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[NCSD/NCCH] More NCSD parsing

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wheremyfoodat 2022-10-02 03:26:24 +03:00
parent 6b6cc7ca2f
commit 71cc187f93
3 changed files with 75 additions and 10 deletions
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60
src/core/loader/ncch.cpp
View file

@ -2,7 +2,7 @@
#include "loader/ncch.hpp"
#include "memory.hpp"
bool NCCH::loadFromHeader(u8* header) {
bool NCCH::loadFromHeader(u8* header, IOFile& file) {
if (header[0x100] != 'N' || header[0x101] != 'C' || header[0x102] != 'C' || header[0x103] != 'H') {
printf("Invalid header on NCCH\n");
return false;
@ -18,8 +18,15 @@ bool NCCH::loadFromHeader(u8* header) {
fixedCryptoKey = (header[0x188 + 7] & 0x1) == 0x1;
mountRomFS = (header[0x188 + 7] & 0x2) != 0x2;
encrypted = (header[0x188 + 7] & 0x4) != 0x4;
// Read ExeFS and RomFS info
exeFS.offset = u64(*(u32*)&header[0x1A0]) * mediaUnit;
exeFS.size = u64(*(u32*)&header[0x1A4]) * mediaUnit;
exeFS.hashRegionSize = u64(*(u32*)&header[0x1A8]) * mediaUnit;
bool encryptedExheader = encrypted;
romFS.offset = u64(*(u32*)&header[0x1B0]) * mediaUnit;
romFS.size = u64(*(u32*)&header[0x1B4]) * mediaUnit;
romFS.hashRegionSize = u64(*(u32*)&header[0x1B8]) * mediaUnit;
if (fixedCryptoKey) {
Helpers::panic("Fixed crypto keys for NCCH");
@ -29,12 +36,13 @@ bool NCCH::loadFromHeader(u8* header) {
const u8* exheader = &header[0x200]; // Extended NCCH header
const u64 jumpID = *(u64*)&exheader[0x1C0 + 0x8];
// TODO: How does this even work
if (u32(programID) == u32(jumpID) && encryptedExheader) {
printf("Exheader is supposedly ecrypted but not actually encrypted\n");
encryptedExheader = false;
} else if (encryptedExheader) {
Helpers::panic("Encrypted exheader");
// It seems like some decryption tools will decrypt the file, without actually setting the NoCrypto flag in the NCCH header
// This is a nice and easy hack to see if a file is pretending to be encrypted, taken from 3DMoo and Citra
if (u32(programID) == u32(jumpID) && encrypted) {
printf("NCSD is supposedly ecrypted but not actually encrypted\n");
encrypted = false;
} else if (encrypted) {
Helpers::panic("Encrypted NCSD file");
}
compressExeFS = (exheader[0xD] & 1) != 0;
@ -44,6 +52,42 @@ bool NCCH::loadFromHeader(u8* header) {
printf("Stack size: %08X\nBSS size: %08X\n", stackSize, bssSize);
// Read ExeFS
if (hasExeFS()) {
printf("ExeFS offset: %08llX, size: %08llX\n", exeFS.offset, exeFS.size);
auto exeFSOffset = fileOffset + exeFS.offset;
constexpr size_t exeFSHeaderSize = 0x200;
u8 exeFSHeader[exeFSHeaderSize];
file.seek(exeFSOffset);
auto [success, bytes] = file.readBytes(exeFSHeader, exeFSHeaderSize);
if (!success || bytes != exeFSHeaderSize) {
printf("Failed to parse ExeFS header\n");
return false;
}
// ExeFS format allows up to 10 files
for (int file = 0; file < 10; file++) {
u8* fileInfo = &exeFSHeader[file * 16];
char name[9];
std::memcpy(name, fileInfo, 8); // Get file name as a string
name[8] = '\0'; // Add null terminator to it just in case there's none
u32 fileOffset = *(u32*)&fileInfo[0x8];
u32 fileSize = *(u32*)&fileInfo[0xC];
if (fileSize != 0) {
printf("File %d. Name: %s, Size: %08X, Offset: %08X\n", file, name, fileSize, fileOffset);
}
}
}
if (hasRomFS()) {
printf("RomFS offset: %08llX, size: %08llX\n", romFS.offset, romFS.size);
}
if (stackSize != VirtualAddrs::DefaultStackSize) {
Helpers::panic("Stack size != 0x4000");
}

6
src/core/loader/ncsd.cpp
View file

@ -42,9 +42,13 @@ std::optional<NCSD> Memory::loadNCSD(const std::filesystem::path& path) {
for (int i = 0; i < 8; i++) {
auto& partition = ncsd.partitions[i];
NCCH& ncch = partition.ncch;
partition.offset = u64(partitionData[i * 2]) * NCSD::mediaUnit;
partition.length = u64(partitionData[i * 2 + 1]) * NCSD::mediaUnit;
ncch.partitionIndex = i;
ncch.fileOffset = partition.offset;
if (partition.length != 0) { // Initialize the NCCH of each partition
ncsd.file.seek(partition.offset);
@ -57,7 +61,7 @@ std::optional<NCSD> Memory::loadNCSD(const std::filesystem::path& path) {
return std::nullopt;
}
if (!partition.ncch.loadFromHeader(ncchHeader)) {
if (!ncch.loadFromHeader(ncchHeader, ncsd.file)) {
printf("Invalid NCCH partition\n");
return std::nullopt;
}