Unverified Commit 6fec0974 authored by Tanel Dettenborn's avatar Tanel Dettenborn Committed by Jörg Thalheim
Browse files

nixos/sd-image: add preBuildCommands option 



Allow running shell commands after the root filesystem image has been
prepared but before the final SD image is assembled. This is useful for
adjusting the rootfs, such as resizing it to a fixed size or injecting
additional files, without having to override the entire build
derivation.

Signed-off-by: default avatarTanel Dettenborn <tanel.dettenborn@tii.ae>
parent 2e7d1530

nixos/modules/installer/sd-card/sd-image.nix

+29 −0
Original line number Diff line number Diff line
@@ -179,6 +179,33 @@ in 
      '';

    };



    preBuildCommands = mkOption {

      type = types.lines;

      example = literalExpression ''

        '''

          if [ ! -w "$root_fs" ]; then

            cp --no-preserve=mode "$root_fs" ./root-fs.img

            root_fs=./root-fs.img

          fi

          resize2fs $root_fs 15G

        '''

      '';

      default = "";

      description = ''

        Shell commands to run after the root filesystem image has been

        prepared, but before the final SD image is assembled.



        The path to the root filesystem image is available in the

        {var}`root_fs` shell variable. This hook can be used to modify

        the rootfs, for example to resize it or inject additional files.



        Note that when {option}`sdImage.compressImage` is disabled,

        {var}`root_fs` points to a read-only store path. To modify it,

        first copy it to a writable location and update {var}`root_fs`

        to point to the copy.

      '';

    };



    postBuildCommands = mkOption {

      type = types.lines;

      example = literalExpression "'' dd if=\${pkgs.myBootLoader}/SPL of=$img bs=1024 seek=1 conv=notrunc ''";
@@ -289,6 +316,8 @@ in 
            zstd -d --no-progress "${config.sdImage.rootFilesystemImage}" -o $root_fs

          ''}



          ${config.sdImage.preBuildCommands}



          # Gap in front of the first partition, in MiB

          gap=${toString config.sdImage.firmwarePartitionOffset}