hle/ui: Basic multi programs support (#1560)

* hos/gui: Add a check of NCA program index in titleid

This add a check to `ApplicationLoader` for the last 2 digits of the game TitleId who seems to be the NCA program index.
We currently return the last index, instead of the lower one.
Same check is added to ApplicationLibrary in the UI.

I've cleaned up both file too.

* hle: implement partial relaunch logic

TODO: make the emulator auto relauch.

* Handle auto relaunch

* hle: Unify update usage system

* hle: Implement support of multi programs in update system

* Add some documentation

* Address rip's comment

Co-authored-by: Ac_K <Acoustik666@gmail.com>

Ryujinx.HLE/HOS/ApplicationLoader.cs

@@ -15,6 +15,7 @@ using Ryujinx.HLE.Loaders.Executables;
 using Ryujinx.HLE.Loaders.Npdm;
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Reflection;
@@ -28,32 +29,33 @@ namespace Ryujinx.HLE.HOS
 
     public class ApplicationLoader
     {
-        private readonly Switch _device;
-        private readonly ContentManager _contentManager;
-        private readonly VirtualFileSystem _fileSystem;
-
-        public BlitStruct<ApplicationControlProperty> ControlData { get; set; }
+        // Binaries from exefs are loaded into mem in this order. Do not change.
+        private static readonly string[] ExeFsPrefixes = { "rtld", "main", "subsdk*", "sdk" };
 
-        public string TitleName { get; private set; }
-        public string DisplayVersion { get; private set; }
+        private readonly Switch            _device;
+        private readonly ContentManager    _contentManager;
+        private readonly VirtualFileSystem _fileSystem;
 
-        public ulong TitleId { get; private set; }
-        public string TitleIdText => TitleId.ToString("x16");
+        private string _titleName;
+        private string _displayVersion;
+        private BlitStruct<ApplicationControlProperty> _controlData;
 
-        public bool TitleIs64Bit { get; private set; }
+        public BlitStruct<ApplicationControlProperty> ControlData => _controlData;
+        public string TitleName => _titleName;
+        public string DisplayVersion => _displayVersion;
 
-        public bool EnablePtc => _device.System.EnablePtc;
+        public ulong  TitleId      { get; private set; }
+        public bool   TitleIs64Bit { get; private set; }
 
-        // Binaries from exefs are loaded into mem in this order. Do not change.
-        private static readonly string[] ExeFsPrefixes = { "rtld", "main", "subsdk*", "sdk" };
+        public string TitleIdText => TitleId.ToString("x16");
 
         public ApplicationLoader(Switch device, VirtualFileSystem fileSystem, ContentManager contentManager)
         {
-            _device = device;
+            _device         = device;
             _contentManager = contentManager;
-            _fileSystem = fileSystem;
+            _fileSystem     = fileSystem;
 
-            ControlData = new BlitStruct<ApplicationControlProperty>(1);
+            _controlData = new BlitStruct<ApplicationControlProperty>(1);
 
             // Clear Mods cache
             _fileSystem.ModLoader.Clear();
@@ -80,19 +82,26 @@ namespace Ryujinx.HLE.HOS
             LoadExeFs(codeFs, metaData);
         }
 
-        private (Nca main, Nca patch, Nca control) GetGameData(PartitionFileSystem pfs)
+        public static (Nca main, Nca patch, Nca control) GetGameData(VirtualFileSystem fileSystem, PartitionFileSystem pfs, int programIndex)
         {
-            Nca mainNca = null;
-            Nca patchNca = null;
+            Nca mainNca    = null;
+            Nca patchNca   = null;
             Nca controlNca = null;
 
-            _fileSystem.ImportTickets(pfs);
+            fileSystem.ImportTickets(pfs);
 
             foreach (DirectoryEntryEx fileEntry in pfs.EnumerateEntries("/", "*.nca"))
             {
                 pfs.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
 
-                Nca nca = new Nca(_fileSystem.KeySet, ncaFile.AsStorage());
+                Nca nca = new Nca(fileSystem.KeySet, ncaFile.AsStorage());
+
+                int ncaProgramIndex = (int)(nca.Header.TitleId & 0xF);
+
+                if (ncaProgramIndex != programIndex)
+                {
+                    continue;
+                }
 
                 if (nca.Header.ContentType == NcaContentType.Program)
                 {
@@ -116,11 +125,77 @@ namespace Ryujinx.HLE.HOS
             return (mainNca, patchNca, controlNca);
         }
 
+        public static (Nca patch, Nca control) GetGameUpdateDataFromPartition(VirtualFileSystem fileSystem, PartitionFileSystem pfs, string titleId, int programIndex)
+        {
+            Nca patchNca = null;
+            Nca controlNca = null;
+
+            fileSystem.ImportTickets(pfs);
+
+            foreach (DirectoryEntryEx fileEntry in pfs.EnumerateEntries("/", "*.nca"))
+            {
+                pfs.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
+
+                Nca nca = new Nca(fileSystem.KeySet, ncaFile.AsStorage());
+
+                int ncaProgramIndex = (int)(nca.Header.TitleId & 0xF);
+
+                if (ncaProgramIndex != programIndex)
+                {
+                    continue;
+                }
+
+                if ($"{nca.Header.TitleId.ToString("x16")[..^3]}000" != titleId)
+                {
+                    break;
+                }
+
+                if (nca.Header.ContentType == NcaContentType.Program)
+                {
+                    patchNca = nca;
+                }
+                else if (nca.Header.ContentType == NcaContentType.Control)
+                {
+                    controlNca = nca;
+                }
+            }
+
+            return (patchNca, controlNca);
+        }
+
+        public static (Nca patch, Nca control) GetGameUpdateData(VirtualFileSystem fileSystem, string titleId, int programIndex, out string updatePath)
+        {
+            updatePath = null;
+
+            if (ulong.TryParse(titleId, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out ulong titleIdBase))
+            {
+                // Clear the program index part.
+                titleIdBase &= 0xFFFFFFFFFFFFFFF0;
+
+                // Load update informations if existing.
+                string titleUpdateMetadataPath = Path.Combine(AppDataManager.GamesDirPath, titleIdBase.ToString("x16"), "updates.json");
+
+                if (File.Exists(titleUpdateMetadataPath))
+                {
+                    updatePath = JsonHelper.DeserializeFromFile<TitleUpdateMetadata>(titleUpdateMetadataPath).Selected;
+
+                    if (File.Exists(updatePath))
+                    {
+                        FileStream file = new FileStream(updatePath, FileMode.Open, FileAccess.Read);
+                        PartitionFileSystem nsp = new PartitionFileSystem(file.AsStorage());
+
+                        return GetGameUpdateDataFromPartition(fileSystem, nsp, titleIdBase.ToString("x16"), programIndex);
+                    }
+                }
+            }
+
+            return (null, null);
+        }
+
         public void LoadXci(string xciFile)
         {
             FileStream file = new FileStream(xciFile, FileMode.Open, FileAccess.Read);
-
-            Xci xci = new Xci(_fileSystem.KeySet, file.AsStorage());
+            Xci        xci  = new Xci(_fileSystem.KeySet, file.AsStorage());
 
             if (!xci.HasPartition(XciPartitionType.Secure))
             {
@@ -131,13 +206,13 @@ namespace Ryujinx.HLE.HOS
 
             PartitionFileSystem securePartition = xci.OpenPartition(XciPartitionType.Secure);
 
-            Nca mainNca = null;
-            Nca patchNca = null;
-            Nca controlNca = null;
+            Nca mainNca;
+            Nca patchNca;
+            Nca controlNca;
 
             try
             {
-                (mainNca, patchNca, controlNca) = GetGameData(securePartition);
+                (mainNca, patchNca, controlNca) = GetGameData(_fileSystem, securePartition, _device.UserChannelPersistence.Index);
             }
             catch (Exception e)
             {
@@ -154,7 +229,6 @@ namespace Ryujinx.HLE.HOS
             }
 
             _contentManager.LoadEntries(_device);
-
             _contentManager.ClearAocData();
             _contentManager.AddAocData(securePartition, xciFile, mainNca.Header.TitleId);
 
@@ -163,17 +237,16 @@ namespace Ryujinx.HLE.HOS
 
         public void LoadNsp(string nspFile)
         {
-            FileStream file = new FileStream(nspFile, FileMode.Open, FileAccess.Read);
-
-            PartitionFileSystem nsp = new PartitionFileSystem(file.AsStorage());
+            FileStream          file = new FileStream(nspFile, FileMode.Open, FileAccess.Read);
+            PartitionFileSystem nsp  = new PartitionFileSystem(file.AsStorage());
 
-            Nca mainNca = null;
-            Nca patchNca = null;
-            Nca controlNca = null;
+            Nca mainNca;
+            Nca patchNca;
+            Nca controlNca;
 
             try
             {
-                (mainNca, patchNca, controlNca) = GetGameData(nsp);
+                (mainNca, patchNca, controlNca) = GetGameData(_fileSystem, nsp, _device.UserChannelPersistence.Index);
             }
             catch (Exception e)
             {
@@ -206,8 +279,7 @@ namespace Ryujinx.HLE.HOS
         public void LoadNca(string ncaFile)
         {
             FileStream file = new FileStream(ncaFile, FileMode.Open, FileAccess.Read);
-
-            Nca nca = new Nca(_fileSystem.KeySet, file.AsStorage(false));
+            Nca        nca  = new Nca(_fileSystem.KeySet, file.AsStorage(false));
 
             LoadNca(nca, null, null);
         }
@@ -221,46 +293,24 @@ namespace Ryujinx.HLE.HOS
                 return;
             }
 
-            IStorage dataStorage = null;
-            IFileSystem codeFs = null;
+            IStorage    dataStorage = null;
+            IFileSystem codeFs      = null;
 
-            // Load Update
-            string titleUpdateMetadataPath = Path.Combine(AppDataManager.GamesDirPath, mainNca.Header.TitleId.ToString("x16"), "updates.json");
+            (Nca updatePatchNca, Nca updateControlNca) = GetGameUpdateData(_fileSystem, mainNca.Header.TitleId.ToString("x16"), _device.UserChannelPersistence.Index, out _);
 
-            if (File.Exists(titleUpdateMetadataPath))
+            if (updatePatchNca != null)
             {
-                string updatePath = JsonHelper.DeserializeFromFile<TitleUpdateMetadata>(titleUpdateMetadataPath).Selected;
-
-                if (File.Exists(updatePath))
-                {
-                    FileStream file = new FileStream(updatePath, FileMode.Open, FileAccess.Read);
-                    PartitionFileSystem nsp = new PartitionFileSystem(file.AsStorage());
-
-                    _fileSystem.ImportTickets(nsp);
-
-                    foreach (DirectoryEntryEx fileEntry in nsp.EnumerateEntries("/", "*.nca"))
-                    {
-                        nsp.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
-
-                        Nca nca = new Nca(_fileSystem.KeySet, ncaFile.AsStorage());
-
-                        if ($"{nca.Header.TitleId.ToString("x16")[..^3]}000" != mainNca.Header.TitleId.ToString("x16"))
-                        {
-                            break;
-                        }
+                patchNca = updatePatchNca;
+            }
 
-                        if (nca.Header.ContentType == NcaContentType.Program)
-                        {
-                            patchNca = nca;
-                        }
-                        else if (nca.Header.ContentType == NcaContentType.Control)
-                        {
-                            controlNca = nca;
-                        }
-                    }
-                }
+            if (updateControlNca != null)
+            {
+                controlNca = updateControlNca;
             }
 
+            // Load program 0 control NCA as we are going to need it for display version.
+            (_, Nca updateProgram0ControlNca) = GetGameUpdateData(_fileSystem, mainNca.Header.TitleId.ToString("x16"), 0, out _);
+
             // Load Aoc
             string titleAocMetadataPath = Path.Combine(AppDataManager.GamesDirPath, mainNca.Header.TitleId.ToString("x16"), "dlc.json");
 
@@ -315,13 +365,23 @@ namespace Ryujinx.HLE.HOS
 
             if (controlNca != null)
             {
-                ReadControlData(controlNca);
+                ReadControlData(_device, controlNca, ref _controlData, ref _titleName, ref _displayVersion);
             }
             else
             {
                 ControlData.ByteSpan.Clear();
             }
 
+            // NOTE: Nintendo doesn't guarantee that the display version will be updated on sub programs when updating a multi program application.
+            // BODY: As such, to avoid PTC cache confusion, we only trust the the program 0 display version when launching a sub program.
+            if (updateProgram0ControlNca != null && _device.UserChannelPersistence.Index != 0)
+            {
+                string dummyTitleName = "";
+                BlitStruct<ApplicationControlProperty> dummyControl = new BlitStruct<ApplicationControlProperty>(1);
+
+                ReadControlData(_device, updateProgram0ControlNca, ref dummyControl, ref dummyTitleName, ref _displayVersion);
+            }
+
             if (dataStorage == null)
             {
                 Logger.Warning?.Print(LogClass.Loader, "No RomFS found in NCA");
@@ -329,6 +389,7 @@ namespace Ryujinx.HLE.HOS
             else
             {
                 IStorage newStorage = _fileSystem.ModLoader.ApplyRomFsMods(TitleId, dataStorage);
+
                 _fileSystem.SetRomFs(newStorage.AsStream(FileAccess.Read));
             }
 
@@ -346,6 +407,7 @@ namespace Ryujinx.HLE.HOS
         private Npdm ReadNpdm(IFileSystem fs)
         {
             Result result = fs.OpenFile(out IFile npdmFile, "/main.npdm".ToU8Span(), OpenMode.Read);
+
             Npdm metaData;
 
             if (ResultFs.PathNotFound.Includes(result))
@@ -359,39 +421,36 @@ namespace Ryujinx.HLE.HOS
                 metaData = new Npdm(npdmFile.AsStream());
             }
 
-            TitleId = metaData.Aci0.TitleId;
+            TitleId      = metaData.Aci0.TitleId;
             TitleIs64Bit = metaData.Is64Bit;
 
             return metaData;
         }
 
-        private void ReadControlData(Nca controlNca)
+        private static void ReadControlData(Switch device, Nca controlNca, ref BlitStruct<ApplicationControlProperty> controlData, ref string titleName, ref string displayVersion)
         {
-            IFileSystem controlFs = controlNca.OpenFileSystem(NcaSectionType.Data, _device.System.FsIntegrityCheckLevel);
-
-            Result result = controlFs.OpenFile(out IFile controlFile, "/control.nacp".ToU8Span(), OpenMode.Read);
+            IFileSystem controlFs = controlNca.OpenFileSystem(NcaSectionType.Data, device.System.FsIntegrityCheckLevel);
+            Result      result    = controlFs.OpenFile(out IFile controlFile, "/control.nacp".ToU8Span(), OpenMode.Read);
 
             if (result.IsSuccess())
             {
-                result = controlFile.Read(out long bytesRead, 0, ControlData.ByteSpan, ReadOption.None);
+                result = controlFile.Read(out long bytesRead, 0, controlData.ByteSpan, ReadOption.None);
 
-                if (result.IsSuccess() && bytesRead == ControlData.ByteSpan.Length)
+                if (result.IsSuccess() && bytesRead == controlData.ByteSpan.Length)
                 {
-                    TitleName = ControlData.Value
-                        .Titles[(int)_device.System.State.DesiredTitleLanguage].Name.ToString();
+                    titleName = controlData.Value.Titles[(int)device.System.State.DesiredTitleLanguage].Name.ToString();
 
-                    if (string.IsNullOrWhiteSpace(TitleName))
+                    if (string.IsNullOrWhiteSpace(titleName))
                     {
-                        TitleName = ControlData.Value.Titles.ToArray()
-                            .FirstOrDefault(x => x.Name[0] != 0).Name.ToString();
+                        titleName = controlData.Value.Titles.ToArray().FirstOrDefault(x => x.Name[0] != 0).Name.ToString();
                     }
 
-                    DisplayVersion = ControlData.Value.DisplayVersion.ToString();
+                    displayVersion = controlData.Value.DisplayVersion.ToString();
                 }
             }
             else
             {
-                ControlData.ByteSpan.Clear();
+                controlData.ByteSpan.Clear();
             }
         }
 
@@ -428,18 +487,18 @@ namespace Ryujinx.HLE.HOS
             // ExeFs file replacements
             bool modified = _fileSystem.ModLoader.ApplyExefsMods(TitleId, nsos);
 
-            var programs = nsos.ToArray();
+            NsoExecutable[] programs = nsos.ToArray();
 
             modified |= _fileSystem.ModLoader.ApplyNsoPatches(TitleId, programs);
 
             _contentManager.LoadEntries(_device);
 
-            if (EnablePtc && modified)
+            if (_device.System.EnablePtc && modified)
             {
                 Logger.Warning?.Print(LogClass.Ptc, $"Detected exefs modifications. PPTC disabled.");
             }
 
-            Ptc.Initialize(TitleIdText, DisplayVersion, EnablePtc && !modified);
+            Ptc.Initialize(TitleIdText, DisplayVersion, _device.System.EnablePtc && !modified);
 
             ProgramLoader.LoadNsos(_device.System.KernelContext, metaData, executables: programs);
         }
@@ -447,15 +506,15 @@ namespace Ryujinx.HLE.HOS
         public void LoadProgram(string filePath)
         {
             Npdm metaData = GetDefaultNpdm();
-
-            bool isNro = Path.GetExtension(filePath).ToLower() == ".nro";
+            bool isNro    = Path.GetExtension(filePath).ToLower() == ".nro";
 
             IExecutable executable;
 
             if (isNro)
             {
-                FileStream input = new FileStream(filePath, FileMode.Open);
-                NroExecutable obj = new NroExecutable(input.AsStorage());
+                FileStream    input = new FileStream(filePath, FileMode.Open);
+                NroExecutable obj   = new NroExecutable(input.AsStorage());
+
                 executable = obj;
 
                 // homebrew NRO can actually have some data after the actual NRO
@@ -466,20 +525,19 @@ namespace Ryujinx.HLE.HOS
                     BinaryReader reader = new BinaryReader(input);
 
                     uint asetMagic = reader.ReadUInt32();
-
                     if (asetMagic == 0x54455341)
                     {
                         uint asetVersion = reader.ReadUInt32();
                         if (asetVersion == 0)
                         {
                             ulong iconOffset = reader.ReadUInt64();
-                            ulong iconSize = reader.ReadUInt64();
+                            ulong iconSize   = reader.ReadUInt64();
 
                             ulong nacpOffset = reader.ReadUInt64();
-                            ulong nacpSize = reader.ReadUInt64();
+                            ulong nacpSize   = reader.ReadUInt64();
 
                             ulong romfsOffset = reader.ReadUInt64();
-                            ulong romfsSize = reader.ReadUInt64();
+                            ulong romfsSize   = reader.ReadUInt64();
 
                             if (romfsSize != 0)
                             {
@@ -533,8 +591,8 @@ namespace Ryujinx.HLE.HOS
 
             _contentManager.LoadEntries(_device);
 
-            TitleName = metaData.TitleName;
-            TitleId = metaData.Aci0.TitleId;
+            _titleName   = metaData.TitleName;
+            TitleId      = metaData.Aci0.TitleId;
             TitleIs64Bit = metaData.Is64Bit;
 
             ProgramLoader.LoadNsos(_device.System.KernelContext, metaData, executables: executable);
@@ -572,25 +630,24 @@ namespace Ryujinx.HLE.HOS
                     "No control file was found for this game. Using a dummy one instead. This may cause inaccuracies in some games.");
             }
 
-            FileSystemClient fs = _fileSystem.FsClient;
-
-            Result rc = fs.EnsureApplicationCacheStorage(out _, applicationId, ref control);
+            FileSystemClient fileSystem = _fileSystem.FsClient;
+            Result           resultCode = fileSystem.EnsureApplicationCacheStorage(out _, applicationId, ref control);
 
-            if (rc.IsFailure())
+            if (resultCode.IsFailure())
             {
-                Logger.Error?.Print(LogClass.Application, $"Error calling EnsureApplicationCacheStorage. Result code {rc.ToStringWithName()}");
+                Logger.Error?.Print(LogClass.Application, $"Error calling EnsureApplicationCacheStorage. Result code {resultCode.ToStringWithName()}");
 
-                return rc;
+                return resultCode;
             }
 
-            rc = EnsureApplicationSaveData(fs, out _, applicationId, ref control, ref user);
+            resultCode = EnsureApplicationSaveData(fileSystem, out _, applicationId, ref control, ref user);
 
-            if (rc.IsFailure())
+            if (resultCode.IsFailure())
             {
-                Logger.Error?.Print(LogClass.Application, $"Error calling EnsureApplicationSaveData. Result code {rc.ToStringWithName()}");
+                Logger.Error?.Print(LogClass.Application, $"Error calling EnsureApplicationSaveData. Result code {resultCode.ToStringWithName()}");
             }
 
-            return rc;
+            return resultCode;
         }
     }
 }

Ryujinx.HLE/HOS/Services/Account/Acc/IManagerForApplication.cs

@@ -126,5 +126,14 @@ namespace Ryujinx.HLE.HOS.Services.Account.Acc
 
             return ResultCode.Success;
         }
+
+        [Command(160)] // 5.0.0+
+        // StoreOpenContext()
+        public ResultCode StoreOpenContext(ServiceCtx context)
+        {
+            Logger.Stub?.PrintStub(LogClass.ServiceAcc);
+
+            return ResultCode.Success;
+        }
     }
 }

Ryujinx.HLE/HOS/Services/Am/AppletOE/ApplicationProxyService/ApplicationProxy/IApplicationFunctions.cs

@@ -5,11 +5,13 @@ using LibHac.Fs;
 using LibHac.Ns;
 using Ryujinx.Common;
 using Ryujinx.Common.Logging;
+using Ryujinx.HLE.Exceptions;
 using Ryujinx.HLE.HOS.Ipc;
 using Ryujinx.HLE.HOS.Kernel.Common;
 using Ryujinx.HLE.HOS.Kernel.Memory;
 using Ryujinx.HLE.HOS.Kernel.Threading;
 using Ryujinx.HLE.HOS.Services.Am.AppletAE.Storage;
+using Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types;
 using Ryujinx.HLE.HOS.Services.Sdb.Pdm.QueryService;
 using Ryujinx.HLE.HOS.SystemState;
 using System;
@@ -35,11 +37,27 @@ namespace Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.Applicati
         }
 
         [Command(1)]
-        // PopLaunchParameter(u32) -> object<nn::am::service::IStorage>
+        // PopLaunchParameter(LaunchParameterKind kind) -> object<nn::am::service::IStorage>
         public ResultCode PopLaunchParameter(ServiceCtx context)
         {
-            // Only the first 0x18 bytes of the Data seems to be actually used.
-            MakeObject(context, new AppletAE.IStorage(StorageHelper.MakeLaunchParams(context.Device.System.State.Account.LastOpenedUser)));
+            LaunchParameterKind kind = (LaunchParameterKind)context.RequestData.ReadUInt32();
+
+            byte[] storageData;
+
+            switch (kind)
+            {
+                case LaunchParameterKind.UserChannel:
+                    storageData = context.Device.UserChannelPersistence.Pop();
+                    break;
+                case LaunchParameterKind.PreselectedUser:
+                    // Only the first 0x18 bytes of the Data seems to be actually used.
+                    storageData = StorageHelper.MakeLaunchParams(context.Device.System.State.Account.LastOpenedUser);
+                    break;
+                default:
+                    throw new NotImplementedException($"Unknown LaunchParameterKind {kind}");
+            }
+
+            MakeObject(context, new AppletAE.IStorage(storageData));
 
             return ResultCode.Success;
         }
@@ -376,14 +394,49 @@ namespace Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.Applicati
             return (ResultCode)QueryPlayStatisticsManager.GetPlayStatistics(context, true);
         }
 
+        [Command(120)] // 5.0.0+
+        // ExecuteProgram(ProgramSpecifyKind kind, u64 value)
+        public ResultCode ExecuteProgram(ServiceCtx context)
+        {
+            ProgramSpecifyKind kind = (ProgramSpecifyKind)context.RequestData.ReadUInt32();
+
+            // padding
+            context.RequestData.ReadUInt32();
+
+            ulong value = context.RequestData.ReadUInt64();
+
+            Logger.Stub?.PrintStub(LogClass.ServiceAm, new { kind, value });
+
+            context.Device.UiHandler.ExecuteProgram(context.Device, kind, value);
+
+            return ResultCode.Success;
+        }
+
+        [Command(121)] // 5.0.0+
+        // ClearUserChannel()
+        public ResultCode ClearUserChannel(ServiceCtx context)
+        {
+            context.Device.UserChannelPersistence.Clear();
+
+            return ResultCode.Success;
+        }
+
+        [Command(122)] // 5.0.0+
+        // UnpopToUserChannel(object<nn::am::service::IStorage> input_storage)
+        public ResultCode UnpopToUserChannel(ServiceCtx context)
+        {
+            AppletAE.IStorage data = GetObject<AppletAE.IStorage>(context, 0);
+
+            context.Device.UserChannelPersistence.Push(data.Data);
+
+            return ResultCode.Success;
+        }
+
         [Command(123)] // 5.0.0+
         // GetPreviousProgramIndex() -> s32 program_index
         public ResultCode GetPreviousProgramIndex(ServiceCtx context)
         {
-            // TODO: The output PreviousProgramIndex is -1 when there was no previous title.
-            //       When multi-process will be supported, return the last program index.
-
-            int previousProgramIndex = -1;
+            int previousProgramIndex = context.Device.UserChannelPersistence.PreviousIndex;
 
             context.ResponseData.Write(previousProgramIndex);
 

Ryujinx.HLE/HOS/Services/Am/AppletOE/ApplicationProxyService/ApplicationProxy/Types/LaunchParameterKind.cs

@@ -0,0 +1,9 @@
+namespace Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types
+{
+    public enum LaunchParameterKind : uint
+    {
+        UserChannel = 1,
+        PreselectedUser,
+        Unknown
+    }
+}

Ryujinx.HLE/HOS/Services/Am/AppletOE/ApplicationProxyService/ApplicationProxy/Types/ProgramSpecifyKind.cs

@@ -0,0 +1,9 @@
+namespace Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types
+{
+    public enum ProgramSpecifyKind : uint
+    {
+        ExecuteProgram,
+        SubApplicationProgram,
+        RestartProgram
+    }
+}

Ryujinx.HLE/HOS/UserChannelPersistence.cs

@@ -0,0 +1,56 @@
+using Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types;
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.HLE.HOS
+{
+    public class UserChannelPersistence
+    {
+        private Stack<byte[]> _userChannelStorages;
+        public int PreviousIndex { get; private set; }
+        public int Index { get; private set; }
+        public ProgramSpecifyKind Kind { get; private set; }
+
+        public UserChannelPersistence()
+        {
+            _userChannelStorages = new Stack<byte[]>();
+            Kind = ProgramSpecifyKind.ExecuteProgram;
+            PreviousIndex = -1;
+            Index = 0;
+        }
+
+        public void Clear()
+        {
+            _userChannelStorages.Clear();
+        }
+
+        public void Push(byte[] data)
+        {
+            _userChannelStorages.Push(data);
+        }
+
+        public byte[] Pop()
+        {
+            return _userChannelStorages.Pop();
+        }
+
+        public bool IsEmpty => _userChannelStorages.Count == 0;
+
+        public void ExecuteProgram(ProgramSpecifyKind kind, ulong value)
+        {
+            Kind = kind;
+            PreviousIndex = Index;
+
+            switch (kind)
+            {
+                case ProgramSpecifyKind.ExecuteProgram:
+                    Index = (int)value;
+                    break;
+                case ProgramSpecifyKind.RestartProgram:
+                    break;
+                default:
+                    throw new NotImplementedException($"{kind} not implemented");
+            }
+        }
+    }
+}

Ryujinx.HLE/IHostUiHandler.cs

@@ -1,4 +1,5 @@
 using Ryujinx.HLE.HOS.Applets;
+using Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types;
 
 namespace Ryujinx.HLE
 {
@@ -22,5 +23,13 @@ namespace Ryujinx.HLE
         /// </summary>
         /// <returns>True when OK is pressed, False otherwise.</returns>
         bool DisplayMessageDialog(ControllerAppletUiArgs args);
+
+        /// <summary>
+        /// Tell the UI that we need to transisition to another program.
+        /// </summary>
+        /// <param name="device">The device instance.</param>
+        /// <param name="kind">The program kind.</param>
+        /// <param name="value">The value associated to the <paramref name="kind"/>.</param>
+        void ExecuteProgram(Switch device, ProgramSpecifyKind kind, ulong value);
     }
 }

Ryujinx.HLE/Switch.cs

@@ -35,13 +35,15 @@ namespace Ryujinx.HLE
 
         public PerformanceStatistics Statistics { get; private set; }
 
+        public UserChannelPersistence UserChannelPersistence { get; }
+
         public Hid Hid { get; private set; }
 
         public IHostUiHandler UiHandler { get; set; }
 
         public bool EnableDeviceVsync { get; set; } = true;
 
-        public Switch(VirtualFileSystem fileSystem, ContentManager contentManager, IRenderer renderer, IAalOutput audioOut)
+        public Switch(VirtualFileSystem fileSystem, ContentManager contentManager, UserChannelPersistence userChannelPersistence, IRenderer renderer, IAalOutput audioOut)
         {
             if (renderer == null)
             {
@@ -53,6 +55,13 @@ namespace Ryujinx.HLE
                 throw new ArgumentNullException(nameof(audioOut));
             }
 
+            if (userChannelPersistence == null)
+            {
+                throw new ArgumentNullException(nameof(userChannelPersistence));
+            }
+
+            UserChannelPersistence = userChannelPersistence;
+
             AudioOut = audioOut;
 
             Memory = new MemoryBlock(1UL << 32);

Ryujinx/Ui/ApplicationLibrary.cs

@@ -5,10 +5,11 @@ using LibHac.Fs.Fsa;
 using LibHac.FsSystem;
 using LibHac.FsSystem.NcaUtils;
 using LibHac.Ns;
-using Ryujinx.Common.Logging;
 using Ryujinx.Common.Configuration;
+using Ryujinx.Common.Logging;
 using Ryujinx.Configuration.System;
 using Ryujinx.HLE.FileSystem;
+using Ryujinx.HLE.HOS;
 using Ryujinx.HLE.Loaders.Npdm;
 using System;
 using System.Collections.Generic;
@@ -39,10 +40,12 @@ namespace Ryujinx.Ui
         public static IEnumerable<string> GetFilesInDirectory(string directory)
         {
             Stack<string> stack = new Stack<string>();
+
             stack.Push(directory);
+
             while (stack.Count > 0)
             {
-                string dir = stack.Pop();
+                string   dir     = stack.Pop();
                 string[] content = { };
 
                 try
@@ -57,7 +60,9 @@ namespace Ryujinx.Ui
                 if (content.Length > 0)
                 {
                     foreach (string file in content)
+                    {
                         yield return file;
+                    }
                 }
 
                 try
@@ -72,7 +77,9 @@ namespace Ryujinx.Ui
                 if (content.Length > 0)
                 {
                     foreach (string subdir in content)
+                    {
                         stack.Push(subdir);
+                    }
                 }
             }
         }
@@ -94,6 +101,7 @@ namespace Ryujinx.Ui
 
             // Builds the applications list with paths to found applications
             List<string> applications = new List<string>();
+
             foreach (string appDir in appDirs)
             {
                 
@@ -128,6 +136,7 @@ namespace Ryujinx.Ui
                 string developer       = "Unknown";
                 string version         = "0";
                 byte[] applicationIcon = null;
+
                 BlitStruct<ApplicationControlProperty> controlHolder = new BlitStruct<ApplicationControlProperty>(1);
 
                 try
@@ -448,23 +457,7 @@ namespace Ryujinx.Ui
 
         private static void GetControlFsAndTitleId(PartitionFileSystem pfs, out IFileSystem controlFs, out string titleId)
         {
-            Nca controlNca = null;
-
-            // Add keys to key set if needed
-            _virtualFileSystem.ImportTickets(pfs);
-
-            // Find the Control NCA and store it in variable called controlNca
-            foreach (DirectoryEntryEx fileEntry in pfs.EnumerateEntries("/", "*.nca"))
-            {
-                pfs.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
-
-                Nca nca = new Nca(_virtualFileSystem.KeySet, ncaFile.AsStorage());
-
-                if (nca.Header.ContentType == NcaContentType.Control)
-                {
-                    controlNca = nca;
-                }
-            }
+            (_, _, Nca controlNca) = ApplicationLoader.GetGameData(_virtualFileSystem, pfs, 0);
 
             // Return the ControlFS
             controlFs = controlNca?.OpenFileSystem(NcaSectionType.Data, IntegrityCheckLevel.None);
@@ -574,6 +567,7 @@ namespace Ryujinx.Ui
                     if (!((U8Span)controlTitle.Name).IsEmpty())
                     {
                         titleName = controlTitle.Name.ToString();
+
                         break;
                     }
                 }
@@ -586,6 +580,7 @@ namespace Ryujinx.Ui
                     if (!((U8Span)controlTitle.Publisher).IsEmpty())
                     {
                         publisher = controlTitle.Publisher.ToString();
+
                         break;
                     }
                 }
@@ -611,68 +606,34 @@ namespace Ryujinx.Ui
 
         private static bool IsUpdateApplied(string titleId, out string version)
         {
-            string jsonPath = Path.Combine(AppDataManager.GamesDirPath, titleId, "updates.json");
+            string updatePath = "(unknown)";
 
-            if (File.Exists(jsonPath))
+            try
             {
-                string updatePath = JsonHelper.DeserializeFromFile<TitleUpdateMetadata>(jsonPath).Selected;
-
-                if (!File.Exists(updatePath))
-                {
-                    version = "";
-
-                    return false;
-                }
+                (Nca patchNca, Nca controlNca) = ApplicationLoader.GetGameUpdateData(_virtualFileSystem, titleId, 0, out updatePath);
 
-                using (FileStream file = new FileStream(updatePath, FileMode.Open, FileAccess.Read))
+                if (patchNca != null && controlNca != null)
                 {
-                    PartitionFileSystem nsp = new PartitionFileSystem(file.AsStorage());
-
-                    _virtualFileSystem.ImportTickets(nsp);
-
-                    foreach (DirectoryEntryEx fileEntry in nsp.EnumerateEntries("/", "*.nca"))
-                    {
-                        nsp.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
-
-                        try
-                        {
-                            Nca nca = new Nca(_virtualFileSystem.KeySet, ncaFile.AsStorage());
-
-                            if ($"{nca.Header.TitleId.ToString("x16")[..^3]}000" != titleId)
-                            {
-                                break;
-                            }
-
-                            if (nca.Header.ContentType == NcaContentType.Control)
-                            {
-                                ApplicationControlProperty controlData = new ApplicationControlProperty();
-
-                                nca.OpenFileSystem(NcaSectionType.Data, IntegrityCheckLevel.None).OpenFile(out IFile nacpFile, "/control.nacp".ToU8Span(), OpenMode.Read).ThrowIfFailure();
+                    ApplicationControlProperty controlData = new ApplicationControlProperty();
 
-                                nacpFile.Read(out _, 0, SpanHelpers.AsByteSpan(ref controlData), ReadOption.None).ThrowIfFailure();
+                    controlNca.OpenFileSystem(NcaSectionType.Data, IntegrityCheckLevel.None).OpenFile(out IFile nacpFile, "/control.nacp".ToU8Span(), OpenMode.Read).ThrowIfFailure();
 
-                                version = controlData.DisplayVersion.ToString();
+                    nacpFile.Read(out _, 0, SpanHelpers.AsByteSpan(ref controlData), ReadOption.None).ThrowIfFailure();
 
-                                return true;
-                            }
-                        }
-                        catch (InvalidDataException)
-                        {
-                            Logger.Warning?.Print(LogClass.Application,
-                                $"The header key is incorrect or missing and therefore the NCA header content type check has failed. Errored File: {updatePath}");
-
-                            break;
-                        }
-                        catch (MissingKeyException exception)
-                        {
-                            Logger.Warning?.Print(LogClass.Application,
-                                $"Your key set is missing a key with the name: {exception.Name}. Errored File: {updatePath}");
+                    version = controlData.DisplayVersion.ToString();
 
-                            break;
-                        }
-                    }
+                    return true;
                 }
             }
+            catch (InvalidDataException)
+            {
+                Logger.Warning?.Print(LogClass.Application,
+                    $"The header key is incorrect or missing and therefore the NCA header content type check has failed. Errored File: {updatePath}");
+            }
+            catch (MissingKeyException exception)
+            {
+                Logger.Warning?.Print(LogClass.Application, $"Your key set is missing a key with the name: {exception.Name}. Errored File: {updatePath}");
+            }
 
             version = "";
 

Ryujinx/Ui/GameTableContextMenu.cs

@@ -13,6 +13,7 @@ using Ryujinx.Common.Configuration;
 using Ryujinx.Common.Logging;
 using Ryujinx.Common.Utilities;
 using Ryujinx.HLE.FileSystem;
+using Ryujinx.HLE.HOS;
 using System;
 using System.Buffers;
 using System.Collections.Generic;
@@ -246,7 +247,7 @@ namespace Ryujinx.Ui
             return workingPath;
         }
 
-        private void ExtractSection(NcaSectionType ncaSectionType)
+        private void ExtractSection(NcaSectionType ncaSectionType, int programIndex = 0)
         {
             FileChooserDialog fileChooser = new FileChooserDialog("Choose the folder to extract into", null, FileChooserAction.SelectFolder, "Cancel", ResponseType.Cancel, "Extract", ResponseType.Accept);
             fileChooser.SetPosition(WindowPosition.Center);
@@ -340,36 +341,12 @@ namespace Ryujinx.Ui
                             return;
                         }
 
-                        string titleUpdateMetadataPath = System.IO.Path.Combine(AppDataManager.GamesDirPath, mainNca.Header.TitleId.ToString("x16"), "updates.json");
 
-                        if (File.Exists(titleUpdateMetadataPath))
-                        {
-                            string updatePath = JsonHelper.DeserializeFromFile<TitleUpdateMetadata>(titleUpdateMetadataPath).Selected;
-
-                            if (File.Exists(updatePath))
-                            {
-                                FileStream updateFile = new FileStream(updatePath, FileMode.Open, FileAccess.Read);
-                                PartitionFileSystem nsp = new PartitionFileSystem(updateFile.AsStorage());
-
-                                _virtualFileSystem.ImportTickets(nsp);
-
-                                foreach (DirectoryEntryEx fileEntry in nsp.EnumerateEntries("/", "*.nca"))
-                                {
-                                    nsp.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
-
-                                    Nca nca = new Nca(_virtualFileSystem.KeySet, ncaFile.AsStorage());
-
-                                    if ($"{nca.Header.TitleId.ToString("x16")[..^3]}000" != mainNca.Header.TitleId.ToString("x16"))
-                                    {
-                                        break;
-                                    }
+                        (Nca updatePatchNca, _) = ApplicationLoader.GetGameUpdateData(_virtualFileSystem, mainNca.Header.TitleId.ToString("x16"), programIndex, out _);
 
-                                    if (nca.Header.ContentType == NcaContentType.Program)
-                                    {
-                                        patchNca = nca;
-                                    }
-                                }
-                            }
+                        if (updatePatchNca != null)
+                        {
+                            patchNca = updatePatchNca;
                         }
 
                         int index = Nca.GetSectionIndexFromType(ncaSectionType, mainNca.Header.ContentType);

Ryujinx/Ui/GtkHostUiHandler.cs

@@ -2,6 +2,7 @@ using Gtk;
 using Ryujinx.Common.Logging;
 using Ryujinx.HLE;
 using Ryujinx.HLE.HOS.Applets;
+using Ryujinx.HLE.HOS.Services.Am.AppletOE.ApplicationProxyService.ApplicationProxy.Types;
 using System;
 using System.Threading;
 
@@ -121,5 +122,11 @@ namespace Ryujinx.Ui
 
             return error || okPressed;
         }
+
+        public void ExecuteProgram(HLE.Switch device, ProgramSpecifyKind kind, ulong value)
+        {
+            device.UserChannelPersistence.ExecuteProgram(kind, value);
+            MainWindow.GlWidget?.Exit();
+        }
     }
 }

Ryujinx/Ui/MainWindow.cs

@@ -11,6 +11,7 @@ using Ryujinx.Graphics.GAL;
 using Ryujinx.Graphics.OpenGL;
 using Ryujinx.HLE.FileSystem;
 using Ryujinx.HLE.FileSystem.Content;
+using Ryujinx.HLE.HOS;
 using Ryujinx.Ui.Diagnostic;
 using System;
 using System.Diagnostics;
@@ -27,6 +28,7 @@ namespace Ryujinx.Ui
     {
         private static VirtualFileSystem _virtualFileSystem;
         private static ContentManager    _contentManager;
+        private static UserChannelPersistence _userChannelPersistence;
 
         private static WindowsMultimediaTimerResolution _windowsMultimediaTimerResolution;
         private static HLE.Switch _emulationContext;
@@ -34,12 +36,15 @@ namespace Ryujinx.Ui
         private static GlRenderer _glWidget;
         private static GtkHostUiHandler _uiHandler;
 
+        public static GlRenderer GlWidget => _glWidget;
+
         private static AutoResetEvent _deviceExitStatus = new AutoResetEvent(false);
 
         private static ListStore _tableStore;
 
         private static bool _updatingGameTable;
         private static bool _gameLoaded;
+        private static string _gamePath;
         private static bool _ending;
 
 #pragma warning disable CS0169, CS0649, IDE0044
@@ -110,6 +115,7 @@ namespace Ryujinx.Ui
             }
 
             _virtualFileSystem = VirtualFileSystem.CreateInstance();
+            _userChannelPersistence = new UserChannelPersistence();
             _contentManager    = new ContentManager(_virtualFileSystem);
 
             if (migrationNeeded)
@@ -181,6 +187,7 @@ namespace Ryujinx.Ui
             _statusBar.Hide();
 
             _uiHandler = new GtkHostUiHandler(this);
+            _gamePath = null;
         }
 
         private void MainWindow_WindowStateEvent(object o, WindowStateEventArgs args)
@@ -278,7 +285,7 @@ namespace Ryujinx.Ui
         {
             _virtualFileSystem.Reload();
 
-            HLE.Switch instance = new HLE.Switch(_virtualFileSystem, _contentManager, InitializeRenderer(), InitializeAudioEngine())
+            HLE.Switch instance = new HLE.Switch(_virtualFileSystem, _contentManager, _userChannelPersistence, InitializeRenderer(), InitializeAudioEngine())
             {
                 UiHandler = _uiHandler
             };
@@ -485,6 +492,7 @@ namespace Ryujinx.Ui
                 }
 
                 _emulationContext = device;
+                _gamePath = path;
 
                 _deviceExitStatus.Reset();
 
@@ -589,6 +597,7 @@ namespace Ryujinx.Ui
                 UpdateGameTable();
 
                 Task.Run(RefreshFirmwareLabel);
+                Task.Run(HandleRelaunch);
 
                 _stopEmulation.Sensitive            = false;
                 _firmwareInstallFile.Sensitive      = true;
@@ -962,6 +971,21 @@ namespace Ryujinx.Ui
             }));
         }
 
+        private void HandleRelaunch()
+        {
+            // If the previous index isn't -1, that mean we are relaunching.
+            if (_userChannelPersistence.PreviousIndex != -1)
+            {
+                LoadApplication(_gamePath);
+            }
+            else
+            {
+                // otherwise, clear state.
+                _userChannelPersistence = new UserChannelPersistence();
+                _gamePath = null;
+            }
+        }
+
         private void HandleInstallerDialog(FileChooserDialog fileChooser)
         {
             if (fileChooser.Run() == (int)ResponseType.Accept)

Ryujinx/Ui/TitleUpdateWindow.cs

@@ -9,6 +9,7 @@ using LibHac.Ns;
 using Ryujinx.Common.Configuration;
 using Ryujinx.Common.Logging;
 using Ryujinx.HLE.FileSystem;
+using Ryujinx.HLE.HOS;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -83,63 +84,47 @@ namespace Ryujinx.Ui
                 {
                     PartitionFileSystem nsp = new PartitionFileSystem(file.AsStorage());
 
-                    _virtualFileSystem.ImportTickets(nsp);
-
-                    foreach (DirectoryEntryEx fileEntry in nsp.EnumerateEntries("/", "*.nca"))
+                    try
                     {
-                        nsp.OpenFile(out IFile ncaFile, fileEntry.FullPath.ToU8Span(), OpenMode.Read).ThrowIfFailure();
+                        (Nca patchNca, Nca controlNca) = ApplicationLoader.GetGameUpdateDataFromPartition(_virtualFileSystem, nsp, _titleId, 0);
 
-                        try
+                        if (controlNca != null && patchNca != null)
                         {
-                            Nca nca = new Nca(_virtualFileSystem.KeySet, ncaFile.AsStorage());
-
-                            if ($"{nca.Header.TitleId.ToString("x16")[..^3]}000" == _titleId)
-                            {
-                                if (nca.Header.ContentType == NcaContentType.Control)
-                                {
-                                    ApplicationControlProperty controlData = new ApplicationControlProperty();
-
-                                    nca.OpenFileSystem(NcaSectionType.Data, IntegrityCheckLevel.None).OpenFile(out IFile nacpFile, "/control.nacp".ToU8Span(), OpenMode.Read).ThrowIfFailure();
-                                    nacpFile.Read(out _, 0, SpanHelpers.AsByteSpan(ref controlData), ReadOption.None).ThrowIfFailure();
-
-                                    RadioButton radioButton = new RadioButton($"Version {controlData.DisplayVersion.ToString()} - {path}");
-                                    radioButton.JoinGroup(_noUpdateRadioButton);
-
-                                    _availableUpdatesBox.Add(radioButton);
-                                    _radioButtonToPathDictionary.Add(radioButton, path);
-
-                                    radioButton.Show();
-                                    radioButton.Active = true;
-                                }
-                            }
-                            else
-                            {
-                                GtkDialog.CreateErrorDialog("The specified file does not contain an update for the selected title!");
-                                
-                                break;
-                            }
+                            ApplicationControlProperty controlData = new ApplicationControlProperty();
+
+                            controlNca.OpenFileSystem(NcaSectionType.Data, IntegrityCheckLevel.None).OpenFile(out IFile nacpFile, "/control.nacp".ToU8Span(), OpenMode.Read).ThrowIfFailure();
+                            nacpFile.Read(out _, 0, SpanHelpers.AsByteSpan(ref controlData), ReadOption.None).ThrowIfFailure();
+
+                            RadioButton radioButton = new RadioButton($"Version {controlData.DisplayVersion.ToString()} - {path}");
+                            radioButton.JoinGroup(_noUpdateRadioButton);
+
+                            _availableUpdatesBox.Add(radioButton);
+                            _radioButtonToPathDictionary.Add(radioButton, path);
+
+                            radioButton.Show();
+                            radioButton.Active = true;
                         }
-                        catch (InvalidDataException exception)
+                        else
                         {
-                            Logger.Error?.Print(LogClass.Application, $"{exception.Message}. Errored File: {path}");
-
-                            if (showErrorDialog)
-                            {
-                                GtkDialog.CreateInfoDialog("Ryujinx - Error", "Add Update Failed!", "The NCA header content type check has failed. This is usually because the header key is incorrect or missing.");
-                            }
-                            
-                            break;
+                            GtkDialog.CreateErrorDialog("The specified file does not contain an update for the selected title!");
                         }
-                        catch (MissingKeyException exception)
-                        {
-                            Logger.Error?.Print(LogClass.Application, $"Your key set is missing a key with the name: {exception.Name}. Errored File: {path}");
+                    }
+                    catch (InvalidDataException exception)
+                    {
+                        Logger.Error?.Print(LogClass.Application, $"{exception.Message}. Errored File: {path}");
 
-                            if (showErrorDialog)
-                            {
-                                GtkDialog.CreateInfoDialog("Ryujinx - Error", "Add Update Failed!", $"Your key set is missing a key with the name: {exception.Name}");
-                            }
+                        if (showErrorDialog)
+                        {
+                            GtkDialog.CreateInfoDialog("Ryujinx - Error", "Add Update Failed!", "The NCA header content type check has failed. This is usually because the header key is incorrect or missing.");
+                        }
+                    }
+                    catch (MissingKeyException exception)
+                    {
+                        Logger.Error?.Print(LogClass.Application, $"Your key set is missing a key with the name: {exception.Name}. Errored File: {path}");
 
-                            break;
+                        if (showErrorDialog)
+                        {
+                            GtkDialog.CreateInfoDialog("Ryujinx - Error", "Add Update Failed!", $"Your key set is missing a key with the name: {exception.Name}");
                         }
                     }
                 }