make-gpu-addon.py --prime-list FILE adds the OS image's .metallib paths
as addons/NativeAdrenoMetal.primelist. The plugin build also links
build/prime-list.txt into the executable's __DATA,__primelist section,
since the render server's sandbox may refuse to read the file.
PosterBoard renders the iPad7,1 variant of wallpaper 7570, a layered
animation whose two HEIC images ImageIO cannot decode without a hardware
HEVC decoder, so the wallpaper stayed black.
scripts/make-wallpaper-overlay.py converts both images to 2732 pixel PNG
and points a copy of main.caml at them. make-gpu-addon.py --wallpaper
packs that directory into the addon. The kernel now creates missing
directories below /private/var/ngpu while it writes the addon, and
mounts /private/var/ngpu/wallpaper as a read-only union over the
animation's directory.
`unixnu build payload --gpu-addon FILE` carries a file made by
scripts/make-gpu-addon.py next to the kernel. The loader hands it over as
/chosen/memory-map/GpuAddon, and before launchd starts the kernel writes
every file whose content or mode differs into /private/var/ngpu of the
mounted Data volume, then mounts the addon views. The Adreno Metal plugin
then no longer has to be part of the Data seed, so the seed's persistent
store survives a plugin rebuild. Every file is zlib compressed to keep
the payload FAT at 192 MiB. Updates DarwinBoot and NativeRamBlock for the
addon handoff.
bluseliu50