Implement reading from RomFS

include/fs/archive_base.hpp

@@ -44,6 +44,18 @@ struct FSPath {
     u32 pointer; // Pointer to the actual path data
 };
 
+class ArchiveBase;
+
+struct FileSession {
+    ArchiveBase* archive = nullptr;
+    FSPath path;
+    bool isOpen;
+
+    FileSession(ArchiveBase* archive, const FSPath& filePath, bool isOpen = true) : archive(archive), isOpen(isOpen) {
+        path = filePath;
+    }
+};
+
 class ArchiveBase {
 protected:
     using Result = u32;
@@ -56,6 +68,10 @@ public:
     virtual bool openFile(const FSPath& path) = 0;
 
     virtual ArchiveBase* openArchive(FSPath& path) = 0;
+
+    // Read size bytes from a file starting at offset "offset" into a certain buffer in memory
+    // Returns the number of bytes read, or nullopt if the read failed
+    virtual std::optional<u32> readFile(FileSession* file, u64 offset, u32 size, u32 dataPointer) = 0;
     
     ArchiveBase(Memory& mem) : mem(mem) {}
 };

include/fs/archive_ncch.hpp

@@ -4,25 +4,11 @@ class SelfNCCHArchive : public ArchiveBase {
 
 public:
 	SelfNCCHArchive(Memory& mem) : ArchiveBase(mem) {}
-	
+
 	u64 getFreeBytes() override { return 0; }
 	const char* name() override { return "SelfNCCH"; }
 
-	bool openFile(const FSPath& path) override {
-		if (path.type != PathType::Binary) {
-			printf("Invalid SelfNCCH path type");
-			return false;
-		}
-
-		return true;
-	}
-
-	ArchiveBase* openArchive(FSPath& path) override {
-		if (path.type != PathType::Empty) {
-			printf("Invalid path type for SelfNCCH archive: %d\n", path.type);
-			return nullptr;
-		}
-
-		return this;
-	}
+	bool openFile(const FSPath& path) override;
+	ArchiveBase* openArchive(FSPath& path) override;
+	std::optional<u32> readFile(FileSession* file, u64 offset, u32 size, u32 dataPointer) override;
 };

include/kernel/kernel.hpp

@@ -84,6 +84,7 @@ class Kernel {
 	MAKE_LOG_FUNCTION(logSVC, svcLogger)
 	MAKE_LOG_FUNCTION(logDebugString, debugStringLogger)
 	MAKE_LOG_FUNCTION(logError, errorLogger)
+	MAKE_LOG_FUNCTION(logFileIO, fileIOLogger)
 
 	// SVC implementations
 	void arbitrateAddress();
@@ -110,6 +111,7 @@ class Kernel {
 
 	// File operations
 	void handleFileOperation(u32 messagePointer, Handle file);
+	void closeFile(u32 messagePointer, Handle file);
 	void readFile(u32 messagePointer, Handle file);
 
 public:

include/kernel/kernel_types.hpp

@@ -93,15 +93,6 @@ struct Session {
     Session(Handle portHandle) : portHandle(portHandle) {}
 };
 
-struct FileSession {
-    ArchiveBase* archive = nullptr;
-    FSPath path;
-
-    FileSession(ArchiveBase* archive, const FSPath& filePath) : archive(archive) {
-        path = filePath;
-    }
-};
-
 enum class ThreadStatus {
     Running,     // Currently running
     Ready,       // Ready to run

include/logger.hpp

@@ -21,6 +21,7 @@ namespace Log {
     static Logger<true> kernelLogger;
     static Logger<true> debugStringLogger; // Enables output for the outputDebugString SVC
     static Logger<true> errorLogger;
+    static Logger<true> fileIOLogger;
     static Logger<true> svcLogger;
     static Logger<true> gpuLogger;
 

include/memory.hpp

@@ -139,6 +139,14 @@ public:
 	u32 getLinearHeapVaddr();
 	u8* getFCRAM() { return fcram; }
 
+	NCCH* getCXI() {
+		if (loadedCXI.has_value()) {
+			return &loadedCXI.value();
+		} else {
+			return nullptr;
+		}
+	}
+
 	// Returns whether "addr" is aligned to a page (4096 byte) boundary
 	static constexpr bool isAligned(u32 addr) {
 		return (addr & pageMask) == 0;
@@ -165,4 +173,9 @@ public:
 	// TODO: Find out
 	// Returns a pointer to the FCRAM block used for the memory if allocation succeeded
 	u8* mapSharedMemory(Handle handle, u32 vaddr, u32 myPerms, u32 otherPerms);
+
+	// Backup of the game's CXI partition info, if any
+	std::optional<NCCH> loadedCXI = std::nullopt;
+	// File handle for reading the loaded ncch
+	IOFile CXIFile;
 };