move make-image to subdirectory

pkgs/liminix-tools/builders/squashfs.nix

@@ -0,0 +1,29 @@
+{
+  stdenv
+, busybox
+, buildPackages
+, callPackage
+, pseudofile
+, runCommand
+, writeText
+} : config :
+let
+  config-pseudofiles = pseudofile.write "config.etc"
+    (config.environment.contents);
+
+  storefs = callPackage <nixpkgs/nixos/lib/make-squashfs.nix> {
+    # add pseudofiles as packages to store so that the packages they
+    # depend on are also added
+    storeContents = [
+      config-pseudofiles
+    ] ++ config.packages ;
+  };
+in runCommand "frob-squashfs" {
+    nativeBuildInputs = with buildPackages; [ squashfsTools qprint ];
+} ''
+    cp ${storefs} ./store.img
+    chmod +w store.img
+    mksquashfs - store.img -no-recovery -quiet -no-progress  -root-becomes store -p "/ d 0755 0 0"
+    mksquashfs - store.img -no-recovery -quiet -no-progress  -root-becomes nix  -p "/ d 0755 0 0" -pf ${config-pseudofiles}
+    cp store.img $out
+''