PSX Mode2/2352 disc geometry Confirmed
The Legend of Legaia disc is a standard PlayStation Mode2/Form1 CD. Sectors are 2352 bytes; only the 2048-byte user-data slice is meaningful for ISO9660 / file content.
Overview
Implementation: crates/iso/src/raw.rs.
Sector layout
| Bytes | Meaning |
|---|---|
| 0..12 | Sync pattern 00 FF FF FF FF FF FF FF FF FF FF 00 |
| 12..16 | Header (M:S:F address + mode byte) |
| 16..24 | Subheader (file/channel/submode/coding) |
| 24..2072 | User data (2048 bytes) |
| 2072..2352 | EDC + ECC error correction |
The iso crate's RawDisc::read_sector(lba) returns just the 2048-byte user data slice. read_user_data(lba, count, buf) reads a contiguous run.
const SECTOR_SIZE: usize = 2352;
const USER_DATA_OFFSET: usize = 24;
const USER_DATA_SIZE: usize = 2048;ISO9660 walk
Implementation: crates/iso/src/iso9660.rs.
Standard ISO9660:
- Primary Volume Descriptor at LBA 16.
- Root directory record at PVD offset 156.
- Each directory record begins with a length byte; records pad to even lengths.
The walker is iterative (not recursive) and yields stable-sorted file paths. The Legend of Legaia (USA) disc produces 45 files:
CDNAME.TXT DMY.DAT PROT.DAT SCUS_942.54 SYSTEM.CNF
MOV/MV1.STR ... MV6.STR
XA/XA1.XA ... XA21.XAMOV/MV*.STR are PSX MDEC video streams (delegate to public decoders like jPSXdec). XA/XA*.XA are XA-ADPCM audio; crates/xa decodes the format spec but the on-disc files use a non-standard interleave. PROT.DAT is the main asset archive - see PROT.DAT TOC. SCUS_942.54 is the executable. Reverse-engineering instructions: tooling/ghidra.md.