From b04e39107fd947d59b76214747a81b8cb6fe92a8 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 28 Oct 2018 14:55:32 -0400
Subject: [PATCH 1/6] control_metadata: Add GetRawBytes function to NACP
 Returns the raw bytes of the NACP file. Needed for GetApplicationControlData
 which returns the raw, unprocessed NACP to the game.

---
 src/core/file_sys/control_metadata.cpp | 6 ++++++
 src/core/file_sys/control_metadata.h   | 1 +
 2 files changed, 7 insertions(+)

diff --git a/src/core/file_sys/control_metadata.cpp b/src/core/file_sys/control_metadata.cpp
index a012c2be93..c8fa912bf8 100644
--- a/src/core/file_sys/control_metadata.cpp
+++ b/src/core/file_sys/control_metadata.cpp
@@ -66,4 +66,10 @@ std::string NACP::GetVersionString() const {
     return Common::StringFromFixedZeroTerminatedBuffer(raw->version_string.data(),
                                                        raw->version_string.size());
 }
+
+std::vector<u8> NACP::GetRawBytes() const {
+    std::vector<u8> out(sizeof(RawNACP));
+    std::memcpy(out.data(), raw.get(), sizeof(RawNACP));
+    return out;
+}
 } // namespace FileSys
diff --git a/src/core/file_sys/control_metadata.h b/src/core/file_sys/control_metadata.h
index 141f7e056b..bfaad46b41 100644
--- a/src/core/file_sys/control_metadata.h
+++ b/src/core/file_sys/control_metadata.h
@@ -81,6 +81,7 @@ public:
     u64 GetTitleId() const;
     u64 GetDLCBaseTitleId() const;
     std::string GetVersionString() const;
+    std::vector<u8> GetRawBytes() const;
 
 private:
     std::unique_ptr<RawNACP> raw;

From f2f679bf3f823592aa9d13294e76c24c47288305 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 28 Oct 2018 14:56:12 -0400
Subject: [PATCH 2/6] loader/nro: Call RegisterRomFS from Load Allows NRO
 homebrew to use the RomFS in the ASET section.

---
 src/core/loader/nro.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/loader/nro.cpp b/src/core/loader/nro.cpp
index bc8e402a80..c8e491fec4 100644
--- a/src/core/loader/nro.cpp
+++ b/src/core/loader/nro.cpp
@@ -12,10 +12,12 @@
 #include "common/swap.h"
 #include "core/core.h"
 #include "core/file_sys/control_metadata.h"
+#include "core/file_sys/romfs_factory.h"
 #include "core/file_sys/vfs_offset.h"
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/vm_manager.h"
+#include "core/hle/service/filesystem/filesystem.h"
 #include "core/loader/nro.h"
 #include "core/loader/nso.h"
 #include "core/memory.h"
@@ -208,6 +210,9 @@ ResultStatus AppLoader_NRO::Load(Kernel::Process& process) {
         return ResultStatus::ErrorLoadingNRO;
     }
 
+    if (romfs != nullptr)
+        Service::FileSystem::RegisterRomFS(std::make_unique<FileSys::RomFSFactory>(*this));
+
     process.Run(base_address, Kernel::THREADPRIO_DEFAULT, Memory::DEFAULT_STACK_SIZE);
 
     is_loaded = true;

From df264d2ccb39a4d7ffd4efd3158e66db3aa6952a Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 28 Oct 2018 14:56:43 -0400
Subject: [PATCH 3/6] savedata_factory: Expose accessors for SaveDataSpace

---
 src/core/file_sys/savedata_factory.cpp        | 34 +++++++++++--------
 src/core/file_sys/savedata_factory.h          |  3 ++
 .../hle/service/filesystem/filesystem.cpp     | 10 ++++++
 src/core/hle/service/filesystem/filesystem.h  |  1 +
 4 files changed, 33 insertions(+), 15 deletions(-)

diff --git a/src/core/file_sys/savedata_factory.cpp b/src/core/file_sys/savedata_factory.cpp
index ef1aaebbb0..1ec54c78f1 100644
--- a/src/core/file_sys/savedata_factory.cpp
+++ b/src/core/file_sys/savedata_factory.cpp
@@ -83,6 +83,24 @@ ResultVal<VirtualDir> SaveDataFactory::Open(SaveDataSpaceId space, SaveDataDescr
     return MakeResult<VirtualDir>(std::move(out));
 }
 
+VirtualDir SaveDataFactory::GetSaveDataSpaceDirectory(SaveDataSpaceId space) {
+    return dir->GetDirectoryRelative(GetSaveDataSpaceIdPath(space));
+}
+
+std::string SaveDataFactory::GetSaveDataSpaceIdPath(SaveDataSpaceId space) {
+    switch (space) {
+    case SaveDataSpaceId::NandSystem:
+        return "/system/";
+    case SaveDataSpaceId::NandUser:
+        return "/user/";
+    case SaveDataSpaceId::TemporaryStorage:
+        return "/temp/";
+    default:
+        ASSERT_MSG(false, "Unrecognized SaveDataSpaceId: {:02X}", static_cast<u8>(space));
+        return "/unrecognized/"; ///< To prevent corruption when ignoring asserts.
+    }
+}
+
 std::string SaveDataFactory::GetFullPath(SaveDataSpaceId space, SaveDataType type, u64 title_id,
                                          u128 user_id, u64 save_id) {
     // According to switchbrew, if a save is of type SaveData and the title id field is 0, it should
@@ -90,21 +108,7 @@ std::string SaveDataFactory::GetFullPath(SaveDataSpaceId space, SaveDataType typ
     if (type == SaveDataType::SaveData && title_id == 0)
         title_id = Core::CurrentProcess()->GetTitleID();
 
-    std::string out;
-
-    switch (space) {
-    case SaveDataSpaceId::NandSystem:
-        out = "/system/";
-        break;
-    case SaveDataSpaceId::NandUser:
-        out = "/user/";
-        break;
-    case SaveDataSpaceId::TemporaryStorage:
-        out = "/temp/";
-        break;
-    default:
-        ASSERT_MSG(false, "Unrecognized SaveDataSpaceId: {:02X}", static_cast<u8>(space));
-    }
+    std::string out = GetSaveDataSpaceIdPath(space);
 
     switch (type) {
     case SaveDataType::SystemSaveData:
diff --git a/src/core/file_sys/savedata_factory.h b/src/core/file_sys/savedata_factory.h
index d69ef6741c..024a305d33 100644
--- a/src/core/file_sys/savedata_factory.h
+++ b/src/core/file_sys/savedata_factory.h
@@ -52,6 +52,9 @@ public:
 
     ResultVal<VirtualDir> Open(SaveDataSpaceId space, SaveDataDescriptor meta);
 
+    VirtualDir GetSaveDataSpaceDirectory(SaveDataSpaceId space);
+
+    static std::string GetSaveDataSpaceIdPath(SaveDataSpaceId space);
     static std::string GetFullPath(SaveDataSpaceId space, SaveDataType type, u64 title_id,
                                    u128 user_id, u64 save_id);
 
diff --git a/src/core/hle/service/filesystem/filesystem.cpp b/src/core/hle/service/filesystem/filesystem.cpp
index e32a7c48e2..ea8fd965a4 100644
--- a/src/core/hle/service/filesystem/filesystem.cpp
+++ b/src/core/hle/service/filesystem/filesystem.cpp
@@ -309,6 +309,16 @@ ResultVal<FileSys::VirtualDir> OpenSaveData(FileSys::SaveDataSpaceId space,
     return save_data_factory->Open(space, save_struct);
 }
 
+ResultVal<FileSys::VirtualDir> OpenSaveDataSpace(FileSys::SaveDataSpaceId space) {
+    LOG_TRACE(Service_FS, "Opening Save Data Space for space_id={:01X}", static_cast<u8>(space));
+
+    if (save_data_factory == nullptr) {
+        return ResultCode(ErrorModule::FS, FileSys::ErrCodes::TitleNotFound);
+    }
+
+    return MakeResult(save_data_factory->GetSaveDataSpaceDirectory(space));
+}
+
 ResultVal<FileSys::VirtualDir> OpenSDMC() {
     LOG_TRACE(Service_FS, "Opening SDMC");
 
diff --git a/src/core/hle/service/filesystem/filesystem.h b/src/core/hle/service/filesystem/filesystem.h
index 6ca5c56369..2cbb70c87c 100644
--- a/src/core/hle/service/filesystem/filesystem.h
+++ b/src/core/hle/service/filesystem/filesystem.h
@@ -45,6 +45,7 @@ ResultVal<FileSys::VirtualFile> OpenRomFS(u64 title_id, FileSys::StorageId stora
                                           FileSys::ContentRecordType type);
 ResultVal<FileSys::VirtualDir> OpenSaveData(FileSys::SaveDataSpaceId space,
                                             FileSys::SaveDataDescriptor save_struct);
+ResultVal<FileSys::VirtualDir> OpenSaveDataSpace(FileSys::SaveDataSpaceId space);
 ResultVal<FileSys::VirtualDir> OpenSDMC();
 
 std::unique_ptr<FileSys::RegisteredCacheUnion> GetUnionContents();

From 2e8177f0c93768e1d1a7d6a830e9c68111c2afd6 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 28 Oct 2018 14:58:09 -0400
Subject: [PATCH 4/6] fsp_srv: Implement command 61:
 OpenSaveDataInfoReaderBySaveDataSpaceId Needed by Checkpoint. Returns an
 object that can iterate through all savedata on the system.

---
 src/core/hle/service/filesystem/fsp_srv.cpp | 13 ++++++++++++-
 src/core/hle/service/filesystem/fsp_srv.h   |  1 +
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index c1c83a11d7..56102a3db2 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -452,6 +452,7 @@ private:
 };
 
 FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
+    // clang-format off
     static const FunctionInfo functions[] = {
         {0, nullptr, "MountContent"},
         {1, &FSP_SRV::Initialize, "Initialize"},
@@ -485,7 +486,7 @@ FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
         {58, nullptr, "ReadSaveDataFileSystemExtraData"},
         {59, nullptr, "WriteSaveDataFileSystemExtraData"},
         {60, nullptr, "OpenSaveDataInfoReader"},
-        {61, nullptr, "OpenSaveDataInfoReaderBySaveDataSpaceId"},
+        {61, &FSP_SRV::OpenSaveDataInfoReaderBySaveDataSpaceId, "OpenSaveDataInfoReaderBySaveDataSpaceId"},
         {62, nullptr, "OpenCacheStorageList"},
         {64, nullptr, "OpenSaveDataInternalStorageFileSystem"},
         {65, nullptr, "UpdateSaveDataMacForDebug"},
@@ -544,6 +545,7 @@ FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
         {1009, nullptr, "GetAndClearMemoryReportInfo"},
         {1100, nullptr, "OverrideSaveDataTransferTokenSignVerificationKey"},
     };
+    // clang-format on
     RegisterHandlers(functions);
 }
 
@@ -618,6 +620,15 @@ void FSP_SRV::OpenReadOnlySaveDataFileSystem(Kernel::HLERequestContext& ctx) {
     MountSaveData(ctx);
 }
 
+void FSP_SRV::OpenSaveDataInfoReaderBySaveDataSpaceId(Kernel::HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    const auto space = rp.PopRaw<FileSys::SaveDataSpaceId>();
+
+    IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushIpcInterface<ISaveDataInfoReader>(std::make_shared<ISaveDataInfoReader>(space));
+}
+
 void FSP_SRV::GetGlobalAccessLogMode(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_FS, "(STUBBED) called");
 
diff --git a/src/core/hle/service/filesystem/fsp_srv.h b/src/core/hle/service/filesystem/fsp_srv.h
index 4aa0358cb6..e7abec0a32 100644
--- a/src/core/hle/service/filesystem/fsp_srv.h
+++ b/src/core/hle/service/filesystem/fsp_srv.h
@@ -25,6 +25,7 @@ private:
     void CreateSaveData(Kernel::HLERequestContext& ctx);
     void MountSaveData(Kernel::HLERequestContext& ctx);
     void OpenReadOnlySaveDataFileSystem(Kernel::HLERequestContext& ctx);
+    void OpenSaveDataInfoReaderBySaveDataSpaceId(Kernel::HLERequestContext& ctx);
     void GetGlobalAccessLogMode(Kernel::HLERequestContext& ctx);
     void OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx);
     void OpenDataStorageByDataId(Kernel::HLERequestContext& ctx);

From 5ee19add1bf221bd5259e4df76089252f04ce060 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sun, 28 Oct 2018 14:59:17 -0400
Subject: [PATCH 5/6] fsp_srv: Implement ISaveDataInfoReader An object to read
 SaveDataInfo objects, which describe a unique save on the system. This
 implementation iterates through all the directories in the save data space
 and uses the paths to reconstruct the metadata.

---
 src/core/hle/service/filesystem/fsp_srv.cpp | 144 ++++++++++++++++++++
 1 file changed, 144 insertions(+)

diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 56102a3db2..3d1c2ecda9 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -11,6 +11,7 @@
 
 #include "common/assert.h"
 #include "common/common_types.h"
+#include "common/hex_util.h"
 #include "common/logging/log.h"
 #include "common/string_util.h"
 #include "core/file_sys/directory.h"
@@ -451,6 +452,149 @@ private:
     VfsDirectoryServiceWrapper backend;
 };
 
+class ISaveDataInfoReader final : public ServiceFramework<ISaveDataInfoReader> {
+public:
+    explicit ISaveDataInfoReader(FileSys::SaveDataSpaceId space)
+        : ServiceFramework("ISaveDataInfoReader") {
+        static const FunctionInfo functions[] = {
+            {0, &ISaveDataInfoReader::ReadSaveDataInfo, "ReadSaveDataInfo"},
+        };
+        RegisterHandlers(functions);
+
+        FindAllSaves(space);
+    }
+
+    void ReadSaveDataInfo(Kernel::HLERequestContext& ctx) {
+        // Calculate how many entries we can fit in the output buffer
+        const u64 count_entries = ctx.GetWriteBufferSize() / sizeof(SaveDataInfo);
+
+        // Cap at total number of entries.
+        const u64 actual_entries = std::min(count_entries, info.size() - next_entry_index);
+
+        // Determine data start and end
+        const auto* begin = reinterpret_cast<u8*>(info.data() + next_entry_index);
+        const auto* end = reinterpret_cast<u8*>(info.data() + next_entry_index + actual_entries);
+        const auto range_size = static_cast<std::size_t>(std::distance(begin, end));
+
+        next_entry_index += actual_entries;
+
+        // Write the data to memory
+        ctx.WriteBuffer(begin, range_size);
+
+        IPC::ResponseBuilder rb{ctx, 4};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push(actual_entries);
+    }
+
+private:
+    static u64 stoull_be(std::string_view str) {
+        if (str.size() != 16)
+            return 0;
+
+        const auto bytes = Common::HexStringToArray<0x8>(str);
+        u64 out{};
+        std::memcpy(&out, bytes.data(), sizeof(u64));
+
+        return Common::swap64(out);
+    }
+
+    static std::array<u8, 0x10> ArraySwap(const std::array<u8, 0x10>& in) {
+        std::array<u8, 0x10> out;
+        for (std::size_t i = 0; i < in.size(); ++i) {
+            out[0xF - i] = in[i];
+        }
+
+        return out;
+    }
+
+    void FindAllSaves(FileSys::SaveDataSpaceId space) {
+        const auto save_root = OpenSaveDataSpace(space);
+        ASSERT(save_root.Succeeded());
+
+        for (const auto& type : (*save_root)->GetSubdirectories()) {
+            if (type->GetName() == "save") {
+                for (const auto& save_id : type->GetSubdirectories()) {
+                    for (const auto& user_id : save_id->GetSubdirectories()) {
+                        const auto save_id_numeric = stoull_be(save_id->GetName());
+                        const auto user_id_numeric =
+                            ArraySwap(Common::HexStringToArray<0x10>(user_id->GetName()));
+                        if (save_id_numeric != 0) {
+                            // System Save Data
+                            info.emplace_back(SaveDataInfo{
+                                0,
+                                space,
+                                FileSys::SaveDataType::SystemSaveData,
+                                {},
+                                user_id_numeric,
+                                save_id_numeric,
+                                0,
+                                user_id->GetSize(),
+                                {},
+                            });
+
+                            continue;
+                        }
+
+                        for (const auto& title_id : user_id->GetSubdirectories()) {
+                            const auto device =
+                                std::all_of(user_id_numeric.begin(), user_id_numeric.end(),
+                                            [](u8 val) { return val == 0; });
+                            info.emplace_back(SaveDataInfo{
+                                0,
+                                space,
+                                device ? FileSys::SaveDataType::DeviceSaveData
+                                       : FileSys::SaveDataType::SaveData,
+                                {},
+                                user_id_numeric,
+                                save_id_numeric,
+                                stoull_be(title_id->GetName()),
+                                title_id->GetSize(),
+                                {},
+                            });
+                        }
+                    }
+                }
+            } else if (space == FileSys::SaveDataSpaceId::TemporaryStorage) {
+                // Temporary Storage
+                for (const auto& user_id : type->GetSubdirectories()) {
+                    for (const auto& title_id : user_id->GetSubdirectories()) {
+                        if (!title_id->GetFiles().empty() ||
+                            !title_id->GetSubdirectories().empty()) {
+                            info.emplace_back(SaveDataInfo{
+                                0,
+                                space,
+                                FileSys::SaveDataType::TemporaryStorage,
+                                {},
+                                Common::HexStringToArray<0x10, true>(user_id->GetName()),
+                                stoull_be(type->GetName()),
+                                stoull_be(title_id->GetName()),
+                                title_id->GetSize(),
+                                {},
+                            });
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    struct SaveDataInfo {
+        u64_le save_id_unknown;
+        FileSys::SaveDataSpaceId space;
+        FileSys::SaveDataType type;
+        INSERT_PADDING_BYTES(0x6);
+        std::array<u8, 0x10> user_id;
+        u64_le save_id;
+        u64_le title_id;
+        u64_le save_image_size;
+        INSERT_PADDING_BYTES(0x28);
+    };
+    static_assert(sizeof(SaveDataInfo) == 0x60, "SaveDataInfo has incorrect size.");
+
+    std::vector<SaveDataInfo> info;
+    u64 next_entry_index = 0;
+};
+
 FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
     // clang-format off
     static const FunctionInfo functions[] = {

From bdaa76c0dbcf6811ae83bbca61ae103e06e93c27 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Mon, 29 Oct 2018 16:20:10 -0400
Subject: [PATCH 6/6] ns: Implement command 400: GetApplicationControlData

Returns the raw NACP bytes and the raw icon bytes into a title-provided buffer. Pulls from Registration Cache for control data, returning all zeros should it not exist.
---
 src/core/file_sys/savedata_factory.cpp      |  2 +-
 src/core/file_sys/savedata_factory.h        |  2 +-
 src/core/hle/service/filesystem/fsp_srv.cpp | 24 ++++----
 src/core/hle/service/ns/ns.cpp              | 64 ++++++++++++++++++++-
 4 files changed, 75 insertions(+), 17 deletions(-)

diff --git a/src/core/file_sys/savedata_factory.cpp b/src/core/file_sys/savedata_factory.cpp
index 1ec54c78f1..5434f21491 100644
--- a/src/core/file_sys/savedata_factory.cpp
+++ b/src/core/file_sys/savedata_factory.cpp
@@ -83,7 +83,7 @@ ResultVal<VirtualDir> SaveDataFactory::Open(SaveDataSpaceId space, SaveDataDescr
     return MakeResult<VirtualDir>(std::move(out));
 }
 
-VirtualDir SaveDataFactory::GetSaveDataSpaceDirectory(SaveDataSpaceId space) {
+VirtualDir SaveDataFactory::GetSaveDataSpaceDirectory(SaveDataSpaceId space) const {
     return dir->GetDirectoryRelative(GetSaveDataSpaceIdPath(space));
 }
 
diff --git a/src/core/file_sys/savedata_factory.h b/src/core/file_sys/savedata_factory.h
index 024a305d33..2a00880406 100644
--- a/src/core/file_sys/savedata_factory.h
+++ b/src/core/file_sys/savedata_factory.h
@@ -52,7 +52,7 @@ public:
 
     ResultVal<VirtualDir> Open(SaveDataSpaceId space, SaveDataDescriptor meta);
 
-    VirtualDir GetSaveDataSpaceDirectory(SaveDataSpaceId space);
+    VirtualDir GetSaveDataSpaceDirectory(SaveDataSpaceId space) const;
 
     static std::string GetSaveDataSpaceIdPath(SaveDataSpaceId space);
     static std::string GetFullPath(SaveDataSpaceId space, SaveDataType type, u64 title_id,
diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 3d1c2ecda9..b9a1d5105e 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -481,9 +481,9 @@ public:
         // Write the data to memory
         ctx.WriteBuffer(begin, range_size);
 
-        IPC::ResponseBuilder rb{ctx, 4};
+        IPC::ResponseBuilder rb{ctx, 3};
         rb.Push(RESULT_SUCCESS);
-        rb.Push(actual_entries);
+        rb.Push<u32>(static_cast<u32>(actual_entries));
     }
 
 private:
@@ -498,15 +498,6 @@ private:
         return Common::swap64(out);
     }
 
-    static std::array<u8, 0x10> ArraySwap(const std::array<u8, 0x10>& in) {
-        std::array<u8, 0x10> out;
-        for (std::size_t i = 0; i < in.size(); ++i) {
-            out[0xF - i] = in[i];
-        }
-
-        return out;
-    }
-
     void FindAllSaves(FileSys::SaveDataSpaceId space) {
         const auto save_root = OpenSaveDataSpace(space);
         ASSERT(save_root.Succeeded());
@@ -516,8 +507,9 @@ private:
                 for (const auto& save_id : type->GetSubdirectories()) {
                     for (const auto& user_id : save_id->GetSubdirectories()) {
                         const auto save_id_numeric = stoull_be(save_id->GetName());
-                        const auto user_id_numeric =
-                            ArraySwap(Common::HexStringToArray<0x10>(user_id->GetName()));
+                        auto user_id_numeric = Common::HexStringToArray<0x10>(user_id->GetName());
+                        std::reverse(user_id_numeric.begin(), user_id_numeric.end());
+
                         if (save_id_numeric != 0) {
                             // System Save Data
                             info.emplace_back(SaveDataInfo{
@@ -560,12 +552,16 @@ private:
                     for (const auto& title_id : user_id->GetSubdirectories()) {
                         if (!title_id->GetFiles().empty() ||
                             !title_id->GetSubdirectories().empty()) {
+                            auto user_id_numeric =
+                                Common::HexStringToArray<0x10>(user_id->GetName());
+                            std::reverse(user_id_numeric.begin(), user_id_numeric.end());
+
                             info.emplace_back(SaveDataInfo{
                                 0,
                                 space,
                                 FileSys::SaveDataType::TemporaryStorage,
                                 {},
-                                Common::HexStringToArray<0x10, true>(user_id->GetName()),
+                                user_id_numeric,
                                 stoull_be(type->GetName()),
                                 stoull_be(title_id->GetName()),
                                 title_id->GetSize(),
diff --git a/src/core/hle/service/ns/ns.cpp b/src/core/hle/service/ns/ns.cpp
index 07c1381feb..1d2978f24e 100644
--- a/src/core/hle/service/ns/ns.cpp
+++ b/src/core/hle/service/ns/ns.cpp
@@ -2,6 +2,9 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include "common/logging/log.h"
+#include "core/file_sys/control_metadata.h"
+#include "core/file_sys/patch_manager.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/kernel/hle_ipc.h"
 #include "core/hle/service/ns/ns.h"
@@ -118,7 +121,7 @@ public:
             {305, nullptr, "TerminateSystemApplet"},
             {306, nullptr, "LaunchOverlayApplet"},
             {307, nullptr, "TerminateOverlayApplet"},
-            {400, nullptr, "GetApplicationControlData"},
+            {400, &IApplicationManagerInterface::GetApplicationControlData, "GetApplicationControlData"},
             {401, nullptr, "InvalidateAllApplicationControlCache"},
             {402, nullptr, "RequestDownloadApplicationControlData"},
             {403, nullptr, "GetMaxApplicationControlCacheCount"},
@@ -243,6 +246,65 @@ public:
 
         RegisterHandlers(functions);
     }
+
+    void GetApplicationControlData(Kernel::HLERequestContext& ctx) {
+        IPC::RequestParser rp{ctx};
+        const auto flag = rp.PopRaw<u64>();
+        LOG_DEBUG(Service_NS, "called with flag={:016X}", flag);
+
+        const auto title_id = rp.PopRaw<u64>();
+
+        const auto size = ctx.GetWriteBufferSize();
+
+        const FileSys::PatchManager pm{title_id};
+        const auto control = pm.GetControlMetadata();
+
+        std::vector<u8> out;
+
+        if (control.first != nullptr) {
+            if (size < 0x4000) {
+                LOG_ERROR(Service_NS,
+                          "output buffer is too small! (actual={:016X}, expected_min=0x4000)",
+                          size);
+                IPC::ResponseBuilder rb{ctx, 2};
+                // TODO(DarkLordZach): Find a better error code for this.
+                rb.Push(ResultCode(-1));
+                return;
+            }
+
+            out.resize(0x4000);
+            const auto bytes = control.first->GetRawBytes();
+            std::memcpy(out.data(), bytes.data(), bytes.size());
+        } else {
+            LOG_WARNING(Service_NS, "missing NACP data for title_id={:016X}, defaulting to zeros.",
+                        title_id);
+            out.resize(std::min<u64>(0x4000, size));
+        }
+
+        if (control.second != nullptr) {
+            if (size < 0x4000 + control.second->GetSize()) {
+                LOG_ERROR(Service_NS,
+                          "output buffer is too small! (actual={:016X}, expected_min={:016X})",
+                          size, 0x4000 + control.second->GetSize());
+                IPC::ResponseBuilder rb{ctx, 2};
+                // TODO(DarkLordZach): Find a better error code for this.
+                rb.Push(ResultCode(-1));
+                return;
+            }
+
+            out.resize(0x4000 + control.second->GetSize());
+            control.second->Read(out.data() + 0x4000, control.second->GetSize());
+        } else {
+            LOG_WARNING(Service_NS, "missing icon data for title_id={:016X}, defaulting to zeros.",
+                        title_id);
+        }
+
+        ctx.WriteBuffer(out);
+
+        IPC::ResponseBuilder rb{ctx, 3};
+        rb.Push(RESULT_SUCCESS);
+        rb.Push<u32>(static_cast<u32>(out.size()));
+    }
 };
 
 class IApplicationVersionInterface final : public ServiceFramework<IApplicationVersionInterface> {