standalone_path is relative to the directories a standalone build
resolves it against, now declared per profile (standalone_directories).
A launcher record that links or passes a whole folder of the BIOS tree
under one of them gives that folder, and platform_layouts rebases the
standalone view once for the builder, the manifest, verify and slots
(launchers.standalone_root, common.standalone_destination).
Flycast on RetroPie and ROCKNIX reads bios/dc, on EmuDeck
bios/flycast/bios, on Batocera (FLYCAST_BIOS_PATH) and RetroBat
(Dreamcast.BiosPath) bios/dc. The ROCKNIX, Batocera and RetroBat
scrapers now record the patched data directory, the environment
variable and the setting that say so.
The scraper reads the start scripts and the configs each package installs at the tag the BIOS list is pinned to: configs that name a BIOS path, the yabasanshiro search, directories handed to DuckStation and the PCSX2 builds, and the ln -s commands that put bios/ where an emulator reads. A package that ships one config per device gets a device field only where the values differ, as melonDS does on AMD64.
Abdessamad Derraz