Batocera builds RetroArch with its core downloader (configure defaults,
qb/config.params.sh:149-150), shown in the menu since it is no Lakka
build (config.def.h:743-745), and configgen sets no URL, so the compiled
one applies: buildbot linux/x86_64 or linux/armhf, none on aarch64
(config.def.h:1855-1861). The targets scraper names that list per board
(downloads, an armv7-A CPU read from arch/Config.in.arm), the builder
and the published target lists add it, and the platform names the union
as installable_cores. applewin, gong, squirreljme and vemulator come
back that way. A build option that compiles the downloader out, or a
shipped retroarch.cfg that blanks its URL, turns it off.
KNULLI's es_systems.yml is Batocera's model: it lists every emulator
its configgen knows, and its Config.in selects many of them only on
x86_64 boards, which KNULLI has none of. The platform list now holds
what at least one board selects, read by the targets scraper, plus a
program the launcher runs from the BIOS folder (lexaloffle). 59 cores
and 44 standalone emulators leave the list, with their launcher records.
The targets scraper follows Config.in and every file it sources, so a
select a package declares itself counts (Batocera's mesa3d-rpi4 gives
the Pi 4 OpenGL). A sourced file absent at the pin is named and read as
empty: KNULLI 20260511 sources package/utils/vtree/Config.in, added in
June.
KNULLI builds per board on Batocera's Kconfig model from its own tree (knulli-cfw/knulli-linux at the tag platforms/knulli.yml pins): configs/knulli-*.board, package/system/knulli-system/Config.in, knulli-es-system/es_systems.yml and the knulli-cfw/buildroot submodule. Ten boards, the armhf library builds excluded.
Abdessamad Derraz