// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <map>
#include <string>
#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"
using Kernel::CodeSet;
using Kernel::SharedPtr;
namespace Loader {
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;
}
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, Data, RoData (in that order)
INSERT_PADDING_BYTES(0x20);
std::array<u32_le, 3> segments_compressed_size;
};
static_assert(sizeof(NsoHeader) == 0x6c, "NsoHeader has incorrect size.");
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_partial(reinterpret_cast<const char*>(compressed_data.data()),
reinterpret_cast<char*>(uncompressed_data.data()),
compressed_size, header.size, header.size);
ASSERT_MSG(bytes_uncompressed == header.size, "%d != %d", bytes_uncompressed, header.size);
return uncompressed_data;
}
struct Symbol {
Symbol(std::string&& name, u64 value) : name(std::move(name)), value(value) {}
std::string name;
u64 value;
};
struct Import {
VAddr ea;
s64 addend;
};
enum class RelocationType : u32 {
ABS64 = 257,
GLOB_DAT = 1025,
JUMP_SLOT = 1026,
RELATIVE = 1027
};
enum DynamicType : u32 {
DT_NULL = 0,
DT_PLTRELSZ = 2,
DT_STRTAB = 5,
DT_SYMTAB = 6,
DT_RELA = 7,
DT_RELASZ = 8,
DT_STRSZ = 10,
DT_JMPREL = 23,
};
void WriteRelocations(const std::vector<Symbol>& symbols, VAddr loadbase, u64 roff, u64 size,
bool is_jump_relocation, std::map<std::string, Import>& imports,
std::map<std::string, VAddr>& exports) {
for (u64 i = 0; i < size; i += 0x18) {
VAddr addr = loadbase + roff + i;
u64 offset = Memory::Read64(addr);
u64 info = Memory::Read64(addr + 8);
u64 addend_unsigned = Memory::Read64(addr + 16);
s64 addend{};
std::memcpy(&addend, &addend_unsigned, sizeof(u64));
RelocationType rtype = static_cast<RelocationType>(info & 0xFFFFFFFF);
u32 rsym = static_cast<u32>(info >> 32);
VAddr ea = loadbase + offset;
const Symbol& symbol = symbols[rsym];
switch (rtype) {
case RelocationType::RELATIVE:
if (!symbol.name.empty()) {
exports[symbol.name] = loadbase + addend;
}
Memory::Write64(ea, loadbase + addend);
break;
case RelocationType::JUMP_SLOT:
case RelocationType::GLOB_DAT:
if (!symbol.value) {
imports[symbol.name] = {ea, 0};
} else {
exports[symbol.name] = symbol.value;
Memory::Write64(ea, symbol.value);
}
break;
case RelocationType::ABS64:
if (!symbol.value) {
imports[symbol.name] = {ea, addend};
} else {
exports[symbol.name] = symbol.value + addend;
Memory::Write64(ea, symbol.value + addend);
}
break;
default:
LOG_CRITICAL(Loader, "Unknown relocation type: %d", rtype);
break;
}
}
}
void Relocate(VAddr loadbase, std::map<std::string, Import>& imports,
std::map<std::string, VAddr>& exports) {
u32 modoff = Memory::Read32(loadbase + 4);
ASSERT_MSG(Memory::Read32(loadbase + modoff) == MakeMagic('M', 'O', 'D', '0'),
"Expected MOD section");
u64 dynoff = loadbase + modoff + Memory::Read32(loadbase + modoff + 4);
std::map<u64, u64> dynamic;
while (1) {
u64 tag = Memory::Read64(dynoff);
u64 value = Memory::Read64(dynoff + 8);
dynoff += 16;
if (tag == DT_NULL) {
break;
}
dynamic[tag] = value;
}
u64 strtabsize = dynamic[DT_STRSZ];
std::vector<u8> strtab;
strtab.resize(strtabsize);
Memory::ReadBlock(loadbase + dynamic[DT_STRTAB], strtab.data(), strtabsize);
VAddr addr = loadbase + dynamic[DT_SYMTAB];
std::vector<Symbol> symbols;
while (1) {
const u32 stname = Memory::Read32(addr);
const u16 stshndx = Memory::Read16(addr + 6);
const u64 stvalue = Memory::Read64(addr + 8);
addr += 24;
if (stname >= strtabsize) {
break;
}
std::string name = reinterpret_cast<char*>(&strtab[stname]);
if (stvalue) {
exports[name] = loadbase + stvalue;
symbols.emplace_back(std::move(name), loadbase + stvalue);
} else {
symbols.emplace_back(std::move(name), 0);
}
}
if (dynamic.find(DT_RELA) != dynamic.end()) {
WriteRelocations(symbols, loadbase, dynamic[DT_RELA], dynamic[DT_RELASZ], false, imports,
exports);
}
if (dynamic.find(DT_JMPREL) != dynamic.end()) {
WriteRelocations(symbols, loadbase, dynamic[DT_JMPREL], dynamic[DT_PLTRELSZ], true, imports,
exports);
}
}
static VAddr GetEntryPoint(const std::map<std::string, VAddr>& exports) {
// Find nnMain function, set entrypoint to that address
const auto& search = exports.find("nnMain");
if (search != exports.end()) {
return search->second;
}
return {};
}
static SharedPtr<CodeSet> LoadModule(const std::string& filepath, VAddr loadbase,
std::map<std::string, Import>& imports,
std::map<std::string, VAddr>& exports) {
FileUtil::IOFile file(filepath, "rb");
if (!file.IsOpen())
return {};
NsoHeader header{};
file.Seek(0, SEEK_SET);
if (sizeof(NsoHeader) != file.ReadBytes(&header, sizeof(NsoHeader)))
return {};
// Build program image
SharedPtr<CodeSet> codeset = CodeSet::Create("", 0);
std::vector<u8> program_image;
for (int i = 0; i < header.segments.size(); ++i) {
std::vector<u8> data =
ReadSegment(file, header.segments[i], header.segments_compressed_size[i]);
program_image.resize(header.segments[i].location);
program_image.insert(program_image.end(), data.begin(), data.end());
codeset->segments[i].addr = header.segments[i].location;
codeset->segments[i].offset = header.segments[i].location;
codeset->segments[i].size = (data.size() + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
}
program_image.resize((program_image.size() + Memory::PAGE_MASK) & ~Memory::PAGE_MASK);
codeset->name = filepath;
codeset->entrypoint = 0; // Set after relocation
codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
return codeset;
}
ResultStatus AppLoader_NSO::Load() {
if (is_loaded)
return ResultStatus::ErrorAlreadyLoaded;
if (!file.IsOpen())
return ResultStatus::Error;
static constexpr VAddr loadbase = 0x7100000000;
std::map<std::string, Import> imports;
std::map<std::string, VAddr> exports;
// Load and relocate "main" NSO
auto codeset = LoadModule(filepath, loadbase, imports, exports);
Kernel::g_current_process = Kernel::Process::Create(codeset);
Kernel::g_current_process->svc_access_mask.set();
Kernel::g_current_process->address_mappings = default_address_mappings;
Kernel::g_current_process->resource_limit =
Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
Kernel::g_current_process->LoadModule(codeset, loadbase);
Relocate(loadbase, imports, exports);
codeset->entrypoint = GetEntryPoint(exports);
Kernel::g_current_process->Run(48, Kernel::DEFAULT_STACK_SIZE);
// Load and relocate "sdk" NSO
static constexpr VAddr sdkbase = 0x7200000000;
const std::string sdkpath = filepath.substr(0, filepath.find_last_of("/\\")) + "/sdk";
auto sdk_codeset = LoadModule(sdkpath, sdkbase, imports, exports);
Kernel::g_current_process->LoadModule(sdk_codeset, sdkbase);
Relocate(sdkbase, imports, exports);
// Resolve imports
for (const auto& import : imports) {
const auto& search = exports.find(import.first);
if (search != exports.end()) {
Memory::Write64(import.second.ea, search->second + import.second.addend);
} else {
LOG_CRITICAL(Loader, "Unresolved import: %s", import.first.c_str());
}
}
is_loaded = true;
return ResultStatus::Success;
}
} // namespace Loader
