On a platform that writes bios/ in front of its destinations (RetroDECK, AmberELEC, EmuELEC), a core extra was grouped, dropped and held under its bare destination while the platform's declaration of the same file used bios/<name>. Beetle PSX's scph5501.bin was kept by the --region japan pack while the declaration was dropped and the installer dropped the path. extra_region_key keys every extra with the platform's declared root, in the builder, the manifest selection, verify's replay and the omissions. The same key gives the declared entries the systems of the core files at their path: every --system case of RetroDECK differed between pack and installer before, none does now.
generate_pack and verify read --system beside --platform through common.resolve_system_arg, built on platform_system_names, the mapping the manifest's system_names comes from. verify --platform --system now reports on the narrowed pack. Unknown names are refused with suggestions before the database is read.
The manifest now carries system_names, each system's native_system names from the platform's own file, and --system, its suggestions and --list-systems read them: --platform batocera --system psx installs sony-playstation.
The platform's files and the core extras for the Master System sat
in two region groups, sega-master-system and sega-mastersystem,
reduced apart. A US pack kept the declared Japanese BIOS. A core
extra's system group now takes the platform's spelling, in the pack,
the report and the installer's manifest fields alike.
Abdessamad Derraz