Avoid parsing RomFS to directory in NCA

src/core/loader/deconstructed_rom_directory.cpp

@@ -7,6 +7,7 @@
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "core/file_sys/content_archive.h"
+#include "core/file_sys/control_metadata.h"
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
@@ -17,8 +18,50 @@
 
 namespace Loader {
 
-AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(FileSys::VirtualFile file)
-    : AppLoader(std::move(file)) {}
+AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(FileSys::VirtualFile file_)
+    : AppLoader(std::move(file_)) {
+    const auto dir = file->GetContainingDirectory();
+
+    // Icon
+    FileSys::VirtualFile icon_file = nullptr;
+    for (const auto& language : FileSys::LANGUAGE_NAMES) {
+        icon_file = dir->GetFile("icon_" + language + ".dat");
+        if (icon_file != nullptr) {
+            icon_data = icon_file->ReadAllBytes();
+            break;
+        }
+    }
+
+    if (icon_data.empty()) {
+        // Any png, jpeg, or bmp file
+        const auto& files = dir->GetFiles();
+        const auto icon_iter =
+            std::find_if(files.begin(), files.end(), [](const FileSys::VirtualFile& file) {
+                return file->GetExtension() == "png" || file->GetExtension() == "jpg" ||
+                       file->GetExtension() == "bmp" || file->GetExtension() == "jpeg";
+            });
+        if (icon_iter != files.end())
+            icon_data = (*icon_iter)->ReadAllBytes();
+    }
+
+    // Metadata
+    FileSys::VirtualFile nacp_file = dir->GetFile("control.nacp");
+    if (nacp_file == nullptr) {
+        const auto& files = dir->GetFiles();
+        const auto nacp_iter =
+            std::find_if(files.begin(), files.end(), [](const FileSys::VirtualFile& file) {
+                return file->GetExtension() == "nacp";
+            });
+        if (nacp_iter != files.end())
+            nacp_file = *nacp_iter;
+    }
+
+    if (nacp_file != nullptr) {
+        FileSys::NACP nacp(nacp_file);
+        title_id = nacp.GetTitleId();
+        name = nacp.GetApplicationName();
+    }
+}
 
 AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(
     FileSys::VirtualDir directory)
@@ -105,4 +148,25 @@ ResultStatus AppLoader_DeconstructedRomDirectory::ReadRomFS(FileSys::VirtualFile
     return ResultStatus::Success;
 }
 
+ResultStatus AppLoader_DeconstructedRomDirectory::ReadIcon(std::vector<u8>& buffer) {
+    if (icon_data.empty())
+        return ResultStatus::ErrorNotUsed;
+    buffer = icon_data;
+    return ResultStatus::Success;
+}
+
+ResultStatus AppLoader_DeconstructedRomDirectory::ReadProgramId(u64& out_program_id) {
+    if (name.empty())
+        return ResultStatus::ErrorNotUsed;
+    out_program_id = title_id;
+    return ResultStatus::Success;
+}
+
+ResultStatus AppLoader_DeconstructedRomDirectory::ReadTitle(std::string& title) {
+    if (name.empty())
+        return ResultStatus::ErrorNotUsed;
+    title = name;
+    return ResultStatus::Success;
+}
+
 } // namespace Loader

src/core/loader/deconstructed_rom_directory.h

@@ -39,11 +39,18 @@ public:
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& dir) override;
+    ResultStatus ReadIcon(std::vector<u8>& buffer) override;
+    ResultStatus ReadProgramId(u64& out_program_id) override;
+    ResultStatus ReadTitle(std::string& title) override;
 
 private:
     FileSys::ProgramMetadata metadata;
     FileSys::VirtualFile romfs;
     FileSys::VirtualDir dir;
+
+    std::vector<u8> icon_data;
+    std::string name;
+    u64 title_id{};
 };
 
 } // namespace Loader

src/core/loader/loader.cpp

@@ -68,7 +68,7 @@ FileType GuessFromFilename(const std::string& name) {
     return FileType::Unknown;
 }
 
-const char* GetFileTypeString(FileType type) {
+std::string GetFileTypeString(FileType type) {
     switch (type) {
     case FileType::ELF:
         return "ELF";

src/core/loader/loader.h

@@ -61,7 +61,7 @@ FileType GuessFromFilename(const std::string& name);
 /**
  * Convert a FileType into a string which can be displayed to the user.
  */
-const char* GetFileTypeString(FileType type);
+std::string GetFileTypeString(FileType type);
 
 /// Return type for functions in Loader namespace
 enum class ResultStatus {

src/core/loader/nca.cpp

@@ -77,8 +77,8 @@ ResultStatus AppLoader_NCA::ReadRomFS(FileSys::VirtualFile& dir) {
 }
 
 ResultStatus AppLoader_NCA::ReadProgramId(u64& out_program_id) {
-    if (nca == nullptr)
-        return ResultStatus::ErrorNotLoaded;
+    if (nca == nullptr || nca->GetStatus() != ResultStatus::Success)
+        return ResultStatus::ErrorInvalidFormat;
     out_program_id = nca->GetTitleId();
     return ResultStatus::Success;
 }

src/core/loader/nca.h

@@ -33,6 +33,7 @@ public:
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& dir) override;
+    ResultStatus ReadProgramId(u64& out_program_id) override;
 
     ResultStatus ReadProgramId(u64& out_program_id) override;
 
@@ -41,6 +42,7 @@ public:
 private:
     FileSys::ProgramMetadata metadata;
 
+    FileSys::NCAHeader header;
     std::unique_ptr<FileSys::NCA> nca;
     std::unique_ptr<AppLoader_DeconstructedRomDirectory> directory_loader;
 };