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// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#include <memory>
#include "common/file_util.h"
#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
*/
u32 LZSS_GetDecompressedSize(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
*/
bool LZSS_Decompress(u8* compressed, u32 compressed_size, u8* decompressed, u32 decompressed_size) {
u8* footer = compressed + compressed_size - 8;
u32 buffer_top_and_bottom = *(u32*)footer;
u32 i, j;
u32 out = decompressed_size;
u32 index = compressed_size - ((buffer_top_and_bottom >> 24) & 0xFF);
u8 control;
u32 stop_index = compressed_size - (buffer_top_and_bottom & 0xFFFFFF);
memset(decompressed, 0, decompressed_size);
memcpy(decompressed, compressed, compressed_size);
while(index > stop_index) {
control = compressed[--index];
for(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(j = 0; j < segment_size; j++) {
u8 data;
// Check if compression is out of bounds
if(out + segment_offset >= decompressed_size) {
return false;
}
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
/// AppLoader_NCCH constructor
AppLoader_NCCH::AppLoader_NCCH(std::string& filename) {
this->filename = filename;
is_loaded = false;
is_compressed = false;
entry_point = 0;
ncch_offset = 0;
exefs_offset = 0;
}
/// AppLoader_NCCH destructor
AppLoader_NCCH::~AppLoader_NCCH() {
}
/**
* Loads .code section into memory for booting
* @return ResultStatus result of function
*/
const ResultStatus AppLoader_NCCH::LoadExec() const {
if (!is_loaded)
return ResultStatus::ErrorNotLoaded;
for (std::vector<u8>::size_type i = 0; i != code.size(); i++) {
Memory::Write8(entry_point + i, code[i]);
}
Kernel::LoadExec(entry_point);
return ResultStatus::Success;
}
/**
* Reads an application ExeFS section of an NCCH file into AppLoader (e.g. .code, .logo, etc.)
* @param file Handle to file to read from
* @param name Name of section to read out of NCCH file
* @param buffer Buffer to read section into.
*/
const ResultStatus AppLoader_NCCH::LoadSectionExeFS(File::IOFile& file, const char* name,
std::vector<u8>& buffer) {
// Iterate through the ExeFs archive until we find the .code file...
for (int i = 0; i < kMaxSections; i++) {
// Load the specified section...
if (strcmp((const char*)exefs_header.section[i].name, name) == 0) {
INFO_LOG(LOADER, "ExeFS section %d:", i);
INFO_LOG(LOADER, " name: %s", exefs_header.section[i].name);
INFO_LOG(LOADER, " offset: 0x%08X", exefs_header.section[i].offset);
INFO_LOG(LOADER, " size: 0x%08X", exefs_header.section[i].size);
s64 section_offset = (exefs_header.section[i].offset + exefs_offset +
sizeof(ExeFs_Header) + ncch_offset);
file.Seek(section_offset, 0);
// Section is compressed...
if (i == 0 && is_compressed) {
// Read compressed .code section...
std::unique_ptr<u8[]> temp_buffer(new u8[exefs_header.section[i].size]);
file.ReadBytes(&temp_buffer[0], exefs_header.section[i].size);
// Decompress .code section...
u32 decompressed_size = LZSS_GetDecompressedSize(&temp_buffer[0], exefs_header.section[i].size);
buffer.resize(decompressed_size);
if (!LZSS_Decompress(&temp_buffer[0], exefs_header.section[i].size, &buffer[0],
decompressed_size)) {
return ResultStatus::ErrorInvalidFormat;
}
// Section is uncompressed...
} else {
buffer.resize(exefs_header.section[i].size);
file.ReadBytes(&buffer[0], exefs_header.section[i].size);
}
return ResultStatus::Success;
}
}
return ResultStatus::ErrorNotUsed;
}
/**
* Loads an NCCH file (e.g. from a CCI, or the first NCCH in a CXI)
* @param error_string Pointer to string to put error message if an error has occurred
* @todo Move NCSD parsing out of here and create a separate function for loading these
* @return True on success, otherwise false
*/
const ResultStatus AppLoader_NCCH::Load() {
INFO_LOG(LOADER, "Loading NCCH file %s...", filename.c_str());
if (is_loaded)
return ResultStatus::ErrorAlreadyLoaded;
File::IOFile file(filename, "rb");
if (file.IsOpen()) {
NCCH_Header ncch_header;
file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
// Skip NCSD header and load first NCCH (NCSD is just a container of NCCH files)...
if (0 == memcmp(&ncch_header.magic, "NCSD", 4)) {
WARN_LOG(LOADER, "Only loading the first (bootable) NCCH within the NCSD file!");
ncch_offset = 0x4000;
file.Seek(ncch_offset, 0);
file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
}
// Verify we are loading the correct file type...
if (0 != memcmp(&ncch_header.magic, "NCCH", 4))
return ResultStatus::ErrorInvalidFormat;
// Read ExHeader...
file.ReadBytes(&exheader_header, sizeof(ExHeader_Header));
is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
entry_point = exheader_header.codeset_info.text.address;
INFO_LOG(LOADER, "Name: %s", exheader_header.codeset_info.name);
INFO_LOG(LOADER, "Code compressed: %s", is_compressed ? "yes" : "no");
INFO_LOG(LOADER, "Entry point: 0x%08X", entry_point);
// Read ExeFS...
exefs_offset = ncch_header.exefs_offset * kBlockSize;
u32 exefs_size = ncch_header.exefs_size * kBlockSize;
INFO_LOG(LOADER, "ExeFS offset: 0x%08X", exefs_offset);
INFO_LOG(LOADER, "ExeFS size: 0x%08X", exefs_size);
file.Seek(exefs_offset + ncch_offset, 0);
file.ReadBytes(&exefs_header, sizeof(ExeFs_Header));
// TODO(bunnei): Check ResultStatus of these...
LoadSectionExeFS(file, ".code", code);
LoadSectionExeFS(file, "banner", banner);
LoadSectionExeFS(file, "icon", icon);
LoadSectionExeFS(file, "logo", logo);
is_loaded = true; // Set state to loaded
LoadExec(); // Load the executable into memory for booting
return ResultStatus::Success;
}
return ResultStatus::Error;
}
} // namespace Loader
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