From 9a040e1cde73f0438fc247c9b5d4e83740458acd Mon Sep 17 00:00:00 2001
From: wheremyfoodat <gponiris2004@gmail.com>
Date: Sat, 1 Oct 2022 03:28:12 +0300
Subject: [PATCH] Add IOFile and headers for NCSD/NCCH

---
 CMakeLists.txt          |  2 +-
 include/io_file.hpp     | 82 +++++++++++++++++++++++++++++++++++++++++
 include/loader/ncch.hpp | 15 ++++++++
 include/loader/ncsd.hpp | 18 +++++++++
 4 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 include/io_file.hpp
 create mode 100644 include/loader/ncch.hpp
 create mode 100644 include/loader/ncsd.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e0fb021b..7deabaef 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -66,7 +66,7 @@ set(HEADER_FILES include/emulator.hpp include/helpers.hpp include/opengl.hpp inc
                  include/services/gsp_gpu.hpp include/services/gsp_lcd.hpp include/arm_defs.hpp
                  include/PICA/gpu.hpp include/PICA/regs.hpp include/services/ndm.hpp
                  include/PICA/shader.hpp include/PICA/shader_unit.hpp include/PICA/float_types.hpp
-                 include/logger.hpp
+                 include/logger.hpp include/loader/ncch.hpp include/loader/ncsd.hpp include/io_file.hpp
 )
 
 set(THIRD_PARTY_SOURCE_FILES third_party/imgui/imgui.cpp
diff --git a/include/io_file.hpp b/include/io_file.hpp
new file mode 100644
index 00000000..3dea5737
--- /dev/null
+++ b/include/io_file.hpp
@@ -0,0 +1,82 @@
+#pragma once
+#include <cstdint>
+#include <cstdio>
+#include <filesystem>
+#include <utility>
+
+#ifdef _MSC_VER
+// 64 bit offsets for MSVC
+#define fseeko _fseeki64
+#define ftello _ftelli64
+#define fileno _fileno
+#endif
+
+#ifdef _CRT_SECURE_NO_WARNINGS
+#undef _CRT_SECURE_NO_WARNINGS
+#endif
+
+class IOFile {
+    FILE* handle = nullptr;
+
+public:
+    bool isOpen() {
+        return handle != nullptr;
+    }
+
+    bool open(const std::filesystem::path& path, const char* permissions = "rb") {
+        const auto str = path.string(); // For some reason converting paths directly with c_str() doesn't work
+        return open(str.c_str(), permissions);
+    }
+
+    bool open(const char* filename, const char* permissions = "rb") {
+        handle = std::fopen(filename, permissions);
+        return isOpen();
+    }
+
+    void close() {
+        if (isOpen()) {
+            fclose(handle);
+            handle = nullptr;
+        }
+    }
+
+    std::pair<bool, std::size_t> read(void* data, std::size_t length, std::size_t dataSize) {
+        if (!isOpen()) {
+            return { false, std::numeric_limits<std::size_t>::max() };
+        }
+
+        if (length == 0) return { true, 0 };
+        return { true, std::fread(data, dataSize, length, handle) };
+    }
+
+    auto readBytes(void* data, std::size_t count) {
+        return read(data, count, sizeof(std::uint8_t));
+    }
+
+    std::uint64_t size() {
+        if (!isOpen()) return 0;
+
+        std::uint64_t pos = ftello(handle);
+        if (fseeko(handle, 0, SEEK_END) != 0) {
+            return 0;
+        }
+
+        std::uint64_t size = ftello(handle);
+        if ((size != pos) && (fseeko(handle, pos, SEEK_SET) != 0)) {
+            return 0;
+        }
+
+        return size;
+    }
+
+    bool seek(std::int64_t offset, int origin = 0) {
+        if (!isOpen() || fseeko(handle, offset, origin) != 0)
+            return false;
+
+        return true;
+    }
+
+    bool rewind() {
+        return seek(0, 0);
+    }
+};
\ No newline at end of file
diff --git a/include/loader/ncch.hpp b/include/loader/ncch.hpp
new file mode 100644
index 00000000..993c29ce
--- /dev/null
+++ b/include/loader/ncch.hpp
@@ -0,0 +1,15 @@
+#include "helpers.hpp"
+
+struct NCCH {
+    bool isNew3DS = false;
+    bool initialized = false;
+    bool mountRomFS = false;
+    bool encrypted = false;
+
+    static constexpr u64 mediaUnit = 0x200;
+    u64 size = 0; // Size of NCCH converted to bytes
+
+    // Header: 0x200 byte NCCH header
+    // Returns true on success, false on failure
+    bool loadFromHeader(u8* header);
+};
\ No newline at end of file
diff --git a/include/loader/ncsd.hpp b/include/loader/ncsd.hpp
new file mode 100644
index 00000000..2a8eddba
--- /dev/null
+++ b/include/loader/ncsd.hpp
@@ -0,0 +1,18 @@
+#include <array>
+#include "helpers.hpp"
+#include "io_file.hpp"
+#include "loader/ncch.hpp"
+
+struct NCSD {
+    static constexpr u64 mediaUnit = 0x200;
+
+    struct Partition {
+        u64 offset = 0; // Offset of partition converted to bytes
+        u64 length = 0; // Length of partition converted to bytes
+        NCCH ncch;
+    };
+
+    IOFile file;
+    u64 size = 0; // Image size according to the header converted to bytes
+    std::array<Partition, 8> partitions; // NCCH partitions
+};