// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <vector>
#include <lz4.h>
#include "common/logging/log.h"
#include "common/swap.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/resource_limit.h"
#include "core/loader/nso.h"
#include "core/memory.h"
namespace Loader {
struct NsoSegmentHeader {
u32_le offset;
u32_le location;
u32_le size;
u32_le alignment;
};
static_assert(sizeof(NsoSegmentHeader) == 0x10, "NsoSegmentHeader has incorrect size.");
struct NsoHeader {
u32_le magic;
INSERT_PADDING_BYTES(0xc);
std::array<NsoSegmentHeader, 3> segments; // Text, RoData, Data (in that order)
u32_le bss_size;
INSERT_PADDING_BYTES(0x1c);
std::array<u32_le, 3> segments_compressed_size;
};
static_assert(sizeof(NsoHeader) == 0x6c, "NsoHeader has incorrect size.");
struct ModHeader {
u32_le magic;
u32_le dynamic_offset;
u32_le bss_start_offset;
u32_le bss_end_offset;
u32_le eh_frame_hdr_start_offset;
u32_le eh_frame_hdr_end_offset;
u32_le module_offset; // Offset to runtime-generated module object. typically equal to .bss base
};
static_assert(sizeof(ModHeader) == 0x1c, "ModHeader has incorrect size.");
FileType AppLoader_NSO::IdentifyType(FileUtil::IOFile& file) {
u32 magic = 0;
file.Seek(0, SEEK_SET);
if (1 != file.ReadArray<u32>(&magic, 1)) {
return FileType::Error;
}
if (MakeMagic('N', 'S', 'O', '0') == magic) {
return FileType::NSO;
}
return FileType::Error;
}
static std::vector<u8> ReadSegment(FileUtil::IOFile& file, const NsoSegmentHeader& header,
int compressed_size) {
std::vector<u8> compressed_data;
compressed_data.resize(compressed_size);
file.Seek(header.offset, SEEK_SET);
if (compressed_size != file.ReadBytes(compressed_data.data(), compressed_size)) {
LOG_CRITICAL(Loader, "Failed to read %d NSO LZ4 compressed bytes", compressed_size);
return {};
}
std::vector<u8> uncompressed_data;
uncompressed_data.resize(header.size);
const int bytes_uncompressed = LZ4_decompress_safe(
reinterpret_cast<const char*>(compressed_data.data()),
reinterpret_cast<char*>(uncompressed_data.data()), compressed_size, header.size);
ASSERT_MSG(bytes_uncompressed == header.size && bytes_uncompressed == uncompressed_data.size(),
"%d != %d != %d", bytes_uncompressed, header.size, uncompressed_data.size());
return uncompressed_data;
}
static constexpr u32 PageAlignSize(u32 size) {
return (size + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
}
VAddr AppLoader_NSO::LoadNso(const std::string& path, VAddr load_base, bool relocate) {
FileUtil::IOFile file(path, "rb");
if (!file.IsOpen()) {
return {};
}
// Read NSO header
NsoHeader nso_header{};
file.Seek(0, SEEK_SET);
if (sizeof(NsoHeader) != file.ReadBytes(&nso_header, sizeof(NsoHeader))) {
return {};
}
if (nso_header.magic != MakeMagic('N', 'S', 'O', '0')) {
return {};
}
// Build program image
Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("", 0);
std::vector<u8> program_image;
for (int i = 0; i < nso_header.segments.size(); ++i) {
std::vector<u8> data =
ReadSegment(file, nso_header.segments[i], nso_header.segments_compressed_size[i]);
program_image.resize(nso_header.segments[i].location);
program_image.insert(program_image.end(), data.begin(), data.end());
codeset->segments[i].addr = nso_header.segments[i].location;
codeset->segments[i].offset = nso_header.segments[i].location;
codeset->segments[i].size = PageAlignSize(static_cast<u32>(data.size()));
}
// MOD header pointer is at .text offset + 4
u32 module_offset;
std::memcpy(&module_offset, program_image.data() + 4, sizeof(u32));
// Read MOD header
ModHeader mod_header{};
u32 bss_size{Memory::PAGE_SIZE}; // Default .bss to page size if MOD0 section doesn't exist
std::memcpy(&mod_header, program_image.data() + module_offset, sizeof(ModHeader));
const bool has_mod_header{mod_header.magic == MakeMagic('M', 'O', 'D', '0')};
if (has_mod_header) {
// Resize program image to include .bss section and page align each section
bss_size = PageAlignSize(mod_header.bss_end_offset - mod_header.bss_start_offset);
codeset->data.size += bss_size;
}
const u32 image_size{PageAlignSize(static_cast<u32>(program_image.size()) + bss_size)};
program_image.resize(image_size);
// Relocate symbols if there was a proper MOD header - This must happen after the image has been
// loaded into memory
if (has_mod_header && relocate) {
Relocate(program_image, module_offset + mod_header.dynamic_offset, load_base);
}
// Load codeset for current process
codeset->name = path;
codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
Kernel::g_current_process->LoadModule(codeset, load_base);
return load_base + image_size;
}
ResultStatus AppLoader_NSO::Load(Kernel::SharedPtr<Kernel::Process>& process) {
if (is_loaded) {
return ResultStatus::ErrorAlreadyLoaded;
}
if (!file.IsOpen()) {
return ResultStatus::Error;
}
// Load and relocate "rtld" NSO
static constexpr VAddr base_addr{Memory::PROCESS_IMAGE_VADDR};
process = Kernel::Process::Create("main");
VAddr next_base_addr{LoadNso(filepath, base_addr)};
if (!next_base_addr) {
return ResultStatus::ErrorInvalidFormat;
}
// Load and relocate remaining submodules
for (const auto& module_name : {"main", "sdk", "subsdk0", "subsdk1"}) {
const std::string module_path =
filepath.substr(0, filepath.find_last_of("/\\")) + "/" + module_name;
next_base_addr = LoadNso(module_path, next_base_addr);
if (!next_base_addr) {
LOG_WARNING(Loader, "failed to find load module: %s", module_name);
}
}
process->svc_access_mask.set();
process->address_mappings = default_address_mappings;
process->resource_limit =
Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
process->Run(base_addr, 48, Kernel::DEFAULT_STACK_SIZE);
ResolveImports();
is_loaded = true;
return ResultStatus::Success;
}
} // namespace Loader