yuzu/src/core/loader/ncch.cpp
2015-01-15 22:23:08 +01:00

270 lines
9.4 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <memory>
#include "core/loader/ncch.h"
#include "core/hle/kernel/kernel.h"
#include "core/mem_map.h"
////////////////////////////////////////////////////////////////////////////////////////////////////
// Loader namespace
namespace Loader {
static const int kMaxSections = 8; ///< Maximum number of sections (files) in an ExeFs
static const int kBlockSize = 0x200; ///< Size of ExeFS blocks (in bytes)
/**
* Get the decompressed size of an LZSS compressed ExeFS file
* @param buffer Buffer of compressed file
* @param size Size of compressed buffer
* @return Size of decompressed buffer
*/
static u32 LZSS_GetDecompressedSize(const u8* buffer, u32 size) {
u32 offset_size = *(u32*)(buffer + size - 4);
return offset_size + size;
}
/**
* Decompress ExeFS file (compressed with LZSS)
* @param compressed Compressed buffer
* @param compressed_size Size of compressed buffer
* @param decompressed Decompressed buffer
* @param decompressed_size Size of decompressed buffer
* @return True on success, otherwise false
*/
static bool LZSS_Decompress(const u8* compressed, u32 compressed_size, u8* decompressed, u32 decompressed_size) {
const u8* footer = compressed + compressed_size - 8;
u32 buffer_top_and_bottom = *reinterpret_cast<const u32*>(footer);
u32 out = decompressed_size;
u32 index = compressed_size - ((buffer_top_and_bottom >> 24) & 0xFF);
u32 stop_index = compressed_size - (buffer_top_and_bottom & 0xFFFFFF);
memset(decompressed, 0, decompressed_size);
memcpy(decompressed, compressed, compressed_size);
while (index > stop_index) {
u8 control = compressed[--index];
for (unsigned i = 0; i < 8; i++) {
if (index <= stop_index)
break;
if (index <= 0)
break;
if (out <= 0)
break;
if (control & 0x80) {
// Check if compression is out of bounds
if (index < 2)
return false;
index -= 2;
u32 segment_offset = compressed[index] | (compressed[index + 1] << 8);
u32 segment_size = ((segment_offset >> 12) & 15) + 3;
segment_offset &= 0x0FFF;
segment_offset += 2;
// Check if compression is out of bounds
if (out < segment_size)
return false;
for (unsigned j = 0; j < segment_size; j++) {
// Check if compression is out of bounds
if (out + segment_offset >= decompressed_size)
return false;
u8 data = decompressed[out + segment_offset];
decompressed[--out] = data;
}
} else {
// Check if compression is out of bounds
if (out < 1)
return false;
decompressed[--out] = compressed[--index];
}
control <<= 1;
}
}
return true;
}
////////////////////////////////////////////////////////////////////////////////////////////////////
// AppLoader_NCCH class
FileType AppLoader_NCCH::IdentifyType(FileUtil::IOFile& file) {
u32 magic;
file.Seek(0x100, SEEK_SET);
if (1 != file.ReadArray<u32>(&magic, 1))
return FileType::Error;
if (MakeMagic('N', 'C', 'S', 'D') == magic)
return FileType::CCI;
if (MakeMagic('N', 'C', 'C', 'H') == magic)
return FileType::CXI;
return FileType::Error;
}
ResultStatus AppLoader_NCCH::LoadExec() const {
if (!is_loaded)
return ResultStatus::ErrorNotLoaded;
std::vector<u8> code;
if (ResultStatus::Success == ReadCode(code)) {
Memory::WriteBlock(entry_point, &code[0], code.size());
Kernel::LoadExec(entry_point);
return ResultStatus::Success;
}
return ResultStatus::Error;
}
ResultStatus AppLoader_NCCH::LoadSectionExeFS(const char* name, std::vector<u8>& buffer) const {
if (!file->IsOpen())
return ResultStatus::Error;
LOG_DEBUG(Loader, "%d sections:", kMaxSections);
// Iterate through the ExeFs archive until we find the .code file...
for (unsigned section_number = 0; section_number < kMaxSections; section_number++) {
const auto& section = exefs_header.section[section_number];
// Load the specified section...
if (strcmp(section.name, name) == 0) {
LOG_DEBUG(Loader, "%d - offset: 0x%08X, size: 0x%08X, name: %s", section_number,
section.offset, section.size, section.name);
s64 section_offset = (section.offset + exefs_offset + sizeof(ExeFs_Header) + ncch_offset);
file->Seek(section_offset, SEEK_SET);
if (is_compressed) {
// Section is compressed, read compressed .code section...
std::unique_ptr<u8[]> temp_buffer;
try {
temp_buffer.reset(new u8[section.size]);
} catch (std::bad_alloc&) {
return ResultStatus::ErrorMemoryAllocationFailed;
}
if (file->ReadBytes(&temp_buffer[0], section.size) != section.size)
return ResultStatus::Error;
// Decompress .code section...
u32 decompressed_size = LZSS_GetDecompressedSize(&temp_buffer[0], section.size);
buffer.resize(decompressed_size);
if (!LZSS_Decompress(&temp_buffer[0], section.size, &buffer[0], decompressed_size))
return ResultStatus::ErrorInvalidFormat;
} else {
// Section is uncompressed...
buffer.resize(section.size);
if (file->ReadBytes(&buffer[0], section.size) != section.size)
return ResultStatus::Error;
}
return ResultStatus::Success;
}
}
return ResultStatus::ErrorNotUsed;
}
ResultStatus AppLoader_NCCH::Load() {
if (is_loaded)
return ResultStatus::ErrorAlreadyLoaded;
if (!file->IsOpen())
return ResultStatus::Error;
// Reset read pointer in case this file has been read before.
file->Seek(0, SEEK_SET);
if (file->ReadBytes(&ncch_header, sizeof(NCCH_Header)) != sizeof(NCCH_Header))
return ResultStatus::Error;
// Skip NCSD header and load first NCCH (NCSD is just a container of NCCH files)...
if (MakeMagic('N', 'C', 'S', 'D') == ncch_header.magic) {
LOG_WARNING(Loader, "Only loading the first (bootable) NCCH within the NCSD file!");
ncch_offset = 0x4000;
file->Seek(ncch_offset, SEEK_SET);
file->ReadBytes(&ncch_header, sizeof(NCCH_Header));
}
// Verify we are loading the correct file type...
if (MakeMagic('N', 'C', 'C', 'H') != ncch_header.magic)
return ResultStatus::ErrorInvalidFormat;
// Read ExHeader...
if (file->ReadBytes(&exheader_header, sizeof(ExHeader_Header)) != sizeof(ExHeader_Header))
return ResultStatus::Error;
is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
entry_point = exheader_header.codeset_info.text.address;
LOG_INFO(Loader, "Name: %s", exheader_header.codeset_info.name);
LOG_DEBUG(Loader, "Code compressed: %s", is_compressed ? "yes" : "no");
LOG_DEBUG(Loader, "Entry point: 0x%08X", entry_point);
// Read ExeFS...
exefs_offset = ncch_header.exefs_offset * kBlockSize;
u32 exefs_size = ncch_header.exefs_size * kBlockSize;
LOG_DEBUG(Loader, "ExeFS offset: 0x%08X", exefs_offset);
LOG_DEBUG(Loader, "ExeFS size: 0x%08X", exefs_size);
file->Seek(exefs_offset + ncch_offset, SEEK_SET);
if (file->ReadBytes(&exefs_header, sizeof(ExeFs_Header)) != sizeof(ExeFs_Header))
return ResultStatus::Error;
is_loaded = true; // Set state to loaded
return LoadExec(); // Load the executable into memory for booting
}
ResultStatus AppLoader_NCCH::ReadCode(std::vector<u8>& buffer) const {
return LoadSectionExeFS(".code", buffer);
}
ResultStatus AppLoader_NCCH::ReadIcon(std::vector<u8>& buffer) const {
return LoadSectionExeFS("icon", buffer);
}
ResultStatus AppLoader_NCCH::ReadBanner(std::vector<u8>& buffer) const {
return LoadSectionExeFS("banner", buffer);
}
ResultStatus AppLoader_NCCH::ReadLogo(std::vector<u8>& buffer) const {
return LoadSectionExeFS("logo", buffer);
}
ResultStatus AppLoader_NCCH::ReadRomFS(std::vector<u8>& buffer) const {
if (!file->IsOpen())
return ResultStatus::Error;
// Check if the NCCH has a RomFS...
if (ncch_header.romfs_offset != 0 && ncch_header.romfs_size != 0) {
u32 romfs_offset = ncch_offset + (ncch_header.romfs_offset * kBlockSize) + 0x1000;
u32 romfs_size = (ncch_header.romfs_size * kBlockSize) - 0x1000;
LOG_DEBUG(Loader, "RomFS offset: 0x%08X", romfs_offset);
LOG_DEBUG(Loader, "RomFS size: 0x%08X", romfs_size);
buffer.resize(romfs_size);
file->Seek(romfs_offset, SEEK_SET);
if (file->ReadBytes(&buffer[0], romfs_size) != romfs_size)
return ResultStatus::Error;
return ResultStatus::Success;
}
LOG_DEBUG(Loader, "NCCH has no RomFS");
return ResultStatus::ErrorNotUsed;
}
u64 AppLoader_NCCH::GetProgramId() const {
return *reinterpret_cast<u64 const*>(&ncch_header.program_id[0]);
}
} // namespace Loader