Attempt to add RomFS dumping

include/memory_mapped_file.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <filesystem>
+#include <system_error>
+
+#include "helpers.hpp"
+#include "mio/mio.hpp"
+
+// Minimal RAII wrapper over memory mapped files
+
+class MemoryMappedFile {
+	std::filesystem::path filePath = "";  // path of our file
+	mio::mmap_sink map;                   // mmap sink for our file
+
+	u8* pointer = nullptr;  // Pointer to the contents of the memory mapped file
+	bool opened = false;
+
+  public:
+	bool exists() const { return opened; }
+	u8* data() const { return pointer; }
+
+	std::error_code flush();
+	MemoryMappedFile();
+	MemoryMappedFile(const std::filesystem::path& path);
+
+	~MemoryMappedFile();
+	// Returns true on success
+	bool open(const std::filesystem::path& path);
+	void close();
+
+	// TODO: For memory-mapped output files we'll need some more stuff such as a constructor that takes path/size/shouldCreate as parameters
+
+	u8& operator[](size_t index) { return pointer[index]; }
+	const u8& operator[](size_t index) const { return pointer[index]; }
+
+	auto begin() { return map.begin(); }
+	auto end() { return map.end(); }
+	auto cbegin() { return map.cbegin(); }
+	auto cend() { return map.cend(); }
+
+	mio::mmap_sink& getSink() { return map; }
+};