eden-emu/eden - eden - InfoTonic

28988 Commits

159 Branches

26 Tags

224 MiB

Tree: f8b7651104

Commit Graph

Author SHA1 Message Date

Author	SHA1	Message	Date
PavelBARABANOV	815325ccec	[loader] add ZBIC (zstd variant) NSO decompression support for Switch 22.0+ (#4482 ) - [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions). - [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md) - [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability. ------------------- A new NSO compression method was introduced in Switch 22.0.0. This is a customized variant of zstd and is used when NSO flags have bit 7 set. Key characteristics: - ZSTD_MAGICNUMBER is set to 0x4349425A (b'ZBIC') instead of 0xFD2FB528 - ZSTD_LEGACY_SUPPORT is set to 0 - ZSTD_TRACE is set to 1, zstd version used is 1.5.7 (10507) - FSE_readNCount is replaced with a BIC (Binary Interpolative Coding) version which improves compression of entropy tables significantly Source: https://switchbrew.org/wiki/22.0.0 Implementation: - Detect ZBIC segments via NSO flag bit 7 (NsoFlags_UseZbicCompression) and/or ZBIC magic scan in nso.cpp - Fall back to LZ4 when ZBIC is not detected or returns unexpected size - Handle segment 0 alternate offset (0x100 vs 0x108) for both ZBIC and LZ4 References: - Atmosphère loader/strat zstd-zbic integration: `082115187a` - nxdumptool ZBIC segment compression support: `441e5c0904` - STORM_SWITCH ZBIC implementation: `1e09eb82b7` Tested with firmware 23.0.0 and ZBIC-compressed NSOs. Co-authored-by: xbzk <xbzk@eden-emu.dev> Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4482 Reviewed-by: CamilleLaVey <camillelavey99@gmail.com> Reviewed-by: lizzie <lizzie@eden-emu.dev> Reviewed-by: Maufeat <sahyno1996@gmail.com>	3 weeks ago

PavelBARABANOV

815325ccec

[loader] add ZBIC (zstd variant) NSO decompression support for Switch 22.0+ (#4482 )

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------
A new NSO compression method was introduced in Switch 22.0.0. This is a
customized variant of zstd and is used when NSO flags have bit 7 set.

Key characteristics:
  - ZSTD_MAGICNUMBER is set to 0x4349425A (b'ZBIC') instead of 0xFD2FB528
  - ZSTD_LEGACY_SUPPORT is set to 0
  - ZSTD_TRACE is set to 1, zstd version used is 1.5.7 (10507)
  - FSE_readNCount is replaced with a BIC (Binary Interpolative Coding)
    version which improves compression of entropy tables significantly

Source: https://switchbrew.org/wiki/22.0.0

Implementation:
  - Detect ZBIC segments via NSO flag bit 7 (NsoFlags_UseZbicCompression)
    and/or ZBIC magic scan in nso.cpp
  - Fall back to LZ4 when ZBIC is not detected or returns unexpected size
  - Handle segment 0 alternate offset (0x100 vs 0x108) for both ZBIC and LZ4

References:
  - Atmosphère loader/strat zstd-zbic integration:
    082115187a
  - nxdumptool ZBIC segment compression support:
    441e5c0904
  - STORM_SWITCH ZBIC implementation:
    1e09eb82b7

Tested with firmware 23.0.0 and ZBIC-compressed NSOs.

Co-authored-by: xbzk <xbzk@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4482
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: lizzie <lizzie@eden-emu.dev>
Reviewed-by: Maufeat <sahyno1996@gmail.com>

3 weeks ago

1 Commits (f8b76511041bb54070c52d1d09ea07d8108c592a)