GZDoom collects its IWAD candidates from [IWADSearch.Directories], reads
the support WAD there and the Load files from the IWAD's own folder
(src/d_iwad.cpp:456-476, 593-624, 862-901). RetroDECK lists
RETRODECKROMSDIR/doom there (gzdoom/rd_assets/rd_config/gzdoom.ini:9),
which component_prepare.sh:27 rewrites to $roms_path/doom. The extractor
read only the BIOS placeholder of a preset: it now records every line
naming the BIOS or the roms folder the script rewrites, with that sed
line in its source. $roms_path, whose default is the roms root
(config/retrodeck/retrodeck.json:5), is read as that root.
The profile names IWADSearch.Directories as a pool and lays its IWADs
and their support and Load files out at its top. On RetroDECK the 20
held IWADs land in roms/doom, the 23 others are named missing there.
The root copies stay for prboom and uzdoom, which claim them. No other
platform hands GZDoom that list, so none changes.
The scraper reads each component's prepare, launcher and functions scripts at the components commit the BIOS list comes from, and the presets they copy: the fixed paths set_setting_value writes (melonDS seven, xemu three, Dolphin GBA), the folders handed over, the dir_prep links (LRPS2 pcsx2/bios back to bios/, Dolphin and PrimeHack GC regions under saves/), package copies into bios/, RetroArch core options naming a file (pcsx2_bios, DuckStation per region), XRoar romlists, the PICO-8 exec and the RPCS3 and Vita3K firmware downloads.
platforms/retrodeck.yml is regenerated at fcd0d729: only the launchers section is new.