nixos: compress make-ext4-fs with zstd

1 files changed, 9 insertions, 4 deletions

diff --git a/nixos/modules/installer/cd-dvd/sd-image.nix b/nixos/modules/installer/cd-dvd/sd-image.nix
index 7865b767f0b7..901c60befb6c 100644
--- a/nixos/modules/installer/cd-dvd/sd-image.nix
+++ b/nixos/modules/installer/cd-dvd/sd-image.nix
@@ -18,6 +18,7 @@ with lib;
 let
   rootfsImage = pkgs.callPackage ../../../lib/make-ext4-fs.nix ({
     inherit (config.sdImage) storePaths;
+    compressImage = true;
     populateImageCommands = config.sdImage.populateRootCommands;
     volumeLabel = "NIXOS_SD";
   } // optionalAttrs (config.sdImage.rootPartitionUUID != null) {
@@ -128,10 +129,11 @@ in
 
     sdImage.storePaths = [ config.system.build.toplevel ];
 
-    system.build.sdImage = pkgs.callPackage ({ stdenv, dosfstools, e2fsprogs, mtools, libfaketime, utillinux, bzip2 }: stdenv.mkDerivation {
+    system.build.sdImage = pkgs.callPackage ({ stdenv, dosfstools, e2fsprogs,
+    mtools, libfaketime, utillinux, bzip2, zstd }: stdenv.mkDerivation {
       name = config.sdImage.imageName;
 
-      nativeBuildInputs = [ dosfstools e2fsprogs mtools libfaketime utillinux bzip2 ];
+      nativeBuildInputs = [ dosfstools e2fsprogs mtools libfaketime utillinux bzip2 zstd ];
 
       inherit (config.sdImage) compressImage;
 
@@ -146,11 +148,14 @@ in
           echo "file sd-image $img" >> $out/nix-support/hydra-build-products
         fi
 
+        echo "Decompressing rootfs image"
+        zstd -d --no-progress "${rootfsImage}" -o ./root-fs.img
+
         # Gap in front of the first partition, in MiB
         gap=8
 
         # Create the image file sized to fit /boot/firmware and /, plus slack for the gap.
-        rootSizeBlocks=$(du -B 512 --apparent-size ${rootfsImage} | awk '{ print $1 }')
+        rootSizeBlocks=$(du -B 512 --apparent-size ./root-fs.img | awk '{ print $1 }')
         firmwareSizeBlocks=$((${toString config.sdImage.firmwareSize} * 1024 * 1024 / 512))
         imageSize=$((rootSizeBlocks * 512 + firmwareSizeBlocks * 512 + gap * 1024 * 1024))
         truncate -s $imageSize $img
@@ -168,7 +173,7 @@ in
 
         # Copy the rootfs into the SD image
         eval $(partx $img -o START,SECTORS --nr 2 --pairs)
-        dd conv=notrunc if=${rootfsImage} of=$img seek=$START count=$SECTORS
+        dd conv=notrunc if=./root-fs.img of=$img seek=$START count=$SECTORS
 
         # Create a FAT32 /boot/firmware partition of suitable size into firmware_part.img
         eval $(partx $img -o START,SECTORS --nr 1 --pairs)