From d6c3eca71b0366f33094141974929409ae9fab53 Mon Sep 17 00:00:00 2001
From: Cole Mickens <cole.mickens@gmail.com>
Date: Fri, 22 Sep 2023 16:48:54 +0200
Subject: [PATCH] nixos/lib/make-squashfs.nix: allow disabling compression

---
 nixos/lib/make-squashfs.nix                  | 4 +++-
 nixos/modules/installer/cd-dvd/iso-image.nix | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/nixos/lib/make-squashfs.nix b/nixos/lib/make-squashfs.nix
index 4b6b567399484ab..52a83c4c8e53d8f 100644
--- a/nixos/lib/make-squashfs.nix
+++ b/nixos/lib/make-squashfs.nix
@@ -14,6 +14,7 @@
 
 let
   pseudoFilesArgs = lib.concatMapStrings (f: ''-p "${f}" '') pseudoFiles;
+  compFlag = if comp == null then "-no-compression" else "-comp ${comp}";
 in
 stdenv.mkDerivation {
   name = "${fileName}.img";
@@ -39,7 +40,8 @@ stdenv.mkDerivation {
 
       # Generate the squashfs image.
       mksquashfs nix-path-registration $(cat $closureInfo/store-paths) $out ${pseudoFilesArgs} \
-        -no-hardlinks ${lib.optionalString noStrip "-no-strip"} -keep-as-directory -all-root -b 1048576 -comp ${comp} \
+        -no-hardlinks ${lib.optionalString noStrip "-no-strip"} -keep-as-directory -all-root -b 1048576 \
+        ${compFlag} \
         -processors $NIX_BUILD_CORES
     '';
 }
diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 0b5135c088eafbe..6adb94e09aff3b1 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -512,9 +512,10 @@ in
                 + lib.optionalString isAarch "-Xbcj arm"
                 + lib.optionalString (isPower && is32bit && isBigEndian) "-Xbcj powerpc"
                 + lib.optionalString (isSparc) "-Xbcj sparc";
-      type = lib.types.str;
+      type = lib.types.nullOr lib.types.str;
       description = lib.mdDoc ''
         Compression settings to use for the squashfs nix store.
+        `null` disables compression.
       '';
       example = "zstd -Xcompression-level 6";
     };