// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#include "common/file_util.h"
#include "core/loader/ncch.h"
#include "core/hle/kernel/kernel.h"
#include "core/mem_map.h"
////////////////////////////////////////////////////////////////////////////////////////////////////
/// NCCH header (Note: "NCCH" appears to be a publically unknown acronym)
struct NCCH_Header {
u8 signature[0x100];
char magic[4];
u32 content_size;
u8 partition_id[8];
u16 maker_code;
u16 version;
u8 reserved_0[4];
u8 program_id[8];
u8 temp_flag;
u8 reserved_1[0x2f];
u8 product_code[0x10];
u8 extended_header_hash[0x20];
u32 extended_header_size;
u8 reserved_2[4];
u8 flags[8];
u32 plain_region_offset;
u32 plain_region_size;
u8 reserved_3[8];
u32 exefs_offset;
u32 exefs_size;
u32 exefs_hash_region_size;
u8 reserved_4[4];
u32 romfs_offset;
u32 romfs_size;
u32 romfs_hash_region_size;
u8 reserved_5[4];
u8 exefs_super_block_hash[0x20];
u8 romfs_super_block_hash[0x20];
};
////////////////////////////////////////////////////////////////////////////////////////////////////
// ExeFS (executable file system) headers
typedef struct {
char name[8];
u32 offset;
u32 size;
} ExeFs_SectionHeader;
typedef struct {
ExeFs_SectionHeader section[8];
u8 reserved[0x80];
u8 hashes[8][0x20];
} ExeFs_Header;
////////////////////////////////////////////////////////////////////////////////////////////////////
// ExHeader (executable file system header) headers
struct ExHeader_SystemInfoFlags{
u8 reserved[5];
u8 flag;
u8 remaster_version[2];
} exheader_systeminfoflags;
struct ExHeader_CodeSegmentInfo{
u32 address;
u32 num_max_pages;
u32 code_size;
} exheader_codesegmentinfo;
struct ExHeader_CodeSetInfo {
u8 name[8];
ExHeader_SystemInfoFlags flags;
ExHeader_CodeSegmentInfo text;
u8 stacksize[4];
ExHeader_CodeSegmentInfo ro;
u8 reserved[4];
ExHeader_CodeSegmentInfo data;
u8 bsssize[4];
};
struct ExHeader_DependencyList{
u8 program_id[0x30][8];
};
struct ExHeader_SystemInfo{
u32 save_data_size;
u8 reserved[4];
u8 jump_id[8];
u8 reserved_2[0x30];
};
struct ExHeader_StorageInfo{
u8 ext_save_data_id[8];
u8 system_save_data_id[8];
u8 reserved[8];
u8 access_info[7];
u8 other_attributes;
};
struct ExHeader_ARM11_SystemLocalCaps{
u8 program_id[8];
u8 flags[8];
u8 resource_limit_descriptor[0x10][2];
ExHeader_StorageInfo storage_info;
u8 service_access_control[0x20][8];
u8 reserved[0x1f];
u8 resource_limit_category;
};
struct ExHeader_ARM11_KernelCaps{
u8 descriptors[28][4];
u8 reserved[0x10];
};
struct ExHeader_ARM9_AccessControl{
u8 descriptors[15];
u8 descversion;
};
struct ExHeader_Header{
ExHeader_CodeSetInfo codeset_info;
ExHeader_DependencyList dependency_list;
ExHeader_SystemInfo system_info;
ExHeader_ARM11_SystemLocalCaps arm11_system_local_caps;
ExHeader_ARM11_KernelCaps arm11_kernel_caps;
ExHeader_ARM9_AccessControl arm9_access_control;
struct {
u8 signature[0x100];
u8 ncch_public_key_modulus[0x100];
ExHeader_ARM11_SystemLocalCaps arm11_system_local_caps;
ExHeader_ARM11_KernelCaps arm11_kernel_caps;
ExHeader_ARM9_AccessControl arm9_access_control;
} access_desc;
};
////////////////////////////////////////////////////////////////////////////////////////////////////
// Loader namespace
namespace Loader {
const int kExeFs_MaxSections = 8; ///< Maximum number of sections (files) in an ExeFs
const int kExeFs_BlockSize = 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
* @param error_string String populated with error message on failure
* @return True on success, otherwise false
*/
bool LZSS_Decompress(u8* compressed, u32 compressed_size, u8* decompressed, u32 decompressed_size,
std::string* error_string) {
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) {
if(index < 2) {
*error_string = "Compression out of bounds";
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;
if(out < segment_size) {
*error_string = "Compression out of bounds";
return false;
}
for(j = 0; j < segment_size; j++) {
u8 data;
if(out + segment_offset >= decompressed_size) {
*error_string = "Compression out of bounds";
return false;
}
data = decompressed[out + segment_offset];
decompressed[--out] = data;
}
} else {
if(out < 1) {
*error_string = "Compression out of bounds";
return false;
}
decompressed[--out] = compressed[--index];
}
control <<= 1;
}
}
return true;
}
/**
* Load a data buffer into memory at the specified address
* @param addr Address to load memory into
* @param buffer Buffer of data to load into memory
* @param size Size of data to load into memory
* @todo Perhaps move this code somewhere more generic?
*/
void LoadBuffer(const u32 addr, const u8* const buffer, const int size) {
u32 *dst = (u32*)Memory::GetPointer(addr);
u32 *src = (u32*)buffer;
int size_aligned = (size + 3) / 4;
for (int j = 0; j < size_aligned; j++) {
*dst++ = (*src++);
}
return;
}
/**
* Loads an NCCH file (e.g. from a CCI, or the first NCCH in a CXI)
* @param filename String filename of NCCH file
* @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
*/
bool Load_NCCH(std::string& filename, std::string* error_string) {
INFO_LOG(LOADER, "Loading NCCH file %s...", filename.c_str());
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)...
int ncch_off = 0; // Offset to NCCH header, can be 0 or after NCSD header
if (memcmp(&ncch_header.magic, "NCSD", 4) == 0) {
WARN_LOG(LOADER, "Only loading the first (bootable) NCCH within the NCSD file!");
ncch_off = 0x4000;
file.Seek(ncch_off, 0);
file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
}
// Verify we are loading the correct file type...
if (memcmp(&ncch_header.magic, "NCCH", 4) != 0) {
*error_string = "Invalid NCCH magic number (likely incorrect file type)";
return false;
}
// Read ExHeader
ExHeader_Header exheader_header;
file.ReadBytes(&exheader_header, sizeof(ExHeader_Header));
bool is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
INFO_LOG(LOADER, "Name: %s", exheader_header.codeset_info.name);
INFO_LOG(LOADER, "Code compressed: %s", is_compressed ? "yes" : "no");
// Read ExeFS
u32 exefs_offset = ncch_header.exefs_offset * kExeFs_BlockSize;
u32 exefs_size = ncch_header.exefs_size * kExeFs_BlockSize;
INFO_LOG(LOADER, "ExeFS offset: 0x%08X", exefs_offset);
INFO_LOG(LOADER, "ExeFS size: 0x%08X", exefs_size);
ExeFs_Header exefs_header;
file.Seek(exefs_offset + ncch_off, 0);
file.ReadBytes(&exefs_header, sizeof(ExeFs_Header));
// Iterate through the ExeFs archive until we find the .code file...
for (int i = 0; i < kExeFs_MaxSections; i++) {
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);
// Load the .code section (executable code)...
if (strcmp((char*) exefs_header.section[i].name, ".code") == 0) {
file.Seek(exefs_header.section[i].offset + exefs_offset + sizeof(ExeFs_Header) +
ncch_off, 0);
u8* buffer = new u8[exefs_header.section[i].size];
file.ReadBytes(buffer, exefs_header.section[i].size);
// Load compressed executable...
if (i == 0 && is_compressed) {
u32 decompressed_size = LZSS_GetDecompressedSize(buffer,
exefs_header.section[i].size);
u8* decompressed_buffer = new u8[decompressed_size];
if (!LZSS_Decompress(buffer, exefs_header.section[i].size, decompressed_buffer,
decompressed_size, error_string)) {
return false;
}
// Load .code section into memory...
LoadBuffer(exheader_header.codeset_info.text.address, decompressed_buffer,
decompressed_size);
delete[] decompressed_buffer;
// Load uncompressed executable...
} else {
// Load .code section into memory...
LoadBuffer(exheader_header.codeset_info.text.address, buffer,
exefs_header.section[i].size);
}
delete[] buffer;
// Setup kernel emulation to boot .code section...
Kernel::LoadExec(exheader_header.codeset_info.text.address);
// No need to load the other files from ExeFS until we do something with them...
return true;
}
}
}
return false;
}
} // namespace Loader
