fix build script oversight, improve documentation

.github/workflows/build-image.yaml

@@ -24,7 +24,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: run build
-        run: sudo DEBUG=1 ./build_complete.sh ${{ matrix.board }} quiet=1
+        run: sudo DEBUG=1 ./build_complete.sh ${{ matrix.board }} compress_img=1 quiet=1
 
       - name: upload img
         uses: actions/upload-artifact@v4

README.md

@@ -47,6 +47,10 @@ Driver support depends on the device you are using shimboot on. The `patch_rootf
 
 This table is incomplete. If you want to contribute a device compatibility report please create a new issue on the Github repository.
 
+On all devices, expect the following features to work:
+- Zram (compressed memory)
+- Disk compression with squashfs
+
 On all devices, the following features will not work:
 - Suspend (disabled by the kernel)
 - Swap (disabled by the kernel)
@@ -67,7 +71,8 @@ PRs and contributions are welcome to help implement these features.
 
 ### Prerequisites:
 - A separate Linux PC for the build process (preferably something Debian-based)
-- A USB that is at least 8GB in size
+  - WSL2 is supported if you are on Windows
+- A USB drive that is at least 8GB in size
 - At least 20GB of free disk space
 - An x86-based Chromebook
 

patch_rootfs.sh

@@ -2,11 +2,6 @@
 
 #patch the target rootfs to add any needed drivers
 
-set -e
-if [ "$DEBUG" ]; then
-  set -x
-fi
-
 . ./common.sh
 . ./image_utils.sh
 
@@ -18,11 +13,6 @@ assert_root
 assert_deps "git gunzip"
 assert_args "$3"
 
-if [ -z "$3" ]; then
-  print_help
-  exit 1
-fi
-
 copy_modules() {
   local shim_rootfs=$(realpath -m $1)
   local reco_rootfs=$(realpath -m $2)
@@ -41,7 +31,10 @@ copy_modules() {
   cp -r "${reco_rootfs}/etc/modprobe.d/"* "${target_rootfs}/etc/modprobe.d/"
 
   #decompress kernel modules if necessary - debian won't recognize these otherwise
-  find "${target_rootfs}/lib/modules" -name "*.gz" | xargs gunzip
+  local compressed_files="$(find "${target_rootfs}/lib/modules" -name '*.gz')"
+  if [ "$compressed_files" ]; then
+    find "${target_rootfs}/lib/modules" -name "*.gz" | xargs gunzip -k
+  fi
 }
 
 copy_firmware() {