mirror of
https://github.com/Abdess/retroarch_system.git
synced 2026-10-20 18:59:07 -05:00
Abdessamad Derraz
a5da20d897
The binary reads two optional settings, BootROM and CDBIOS, each a path the user picks. The retail Jaguar CD BIOS is recognised by a 64-bit FNV-1a of its first 16 KB, which the collected dump matches.
69 lines
3.1 KiB
YAML
69 lines
3.1 KiB
YAML
emulator: BigPEmu
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type: standalone
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source: "https://www.richwhitehouse.com/jaguar/"
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upstream: "https://www.richwhitehouse.com/jaguar/"
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version_source:
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url: "https://www.richwhitehouse.com/jaguar/index.php?content=download"
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pattern: 'Current Version: <strong>([0-9.]+)</strong>'
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profiled_date: "2026-10-20"
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core_version: "1.221"
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display_name: "BigPEmu (Atari Jaguar)"
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cores:
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- bigpemu
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systems:
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- atari-jaguar
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- atari-jaguarcd
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mode: standalone
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notes: |
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Closed-source Atari Jaguar and Jaguar CD emulator by Rich Whitehouse. Read
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from the Linux x64 binary of BigPEmu_Linux64_v1221.tar.gz (sha1
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11e8188481ec3dd6508f2497fb35c6ae15907975, from the author's builds page),
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decompiled with Ghidra at its default image base of 0x100000. The Windows
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archive BigPEmu_v1221.zip (sha1 879cf1c2ecb426a066703b742f626e14f37d683e)
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carries the same settings and strings.
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Both firmware images are optional settings, BootROM and CDBIOS, each holding
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a path the user picks in the menu (Boot ROM Image, CD BIOS Image). Nothing
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is searched by name. A set path is read whole into memory when an image is
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booted, through the same reader that loads software images, which also
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accepts a zip. No size is checked.
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ref: bigpemu FUN_006d8be0 (BootROM and CDBIOS read at boot),
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FUN_006f4e20 (setting path to buffer), FUN_007d7e20 (image reader),
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FUN_00762210 and FUN_00761d50 (CDBIOS path setting and browser)
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Without a boot ROM a cartridge runs from its own entry point. Without a CD
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BIOS a disc boots on three replacement blocks decompressed from the
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executable, 4 KB, 8 KB and 4 KB. The CD BIOS is read only when a disc is mounted. Audio discs
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refuse to load without one, and the System Audio virtual disc asks for one.
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ref: bigpemu FUN_006d8be0 (embedded CD boot blocks), FUN_0075f5a0
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(STR_AUDIO_CD_NO_BIOS), FUN_00762550 (STR_VDISC_NEEDBIOS)
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EEPROM and memory track files are written by the emulator itself, named
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game<hash>_eeprom.bigpeep and game<hash>_memtrack.bigpmt, beside the image
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or in user data. Scripts, screen effects, VR lenses and cheat_codes.json
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ship in the archive.
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ref: bigpemu FUN_007d55b0, FUN_007d5690
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files:
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- name: "[BIOS] Atari Jaguar (World).j64"
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system: atari-jaguar
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required: false
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config_key: BootROM
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description: "Jaguar cartridge boot ROM, read when the Boot ROM Image setting is set"
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source_ref: "bigpemu FUN_006d8be0 (BootROM read), FUN_006a0c30 (handed to the machine)"
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note: >-
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The setting accepts any image under any name and no content is checked.
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The name is a label for the retail boot ROM.
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- name: "[BIOS] Atari Jaguar CD (World).j64"
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system: atari-jaguarcd
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required: false
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config_key: CDBIOS
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description: "Jaguar CD BIOS, read when the CD BIOS Image setting is set and a disc is mounted"
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source_ref: "bigpemu FUN_006d8be0 (CDBIOS read), FUN_006a8ae0 (FNV-1a check), FUN_0075f5a0 (audio discs)"
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note: >-
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Any image is used. The retail CD BIOS is recognised by the 64-bit FNV-1a
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of its first 16384 bytes, 0x7000d38f77b6d407, which installs a dedicated
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handler set for it. Needed to play audio discs.
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