nixos-hardware/raspberry-pi/4/apply-overlays-dtmerge.nix
2022-08-08 18:41:30 +02:00

31 lines
1.2 KiB
Nix

# modification of nixpkgs deviceTree.applyOverlays to resolve https://github.com/NixOS/nixpkgs/issues/125354
# https://github.com/NixOS/nixpkgs/blob/master/pkgs/os-specific/linux/device-tree/default.nix
{ lib, pkgs, stdenvNoCC, dtc, libraspberrypi }:
with lib; (base: overlays': stdenvNoCC.mkDerivation {
name = "device-tree-overlays";
nativeBuildInputs = [ dtc libraspberrypi ];
buildCommand = let
overlays = toList overlays';
in ''
mkdir -p $out
cd ${base}
find . -type f -name '*.dtb' -print0 \
| xargs -0 cp -v --no-preserve=mode --target-directory $out --parents
for dtb in $(find $out -type f -name '*.dtb'); do
dtbCompat="$( fdtget -t s $dtb / compatible )"
${flip (concatMapStringsSep "\n") overlays (o: ''
overlayCompat="$( fdtget -t s ${o.dtboFile} / compatible )"
# overlayCompat in dtbCompat
if [[ "$dtbCompat" =~ "$overlayCompat" ]]; then
echo "Applying overlay ${o.name} to $( basename $dtb )"
mv $dtb{,.in}
cp ${o.dtboFile}{,.dtbo}
${libraspberrypi}/bin/dtmerge "$dtb.in" "$dtb" ${o.dtboFile}.dtbo;
rm $dtb.in ${o.dtboFile}.dtbo
fi
'')}
done
'';
});