fix(zyxel/nwa50ax): ubi cannot run on phram

Discovered the hard way.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

pkgs/default.nix

@@ -13,6 +13,7 @@ in {
   liminix = {
     builders =  {
       squashfs = callPackage ./liminix-tools/builders/squashfs.nix {};
+      jffs2 = callPackage ./liminix-tools/builders/jffs2.nix {};
       dtb = callPackage ./kernel/dtb.nix {};
       uimage = callPackage ./kernel/uimage.nix {};
       kernel = callPackage ./kernel {};

pkgs/liminix-tools/builders/jffs2.nix

@@ -0,0 +1,17 @@
+{
+  stdenv
+, busybox
+, buildPackages
+, callPackage
+, pseudofile
+, runCommand
+, writeText
+} : { eraseBlockSize, bootableRootDirectory }:
+let
+  endian = if stdenv.isBigEndian then "--big-endian" else "--little-endian";
+in runCommand "frob-jffs2" {
+    depsBuildBuild = [ buildPackages.mtdutils ];
+  } ''
+    tree=${bootableRootDirectory}
+    (cd $tree && mkfs.jffs2 --compression-mode=size ${endian} -e ${toString eraseBlockSize} --enable-compressor=lzo --pad --root . --output $out --squash --faketime)
+  ''