Files
sphaira/sphaira/source/yati/container/nsp.cpp
2025-06-09 12:11:05 +01:00

145 lines
4.0 KiB
C++

#include "yati/container/nsp.hpp"
#include "defines.hpp"
#include "log.hpp"
#include <memory>
#include <cstring>
namespace sphaira::yati::container {
namespace {
#define PFS0_MAGIC 0x30534650
struct Pfs0Header {
u32 magic;
u32 total_files;
u32 string_table_size;
u32 padding;
};
struct Pfs0FileTableEntry {
u64 data_offset;
u64 data_size;
u32 name_offset;
u32 padding;
};
// stdio-like wrapper for std::vector
struct BufHelper {
BufHelper() = default;
BufHelper(std::span<const u8> data) {
write(data);
}
void write(const void* data, u64 size) {
if (offset + size >= buf.size()) {
buf.resize(offset + size);
}
std::memcpy(buf.data() + offset, data, size);
offset += size;
}
void write(std::span<const u8> data) {
write(data.data(), data.size());
}
void seek(u64 where_to) {
offset = where_to;
}
[[nodiscard]]
auto tell() const {
return offset;
}
std::vector<u8> buf;
u64 offset{};
};
} // namespace
Result Nsp::GetCollections(Collections& out) {
u64 bytes_read;
s64 off = 0;
// get header
Pfs0Header header{};
R_TRY(m_source->Read(std::addressof(header), off, sizeof(header), std::addressof(bytes_read)));
R_UNLESS(header.magic == PFS0_MAGIC, Result_NspBadMagic);
off += bytes_read;
// get file table
std::vector<Pfs0FileTableEntry> file_table(header.total_files);
R_TRY(m_source->Read(file_table.data(), off, file_table.size() * sizeof(Pfs0FileTableEntry), std::addressof(bytes_read)))
off += bytes_read;
// get string table
std::vector<char> string_table(header.string_table_size);
R_TRY(m_source->Read(string_table.data(), off, string_table.size(), std::addressof(bytes_read)))
off += bytes_read;
out.reserve(header.total_files);
for (u32 i = 0; i < header.total_files; i++) {
CollectionEntry entry;
entry.name = string_table.data() + file_table[i].name_offset;
entry.offset = off + file_table[i].data_offset;
entry.size = file_table[i].data_size;
out.emplace_back(entry);
}
R_SUCCEED();
}
auto Nsp::Build(std::span<CollectionEntry> entries, s64& size) -> std::vector<u8> {
BufHelper buf;
Pfs0Header header{};
std::vector<Pfs0FileTableEntry> file_table(entries.size());
std::vector<char> string_table;
u64 string_offset{};
u64 data_offset{};
for (u32 i = 0; i < entries.size(); i++) {
file_table[i].data_offset = data_offset;
file_table[i].data_size = entries[i].size;
file_table[i].name_offset = string_offset;
file_table[i].padding = 0;
string_table.resize(string_offset + entries[i].name.length() + 1);
std::memcpy(string_table.data() + string_offset, entries[i].name.c_str(), entries[i].name.length() + 1);
data_offset += file_table[i].data_size;
string_offset += entries[i].name.length() + 1;
}
// Add padding to the string table so that the header as a whole is well-aligned
const auto nameless_header_size = sizeof(Pfs0Header) + (file_table.size() * sizeof(Pfs0FileTableEntry));
auto padded_string_table_size = ((nameless_header_size + string_table.size() + 0x1F) & ~0x1F) - nameless_header_size;
// Add manual padding if the full Partition FS header would already be properly aligned.
if (padded_string_table_size == string_table.size()) {
padded_string_table_size += 0x20;
}
string_table.resize(padded_string_table_size);
header.magic = PFS0_MAGIC;
header.total_files = entries.size();
header.string_table_size = string_table.size();
header.padding = 0;
buf.write(&header, sizeof(header));
buf.write(file_table.data(), sizeof(Pfs0FileTableEntry) * file_table.size());
buf.write(string_table.data(), string_table.size());
// calculate nsp size.
size = buf.tell();
for (const auto& e : file_table) {
size += e.data_size;
}
return buf.buf;
}
} // namespace sphaira::yati::container