Commit 0c848e9e authored by Ganga Ram's avatar Ganga Ram
Browse files

fix build: sdimage 



Increase extra space to 20% to accomodate file system overhead.
Align image size to 1 MiB.

Signed-off-by: default avatarGanga Ram <Ganga.Ram@tii.ae>
parent 331fb156

nixos/lib/make-ext4-fs.nix

+9 −1
Original line number Diff line number Diff line
@@ -58,10 +58,18 @@ pkgs.stdenv.mkDerivation { 
      # Make a crude approximation of the size of the target image.

      # If the script starts failing, increase the fudge factors here.

      numInodes=$(find ./rootImage | wc -l)

      numDataBlocks=$(du -s -c -B 4096 --apparent-size ./rootImage | tail -1 | awk '{ print int($1 * 1.10) }')

      numDataBlocks=$(du -s -c -B 4096 --apparent-size ./rootImage | tail -1 | awk '{ print int($1 * 1.20) }')

      bytes=$((2 * 4096 * $numInodes + 4096 * $numDataBlocks))

      echo "Creating an EXT4 image of $bytes bytes (numInodes=$numInodes, numDataBlocks=$numDataBlocks)"



      mebibyte=$(( 1024 * 1024 ))

      # Round up to the nearest mebibyte.

      # This ensures whole 512 bytes sector sizes in the disk image

      # and helps towards aligning partitions optimally.

      if (( bytes % mebibyte )); then

        bytes=$(( ( bytes / mebibyte + 1) * mebibyte ))

      fi



      truncate -s $bytes $img



      faketime -f "1970-01-01 00:00:01" fakeroot mkfs.ext4 -L ${volumeLabel} -U ${uuid} -d ./rootImage $img