Libretro Core Descriptor Specification 1.0
This is the first version of the Libretro Core Descriptor specification used by RetroGTK. These descriptor specification's goal is to help Libretro frontends to know the capabilities and requirements of a Libretro core, avoiding the user to manually select one or to hardcode this information.
This specification is mainly thought for Libretro cores installed
$(libdir)/libretro, where the Libretro
core descriptor files are expected to be found with the
.info files have a few problems like lacking:
Their syntax also feels a bit out of place in the realm of GNOME.
It's problably the NIH syndrome hitting again, but better can probably be done for RetroGTK with this Libretro core descriptor specification by focusing on improving readability and extensibility, by making the files blend better into the GNOME environment and by supporting the needs of RetroGTK better.
The Libretro cores can be of different types, different types don't have access to the same sections.
The current version of the Libretro core description specification recognizes these types:
Game: represents a standalone game; games should only contain the
Libretrosection and must be run without a game file;
Emulator: represents a video game console emulator; emulators must be run with a game, they must support at least one platform and the platforms may require firmwares.
|Type||string||Yes||To allow the addition of new types in the future (such as
|Version||string||No||Version of the Libretro Core Descriptor Specification that the descriptor conforms with. Descriptors that conform with this version of the specification should use 1.0. Note that the version field is not required to be present.|
|Name||localestring||Yes||Specific name of the Libretro core, for example "Nestopia".|
|Icon||localestring||No||Icon to display in the Libretro frontend, etc. If the name is an absolute path, the given file will be used. If the name is not an absolute path, the algorithm described in the Icon Theme Specification will be used to locate the icon.|
|Module||string||Yes||Module file containing the Libretro core this descriptor is describing.|
|LibretroVersion||string||Yes||The version of Libretro implemented by this core.|
|Authors||localestring(s)||No||The authors names in the form "
|License||string(s)||No||A license identifier from the SPDX License List or MAME.|
Only available to the
|MimeType||string(s)||Yes||The MIME type(s) supported by this Libretro core.|
|Firmwares||string(s)||No||The firmwares used for this platform.|
Only available to the
|Path||string||Yes||The path to the firmware file. If relative, it is from the "system" directory (cf. the Libretro API).|
|MD5||string||No||The MD5 checksum of the firmware file.|
|SHA-512||string||No||The SHA-512 checksum of the firmware file.|
|Mandatory||boolean||Yes||Whether the firmware is mandatory to run the games or not. All mandatory firmwares for a platform must exist in order to run a game from that platform, even if not all are actually needed: being stricter than needed helps solving complex cases like per-region firmwares or requiring multiple firmwares.|
To help Libretro cores advertise which platforms they support and to help Libretro frontends find a core for a specific platform, it is better to have a unique known name per platform.
To ensure consistency in the names, here are the rules to set the name of a platform:
Following is a list of well known platforms, feel free to expand it as long as you follow the previous rules.
It is possible to add custom keys, to do so the key must have the form
PRODUCT is the
name of the party adding the key in CamelCase and
is the actual key in CamelCase; for example:
It is also possible to add custom groups, to do so the group must have the
[X-PRODUCT GROUPNAME], where
PRODUCT is the name of the party adding the key in
GROUPNAME is the actual group name; for
These rules are necessary to avoid name clashes between keys and group added by different products. See https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s11.html for more information.
An example Libretro descriptor entry for a standalone game:
1 2 3 4 5 6 7 8 9
[Libretro] Type=Game Version=1.0 Name=My Game Icon=my-game Module=my-game_libretro.so LibretroVersion=1 Authors=John Smith;Jane Doe <firstname.lastname@example.org>; License=GPL-3.0+;
An example Libretro descriptor entry for a Sega Genesis emulator:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
[Libretro] Type=Emulator Version=1.0 Name=My Genesis Emulator Icon=my-genesis-emulator Module=my-genesis-emulator_libretro.so LibretroVersion=1 Authors=John Smith;Jane Doe <email@example.com>; License=GPL-3.0+; [Platform:SegaGenesis] MimeType=application/x-genesis-rom; [Platform:Sega32X] MimeType=application/x-genesis-32x-rom; [Platform:SegaCD] MimeType=application/x-cue;application/x-sega-cd-rom; Firmwares=SegaCDE;SegaCDJ;SegaCDU; [Firmware:SegaCDE] Path=bios_CD_E.bin MD5=e66fa1dc5820d254611fdcdba0662372 SHA-512=b3725b0577260d8e2b12b782869573824741f5cbe09f2bc49fd8b2346229d1b308a9f54ef08177aa26be7a3580fa8317d0426a2ef7f6bb5103ce039c8e25148f Mandatory=true [Firmware:SegaCDJ] Path=bios_CD_J.bin MD5=2efd74e3232ff260e371b99f84024f7f SHA-512=abdaecbc7222392ba4c0c25bc700316ec0a80fcf3e3080a49d6b736fea58e6ec750ac8c477b8ae016c76cf536c1442d834c243fab939d17b856fbc9ed8db8fde Mandatory=true [Firmware:SegaCDU] Path=bios_CD_U.bin MD5=278a9397d192149e84e820ac621a8edd SHA-512=abc4347551b6b8a9b4b913b333c8bc35f47cc85e35be1155c7a7287dad05373d0e497f2b73fde56f7ed43fae6d1287faaed3cbf338700a21396262e4180b9158 Mandatory=true