1 files changed, 175 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs b/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs
new file mode 100644
index 00000000..473f374d
--- /dev/null
+++ b/src/Ryujinx.HLE/Loaders/Processes/Extensions/NcaExtensions.cs
@@ -0,0 +1,175 @@
+using LibHac;
+using LibHac.Common;
+using LibHac.Fs;
+using LibHac.Fs.Fsa;
+using LibHac.Loader;
+using LibHac.Ncm;
+using LibHac.Ns;
+using LibHac.Tools.FsSystem;
+using LibHac.Tools.FsSystem.NcaUtils;
+using Ryujinx.Common.Logging;
+using System.IO;
+using System.Linq;
+using ApplicationId = LibHac.Ncm.ApplicationId;
+
+namespace Ryujinx.HLE.Loaders.Processes.Extensions
+{
+    static class NcaExtensions
+    {
+        public static ProcessResult Load(this Nca nca, Switch device, Nca patchNca, Nca controlNca)
+        {
+            // Extract RomFs and ExeFs from NCA.
+            IStorage    romFs = nca.GetRomFs(device, patchNca);
+            IFileSystem exeFs = nca.GetExeFs(device, patchNca);
+
+            if (exeFs == null)
+            {
+                Logger.Error?.Print(LogClass.Loader, "No ExeFS found in NCA");
+
+                return ProcessResult.Failed;
+            }
+
+            // Load Npdm file.
+            MetaLoader metaLoader = exeFs.GetNpdm();
+
+            // Collecting mods related to AocTitleIds and ProgramId.
+            device.Configuration.VirtualFileSystem.ModLoader.CollectMods(
+                device.Configuration.ContentManager.GetAocTitleIds().Prepend(metaLoader.GetProgramId()),
+                device.Configuration.VirtualFileSystem.ModLoader.GetModsBasePath(),
+                device.Configuration.VirtualFileSystem.ModLoader.GetSdModsBasePath());
+
+            // Load Nacp file.
+            var nacpData = new BlitStruct<ApplicationControlProperty>(1);
+
+            if (controlNca != null)
+            {
+                nacpData = controlNca.GetNacp(device);
+            }
+
+            /* TODO: Rework this since it's wrong and doesn't work as it takes the DisplayVersion from a "potential" inexistant update.
+
+            // Load program 0 control NCA as we are going to need it for display version.
+            (_, Nca updateProgram0ControlNca) = GetGameUpdateData(_device.Configuration.VirtualFileSystem, mainNca.Header.TitleId.ToString("x16"), 0, out _);
+
+            // NOTE: Nintendo doesn't guarantee that the display version will be updated on sub programs when updating a multi program application.
+            //       As such, to avoid PTC cache confusion, we only trust the program 0 display version when launching a sub program.
+            if (updateProgram0ControlNca != null && _device.Configuration.UserChannelPersistence.Index != 0)
+            {
+                nacpData.Value.DisplayVersion = updateProgram0ControlNca.GetNacp(_device).Value.DisplayVersion;
+            }
+
+            */
+
+            ProcessResult processResult = exeFs.Load(device, nacpData, metaLoader);
+
+            // Load RomFS.
+            if (romFs == null)
+            {
+                Logger.Warning?.Print(LogClass.Loader, "No RomFS found in NCA");
+            }
+            else
+            {
+                romFs = device.Configuration.VirtualFileSystem.ModLoader.ApplyRomFsMods(processResult.ProgramId, romFs);
+
+                device.Configuration.VirtualFileSystem.SetRomFs(processResult.ProcessId, romFs.AsStream(FileAccess.Read));
+            }
+
+            // Don't create save data for system programs.
+            if (processResult.ProgramId != 0 && (processResult.ProgramId < SystemProgramId.Start.Value || processResult.ProgramId > SystemAppletId.End.Value))
+            {
+                // Multi-program applications can technically use any program ID for the main program, but in practice they always use 0 in the low nibble.
+                // We'll know if this changes in the future because applications will get errors when trying to mount the correct save.
+                ProcessLoaderHelper.EnsureSaveData(device, new ApplicationId(processResult.ProgramId & ~0xFul), nacpData);
+            }
+
+            return processResult;
+        }
+
+        public static int GetProgramIndex(this Nca nca)
+        {
+            return (int)(nca.Header.TitleId & 0xF);
+        }
+
+        public static bool IsProgram(this Nca nca)
+        {
+            return nca.Header.ContentType == NcaContentType.Program;
+        }
+
+        public static bool IsPatch(this Nca nca)
+        {
+            int dataIndex = Nca.GetSectionIndexFromType(NcaSectionType.Data, NcaContentType.Program);
+
+            return nca.IsProgram() && nca.SectionExists(NcaSectionType.Data) && nca.Header.GetFsHeader(dataIndex).IsPatchSection();
+        }
+
+        public static bool IsControl(this Nca nca)
+        {
+            return nca.Header.ContentType == NcaContentType.Control;
+        }
+
+        public static IFileSystem GetExeFs(this Nca nca, Switch device, Nca patchNca = null)
+        {
+            IFileSystem exeFs = null;
+
+            if (patchNca == null)
+            {
+                if (nca.CanOpenSection(NcaSectionType.Code))
+                {
+                    exeFs = nca.OpenFileSystem(NcaSectionType.Code, device.System.FsIntegrityCheckLevel);
+                }
+            }
+            else
+            {
+                if (patchNca.CanOpenSection(NcaSectionType.Code))
+                {
+                    exeFs = nca.OpenFileSystemWithPatch(patchNca, NcaSectionType.Code, device.System.FsIntegrityCheckLevel);
+                }
+            }
+
+            return exeFs;
+        }
+
+        public static IStorage GetRomFs(this Nca nca, Switch device, Nca patchNca = null)
+        {
+            IStorage romFs = null;
+
+            if (patchNca == null)
+            {
+                if (nca.CanOpenSection(NcaSectionType.Data))
+                {
+                    romFs = nca.OpenStorage(NcaSectionType.Data, device.System.FsIntegrityCheckLevel);
+                }
+            }
+            else
+            {
+                if (patchNca.CanOpenSection(NcaSectionType.Data))
+                {
+                    romFs = nca.OpenStorageWithPatch(patchNca, NcaSectionType.Data, device.System.FsIntegrityCheckLevel);
+                }
+            }
+
+            return romFs;
+        }
+
+        public static BlitStruct<ApplicationControlProperty> GetNacp(this Nca controlNca, Switch device)
+        {
+            var nacpData = new BlitStruct<ApplicationControlProperty>(1);
+
+            using var controlFile = new UniqueRef<IFile>();
+
+            Result result = controlNca.OpenFileSystem(NcaSectionType.Data, device.System.FsIntegrityCheckLevel)
+                                      .OpenFile(ref controlFile.Ref, "/control.nacp".ToU8Span(), OpenMode.Read);
+
+            if (result.IsSuccess())
+            {
+                result = controlFile.Get.Read(out long bytesRead, 0, nacpData.ByteSpan, ReadOption.None);
+            }
+            else
+            {
+                nacpData.ByteSpan.Clear();
+            }
+
+            return nacpData;
+        }
+    }
+}
+\ No newline at end of file