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ymir - RetroBIOS
Type standalone + libretro
Classification Community forks
Source standalone, libretro
Upstream https://github.com/StrikerX3/Ymir
Version {'standalone': 'v0.2.1', 'libretro': 'PR#746'}
Profiled 2026-03-26
Cores ymir
Systems sega-saturn
Technical notes

Ymir is a Sega Saturn emulator by StrikerX3. The libretro port by warmenhoven wraps the shared ymir-core library (PR #746, not yet merged). No .info file exists in libretro-core-info.

Standalone: scans configured directories recursively for files matching the expected size. No specific filenames required. Identifies known ROMs by XXH128 hash from an internal database (19 IPL variants, 4 CD Block versions, 2 ROM carts). Unknown files are accepted if size matches.

Libretro: searches {system}/sega_101.bin, mpr-17933.bin, saturn_bios.bin in order. First file found with exact 512 KiB size wins.

Batocera standalone: configgen maps IPLROMImages to /userdata/bios, CDBlockROMImages to /userdata/roms/saturn/cdb/, ROMCartImages to /userdata/roms/saturn.

No HLE fallback for IPL ROM. CD Block LLE is optional; falls back to HLE when disabled or no ROM found. Known CDB versions: 1.04, 1.05, 1.06.

ROM cartridges: KoF95 and Ultraman shipped with physical ROM carts. Auto-detected from game database when loading a disc.

Addon cartridges: 1M/4M DRAM expansion handled via core option (no files).

XXH128 hashes used for ROM identification only, not validation. All file loading validates size only.

4 files | 1 required, 3 optional | 4 in repo, 0 missing | 1 with HLE fallback Categories: 2 BIOS, 2 game data

sega_101.bin required in repo
Saturn IPL ROM (BIOS). Any region accepted.

  • System: sega-saturn
  • Size: 512.0 KB
  • Aliases: mpr-17933.bin, saturn_bios.bin
  • Validation: size
  • Source: {'standalone': 'apps/ymir-sdl3/src/util/rom_loader.cpp:9-22, apps/ymir-sdl3/src/app/rom_manager.cpp:14-56, libs/ymir-core/include/ymir/sys/memory_defs.hpp:9', 'libretro': 'libretro.cpp:260-263,534-558'}
  • Platforms: batocera, emudeck, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, romm

cdb/cdb_rom.bin optional in repo HLE fallback
SH1 CD Block ROM for low-level CD drive emulation. Scans cdb/ subdirectory for any matching file.

  • System: sega-saturn
  • Size: 64.0 KB
  • Validation: size
  • Source: {'standalone': 'apps/ymir-sdl3/src/util/rom_loader.cpp:25-38, apps/ymir-sdl3/src/app/rom_manager.cpp:58-93, libs/ymir-core/include/ymir/hw/sh1/sh1_defs.hpp:7', 'libretro': 'libretro.cpp:567-591'}

mpr-18811-mx.ic1 optional in repo game_data
ROM cartridge for The King of Fighters '95.

mpr-19367-mx.ic1 optional in repo game_data
ROM cartridge for Ultraman: Hikari no Kyojin Densetsu.

Generated on 2026-04-03T20:37:39Z