40 files changed, 673 insertions, 203 deletions

diff --git a/src/audio_core/CMakeLists.txt b/src/audio_core/CMakeLists.txt
index b0d1c7eb6..c4bad8cb0 100644
--- a/src/audio_core/CMakeLists.txt
+++ b/src/audio_core/CMakeLists.txt
@@ -1,11 +1,13 @@
 set(SRCS
             audio_core.cpp
+            codec.cpp
             hle/dsp.cpp
             hle/pipe.cpp
             )
 
 set(HEADERS
             audio_core.h
+            codec.h
             hle/dsp.h
             hle/pipe.h
             sink.h
diff --git a/src/audio_core/codec.cpp b/src/audio_core/codec.cpp
new file mode 100644
index 000000000..ab65514b7
--- /dev/null
+++ b/src/audio_core/codec.cpp
@@ -0,0 +1,122 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <cstddef>
+#include <cstring>
+#include <vector>
+
+#include "audio_core/codec.h"
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "common/math_util.h"
+
+namespace Codec {
+
+StereoBuffer16 DecodeADPCM(const u8* const data, const size_t sample_count, const std::array<s16, 16>& adpcm_coeff, ADPCMState& state) {
+    // GC-ADPCM with scale factor and variable coefficients.
+    // Frames are 8 bytes long containing 14 samples each.
+    // Samples are 4 bits (one nibble) long.
+
+    constexpr size_t FRAME_LEN = 8;
+    constexpr size_t SAMPLES_PER_FRAME = 14;
+    constexpr std::array<int, 16> SIGNED_NIBBLES {{ 0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1 }};
+
+    const size_t ret_size = sample_count % 2 == 0 ? sample_count : sample_count + 1; // Ensure multiple of two.
+    StereoBuffer16 ret(ret_size);
+
+    int yn1 = state.yn1,
+        yn2 = state.yn2;
+
+    const size_t NUM_FRAMES = (sample_count + (SAMPLES_PER_FRAME - 1)) / SAMPLES_PER_FRAME; // Round up.
+    for (size_t framei = 0; framei < NUM_FRAMES; framei++) {
+        const int frame_header = data[framei * FRAME_LEN];
+        const int scale = 1 << (frame_header & 0xF);
+        const int idx = (frame_header >> 4) & 0x7;
+
+        // Coefficients are fixed point with 11 bits fractional part.
+        const int coef1 = adpcm_coeff[idx * 2 + 0];
+        const int coef2 = adpcm_coeff[idx * 2 + 1];
+
+        // Decodes an audio sample. One nibble produces one sample.
+        const auto decode_sample = [&](const int nibble) -> s16 {
+            const int xn = nibble * scale;
+            // We first transform everything into 11 bit fixed point, perform the second order digital filter, then transform back.
+            // 0x400 == 0.5 in 11 bit fixed point.
+            // Filter: y[n] = x[n] + 0.5 + c1 * y[n-1] + c2 * y[n-2]
+            int val = ((xn << 11) + 0x400 + coef1 * yn1 + coef2 * yn2) >> 11;
+            // Clamp to output range.
+            val = MathUtil::Clamp(val, -32768, 32767);
+            // Advance output feedback.
+            yn2 = yn1;
+            yn1 = val;
+            return (s16)val;
+        };
+
+        size_t outputi = framei * SAMPLES_PER_FRAME;
+        size_t datai = framei * FRAME_LEN + 1;
+        for (size_t i = 0; i < SAMPLES_PER_FRAME && outputi < sample_count; i += 2) {
+            const s16 sample1 = decode_sample(SIGNED_NIBBLES[data[datai] & 0xF]);
+            ret[outputi].fill(sample1);
+            outputi++;
+
+            const s16 sample2 = decode_sample(SIGNED_NIBBLES[data[datai] >> 4]);
+            ret[outputi].fill(sample2);
+            outputi++;
+
+            datai++;
+        }
+    }
+
+    state.yn1 = yn1;
+    state.yn2 = yn2;
+
+    return ret;
+}
+
+static s16 SignExtendS8(u8 x) {
+    // The data is actually signed PCM8.
+    // We sign extend this to signed PCM16.
+    return static_cast<s16>(static_cast<s8>(x));
+}
+
+StereoBuffer16 DecodePCM8(const unsigned num_channels, const u8* const data, const size_t sample_count) {
+    ASSERT(num_channels == 1 || num_channels == 2);
+
+    StereoBuffer16 ret(sample_count);
+
+    if (num_channels == 1) {
+        for (size_t i = 0; i < sample_count; i++) {
+            ret[i].fill(SignExtendS8(data[i]));
+        }
+    } else {
+        for (size_t i = 0; i < sample_count; i++) {
+            ret[i][0] = SignExtendS8(data[i * 2 + 0]);
+            ret[i][1] = SignExtendS8(data[i * 2 + 1]);
+        }
+    }
+
+    return ret;
+}
+
+StereoBuffer16 DecodePCM16(const unsigned num_channels, const u8* const data, const size_t sample_count) {
+    ASSERT(num_channels == 1 || num_channels == 2);
+
+    StereoBuffer16 ret(sample_count);
+
+    if (num_channels == 1) {
+        for (size_t i = 0; i < sample_count; i++) {
+            s16 sample;
+            std::memcpy(&sample, data + i * sizeof(s16), sizeof(s16));
+            ret[i].fill(sample);
+        }
+    } else {
+        std::memcpy(ret.data(), data, sample_count * 2 * sizeof(u16));
+    }
+
+    return ret;
+}
+
+};
diff --git a/src/audio_core/codec.h b/src/audio_core/codec.h
new file mode 100644
index 000000000..e695f2edc
--- /dev/null
+++ b/src/audio_core/codec.h
@@ -0,0 +1,50 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <vector>
+
+#include "common/common_types.h"
+
+namespace Codec {
+
+/// A variable length buffer of signed PCM16 stereo samples.
+using StereoBuffer16 = std::vector<std::array<s16, 2>>;
+
+/// See: Codec::DecodeADPCM
+struct ADPCMState {
+    // Two historical samples from previous processed buffer,
+    // required for ADPCM decoding
+    s16 yn1; ///< y[n-1]
+    s16 yn2; ///< y[n-2]
+};
+
+/**
+ * @param data Pointer to buffer that contains ADPCM data to decode
+ * @param sample_count Length of buffer in terms of number of samples
+ * @param adpcm_coeff ADPCM coefficients
+ * @param state ADPCM state, this is updated with new state
+ * @return Decoded stereo signed PCM16 data, sample_count in length
+ */
+StereoBuffer16 DecodeADPCM(const u8* const data, const size_t sample_count, const std::array<s16, 16>& adpcm_coeff, ADPCMState& state);
+
+/**
+ * @param num_channels Number of channels
+ * @param data Pointer to buffer that contains PCM8 data to decode
+ * @param sample_count Length of buffer in terms of number of samples
+ * @return Decoded stereo signed PCM16 data, sample_count in length
+ */
+StereoBuffer16 DecodePCM8(const unsigned num_channels, const u8* const data, const size_t sample_count);
+
+/**
+ * @param num_channels Number of channels
+ * @param data Pointer to buffer that contains PCM16 data to decode
+ * @param sample_count Length of buffer in terms of number of samples
+ * @return Decoded stereo signed PCM16 data, sample_count in length
+ */
+StereoBuffer16 DecodePCM16(const unsigned num_channels, const u8* const data, const size_t sample_count);
+
+};
diff --git a/src/core/arm/skyeye_common/armstate.cpp b/src/core/arm/skyeye_common/armstate.cpp
index 2d814345a..5550c112e 100644
--- a/src/core/arm/skyeye_common/armstate.cpp
+++ b/src/core/arm/skyeye_common/armstate.cpp
@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <algorithm>
 #include "common/swap.h"
 #include "common/logging/log.h"
 #include "core/memory.h"
@@ -48,8 +49,7 @@ void ARMul_State::ChangePrivilegeMode(u32 new_mode)
             Spsr[UNDEFBANK] = Spsr_copy;
             break;
         case FIQ32MODE:
-            Reg_firq[0] = Reg[13];
-            Reg_firq[1] = Reg[14];
+            std::copy(Reg.begin() + 8, Reg.end() - 1, Reg_firq.begin());
             Spsr[FIQBANK] = Spsr_copy;
             break;
         }
@@ -85,8 +85,7 @@ void ARMul_State::ChangePrivilegeMode(u32 new_mode)
             Bank = UNDEFBANK;
             break;
         case FIQ32MODE:
-            Reg[13] = Reg_firq[0];
-            Reg[14] = Reg_firq[1];
+            std::copy(Reg_firq.begin(), Reg_firq.end(), Reg.begin() + 8);
             Spsr_copy = Spsr[FIQBANK];
             Bank = FIQBANK;
             break;
diff --git a/src/core/file_sys/archive_backend.h b/src/core/file_sys/archive_backend.h
index 601e95d8c..5d91e47f3 100644
--- a/src/core/file_sys/archive_backend.h
+++ b/src/core/file_sys/archive_backend.h
@@ -11,6 +11,7 @@
 
 #include "common/bit_field.h"
 #include "common/common_types.h"
+#include "common/swap.h"
 
 #include "core/hle/result.h"
 
@@ -62,6 +63,14 @@ private:
     std::u16string u16str;
 };
 
+struct ArchiveFormatInfo {
+    u32_le total_size; ///< The pre-defined size of the archive, as specified in the Create or Format call
+    u32_le number_directories; ///< The pre-defined number of directories in the archive, as specified in the Create or Format call
+    u32_le number_files; ///< The pre-defined number of files in the archive, as specified in the Create or Format call
+    u8 duplicate_data; ///< Whether the archive should duplicate the data, as specified in the Create or Format call
+};
+static_assert(std::is_pod<ArchiveFormatInfo>::value, "ArchiveFormatInfo is not POD");
+
 class ArchiveBackend : NonCopyable {
 public:
     virtual ~ArchiveBackend() {
@@ -76,16 +85,16 @@ public:
      * 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 nullptr
+     * @return Opened file, or error code
      */
-    virtual std::unique_ptr<FileBackend> OpenFile(const Path& path, const Mode mode) const = 0;
+    virtual ResultVal<std::unique_ptr<FileBackend>> OpenFile(const Path& path, const Mode mode) const = 0;
 
     /**
      * Delete a file specified by its path
      * @param path Path relative to the archive
-     * @return Whether the file could be deleted
+     * @return Result of the operation
      */
-    virtual bool DeleteFile(const Path& path) const = 0;
+    virtual ResultCode DeleteFile(const Path& path) const = 0;
 
     /**
      * Rename a File specified by its path
@@ -108,7 +117,7 @@ public:
      * @param size The size of the new file, filled with zeroes
      * @return File creation result code
      */
-    virtual ResultCode CreateFile(const Path& path, u32 size) const = 0;
+    virtual ResultCode CreateFile(const Path& path, u64 size) const = 0;
 
     /**
      * Create a directory specified by its path
@@ -159,9 +168,17 @@ 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) = 0;
+    virtual ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) = 0;
+
+    /**
+     * Retrieves the format info about the archive with the specified path
+     * @param path Path to the archive
+     * @return Format information about the archive or error code
+     */
+    virtual ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const = 0;
 };
 
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_extsavedata.cpp b/src/core/file_sys/archive_extsavedata.cpp
index 92dad8e6f..961264fe5 100644
--- a/src/core/file_sys/archive_extsavedata.cpp
+++ b/src/core/file_sys/archive_extsavedata.cpp
@@ -58,7 +58,7 @@ Path ConstructExtDataBinaryPath(u32 media_type, u32 high, u32 low) {
 }
 
 ArchiveFactory_ExtSaveData::ArchiveFactory_ExtSaveData(const std::string& mount_location, bool shared)
-        : mount_point(GetExtDataContainerPath(mount_location, shared)) {
+        : shared(shared), mount_point(GetExtDataContainerPath(mount_location, shared)) {
     LOG_INFO(Service_FS, "Directory %s set as base for ExtSaveData.", mount_point.c_str());
 }
 
@@ -74,21 +74,59 @@ bool ArchiveFactory_ExtSaveData::Initialize() {
 ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_ExtSaveData::Open(const Path& path) {
     std::string fullpath = GetExtSaveDataPath(mount_point, path) + "user/";
     if (!FileUtil::Exists(fullpath)) {
-        // TODO(Subv): Check error code, this one is probably wrong
-        return ResultCode(ErrorDescription::FS_NotFormatted, ErrorModule::FS,
-            ErrorSummary::InvalidState, ErrorLevel::Status);
+        // TODO(Subv): Verify the archive behavior of SharedExtSaveData compared to ExtSaveData.
+        // ExtSaveData seems to return FS_NotFound (120) when the archive doesn't exist.
+        if (!shared) {
+            return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS,
+                              ErrorSummary::InvalidState, ErrorLevel::Status);
+        } else {
+            return ResultCode(ErrorDescription::FS_NotFormatted, ErrorModule::FS,
+                              ErrorSummary::InvalidState, ErrorLevel::Status);
+        }
     }
     auto archive = Common::make_unique<DiskArchive>(fullpath);
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_ExtSaveData::Format(const Path& path) {
+ResultCode ArchiveFactory_ExtSaveData::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     // These folders are always created with the ExtSaveData
     std::string user_path = GetExtSaveDataPath(mount_point, path) + "user/";
     std::string boss_path = GetExtSaveDataPath(mount_point, path) + "boss/";
     FileUtil::CreateFullPath(user_path);
     FileUtil::CreateFullPath(boss_path);
+
+    // Write the format metadata
+    std::string metadata_path = GetExtSaveDataPath(mount_point, path) + "metadata";
+    FileUtil::IOFile file(metadata_path, "wb");
+
+    if (!file.IsOpen()) {
+        // TODO(Subv): Find the correct error code
+        return ResultCode(-1);
+    }
+
+    file.WriteBytes(&format_info, sizeof(format_info));
     return RESULT_SUCCESS;
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_ExtSaveData::GetFormatInfo(const Path& path) const {
+    std::string metadata_path = GetExtSaveDataPath(mount_point, path) + "metadata";
+    FileUtil::IOFile file(metadata_path, "rb");
+
+    if (!file.IsOpen()) {
+        LOG_ERROR(Service_FS, "Could not open metadata information for archive");
+        // TODO(Subv): Verify error code
+        return ResultCode(ErrorDescription::FS_NotFormatted, ErrorModule::FS, ErrorSummary::InvalidState, ErrorLevel::Status);
+    }
+
+    ArchiveFormatInfo info = {};
+    file.ReadBytes(&info, sizeof(info));
+    return MakeResult<ArchiveFormatInfo>(info);
+}
+
+void ArchiveFactory_ExtSaveData::WriteIcon(const Path& path, const u8* icon_data, size_t icon_size) {
+    std::string game_path = FileSys::GetExtSaveDataPath(GetMountPoint(), path);
+    FileUtil::IOFile icon_file(game_path + "icon", "wb");
+    icon_file.WriteBytes(icon_data, icon_size);
+}
+
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_extsavedata.h b/src/core/file_sys/archive_extsavedata.h
index ec8d770fc..e9a72850d 100644
--- a/src/core/file_sys/archive_extsavedata.h
+++ b/src/core/file_sys/archive_extsavedata.h
@@ -31,11 +31,22 @@ public:
     std::string GetName() const override { return "ExtSaveData"; }
 
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
     const std::string& GetMountPoint() const { return mount_point; }
 
+    /**
+     * Writes the SMDH icon of the ExtSaveData to file
+     * @param path Path of this ExtSaveData
+     * @param icon_data Binary data of the icon
+     * @param icon_size Size of the icon data
+     */
+    void WriteIcon(const Path& path, const u8* icon_data, size_t icon_size);
+
 private:
+    bool shared; ///< Whether this archive represents an ExtSaveData archive or a SharedExtSaveData archive
+
     /**
      * This holds the full directory path for this archive, it is only set after a successful call
      * to Open, this is formed as <base extsavedatapath>/<type>/<high>/<low>.
diff --git a/src/core/file_sys/archive_romfs.cpp b/src/core/file_sys/archive_romfs.cpp
index 696b51a94..a9a29ebde 100644
--- a/src/core/file_sys/archive_romfs.cpp
+++ b/src/core/file_sys/archive_romfs.cpp
@@ -29,11 +29,17 @@ ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_RomFS::Open(const Path
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_RomFS::Format(const Path& path) {
+ResultCode ArchiveFactory_RomFS::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     LOG_ERROR(Service_FS, "Attempted to format a RomFS archive.");
     // TODO: Verify error code
     return ResultCode(ErrorDescription::NotAuthorized, ErrorModule::FS,
             ErrorSummary::NotSupported, ErrorLevel::Permanent);
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_RomFS::GetFormatInfo(const Path& path) const {
+    // TODO(Subv): Implement
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    return ResultCode(-1);
+}
+
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_romfs.h b/src/core/file_sys/archive_romfs.h
index 2bedfa9c6..c5a329122 100644
--- a/src/core/file_sys/archive_romfs.h
+++ b/src/core/file_sys/archive_romfs.h
@@ -26,7 +26,8 @@ public:
 
     std::string GetName() const override { return "RomFS"; }
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
 private:
     std::shared_ptr<FileUtil::IOFile> romfs_file;
diff --git a/src/core/file_sys/archive_savedata.cpp b/src/core/file_sys/archive_savedata.cpp
index 12876899f..fe020d21c 100644
--- a/src/core/file_sys/archive_savedata.cpp
+++ b/src/core/file_sys/archive_savedata.cpp
@@ -26,11 +26,17 @@ static std::string GetSaveDataContainerPath(const std::string& sdmc_directory) {
 }
 
 static std::string GetSaveDataPath(const std::string& mount_location, u64 program_id) {
-    u32 high = program_id >> 32;
-    u32 low = program_id & 0xFFFFFFFF;
+    u32 high = (u32)(program_id >> 32);
+    u32 low = (u32)(program_id & 0xFFFFFFFF);
     return Common::StringFromFormat("%s%08x/%08x/data/00000001/", mount_location.c_str(), high, low);
 }
 
+static std::string GetSaveDataMetadataPath(const std::string& mount_location, u64 program_id) {
+    u32 high = (u32)(program_id >> 32);
+    u32 low = (u32)(program_id & 0xFFFFFFFF);
+    return Common::StringFromFormat("%s%08x/%08x/data/00000001.metadata", mount_location.c_str(), high, low);
+}
+
 ArchiveFactory_SaveData::ArchiveFactory_SaveData(const std::string& sdmc_directory)
         : mount_point(GetSaveDataContainerPath(sdmc_directory)) {
     LOG_INFO(Service_FS, "Directory %s set as SaveData.", this->mount_point.c_str());
@@ -51,11 +57,35 @@ ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_SaveData::Open(const P
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_SaveData::Format(const Path& path) {
+ResultCode ArchiveFactory_SaveData::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     std::string concrete_mount_point = GetSaveDataPath(mount_point, Kernel::g_current_process->codeset->program_id);
     FileUtil::DeleteDirRecursively(concrete_mount_point);
     FileUtil::CreateFullPath(concrete_mount_point);
+
+    // Write the format metadata
+    std::string metadata_path = GetSaveDataMetadataPath(mount_point, Kernel::g_current_process->codeset->program_id);
+    FileUtil::IOFile file(metadata_path, "wb");
+
+    if (file.IsOpen()) {
+        file.WriteBytes(&format_info, sizeof(format_info));
+        return RESULT_SUCCESS;
+    }
     return RESULT_SUCCESS;
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_SaveData::GetFormatInfo(const Path& path) const {
+    std::string metadata_path = GetSaveDataMetadataPath(mount_point, Kernel::g_current_process->codeset->program_id);
+    FileUtil::IOFile file(metadata_path, "rb");
+
+    if (!file.IsOpen()) {
+        LOG_ERROR(Service_FS, "Could not open metadata information for archive");
+        // TODO(Subv): Verify error code
+        return ResultCode(ErrorDescription::FS_NotFormatted, ErrorModule::FS, ErrorSummary::InvalidState, ErrorLevel::Status);
+    }
+
+    ArchiveFormatInfo info = {};
+    file.ReadBytes(&info, sizeof(info));
+    return MakeResult<ArchiveFormatInfo>(info);
+}
+
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_savedata.h b/src/core/file_sys/archive_savedata.h
index 1f65297dd..7a5a24089 100644
--- a/src/core/file_sys/archive_savedata.h
+++ b/src/core/file_sys/archive_savedata.h
@@ -23,7 +23,9 @@ public:
     std::string GetName() const override { return "SaveData"; }
 
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
 private:
     std::string mount_point;
diff --git a/src/core/file_sys/archive_savedatacheck.cpp b/src/core/file_sys/archive_savedatacheck.cpp
index ea1dfe2c7..3db11c500 100644
--- a/src/core/file_sys/archive_savedatacheck.cpp
+++ b/src/core/file_sys/archive_savedatacheck.cpp
@@ -48,11 +48,17 @@ ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_SaveDataCheck::Open(co
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_SaveDataCheck::Format(const Path& path) {
+ResultCode ArchiveFactory_SaveDataCheck::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     LOG_ERROR(Service_FS, "Attempted to format a SaveDataCheck archive.");
     // TODO: Verify error code
     return ResultCode(ErrorDescription::NotAuthorized, ErrorModule::FS,
         ErrorSummary::NotSupported, ErrorLevel::Permanent);
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_SaveDataCheck::GetFormatInfo(const Path& path) const {
+    // TODO(Subv): Implement
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    return ResultCode(-1);
+}
+
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_savedatacheck.h b/src/core/file_sys/archive_savedatacheck.h
index b14aefe8b..ea2624d64 100644
--- a/src/core/file_sys/archive_savedatacheck.h
+++ b/src/core/file_sys/archive_savedatacheck.h
@@ -23,7 +23,8 @@ public:
     std::string GetName() const override { return "SaveDataCheck"; }
 
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
 private:
     std::string mount_point;
diff --git a/src/core/file_sys/archive_sdmc.cpp b/src/core/file_sys/archive_sdmc.cpp
index 5c825f429..657221cbf 100644
--- a/src/core/file_sys/archive_sdmc.cpp
+++ b/src/core/file_sys/archive_sdmc.cpp
@@ -40,9 +40,14 @@ ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_SDMC::Open(const Path&
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_SDMC::Format(const Path& path) {
+ResultCode ArchiveFactory_SDMC::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     // This is kind of an undesirable operation, so let's just ignore it. :)
     return RESULT_SUCCESS;
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_SDMC::GetFormatInfo(const Path& path) const {
+    // TODO(Subv): Implement
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    return ResultCode(-1);
+}
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_sdmc.h b/src/core/file_sys/archive_sdmc.h
index 10b273bdb..35c0f3725 100644
--- a/src/core/file_sys/archive_sdmc.h
+++ b/src/core/file_sys/archive_sdmc.h
@@ -29,7 +29,8 @@ public:
     std::string GetName() const override { return "SDMC"; }
 
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
 private:
     std::string sdmc_directory;
diff --git a/src/core/file_sys/archive_systemsavedata.cpp b/src/core/file_sys/archive_systemsavedata.cpp
index 896f89529..e1780de2f 100644
--- a/src/core/file_sys/archive_systemsavedata.cpp
+++ b/src/core/file_sys/archive_systemsavedata.cpp
@@ -63,11 +63,17 @@ ResultVal<std::unique_ptr<ArchiveBackend>> ArchiveFactory_SystemSaveData::Open(c
     return MakeResult<std::unique_ptr<ArchiveBackend>>(std::move(archive));
 }
 
-ResultCode ArchiveFactory_SystemSaveData::Format(const Path& path) {
+ResultCode ArchiveFactory_SystemSaveData::Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) {
     std::string fullpath = GetSystemSaveDataPath(base_path, path);
     FileUtil::DeleteDirRecursively(fullpath);
     FileUtil::CreateFullPath(fullpath);
     return RESULT_SUCCESS;
 }
 
+ResultVal<ArchiveFormatInfo> ArchiveFactory_SystemSaveData::GetFormatInfo(const Path& path) const {
+    // TODO(Subv): Implement
+    LOG_ERROR(Service_FS, "Unimplemented GetFormatInfo archive %s", GetName().c_str());
+    return ResultCode(-1);
+}
+
 } // namespace FileSys
diff --git a/src/core/file_sys/archive_systemsavedata.h b/src/core/file_sys/archive_systemsavedata.h
index afc689848..2bc13d4ee 100644
--- a/src/core/file_sys/archive_systemsavedata.h
+++ b/src/core/file_sys/archive_systemsavedata.h
@@ -23,7 +23,8 @@ public:
     ArchiveFactory_SystemSaveData(const std::string& mount_point);
 
     ResultVal<std::unique_ptr<ArchiveBackend>> Open(const Path& path) override;
-    ResultCode Format(const Path& path) override;
+    ResultCode Format(const Path& path, const FileSys::ArchiveFormatInfo& format_info) override;
+    ResultVal<ArchiveFormatInfo> GetFormatInfo(const Path& path) const override;
 
     std::string GetName() const override { return "SystemSaveData"; }
 
diff --git a/src/core/file_sys/disk_archive.cpp b/src/core/file_sys/disk_archive.cpp
index a51416774..8e4ea01c5 100644
--- a/src/core/file_sys/disk_archive.cpp
+++ b/src/core/file_sys/disk_archive.cpp
@@ -17,16 +17,28 @@
 
 namespace FileSys {
 
-std::unique_ptr<FileBackend> DiskArchive::OpenFile(const Path& path, const Mode mode) const {
+ResultVal<std::unique_ptr<FileBackend>> DiskArchive::OpenFile(const Path& path, const Mode mode) const {
     LOG_DEBUG(Service_FS, "called path=%s mode=%01X", path.DebugStr().c_str(), mode.hex);
     auto file = Common::make_unique<DiskFile>(*this, path, mode);
-    if (!file->Open())
-        return nullptr;
-    return std::move(file);
+    ResultCode result = file->Open();
+    if (result.IsError())
+        return result;
+    return MakeResult<std::unique_ptr<FileBackend>>(std::move(file));
 }
 
-bool DiskArchive::DeleteFile(const Path& path) const {
-    return FileUtil::Delete(mount_point + path.AsString());
+ResultCode DiskArchive::DeleteFile(const Path& path) const {
+    std::string file_path = mount_point + path.AsString();
+
+    if (FileUtil::IsDirectory(file_path))
+        return ResultCode(ErrorDescription::FS_NotAFile, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+
+    if (!FileUtil::Exists(file_path))
+        return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS, ErrorSummary::NotFound, ErrorLevel::Status);
+
+    if (FileUtil::Delete(file_path))
+        return RESULT_SUCCESS;
+
+    return ResultCode(ErrorDescription::FS_NotAFile, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
 }
 
 bool DiskArchive::RenameFile(const Path& src_path, const Path& dest_path) const {
@@ -37,11 +49,14 @@ bool DiskArchive::DeleteDirectory(const Path& path) const {
     return FileUtil::DeleteDir(mount_point + path.AsString());
 }
 
-ResultCode DiskArchive::CreateFile(const FileSys::Path& path, u32 size) const {
+ResultCode DiskArchive::CreateFile(const FileSys::Path& path, u64 size) const {
     std::string full_path = mount_point + path.AsString();
 
+    if (FileUtil::IsDirectory(full_path))
+        return ResultCode(ErrorDescription::FS_NotAFile, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+
     if (FileUtil::Exists(full_path))
-        return ResultCode(ErrorDescription::AlreadyExists, ErrorModule::FS, ErrorSummary::NothingHappened, ErrorLevel::Info);
+        return ResultCode(ErrorDescription::FS_AlreadyExists, ErrorModule::FS, ErrorSummary::NothingHappened, ErrorLevel::Status);
 
     if (size == 0) {
         FileUtil::CreateEmptyFile(full_path);
@@ -89,38 +104,57 @@ DiskFile::DiskFile(const DiskArchive& archive, const Path& path, const Mode mode
     this->mode.hex = mode.hex;
 }
 
-bool DiskFile::Open() {
-    if (!mode.create_flag && !FileUtil::Exists(path)) {
-        LOG_ERROR(Service_FS, "Non-existing file %s can't be open without mode create.", path.c_str());
-        return false;
+ResultCode DiskFile::Open() {
+    if (FileUtil::IsDirectory(path))
+        return ResultCode(ErrorDescription::FS_NotAFile, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+
+    // Specifying only the Create flag is invalid
+    if (mode.create_flag && !mode.read_flag && !mode.write_flag) {
+        return ResultCode(ErrorDescription::FS_InvalidOpenFlags, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+    }
+
+    if (!FileUtil::Exists(path)) {
+        if (!mode.create_flag) {
+            LOG_ERROR(Service_FS, "Non-existing file %s can't be open without mode create.", path.c_str());
+            return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS, ErrorSummary::NotFound, ErrorLevel::Status);
+        } else {
+            // Create the file
+            FileUtil::CreateEmptyFile(path);
+        }
     }
 
-    std::string mode_string;
-    if (mode.create_flag)
-        mode_string = "w+";
-    else if (mode.write_flag)
-        mode_string = "r+"; // Files opened with Write access can be read from
+    std::string mode_string = "";
+    if (mode.write_flag)
+        mode_string += "r+"; // Files opened with Write access can be read from
     else if (mode.read_flag)
-        mode_string = "r";
+        mode_string += "r";
 
     // Open the file in binary mode, to avoid problems with CR/LF on Windows systems
     mode_string += "b";
 
     file = Common::make_unique<FileUtil::IOFile>(path, mode_string.c_str());
-    return file->IsOpen();
+    if (file->IsOpen())
+        return RESULT_SUCCESS;
+    return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS, ErrorSummary::NotFound, ErrorLevel::Status);
 }
 
-size_t DiskFile::Read(const u64 offset, const size_t length, u8* buffer) const {
+ResultVal<size_t> DiskFile::Read(const u64 offset, const size_t length, u8* buffer) const {
+    if (!mode.read_flag && !mode.write_flag)
+        return ResultCode(ErrorDescription::FS_InvalidOpenFlags, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+
     file->Seek(offset, SEEK_SET);
-    return file->ReadBytes(buffer, length);
+    return MakeResult<size_t>(file->ReadBytes(buffer, length));
 }
 
-size_t DiskFile::Write(const u64 offset, const size_t length, const bool flush, const u8* buffer) const {
+ResultVal<size_t> DiskFile::Write(const u64 offset, const size_t length, const bool flush, const u8* buffer) const {
+    if (!mode.write_flag)
+        return ResultCode(ErrorDescription::FS_InvalidOpenFlags, ErrorModule::FS, ErrorSummary::Canceled, ErrorLevel::Status);
+
     file->Seek(offset, SEEK_SET);
     size_t written = file->WriteBytes(buffer, length);
     if (flush)
         file->Flush();
-    return written;
+    return MakeResult<size_t>(written);
 }
 
 u64 DiskFile::GetSize() const {
diff --git a/src/core/file_sys/disk_archive.h b/src/core/file_sys/disk_archive.h
index ef9a98057..b4cc2f702 100644
--- a/src/core/file_sys/disk_archive.h
+++ b/src/core/file_sys/disk_archive.h
@@ -33,11 +33,11 @@ public:
 
     virtual std::string GetName() const override { return "DiskArchive: " + mount_point; }
 
-    std::unique_ptr<FileBackend> OpenFile(const Path& path, const Mode mode) const override;
-    bool DeleteFile(const Path& path) const override;
+    ResultVal<std::unique_ptr<FileBackend>> OpenFile(const Path& path, const Mode mode) const override;
+    ResultCode DeleteFile(const Path& path) const override;
     bool RenameFile(const Path& src_path, const Path& dest_path) const override;
     bool DeleteDirectory(const Path& path) const override;
-    ResultCode CreateFile(const Path& path, u32 size) const override;
+    ResultCode CreateFile(const Path& path, u64 size) const override;
     bool CreateDirectory(const Path& path) const override;
     bool RenameDirectory(const Path& src_path, const Path& dest_path) const override;
     std::unique_ptr<DirectoryBackend> OpenDirectory(const Path& path) const override;
@@ -54,9 +54,9 @@ class DiskFile : public FileBackend {
 public:
     DiskFile(const DiskArchive& archive, const Path& path, const Mode mode);
 
-    bool Open() override;
-    size_t Read(u64 offset, size_t length, u8* buffer) const override;
-    size_t Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
+    ResultCode Open() override;
+    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;
diff --git a/src/core/file_sys/file_backend.h b/src/core/file_sys/file_backend.h
index df7165df3..9137bbbad 100644
--- a/src/core/file_sys/file_backend.h
+++ b/src/core/file_sys/file_backend.h
@@ -7,6 +7,7 @@
 #include <cstddef>
 
 #include "common/common_types.h"
+#include "core/hle/result.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 // FileSys namespace
@@ -20,18 +21,18 @@ public:
 
     /**
      * Open the file
-     * @return true if the file opened correctly
+     * @return Result of the file operation
      */
-    virtual bool Open() = 0;
+    virtual ResultCode Open() = 0;
 
     /**
      * 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
+     * @return Number of bytes read, or error code
      */
-    virtual size_t Read(u64 offset, size_t length, u8* buffer) const = 0;
+    virtual ResultVal<size_t> Read(u64 offset, size_t length, u8* buffer) const = 0;
 
     /**
      * Write data to the file
@@ -39,9 +40,9 @@ public:
      * @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
+     * @return Number of bytes written, or error code
      */
-    virtual size_t Write(u64 offset, size_t length, bool flush, const u8* buffer) const = 0;
+    virtual ResultVal<size_t> Write(u64 offset, size_t length, bool flush, const u8* buffer) const = 0;
 
     /**
      * Get the size of the file in bytes
diff --git a/src/core/file_sys/ivfc_archive.cpp b/src/core/file_sys/ivfc_archive.cpp
index 2efc31a8c..a8e9a72ef 100644
--- a/src/core/file_sys/ivfc_archive.cpp
+++ b/src/core/file_sys/ivfc_archive.cpp
@@ -20,13 +20,15 @@ std::string IVFCArchive::GetName() const {
     return "IVFC";
 }
 
-std::unique_ptr<FileBackend> IVFCArchive::OpenFile(const Path& path, const Mode mode) const {
-    return Common::make_unique<IVFCFile>(romfs_file, data_offset, data_size);
+ResultVal<std::unique_ptr<FileBackend>> IVFCArchive::OpenFile(const Path& path, const Mode mode) const {
+    return MakeResult<std::unique_ptr<FileBackend>>(Common::make_unique<IVFCFile>(romfs_file, data_offset, data_size));
 }
 
-bool IVFCArchive::DeleteFile(const Path& path) const {
+ResultCode IVFCArchive::DeleteFile(const Path& path) const {
     LOG_CRITICAL(Service_FS, "Attempted to delete a file from an IVFC archive (%s).", GetName().c_str());
-    return false;
+    // TODO(Subv): Verify error code
+    return ResultCode(ErrorDescription::NoData, ErrorModule::FS,
+                      ErrorSummary::Canceled, ErrorLevel::Status);
 }
 
 bool IVFCArchive::RenameFile(const Path& src_path, const Path& dest_path) const {
@@ -39,7 +41,7 @@ bool IVFCArchive::DeleteDirectory(const Path& path) const {
     return false;
 }
 
-ResultCode IVFCArchive::CreateFile(const Path& path, u32 size) const {
+ResultCode IVFCArchive::CreateFile(const Path& path, u64 size) const {
     LOG_CRITICAL(Service_FS, "Attempted to create a file in an IVFC archive (%s).", GetName().c_str());
     // TODO: Verify error code
     return ResultCode(ErrorDescription::NotAuthorized, ErrorModule::FS, ErrorSummary::NotSupported, ErrorLevel::Permanent);
@@ -66,17 +68,18 @@ u64 IVFCArchive::GetFreeBytes() const {
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-size_t IVFCFile::Read(const u64 offset, const size_t length, u8* buffer) const {
+ResultVal<size_t> IVFCFile::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);
     size_t read_length = (size_t)std::min((u64)length, data_size - offset);
 
-    return romfs_file->ReadBytes(buffer, read_length);
+    return MakeResult<size_t>(romfs_file->ReadBytes(buffer, read_length));
 }
 
-size_t IVFCFile::Write(const u64 offset, const size_t length, const bool flush, const u8* buffer) const {
+ResultVal<size_t> IVFCFile::Write(const u64 offset, const size_t length, const bool flush, const u8* buffer) const {
     LOG_ERROR(Service_FS, "Attempted to write to IVFC file");
-    return 0;
+    // TODO(Subv): Find error code
+    return MakeResult<size_t>(0);
 }
 
 u64 IVFCFile::GetSize() const {
diff --git a/src/core/file_sys/ivfc_archive.h b/src/core/file_sys/ivfc_archive.h
index f3fd82de4..19d32dcca 100644
--- a/src/core/file_sys/ivfc_archive.h
+++ b/src/core/file_sys/ivfc_archive.h
@@ -34,11 +34,11 @@ public:
 
     std::string GetName() const override;
 
-    std::unique_ptr<FileBackend> OpenFile(const Path& path, const Mode mode) const override;
-    bool DeleteFile(const Path& path) const override;
+    ResultVal<std::unique_ptr<FileBackend>> OpenFile(const Path& path, const Mode mode) const override;
+    ResultCode DeleteFile(const Path& path) const override;
     bool RenameFile(const Path& src_path, const Path& dest_path) const override;
     bool DeleteDirectory(const Path& path) const override;
-    ResultCode CreateFile(const Path& path, u32 size) const override;
+    ResultCode CreateFile(const Path& path, u64 size) const override;
     bool CreateDirectory(const Path& path) const override;
     bool RenameDirectory(const Path& src_path, const Path& dest_path) const override;
     std::unique_ptr<DirectoryBackend> OpenDirectory(const Path& path) const override;
@@ -55,9 +55,9 @@ public:
     IVFCFile(std::shared_ptr<FileUtil::IOFile> file, u64 offset, u64 size)
         : romfs_file(file), data_offset(offset), data_size(size) {}
 
-    bool Open() override { return true; }
-    size_t Read(u64 offset, size_t length, u8* buffer) const override;
-    size_t Write(u64 offset, size_t length, bool flush, const u8* buffer) const override;
+    ResultCode Open() override { return RESULT_SUCCESS; }
+    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; }
diff --git a/src/core/gdbstub/gdbstub.h b/src/core/gdbstub/gdbstub.h
index aff705a32..4f21da23b 100644
--- a/src/core/gdbstub/gdbstub.h
+++ b/src/core/gdbstub/gdbstub.h
@@ -7,6 +7,8 @@
 #pragma once
 #include <atomic>
 
+#include "common/common_types.h"
+
 namespace GDBStub {
 
 /// Breakpoint Method
diff --git a/src/core/hle/kernel/session.h b/src/core/hle/kernel/session.h
index adaffcafe..6ddaf970e 100644
--- a/src/core/hle/kernel/session.h
+++ b/src/core/hle/kernel/session.h
@@ -16,23 +16,23 @@
 
 namespace IPC {
 
-inline u32 MakeHeader(u16 command_id, unsigned int regular_params, unsigned int translate_params) {
+constexpr u32 MakeHeader(u16 command_id, unsigned int regular_params, unsigned int translate_params) {
     return ((u32)command_id << 16) | (((u32)regular_params & 0x3F) << 6) | (((u32)translate_params & 0x3F) << 0);
 }
 
-inline u32 MoveHandleDesc(unsigned int num_handles = 1) {
+constexpr u32 MoveHandleDesc(unsigned int num_handles = 1) {
     return 0x0 | ((num_handles - 1) << 26);
 }
 
-inline u32 CopyHandleDesc(unsigned int num_handles = 1) {
+constexpr u32 CopyHandleDesc(unsigned int num_handles = 1) {
     return 0x10 | ((num_handles - 1) << 26);
 }
 
-inline u32 CallingPidDesc() {
+constexpr u32 CallingPidDesc() {
     return 0x20;
 }
 
-inline u32 StaticBufferDesc(u32 size, unsigned int buffer_id) {
+constexpr u32 StaticBufferDesc(u32 size, unsigned int buffer_id) {
     return 0x2 | (size << 14) | ((buffer_id & 0xF) << 10);
 }
 
@@ -42,7 +42,7 @@ enum MappedBufferPermissions {
     RW = R | W,
 };
 
-inline u32 MappedBufferDesc(u32 size, MappedBufferPermissions perms) {
+constexpr u32 MappedBufferDesc(u32 size, MappedBufferPermissions perms) {
     return 0x8 | (size << 4) | (u32)perms;
 }
 
diff --git a/src/core/hle/result.h b/src/core/hle/result.h
index 69613fbbb..0cb76ba1c 100644
--- a/src/core/hle/result.h
+++ b/src/core/hle/result.h
@@ -19,8 +19,12 @@
 enum class ErrorDescription : u32 {
     Success = 0,
     WrongAddress = 53,
-    FS_NotFound = 100,
+    FS_NotFound = 120,
+    FS_AlreadyExists = 190,
+    FS_InvalidOpenFlags = 230,
+    FS_NotAFile = 250,
     FS_NotFormatted = 340, ///< This is used by the FS service when creating a SaveData archive
+    FS_InvalidPath = 702,
     InvalidSection = 1000,
     TooLarge = 1001,
     NotAuthorized = 1002,
diff --git a/src/core/hle/service/cfg/cfg.cpp b/src/core/hle/service/cfg/cfg.cpp
index 4c82a58e4..525432957 100644
--- a/src/core/hle/service/cfg/cfg.cpp
+++ b/src/core/hle/service/cfg/cfg.cpp
@@ -310,7 +310,8 @@ ResultCode UpdateConfigNANDSavegame() {
 
 ResultCode FormatConfig() {
     ResultCode res = DeleteConfigNANDSaveFile();
-    if (!res.IsSuccess())
+    // The delete command fails if the file doesn't exist, so we have to check that too
+    if (!res.IsSuccess() && res.description != ErrorDescription::FS_NotFound)
         return res;
     // Delete the old data
     cfg_config_file_buffer.fill(0);
@@ -407,7 +408,7 @@ void Init() {
     // If the archive didn't exist, create the files inside
     if (archive_result.Code().description == ErrorDescription::FS_NotFormatted) {
         // Format the archive to create the directories
-        Service::FS::FormatArchive(Service::FS::ArchiveIdCode::SystemSaveData, archive_path);
+        Service::FS::FormatArchive(Service::FS::ArchiveIdCode::SystemSaveData, FileSys::ArchiveFormatInfo(), archive_path);
 
         // Open it again to get a valid archive now that the folder exists
         archive_result = Service::FS::OpenArchive(Service::FS::ArchiveIdCode::SystemSaveData, archive_path);
diff --git a/src/core/hle/service/fs/archive.cpp b/src/core/hle/service/fs/archive.cpp
index d64b3656a..590697e76 100644
--- a/src/core/hle/service/fs/archive.cpp
+++ b/src/core/hle/service/fs/archive.cpp
@@ -103,7 +103,18 @@ ResultVal<bool> File::SyncRequest() {
             u32 address = cmd_buff[5];
             LOG_TRACE(Service_FS, "Read %s %s: offset=0x%llx length=%d address=0x%x",
                       GetTypeName().c_str(), GetName().c_str(), offset, length, address);
-            cmd_buff[2] = static_cast<u32>(backend->Read(offset, length, Memory::GetPointer(address)));
+
+            if (offset + length > backend->GetSize()) {
+                LOG_ERROR(Service_FS, "Reading from out of bounds offset=0x%llX length=0x%08X file_size=0x%llX",
+                          offset, length, backend->GetSize());
+            }
+
+            ResultVal<size_t> read = backend->Read(offset, length, Memory::GetPointer(address));
+            if (read.Failed()) {
+                cmd_buff[1] = read.Code().raw;
+                return read.Code();
+            }
+            cmd_buff[2] = static_cast<u32>(*read);
             break;
         }
 
@@ -116,7 +127,13 @@ ResultVal<bool> File::SyncRequest() {
             u32 address = cmd_buff[6];
             LOG_TRACE(Service_FS, "Write %s %s: offset=0x%llx length=%d address=0x%x, flush=0x%x",
                       GetTypeName().c_str(), GetName().c_str(), offset, length, address, flush);
-            cmd_buff[2] = static_cast<u32>(backend->Write(offset, length, flush != 0, Memory::GetPointer(address)));
+
+            ResultVal<size_t> written = backend->Write(offset, length, flush != 0, Memory::GetPointer(address));
+            if (written.Failed()) {
+                cmd_buff[1] = written.Code().raw;
+                return written.Code();
+            }
+            cmd_buff[2] = static_cast<u32>(*written);
             break;
         }
 
@@ -294,13 +311,11 @@ ResultVal<Kernel::SharedPtr<File>> OpenFileFromArchive(ArchiveHandle archive_han
     if (archive == nullptr)
         return ERR_INVALID_HANDLE;
 
-    std::unique_ptr<FileSys::FileBackend> backend = archive->OpenFile(path, mode);
-    if (backend == nullptr) {
-        return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS,
-                          ErrorSummary::NotFound, ErrorLevel::Status);
-    }
+    auto backend = archive->OpenFile(path, mode);
+    if (backend.Failed())
+        return backend.Code();
 
-    auto file = Kernel::SharedPtr<File>(new File(std::move(backend), path));
+    auto file = Kernel::SharedPtr<File>(new File(backend.MoveFrom(), path));
     return MakeResult<Kernel::SharedPtr<File>>(std::move(file));
 }
 
@@ -309,10 +324,7 @@ ResultCode DeleteFileFromArchive(ArchiveHandle archive_handle, const FileSys::Pa
     if (archive == nullptr)
         return ERR_INVALID_HANDLE;
 
-    if (archive->DeleteFile(path))
-        return RESULT_SUCCESS;
-    return ResultCode(ErrorDescription::NoData, ErrorModule::FS, // TODO: verify description
-                      ErrorSummary::Canceled, ErrorLevel::Status);
+    return archive->DeleteFile(path);
 }
 
 ResultCode RenameFileBetweenArchives(ArchiveHandle src_archive_handle, const FileSys::Path& src_path,
@@ -347,7 +359,7 @@ ResultCode DeleteDirectoryFromArchive(ArchiveHandle archive_handle, const FileSy
                       ErrorSummary::Canceled, ErrorLevel::Status);
 }
 
-ResultCode CreateFileInArchive(ArchiveHandle archive_handle, const FileSys::Path& path, u32 file_size) {
+ResultCode CreateFileInArchive(ArchiveHandle archive_handle, const FileSys::Path& path, u64 file_size) {
     ArchiveBackend* archive = GetArchive(archive_handle);
     if (archive == nullptr)
         return ERR_INVALID_HANDLE;
@@ -395,7 +407,7 @@ ResultVal<Kernel::SharedPtr<Directory>> OpenDirectoryFromArchive(ArchiveHandle a
 
     std::unique_ptr<FileSys::DirectoryBackend> backend = archive->OpenDirectory(path);
     if (backend == nullptr) {
-        return ResultCode(ErrorDescription::NotFound, ErrorModule::FS,
+        return ResultCode(ErrorDescription::FS_NotFound, ErrorModule::FS,
                           ErrorSummary::NotFound, ErrorLevel::Permanent);
     }
 
@@ -410,49 +422,45 @@ ResultVal<u64> GetFreeBytesInArchive(ArchiveHandle archive_handle) {
     return MakeResult<u64>(archive->GetFreeBytes());
 }
 
-ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::Path& path) {
+ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::ArchiveFormatInfo& format_info, const FileSys::Path& path) {
     auto archive_itr = id_code_map.find(id_code);
     if (archive_itr == id_code_map.end()) {
         return UnimplementedFunction(ErrorModule::FS); // TODO(Subv): Find the right error
     }
 
-    return archive_itr->second->Format(path);
+    return archive_itr->second->Format(path, format_info);
+}
+
+ResultVal<FileSys::ArchiveFormatInfo> GetArchiveFormatInfo(ArchiveIdCode id_code, FileSys::Path& archive_path) {
+    auto archive = id_code_map.find(id_code);
+    if (archive == id_code_map.end()) {
+        return UnimplementedFunction(ErrorModule::FS); // TODO(Subv): Find the right error
+    }
+
+    return archive->second->GetFormatInfo(archive_path);
 }
 
-ResultCode CreateExtSaveData(MediaType media_type, u32 high, u32 low, VAddr icon_buffer, u32 icon_size) {
+ResultCode CreateExtSaveData(MediaType media_type, u32 high, u32 low, VAddr icon_buffer, u32 icon_size, const FileSys::ArchiveFormatInfo& format_info) {
     // Construct the binary path to the archive first
     FileSys::Path path = FileSys::ConstructExtDataBinaryPath(static_cast<u32>(media_type), high, low);
 
-    std::string media_type_directory;
-    if (media_type == MediaType::NAND) {
-        media_type_directory = FileUtil::GetUserPath(D_NAND_IDX);
-    } else if (media_type == MediaType::SDMC) {
-        media_type_directory = FileUtil::GetUserPath(D_SDMC_IDX);
-    } else {
-        LOG_ERROR(Service_FS, "Unsupported media type %u", media_type);
-        return ResultCode(-1); // TODO(Subv): Find the right error code
+    auto archive = id_code_map.find(media_type == MediaType::NAND ? ArchiveIdCode::SharedExtSaveData : ArchiveIdCode::ExtSaveData);
+
+    if (archive == id_code_map.end()) {
+        return UnimplementedFunction(ErrorModule::FS); // TODO(Subv): Find the right error
     }
 
-    std::string base_path = FileSys::GetExtDataContainerPath(media_type_directory, media_type == MediaType::NAND);
-    std::string game_path = FileSys::GetExtSaveDataPath(base_path, path);
-    // These two folders are always created with the ExtSaveData
-    std::string user_path = game_path + "user/";
-    std::string boss_path = game_path + "boss/";
-    if (!FileUtil::CreateFullPath(user_path))
-        return ResultCode(-1); // TODO(Subv): Find the right error code
-    if (!FileUtil::CreateFullPath(boss_path))
-        return ResultCode(-1); // TODO(Subv): Find the right error code
+    auto ext_savedata = static_cast<FileSys::ArchiveFactory_ExtSaveData*>(archive->second.get());
+
+    ResultCode result = ext_savedata->Format(path, format_info);
+    if (result.IsError())
+        return result;
 
     u8* smdh_icon = Memory::GetPointer(icon_buffer);
     if (!smdh_icon)
         return ResultCode(-1); // TODO(Subv): Find the right error code
 
-    // Create the icon
-    FileUtil::IOFile icon_file(game_path + "icon", "wb+");
-    if (!icon_file.IsGood())
-        return ResultCode(-1); // TODO(Subv): Find the right error code
-
-    icon_file.WriteBytes(smdh_icon, icon_size);
+    ext_savedata->WriteIcon(path, smdh_icon, icon_size);
     return RESULT_SUCCESS;
 }
 
@@ -473,7 +481,7 @@ ResultCode DeleteExtSaveData(MediaType media_type, u32 high, u32 low) {
     // Delete all directories (/user, /boss) and the icon file.
     std::string base_path = FileSys::GetExtDataContainerPath(media_type_directory, media_type == MediaType::NAND);
     std::string extsavedata_path = FileSys::GetExtSaveDataPath(base_path, path);
-    if (!FileUtil::DeleteDirRecursively(extsavedata_path))
+    if (FileUtil::Exists(extsavedata_path) && !FileUtil::DeleteDirRecursively(extsavedata_path))
         return ResultCode(-1); // TODO(Subv): Find the right error code
     return RESULT_SUCCESS;
 }
diff --git a/src/core/hle/service/fs/archive.h b/src/core/hle/service/fs/archive.h
index 952deb4d4..006606740 100644
--- a/src/core/hle/service/fs/archive.h
+++ b/src/core/hle/service/fs/archive.h
@@ -136,7 +136,7 @@ ResultCode DeleteDirectoryFromArchive(ArchiveHandle archive_handle, const FileSy
  * @param file_size The size of the new file, filled with zeroes
  * @return File creation result code
  */
-ResultCode CreateFileInArchive(ArchiveHandle archive_handle, const FileSys::Path& path, u32 file_size);
+ResultCode CreateFileInArchive(ArchiveHandle archive_handle, const FileSys::Path& path, u64 file_size);
 
 /**
  * Create a Directory from an Archive
@@ -177,10 +177,20 @@ ResultVal<u64> GetFreeBytesInArchive(ArchiveHandle archive_handle);
  * Erases the contents of the physical folder that contains the archive
  * identified by the specified id code and path
  * @param id_code The id of the archive to format
+ * @param format_info Format information about the new archive
  * @param path The path to the archive, if relevant.
  * @return ResultCode 0 on success or the corresponding code on error
  */
-ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::Path& path = FileSys::Path());
+ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::ArchiveFormatInfo& format_info, const FileSys::Path& path = FileSys::Path());
+
+/**
+ * Retrieves the format info about the archive of the specified type and path.
+ * The format info is supplied by the client code when creating archives.
+ * @param id_code The id of the archive
+ * @param archive_path The path of the archive, if relevant
+ * @return The format info of the archive, or the corresponding error code if failed.
+ */
+ResultVal<FileSys::ArchiveFormatInfo> GetArchiveFormatInfo(ArchiveIdCode id_code, FileSys::Path& archive_path);
 
 /**
  * Creates a blank SharedExtSaveData archive for the specified extdata ID
@@ -189,9 +199,10 @@ ResultCode FormatArchive(ArchiveIdCode id_code, const FileSys::Path& path = File
  * @param low The low word of the extdata id to create
  * @param icon_buffer VAddr of the SMDH icon for this ExtSaveData
  * @param icon_size Size of the SMDH icon
+ * @param format_info Format information about the new archive
  * @return ResultCode 0 on success or the corresponding code on error
  */
-ResultCode CreateExtSaveData(MediaType media_type, u32 high, u32 low, VAddr icon_buffer, u32 icon_size);
+ResultCode CreateExtSaveData(MediaType media_type, u32 high, u32 low, VAddr icon_buffer, u32 icon_size, const FileSys::ArchiveFormatInfo& format_info);
 
 /**
  * Deletes the SharedExtSaveData archive for the specified extdata ID
diff --git a/src/core/hle/service/fs/fs_user.cpp b/src/core/hle/service/fs/fs_user.cpp
index e6c1f3616..3ec7ceb30 100644
--- a/src/core/hle/service/fs/fs_user.cpp
+++ b/src/core/hle/service/fs/fs_user.cpp
@@ -234,7 +234,7 @@ static void DeleteDirectory(Service::Interface* self) {
  *      3 : Archive handle upper word
  *      4 : File path string type
  *      5 : File path string size
- *      7 : File size (filled with zeroes)
+ *      7-8 : File size
  *      10: File path string data
  *  Outputs:
  *      1 : Result of function, 0 on success, otherwise error code
@@ -245,12 +245,12 @@ static void CreateFile(Service::Interface* self) {
     ArchiveHandle archive_handle = MakeArchiveHandle(cmd_buff[2], cmd_buff[3]);
     auto filename_type    = static_cast<FileSys::LowPathType>(cmd_buff[4]);
     u32 filename_size     = cmd_buff[5];
-    u32 file_size         = cmd_buff[7];
+    u64 file_size         = ((u64)cmd_buff[8] << 32) | cmd_buff[7];
     u32 filename_ptr      = cmd_buff[10];
 
     FileSys::Path file_path(filename_type, filename_size, filename_ptr);
 
-    LOG_DEBUG(Service_FS, "type=%d size=%d data=%s", filename_type, filename_size, file_path.DebugStr().c_str());
+    LOG_DEBUG(Service_FS, "type=%d size=%llu data=%s", filename_type, filename_size, file_path.DebugStr().c_str());
 
     cmd_buff[1] = CreateFileInArchive(archive_handle, file_path, file_size).raw;
 }
@@ -443,17 +443,22 @@ static void IsSdmcWriteable(Service::Interface* self) {
  *  Inputs:
  *      0  : 0x084C0242
  *      1  : Archive ID
- *      2  : Archive low path type
- *      3  : Archive low path size
- *      10 : (LowPathSize << 14) | 2
+ *      2  : Archive path type
+ *      3  : Archive path size
+ *      4  : Size in Blocks (1 block = 512 bytes)
+ *      5  : Number of directories
+ *      6  : Number of files
+ *      7  : Directory bucket count
+ *      8  : File bucket count
+ *      9  : Duplicate data
+ *      10 : (PathSize << 14) | 2
  *      11 : Archive low path
  *  Outputs:
  *      1 : Result of function, 0 on success, otherwise error code
  */
 static void FormatSaveData(Service::Interface* self) {
-    // TODO(Subv): Find out what the other inputs and outputs of this function are
     u32* cmd_buff = Kernel::GetCommandBuffer();
-    LOG_DEBUG(Service_FS, "(STUBBED)");
+    LOG_WARNING(Service_FS, "(STUBBED)");
 
     auto archive_id = static_cast<FS::ArchiveIdCode>(cmd_buff[1]);
     auto archivename_type = static_cast<FileSys::LowPathType>(cmd_buff[2]);
@@ -464,9 +469,9 @@ static void FormatSaveData(Service::Interface* self) {
     LOG_DEBUG(Service_FS, "archive_path=%s", archive_path.DebugStr().c_str());
 
     if (archive_id != FS::ArchiveIdCode::SaveData) {
-        // TODO(Subv): What should happen if somebody attempts to format a different archive?
-        LOG_ERROR(Service_FS, "tried to format an archive different than SaveData, %u", cmd_buff[1]);
-        cmd_buff[1] = UnimplementedFunction(ErrorModule::FS).raw;
+        LOG_ERROR(Service_FS, "tried to format an archive different than SaveData, %u", archive_id);
+        cmd_buff[1] = ResultCode(ErrorDescription::FS_InvalidPath, ErrorModule::FS,
+                                 ErrorSummary::InvalidArgument, ErrorLevel::Usage).raw;
         return;
     }
 
@@ -477,23 +482,40 @@ static void FormatSaveData(Service::Interface* self) {
         return;
     }
 
-    cmd_buff[1] = FormatArchive(ArchiveIdCode::SaveData).raw;
+    FileSys::ArchiveFormatInfo format_info;
+    format_info.duplicate_data = cmd_buff[9] & 0xFF;
+    format_info.number_directories = cmd_buff[5];
+    format_info.number_files = cmd_buff[6];
+    format_info.total_size = cmd_buff[4] * 512;
+
+    cmd_buff[1] = FormatArchive(ArchiveIdCode::SaveData, format_info).raw;
 }
 
 /**
  * FS_User::FormatThisUserSaveData service function
  *  Inputs:
  *      0: 0x080F0180
+ *      1  : Size in Blocks (1 block = 512 bytes)
+ *      2  : Number of directories
+ *      3  : Number of files
+ *      4  : Directory bucket count
+ *      5  : File bucket count
+ *      6  : Duplicate data
  *  Outputs:
  *      1 : Result of function, 0 on success, otherwise error code
  */
 static void FormatThisUserSaveData(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
-    LOG_DEBUG(Service_FS, "(STUBBED)");
 
-    // TODO(Subv): Find out what the inputs and outputs of this function are
+    FileSys::ArchiveFormatInfo format_info;
+    format_info.duplicate_data = cmd_buff[6] & 0xFF;
+    format_info.number_directories = cmd_buff[2];
+    format_info.number_files = cmd_buff[3];
+    format_info.total_size = cmd_buff[1] * 512;
 
-    cmd_buff[1] = FormatArchive(ArchiveIdCode::SaveData).raw;
+    cmd_buff[1] = FormatArchive(ArchiveIdCode::SaveData, format_info).raw;
+
+    LOG_TRACE(Service_FS, "called");
 }
 
 /**
@@ -531,10 +553,9 @@ static void GetFreeBytes(Service::Interface* self) {
  *      2 : Low word of the saveid to create
  *      3 : High word of the saveid to create
  *      4 : Unknown
- *      5 : Unknown
- *      6 : Unknown
- *      7 : Unknown
- *      8 : Unknown
+ *      5 : Number of directories
+ *      6 : Number of files
+ *      7-8 : Size limit
  *      9 : Size of the SMDH icon
  *      10: (SMDH Size << 4) | 0x0000000A
  *      11: Pointer to the SMDH icon for the new ExtSaveData
@@ -556,7 +577,12 @@ static void CreateExtSaveData(Service::Interface* self) {
             cmd_buff[3], cmd_buff[4], cmd_buff[5], cmd_buff[6], cmd_buff[7], cmd_buff[8], icon_size,
             cmd_buff[10], icon_buffer);
 
-    cmd_buff[1] = CreateExtSaveData(media_type, save_high, save_low, icon_buffer, icon_size).raw;
+    FileSys::ArchiveFormatInfo format_info;
+    format_info.number_directories = cmd_buff[5];
+    format_info.number_files = cmd_buff[6];
+    format_info.duplicate_data = false;
+    format_info.total_size = 0;
+    cmd_buff[1] = CreateExtSaveData(media_type, save_high, save_low, icon_buffer, icon_size, format_info).raw;
 }
 
 /**
@@ -731,6 +757,51 @@ static void GetArchiveResource(Service::Interface* self) {
     cmd_buff[5] = 0x80000; // 8GiB free
 }
 
+/**
+ * FS_User::GetFormatInfo service function.
+ *  Inputs:
+ *      0 : 0x084500C2
+ *      1 : Archive ID
+ *      2 : Archive path type
+ *      3 : Archive path size
+ *      4 : (PathSize << 14) | 2
+ *      5 : Archive low path
+ *  Outputs:
+ *      0 : 0x08450140
+ *      1 : Result of function, 0 on success, otherwise error code
+ *      2 : Total size
+ *      3 : Number of directories
+ *      4 : Number of files
+ *      5 : Duplicate data
+ */
+static void GetFormatInfo(Service::Interface* self) {
+    u32* cmd_buff = Kernel::GetCommandBuffer();
+
+    auto archive_id = static_cast<FS::ArchiveIdCode>(cmd_buff[1]);
+    auto archivename_type = static_cast<FileSys::LowPathType>(cmd_buff[2]);
+    u32 archivename_size = cmd_buff[3];
+    u32 archivename_ptr = cmd_buff[5];
+    FileSys::Path archive_path(archivename_type, archivename_size, archivename_ptr);
+
+    LOG_DEBUG(Service_FS, "archive_path=%s", archive_path.DebugStr().c_str());
+
+    cmd_buff[0] = IPC::MakeHeader(0x0845, 5, 0);
+
+    auto format_info = GetArchiveFormatInfo(archive_id, archive_path);
+
+    if (format_info.Failed()) {
+        LOG_ERROR(Service_FS, "Failed to retrieve the format info");
+        cmd_buff[1] = format_info.Code().raw;
+        return;
+    }
+
+    cmd_buff[1] = RESULT_SUCCESS.raw;
+    cmd_buff[2] = format_info->total_size;
+    cmd_buff[3] = format_info->number_directories;
+    cmd_buff[4] = format_info->number_files;
+    cmd_buff[5] = format_info->duplicate_data;
+}
+
 const Interface::FunctionInfo FunctionTable[] = {
     {0x000100C6, nullptr,                  "Dummy1"},
     {0x040100C4, nullptr,                  "Control"},
@@ -802,7 +873,7 @@ const Interface::FunctionInfo FunctionTable[] = {
     {0x08420040, nullptr,                  "DeleteAllExtSaveDataOnNand"},
     {0x08430000, nullptr,                  "InitializeCtrFileSystem"},
     {0x08440000, nullptr,                  "CreateSeed"},
-    {0x084500C2, nullptr,                  "GetFormatInfo"},
+    {0x084500C2, GetFormatInfo,            "GetFormatInfo"},
     {0x08460102, nullptr,                  "GetLegacyRomHeader2"},
     {0x08470180, nullptr,                  "FormatCtrCardUserSaveData"},
     {0x08480042, nullptr,                  "GetSdmcCtrRootPath"},
diff --git a/src/core/hle/service/ptm/ptm.cpp b/src/core/hle/service/ptm/ptm.cpp
index 6bdee4d9e..94f494690 100644
--- a/src/core/hle/service/ptm/ptm.cpp
+++ b/src/core/hle/service/ptm/ptm.cpp
@@ -103,7 +103,7 @@ void Init() {
     // If the archive didn't exist, create the files inside
     if (archive_result.Code().description == ErrorDescription::FS_NotFormatted) {
         // Format the archive to create the directories
-        Service::FS::FormatArchive(Service::FS::ArchiveIdCode::SharedExtSaveData, archive_path);
+        Service::FS::FormatArchive(Service::FS::ArchiveIdCode::SharedExtSaveData, FileSys::ArchiveFormatInfo(), archive_path);
         // Open it again to get a valid archive now that the folder exists
         archive_result = Service::FS::OpenArchive(Service::FS::ArchiveIdCode::SharedExtSaveData, archive_path);
         ASSERT_MSG(archive_result.Succeeded(), "Could not open the PTM SharedExtSaveData archive!");
diff --git a/src/core/hle/service/soc_u.cpp b/src/core/hle/service/soc_u.cpp
index b52e52d4a..ff0af8f12 100644
--- a/src/core/hle/service/soc_u.cpp
+++ b/src/core/hle/service/soc_u.cpp
@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <cstring>
 #include <unordered_map>
+#include <vector>
 
 #include "common/assert.h"
 #include "common/bit_field.h"
@@ -593,17 +594,13 @@ static void Poll(Service::Interface* self) {
 
     // The 3ds_pollfd and the pollfd structures may be different (Windows/Linux have different sizes)
     // so we have to copy the data
-    pollfd* platform_pollfd = new pollfd[nfds];
-    for (unsigned current_fds = 0; current_fds < nfds; ++current_fds)
-        platform_pollfd[current_fds] = CTRPollFD::ToPlatform(input_fds[current_fds]);
+    std::vector<pollfd> platform_pollfd(nfds);
+    std::transform(input_fds, input_fds + nfds, platform_pollfd.begin(), CTRPollFD::ToPlatform);
 
-    int ret = ::poll(platform_pollfd, nfds, timeout);
+    const int ret = ::poll(platform_pollfd.data(), nfds, timeout);
 
     // Now update the output pollfd structure
-    for (unsigned current_fds = 0; current_fds < nfds; ++current_fds)
-        output_fds[current_fds] = CTRPollFD::FromPlatform(platform_pollfd[current_fds]);
-
-    delete[] platform_pollfd;
+    std::transform(platform_pollfd.begin(), platform_pollfd.end(), output_fds, CTRPollFD::FromPlatform);
 
     int result = 0;
     if (ret == SOCKET_ERROR_VALUE)
diff --git a/src/core/loader/loader.h b/src/core/loader/loader.h
index a7f2715ba..84a4ce5fc 100644
--- a/src/core/loader/loader.h
+++ b/src/core/loader/loader.h
@@ -74,7 +74,7 @@ enum class ResultStatus {
     ErrorEncrypted,
 };
 
-static inline u32 MakeMagic(char a, char b, char c, char d) {
+constexpr u32 MakeMagic(char a, char b, char c, char d) {
     return a | b << 8 | c << 16 | d << 24;
 }
 
diff --git a/src/video_core/command_processor.cpp b/src/video_core/command_processor.cpp
index 4b59984ad..028b59348 100644
--- a/src/video_core/command_processor.cpp
+++ b/src/video_core/command_processor.cpp
@@ -75,12 +75,17 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
             GSP_GPU::SignalInterrupt(GSP_GPU::InterruptId::P3D);
             break;
 
+        case PICA_REG_INDEX_WORKAROUND(triangle_topology, 0x25E):
+            g_state.primitive_assembler.Reconfigure(regs.triangle_topology);
+            break;
+
+        case PICA_REG_INDEX_WORKAROUND(restart_primitive, 0x25F):
+            g_state.primitive_assembler.Reset();
+            break;
+
         case PICA_REG_INDEX_WORKAROUND(vs_default_attributes_setup.index, 0x232):
-            if (regs.vs_default_attributes_setup.index == 15) {
-                // Reset immediate primitive state
-                g_state.immediate.primitive_assembler.Reconfigure(regs.triangle_topology);
-                g_state.immediate.attribute_id = 0;
-            }
+            g_state.immediate.current_attribute = 0;
+            default_attr_counter = 0;
             break;
 
         // Load default vertex input attributes
@@ -105,7 +110,7 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
                     break;
                 }
 
-                Math::Vec4<float24>& attribute = g_state.vs.default_attributes[setup.index];
+                Math::Vec4<float24> attribute;
 
                 // NOTE: The destination component order indeed is "backwards"
                 attribute.w = float24::FromRaw(default_attr_write_buffer[0] >> 8);
@@ -119,26 +124,29 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
 
                 // TODO: Verify that this actually modifies the register!
                 if (setup.index < 15) {
+                    g_state.vs.default_attributes[setup.index] = attribute;
                     setup.index++;
                 } else {
                     // Put each attribute into an immediate input buffer.
                     // When all specified immediate attributes are present, the Vertex Shader is invoked and everything is
                     // sent to the primitive assembler.
 
-                    auto& immediate_input = g_state.immediate.input;
-                    auto& immediate_attribute_id = g_state.immediate.attribute_id;
-                    const auto& attribute_config = regs.vertex_attributes;
+                    auto& immediate_input = g_state.immediate.input_vertex;
+                    auto& immediate_attribute_id = g_state.immediate.current_attribute;
 
                     immediate_input.attr[immediate_attribute_id++] = attribute;
 
-                    if (immediate_attribute_id >= attribute_config.GetNumTotalAttributes()) {
+                    if (immediate_attribute_id >= regs.vs.num_input_attributes+1) {
                         immediate_attribute_id = 0;
 
                         Shader::UnitState<false> shader_unit;
                         Shader::Setup(shader_unit);
 
+                        if (g_debug_context)
+                            g_debug_context->OnEvent(DebugContext::Event::VertexLoaded, static_cast<void*>(&immediate_input));
+
                         // Send to vertex shader
-                        Shader::OutputVertex output = Shader::Run(shader_unit, immediate_input, attribute_config.GetNumTotalAttributes());
+                        Shader::OutputVertex output = Shader::Run(shader_unit, immediate_input, regs.vs.num_input_attributes+1);
 
                         // Send to renderer
                         using Pica::Shader::OutputVertex;
@@ -146,7 +154,7 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
                             VideoCore::g_renderer->Rasterizer()->AddTriangle(v0, v1, v2);
                         };
 
-                        g_state.immediate.primitive_assembler.SubmitVertex(output, AddTriangle);
+                        g_state.primitive_assembler.SubmitVertex(output, AddTriangle);
                     }
                 }
             }
@@ -154,9 +162,13 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
         }
 
         case PICA_REG_INDEX(gpu_mode):
-            if (regs.gpu_mode == Regs::GPUMode::Configuring && regs.vs_default_attributes_setup.index == 15) {
+            if (regs.gpu_mode == Regs::GPUMode::Configuring) {
                 // Draw immediate mode triangles when GPU Mode is set to GPUMode::Configuring
                 VideoCore::g_renderer->Rasterizer()->DrawTriangles();
+
+                if (g_debug_context) {
+                    g_debug_context->OnEvent(DebugContext::Event::FinishedPrimitiveBatch, nullptr);
+                }
             }
             break;
 
@@ -241,7 +253,7 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
             DebugUtils::GeometryDumper geometry_dumper;
             PrimitiveAssembler<DebugUtils::GeometryDumper::Vertex> dumping_primitive_assembler(regs.triangle_topology.Value());
 #endif
-            PrimitiveAssembler<Shader::OutputVertex> primitive_assembler(regs.triangle_topology.Value());
+            PrimitiveAssembler<Shader::OutputVertex>& primitive_assembler = g_state.primitive_assembler;
 
             if (g_debug_context) {
                 for (int i = 0; i < 3; ++i) {
@@ -412,16 +424,10 @@ static void WritePicaReg(u32 id, u32 value, u32 mask) {
                                                           range.second, range.first);
             }
 
-            VideoCore::g_renderer->Rasterizer()->DrawTriangles();
-
 #if PICA_DUMP_GEOMETRY
             geometry_dumper.Dump();
 #endif
 
-            if (g_debug_context) {
-                g_debug_context->OnEvent(DebugContext::Event::FinishedPrimitiveBatch, nullptr);
-            }
-
             break;
         }
 
diff --git a/src/video_core/pica.cpp b/src/video_core/pica.cpp
index 32ad72674..ccbaf071b 100644
--- a/src/video_core/pica.cpp
+++ b/src/video_core/pica.cpp
@@ -493,12 +493,25 @@ std::string Regs::GetCommandName(int index) {
 }
 
 void Init() {
+    g_state.Reset();
 }
 
 void Shutdown() {
     Shader::Shutdown();
+}
+
+template <typename T>
+void Zero(T& o) {
+    memset(&o, 0, sizeof(o));
+}
 
-    memset(&g_state, 0, sizeof(State));
+void State::Reset() {
+    Zero(regs);
+    Zero(vs);
+    Zero(gs);
+    Zero(cmd_list);
+    Zero(immediate);
+    primitive_assembler.Reconfigure(Regs::TriangleTopology::List);
 }
 
 }
diff --git a/src/video_core/pica.h b/src/video_core/pica.h
index 337cff8ce..16f9e4006 100644
--- a/src/video_core/pica.h
+++ b/src/video_core/pica.h
@@ -71,7 +71,7 @@ struct Regs {
     BitField<0, 24, u32> viewport_depth_range; // float24
     BitField<0, 24, u32> viewport_depth_far_plane; // float24
 
-    INSERT_PADDING_WORDS(0x1);
+    BitField<0, 3, u32> vs_output_total;
 
     union VSOutputAttributes {
         // Maps components of output vertex attributes to semantics
@@ -1123,7 +1123,12 @@ struct Regs {
             BitField<24, 8, u32> w;
         } int_uniforms[4];
 
-        INSERT_PADDING_WORDS(0x5);
+        INSERT_PADDING_WORDS(0x4);
+
+        union {
+            // Number of input attributes to shader unit - 1
+            BitField<0, 4, u32> num_input_attributes;
+        };
 
         // Offset to shader program entry point (in words)
         BitField<0, 16, u32> main_offset;
@@ -1157,8 +1162,10 @@ struct Regs {
             }
         } input_register_map;
 
-        // OUTMAP_MASK, 0x28E, CODETRANSFER_END
-        INSERT_PADDING_WORDS(0x3);
+        BitField<0, 16, u32> output_mask;
+
+        // 0x28E, CODETRANSFER_END
+        INSERT_PADDING_WORDS(0x2);
 
         struct {
             enum Format : u32
diff --git a/src/video_core/pica_state.h b/src/video_core/pica_state.h
index c7616bc55..323290054 100644
--- a/src/video_core/pica_state.h
+++ b/src/video_core/pica_state.h
@@ -12,6 +12,8 @@ namespace Pica {
 
 /// Struct used to describe current Pica state
 struct State {
+    void Reset();
+
     /// Pica registers
     Regs regs;
 
@@ -46,13 +48,14 @@ struct State {
 
     /// Struct used to describe immediate mode rendering state
     struct ImmediateModeState {
-        Shader::InputVertex input;
-        // This is constructed with a dummy triangle topology
-        PrimitiveAssembler<Shader::OutputVertex> primitive_assembler;
-        int attribute_id = 0;
-
-        ImmediateModeState() : primitive_assembler(Regs::TriangleTopology::List) {}
+        // Used to buffer partial vertices for immediate-mode rendering.
+        Shader::InputVertex input_vertex;
+        // Index of the next attribute to be loaded into `input_vertex`.
+        int current_attribute = 0;
     } immediate;
+
+    // This is constructed with a dummy triangle topology
+    PrimitiveAssembler<Shader::OutputVertex> primitive_assembler;
 };
 
 extern State g_state; ///< Current Pica state
diff --git a/src/video_core/primitive_assembly.h b/src/video_core/primitive_assembly.h
index cc6e5fde5..9396b4c85 100644
--- a/src/video_core/primitive_assembly.h
+++ b/src/video_core/primitive_assembly.h
@@ -20,7 +20,7 @@ struct PrimitiveAssembler {
                                                VertexType& v1,
                                                VertexType& v2)>;
 
-    PrimitiveAssembler(Regs::TriangleTopology topology);
+    PrimitiveAssembler(Regs::TriangleTopology topology = Regs::TriangleTopology::List);
 
     /*
      * Queues a vertex, builds primitives from the vertex queue according to the given
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index b3dc6aa19..1fadcf5ae 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -190,6 +190,9 @@ void RasterizerOpenGL::AddTriangle(const Pica::Shader::OutputVertex& v0,
 }
 
 void RasterizerOpenGL::DrawTriangles() {
+    if (vertex_batch.empty())
+        return;
+
     SyncFramebuffer();
     SyncDrawState();
 
diff --git a/src/video_core/shader/shader.cpp b/src/video_core/shader/shader.cpp
index 509558fc0..eb1db0778 100644
--- a/src/video_core/shader/shader.cpp
+++ b/src/video_core/shader/shader.cpp
@@ -121,15 +121,23 @@ OutputVertex Run(UnitState<false>& state, const InputVertex& input, int num_attr
     OutputVertex ret;
     // TODO(neobrain): Under some circumstances, up to 16 attributes may be output. We need to
     // figure out what those circumstances are and enable the remaining outputs then.
-    for (int i = 0; i < 7; ++i) {
-        const auto& output_register_map = g_state.regs.vs_output_attributes[i]; // TODO: Don't hardcode VS here
+    unsigned index = 0;
+    for (unsigned i = 0; i < 7; ++i) {
+
+        if (index >= g_state.regs.vs_output_total)
+            break;
+
+        if ((g_state.regs.vs.output_mask & (1 << i)) == 0)
+            continue;
+
+        const auto& output_register_map = g_state.regs.vs_output_attributes[index]; // TODO: Don't hardcode VS here
 
         u32 semantics[4] = {
             output_register_map.map_x, output_register_map.map_y,
             output_register_map.map_z, output_register_map.map_w
         };
 
-        for (int comp = 0; comp < 4; ++comp) {
+        for (unsigned comp = 0; comp < 4; ++comp) {
             float24* out = ((float24*)&ret) + semantics[comp];
             if (semantics[comp] != Regs::VSOutputAttributes::INVALID) {
                 *out = state.registers.output[i][comp];
@@ -139,10 +147,12 @@ OutputVertex Run(UnitState<false>& state, const InputVertex& input, int num_attr
                 memset(out, 0, sizeof(*out));
             }
         }
+
+        index++;
     }
 
     // The hardware takes the absolute and saturates vertex colors like this, *before* doing interpolation
-    for (int i = 0; i < 4; ++i) {
+    for (unsigned i = 0; i < 4; ++i) {
         ret.color[i] = float24::FromFloat32(
             std::fmin(std::fabs(ret.color[i].ToFloat32()), 1.0f));
     }
diff --git a/src/video_core/shader/shader_interpreter.cpp b/src/video_core/shader/shader_interpreter.cpp
index 02e1a1cb1..9b978583e 100644
--- a/src/video_core/shader/shader_interpreter.cpp
+++ b/src/video_core/shader/shader_interpreter.cpp
@@ -2,10 +2,10 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <common/file_util.h>
-
+#include <numeric>
 #include <nihstro/shader_bytecode.h>
 
+#include "common/file_util.h"
 #include "video_core/pica.h"
 #include "video_core/pica_state.h"
 #include "video_core/shader/shader.h"
@@ -214,10 +214,8 @@ void RunInterpreter(UnitState<Debug>& state) {
                 if (opcode == OpCode::Id::DPH || opcode == OpCode::Id::DPHI)
                     src1[3] = float24::FromFloat32(1.0f);
 
-                float24 dot = float24::FromFloat32(0.f);
                 int num_components = (opcode == OpCode::Id::DP3) ? 3 : 4;
-                for (int i = 0; i < num_components; ++i)
-                    dot = dot + src1[i] * src2[i];
+                float24 dot = std::inner_product(src1, src1 + num_components, src2, float24::FromFloat32(0.f));
 
                 for (int i = 0; i < 4; ++i) {
                     if (!swizzle.DestComponentEnabled(i))