset for is_archive in Entry.");
-static_assert(offsetof(Entry, file_size) == 0x220, "Wrong offset for file_size in Entry.");
+static_assert(sizeof(Entry) == 0x310, "Directory Entry struct isn't exactly 0x310 bytes long!");
+static_assert(offsetof(Entry, type) == 0x304, "Wrong offset for type in Entry.");
+static_assert(offsetof(Entry, file_size) == 0x308, "Wrong offset for file_size in Entry.");
 
 class DirectoryBackend : NonCopyable {
 public:
@@ -46,7 +40,10 @@ public:
      * @param entries Buffer to read data into
      * @return Number of entries listed
      */
-    virtual u32 Read(const u32 count, Entry* entries) = 0;
+    virtual u64 Read(const u64 count, Entry* entries) = 0;
+
+    /// Returns the number of entries still left to read.
+    virtual u64 GetEntryCount() const = 0;
 
     /**
      * Close the directory
diff --git a/src/core/file_sys/disk_filesystem.cpp b/src/core/file_sys/disk_filesystem.cpp
new file mode 100644
index 000000000..4235f3935
--- /dev/null
+++ b/src/core/file_sys/disk_filesystem.cpp
@@ -0,0 +1,228 @@
+// 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 Path& path) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    // TODO(bunnei): Use correct error code
+    return ResultCode(-1);
+}
+
+ResultCode Disk_FileSystem::RenameFile(const Path& src_path, const Path& dest_path) const {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+    // TODO(wwylele): Use correct error code
+    return 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 %s", full_path.c_str());
+    // 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=%llu, length=%zu", 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) : directory() {
+    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 %s: size=%llu dir=%d", filename.c_str(), 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
diff --git a/src/core/file_sys/disk_filesystem.h b/src/core/file_sys/disk_filesystem.h
new file mode 100644
index 000000000..742d7db1a
--- /dev/null
+++ b/src/core/file_sys/disk_filesystem.h
@@ -0,0 +1,85 @@
+// 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 Path& path) const override;
+    ResultCode RenameFile(const Path& src_path, const Path& 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:
+    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:
+    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:
+    u32 total_entries_in_directory;
+    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
diff --git a/src/core/file_sys/errors.h b/src/core/file_sys/errors.h
index be3224ef8..0ed7d2a0c 100644
--- a/src/core/file_sys/errors.h
+++ b/src/core/file_sys/errors.h
@@ -10,36 +10,17 @@ namespace FileSys {
 
 namespace ErrCodes {
 enum {
-    RomFSNotFound = 100,
-    ArchiveNotMounted = 101,
-    FileNotFound = 112,
-    PathNotFound = 113,
-    GameCardNotInserted = 141,
-    NotFound = 120,
-    FileAlreadyExists = 180,
-    DirectoryAlreadyExists = 185,
-    AlreadyExists = 190,
-    InvalidOpenFlags = 230,
-    DirectoryNotEmpty = 240,
-    NotAFile = 250,
-    NotFormatted = 340, ///< This is used by the FS service when creating a SaveData archive
-    ExeFSSectionNotFound = 567,
-    CommandNotAllowed = 630,
-    InvalidReadFlag = 700,
-    InvalidPath = 702,
-    WriteBeyondEnd = 705,
-    UnsupportedOpenFlags = 760,
-    IncorrectExeFSReadSize = 761,
-    UnexpectedFileOrDirectory = 770,
+    NotFound = 1,
 };
 }
 
+constexpr ResultCode ERROR_PATH_NOT_FOUND(ErrorModule::FS, ErrCodes::NotFound);
+
 // TODO(bunnei): Replace these with correct errors for Switch OS
 constexpr ResultCode ERROR_INVALID_PATH(ResultCode(-1));
 constexpr ResultCode ERROR_UNSUPPORTED_OPEN_FLAGS(ResultCode(-1));
 constexpr ResultCode ERROR_INVALID_OPEN_FLAGS(ResultCode(-1));
 constexpr ResultCode ERROR_FILE_NOT_FOUND(ResultCode(-1));
-constexpr ResultCode ERROR_PATH_NOT_FOUND(ResultCode(-1));
 constexpr ResultCode ERROR_UNEXPECTED_FILE_OR_DIRECTORY(ResultCode(-1));
 constexpr ResultCode ERROR_DIRECTORY_ALREADY_EXISTS(ResultCode(-1));
 constexpr ResultCode ERROR_FILE_ALREADY_EXISTS(ResultCode(-1));
diff --git a/src/core/file_sys/filesystem.h b/src/core/file_sys/filesystem.h
index 02705506b..399427ca2 100644
--- a/src/core/file_sys/filesystem.h
+++ b/src/core/file_sys/filesystem.h
@@ -27,11 +27,15 @@ enum LowPathType : u32 {
     Wchar = 4,
 };
 
-union Mode {
-    u32 hex;
-    BitField<0, 1, u32> read_flag;
-    BitField<1, 1, u32> write_flag;
-    BitField<2, 1, u32> create_flag;
+enum EntryType : u8 {
+    Directory = 0,
+    File = 1,
+};
+
+enum class Mode : u32 {
+    Read = 1,
+    Write = 2,
+    Append = 4,
 };
 
 class Path {
@@ -86,7 +90,7 @@ public:
      * @param size The size of the new file, filled with zeroes
      * @return Result of the operation
      */
-    virtual ResultCode CreateFile(const Path& path, u64 size) const = 0;
+    virtual ResultCode CreateFile(const std::string& path, u64 size) const = 0;
 
     /**
      * Delete a file specified by its path
@@ -100,7 +104,7 @@ public:
      * @param path Path relative to the archive
      * @return Result of the operation
      */
-    virtual ResultCode CreateDirectory(const Path& path) const = 0;
+    virtual ResultCode CreateDirectory(const std::string& path) const = 0;
 
     /**
      * Delete a directory specified by its path
@@ -138,21 +142,28 @@ public:
      * @param mode Mode to open the file with
      * @return Opened file, or error code
      */
-    virtual ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const Path& path,
-                                                                const Mode& mode) const = 0;
+    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 Path& path) const = 0;
+    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;
 };
 
 class FileSystemFactory : NonCopyable {
@@ -174,10 +185,9 @@ public:
     /**
      * Deletes the archive contents and then re-creates the base folder
      * @param path Path to the archive
-     * @param format_info Format information for the new archive
      * @return ResultCode of the operation, 0 on success
      */
-    virtual ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) = 0;
+    virtual ResultCode Format(const Path& path) = 0;
 
     /**
      * Retrieves the format info about the archive with the specified path
diff --git a/src/core/file_sys/romfs_factory.cpp b/src/core/file_sys/romfs_factory.cpp
index e0de49f05..b21427948 100644
--- a/src/core/file_sys/romfs_factory.cpp
+++ b/src/core/file_sys/romfs_factory.cpp
@@ -23,7 +23,7 @@ ResultVal<std::unique_ptr<FileSystemBackend>> RomFS_Factory::Open(const Path& pa
     return MakeResult<std::unique_ptr<FileSystemBackend>>(std::move(archive));
 }
 
-ResultCode RomFS_Factory::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
+ResultCode RomFS_Factory::Format(const Path& path) {
     LOG_ERROR(Service_FS, "Unimplemented Format archive %s", GetName().c_str());
     // TODO(bunnei): Find the right error code for this
     return ResultCode(-1);
diff --git a/src/core/file_sys/romfs_factory.h b/src/core/file_sys/romfs_factory.h
index 10ea13966..e0698e642 100644
--- a/src/core/file_sys/romfs_factory.h
+++ b/src/core/file_sys/romfs_factory.h
@@ -23,7 +23,7 @@ public:
         return "ArchiveFactory_RomFS";
     }
     ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultCode Format(const Path& path) override;
     ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
 private:
diff --git a/src/core/file_sys/romfs_filesystem.cpp b/src/core/file_sys/romfs_filesystem.cpp
index ca1463d7c..0c6cc3157 100644
--- a/src/core/file_sys/romfs_filesystem.cpp
+++ b/src/core/file_sys/romfs_filesystem.cpp
@@ -14,8 +14,8 @@ std::string RomFS_FileSystem::GetName() const {
     return "RomFS";
 }
 
-ResultVal<std::unique_ptr<StorageBackend>> RomFS_FileSystem::OpenFile(const Path& path,
-                                                                      const Mode& mode) const {
+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));
 }
@@ -48,14 +48,14 @@ ResultCode RomFS_FileSystem::DeleteDirectoryRecursively(const Path& path) const
     return ResultCode(-1);
 }
 
-ResultCode RomFS_FileSystem::CreateFile(const Path& path, u64 size) const {
+ResultCode RomFS_FileSystem::CreateFile(const std::string& path, u64 size) const {
     LOG_CRITICAL(Service_FS, "Attempted to create a file in an ROMFS archive (%s).",
                  GetName().c_str());
     // TODO(bunnei): Use correct error code
     return ResultCode(-1);
 }
 
-ResultCode RomFS_FileSystem::CreateDirectory(const Path& path) const {
+ResultCode RomFS_FileSystem::CreateDirectory(const std::string& path) const {
     LOG_CRITICAL(Service_FS, "Attempted to create a directory in an ROMFS archive (%s).",
                  GetName().c_str());
     // TODO(wwylele): Use correct error code
@@ -70,7 +70,8 @@ ResultCode RomFS_FileSystem::RenameDirectory(const Path& src_path, const Path& d
 }
 
 ResultVal<std::unique_ptr<DirectoryBackend>> RomFS_FileSystem::OpenDirectory(
-    const Path& path) const {
+    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>());
 }
 
@@ -79,6 +80,12 @@ u64 RomFS_FileSystem::GetFreeSpaceSize() const {
     return 0;
 }
 
+ResultVal<FileSys::EntryType> RomFS_FileSystem::GetEntryType(const std::string& path) const {
+    LOG_CRITICAL(Service_FS, "Called within an ROMFS archive (path %s).", path.c_str());
+    // 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=%llu, length=%zu", offset, length);
     romfs_file->Seek(data_offset + offset, SEEK_SET);
diff --git a/src/core/file_sys/romfs_filesystem.h b/src/core/file_sys/romfs_filesystem.h
index 900ea567a..3f94c04d0 100644
--- a/src/core/file_sys/romfs_filesystem.h
+++ b/src/core/file_sys/romfs_filesystem.h
@@ -29,17 +29,19 @@ public:
 
     std::string GetName() const override;
 
-    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const Path& path,
-                                                        const Mode& mode) const override;
+    ResultVal<std::unique_ptr<StorageBackend>> OpenFile(const std::string& path,
+                                                        Mode mode) const override;
     ResultCode DeleteFile(const Path& path) const override;
     ResultCode RenameFile(const Path& src_path, const Path& dest_path) const override;
     ResultCode DeleteDirectory(const Path& path) const override;
     ResultCode DeleteDirectoryRecursively(const Path& path) const override;
-    ResultCode CreateFile(const Path& path, u64 size) const override;
-    ResultCode CreateDirectory(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 Path& 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;
@@ -69,7 +71,10 @@ private:
 
 class ROMFSDirectory : public DirectoryBackend {
 public:
-    u32 Read(const u32 count, Entry* entries) override {
+    u64 Read(const u64 count, Entry* entries) override {
+        return 0;
+    }
+    u64 GetEntryCount() const override {
         return 0;
     }
     bool Close() const override {
diff --git a/src/core/file_sys/savedata_factory.cpp b/src/core/file_sys/savedata_factory.cpp
new file mode 100644
index 000000000..14868fed2
--- /dev/null
+++ b/src/core/file_sys/savedata_factory.cpp
@@ -0,0 +1,57 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cinttypes>
+#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/savedata_factory.h"
+#include "core/hle/kernel/process.h"
+
+namespace FileSys {
+
+SaveData_Factory::SaveData_Factory(std::string nand_directory)
+    : nand_directory(std::move(nand_directory)) {}
+
+ResultVal<std::unique_ptr<FileSystemBackend>> SaveData_Factory::Open(const Path& path) {
+    std::string save_directory = GetFullPath();
+    // Return an error if the save data doesn't actually exist.
+    if (!FileUtil::IsDirectory(save_directory)) {
+        // 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));
+}
+
+ResultCode SaveData_Factory::Format(const Path& path) {
+    LOG_WARNING(Service_FS, "Format archive %s", GetName().c_str());
+    // Create the save data directory.
+    if (!FileUtil::CreateFullPath(GetFullPath())) {
+        // TODO(Subv): Find the correct error code.
+        return ResultCode(-1);
+    }
+
+    return RESULT_SUCCESS;
+}
+
+ResultVal<ArchiveFormatInfo> SaveData_Factory::GetFormatInfo(const Path& path) const {
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+std::string SaveData_Factory::GetFullPath() const {
+    u64 title_id = Core::CurrentProcess()->program_id;
+    // TODO(Subv): Somehow obtain this value.
+    u32 user = 0;
+    return Common::StringFromFormat("%ssave/%016" PRIX64 "/%08X/", nand_directory.c_str(), title_id,
+                                    user);
+}
+
+} // namespace FileSys
diff --git a/src/core/file_sys/savedata_factory.h b/src/core/file_sys/savedata_factory.h
new file mode 100644
index 000000000..73a42aab6
--- /dev/null
+++ b/src/core/file_sys/savedata_factory.h
@@ -0,0 +1,33 @@
+// 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 "common/common_types.h"
+#include "core/file_sys/filesystem.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+/// File system interface to the SaveData archive
+class SaveData_Factory final : public FileSystemFactory {
+public:
+    explicit SaveData_Factory(std::string nand_directory);
+
+    std::string GetName() const override {
+        return "SaveData_Factory";
+    }
+    ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
+    ResultCode Format(const Path& path) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
+
+private:
+    std::string nand_directory;
+
+    std::string GetFullPath() const;
+};
+
+} // namespace FileSys
diff --git a/src/core/file_sys/sdmc_factory.cpp b/src/core/file_sys/sdmc_factory.cpp
new file mode 100644
index 000000000..00e80d2a7
--- /dev/null
+++ b/src/core/file_sys/sdmc_factory.cpp
@@ -0,0 +1,40 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cinttypes>
+#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 {
+
+SDMC_Factory::SDMC_Factory(std::string sd_directory) : sd_directory(std::move(sd_directory)) {}
+
+ResultVal<std::unique_ptr<FileSystemBackend>> SDMC_Factory::Open(const Path& path) {
+    // 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));
+}
+
+ResultCode SDMC_Factory::Format(const Path& path) {
+    LOG_ERROR(Service_FS, "Unimplemented Format archive %s", GetName().c_str());
+    // TODO(Subv): Find the right error code for this
+    return ResultCode(-1);
+}
+
+ResultVal<ArchiveFormatInfo> SDMC_Factory::GetFormatInfo(const Path& path) const {
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    // TODO(bunnei): Find the right error code for this
+    return ResultCode(-1);
+}
+
+} // namespace FileSys
diff --git a/src/core/file_sys/sdmc_factory.h b/src/core/file_sys/sdmc_factory.h
new file mode 100644
index 000000000..93becda25
--- /dev/null
+++ b/src/core/file_sys/sdmc_factory.h
@@ -0,0 +1,31 @@
+// 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 "common/common_types.h"
+#include "core/file_sys/filesystem.h"
+#include "core/hle/result.h"
+
+namespace FileSys {
+
+/// File system interface to the SDCard archive
+class SDMC_Factory final : public FileSystemFactory {
+public:
+    explicit SDMC_Factory(std::string sd_directory);
+
+    std::string GetName() const override {
+        return "SDMC_Factory";
+    }
+    ResultVal<std::unique_ptr<FileSystemBackend>> Open(const Path& path) override;
+    ResultCode Format(const Path& path) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
+
+private:
+    std::string sd_directory;
+};
+
+} // namespace FileSys