libretro/emulators/pcsx2-legacy.yml

emulator: PCSX2 Legacy
type: standalone
core_classification: frozen_snapshot
bios_mode: agnostic
source: "https://github.com/PCSX2/pcsx2"
upstream: "https://github.com/PCSX2/pcsx2"
profiled_date: "2026-08-08"
source_commit: "aaaf29557fe63870ede815dd6d2e48a98279ca59"
core_version: "1.6.0"
display_name: "Sony - PlayStation 2 (PCSX2 Legacy)"
cores:
  - pcsx2-legacy
  - PCSX2-LEGACY
systems:
  - sony-playstation-2
mode: standalone

notes: |
  wxWidgets line, frozen at 1.6.0. Emulation is split across separate plugin
  binaries loaded at runtime: GSdx, Spu2-X, LilyPad, cdvdGigaherz, DEV9ghzdrk,
  USBnull and FWnull. Default BIOS folder is bios/ under the user documents
  directory.
  ref: pcsx2/gui/AppConfig.cpp:76-80, pcsx2/gui/AppConfig.cpp:192-195

  BIOS selection lists every file in the folder with a *.* mask and keeps the
  ones whose romdir carries a RESET entry followed by a readable ROMVER, which
  supplies the version, the zone letter and the build date. Neither size nor
  hash is checked; the length test that would reject small images is commented
  out. A missing or zero-length image raises BiosLoadFailed.
  ref: pcsx2/gui/Panels/BiosSelectorPanel.cpp:151-177,
       pcsx2/ps2/BiosTools.cpp:74-167, pcsx2/ps2/BiosTools.cpp:325-341,
       pcsx2/ps2/BiosTools.cpp:261-323

  The three companion ROMs derive from the selected BIOS path. Each extension
  is first appended to the full name, then substituted for the existing one, so
  a BIOS at scph39001.bin is followed by scph39001.bin.rom1 then scph39001.rom1.
  A missing companion is logged and skipped, and a read error is downgraded to a
  warning. Every read is truncated to its destination region: 256 KB for rom1,
  512 KB for rom2, 1.75 MB for erom.
  ref: pcsx2/ps2/BiosTools.cpp:190-229, pcsx2/ps2/BiosTools.cpp:298-300,
       pcsx2/MemoryTypes.h:21-24

  The nvm and mec companions follow the same naming rule and are written with
  defaults when absent, so neither is user-supplied: 1024 zero bytes plus an
  iLink id for nvm, the four bytes 03 06 02 00 for mec.
  ref: pcsx2/CDVD/CDVD.cpp:93-122, pcsx2/CDVD/CDVD.cpp:138-182

  Two entries pair an XOR fold of the whole 4 MB ROM region with a ROMVER
  version to select debugger thread offsets. They gate nothing and cover no
  file on disk.
  ref: pcsx2/ps2/BiosTools.cpp:57-62, pcsx2/ps2/BiosTools.cpp:175-181,
       pcsx2/ps2/BiosTools.cpp:305-313

  An IRX image is injected at ROM+0x3C0000 when one is named on the command
  line. The path is whatever the user passes, so there is no fixed file.
  ref: pcsx2/ps2/BiosTools.cpp:302-303, pcsx2/gui/AppInit.cpp:542

  Shipped in the distribution tree and read from it: GameIndex.dbf, the
  widescreen patch archive cheats_ws.zip, which is skipped when a cheats_ws
  folder holds the patches, the pcsx2_Main and pcsx2_Iconized catalogs under
  Langs, and the external shader pair shaders/GSdx.fx and
  shaders/GSdx_FX_Settings.ini, off by default.
  ref: pcsx2/gui/AppGameDatabase.h:53, pcsx2/gui/AppCoreThread.cpp:459-465,
       pcsx2/gui/i18n.cpp:82-89, plugins/GSdx/GSdx.cpp:441-443

  host.irx sits behind a comment. ps2hw.dat is read only by zerogs and
  zzogl-pg, both gated on EXTRA_PLUGINS, which carries no default and is off,
  and both absent from the Windows solution that builds the release. USBqemu
  ships in the same disused solution and GSdx_legacy is gated on GSDX_LEGACY.
  ref: pcsx2/ps2/BiosTools.cpp:296, cmake/SelectPcsx2Plugins.cmake:178-209,
       cmake/BuildParameters.cmake:41-50, old_plugins.sln

files:
  - name: ps2-0230a-20080220.bin
    system: sony-playstation-2
    required: true
    description: "PS2 console BIOS"
    note: "Any file in the BIOS folder whose romdir holds RESET and ROMVER is accepted, whatever its name or size. Naming convention ps2-VVVVr-YYYYMMDD.bin carries version, region and date."
    source_ref: "pcsx2/ps2/BiosTools.cpp:261-323, pcsx2/ps2/BiosTools.cpp:74-167"

  - name: rom1.bin
    system: sony-playstation-2
    required: false
    max_size: 262144
    description: "DVD player ROM"
    note: "Tried as {bios}.rom1 then {biosbase}.rom1. Read into the 256 KB ROM1 region and truncated to it. Logged and skipped when absent."
    source_ref: "pcsx2/ps2/BiosTools.cpp:190-229, pcsx2/ps2/BiosTools.cpp:298, pcsx2/MemoryTypes.h:22"

  - name: ROM2.BIN
    system: sony-playstation-2
    required: false
    max_size: 524288
    description: "Chinese ROM extension"
    note: "Tried as {bios}.rom2 then {biosbase}.rom2. Read into the 512 KB ROM2 region and truncated to it. Present on Chinese region consoles."
    source_ref: "pcsx2/ps2/BiosTools.cpp:190-229, pcsx2/ps2/BiosTools.cpp:299, pcsx2/MemoryTypes.h:23"

  - name: EROM.BIN
    system: sony-playstation-2
    required: false
    max_size: 1835008
    description: "DVD player extension ROM"
    note: "Tried as {bios}.erom then {biosbase}.erom. Read into the 1.75 MB EROM region and truncated to it."
    source_ref: "pcsx2/ps2/BiosTools.cpp:190-229, pcsx2/ps2/BiosTools.cpp:300, pcsx2/MemoryTypes.h:24"

  - name: eeprom.dat
    system: sony-playstation-2
    required: false
    hle_fallback: true
    size: 64
    description: "DEV9 network adapter EEPROM"
    note: "Opened by the DEV9ghzdrk plugin from the working directory and mapped over 64 bytes. A compiled-in EEPROM holding the default MAC stands in when the file is missing or cannot be mapped."
    source_ref: "plugins/dev9ghzdrk/DEV9.cpp:176-227, plugins/dev9ghzdrk/DEV9.cpp:71-81"

  - name: flash.dat
    system: sony-playstation-2
    required: false
    hle_fallback: true
    max_size: 8650752
    description: "DEV9 SmartMedia flash image"
    note: "Opened by the DEV9ghzdrk plugin from the working directory at init and read as 1024 blocks of 16 pages of 512 bytes plus 16 ECC bytes. The card is filled with 0xFF when the file is absent or short."
    source_ref: "plugins/dev9ghzdrk/flash.cpp:60-83, plugins/dev9ghzdrk/flash.cpp:21-28"