generate-defconfig.sh: Allow to have multiple change configurations

Example: one common.conf and one arch-specific config

utils/generate-defconfig.sh

@@ -1,5 +1,6 @@
 #!/bin/sh
 # Create new defconfigs by only applying the changes from a standard defconfig
+
 set -e
 
 SCRIPT_DIR="$(readlink -f $(dirname -- "$0"))"
@@ -7,28 +8,27 @@ MERGE_CONFIG="${SCRIPT_DIR}/../buildroot/support/kconfig/merge_config.sh"
 
 usage() {
     cat <<EOF
-Usage: $(basename "$0") -b BASE_CONFIG -c CHANGES -o OUTPUT_FILE
-
+Usage: $(basename "$0") -b BASE_CONFIG -c CHANGES... -o OUTPUT_FILE
 Create a new defconfig by applying changes to a base configuration.
 
 Required Options:
     -b, --base BASE          Path to base defconfig file
-    -c, --changes CHANGES    Path to config changes to apply
+    -c, --changes CHANGES    Path to config changes to apply (can be specified multiple times)
     -o, --output OUTPUT      Path to output defconfig file
 
 Example:
     $(basename "$0") \\
         -b configs/aarch64_defconfig \\
         -c changes/no-containers.conf \\
-        -o configs/aarch64_wo_containers_defconfig
-
+        -c changes/extra-features.conf \\
+        -o configs/aarch64_custom_defconfig
 EOF
     exit 1
 }
+
 check_file() {
     file="$1"
     type="$2"
-
     if [ ! -f "$file" ]; then
         echo "Error: $type file does not exist: $file" >&2
         exit 1
@@ -38,31 +38,34 @@ check_file() {
     fi
 }
 
+base=""
+output=""
+changes=""
 
 while [ $# -gt 0 ]; do
     case $1 in
-            -b|--base)
-		    base="$2"
-		    shift 2
-		    ;;
-	    -c|--changes)
-		    changes="$2"
-		    shift 2
-		    ;;
-	    -o|--output)
-		    output="$2"
-		    shift 2
-		    ;;
-            *)
-		    usage
-		    exit 1
-		    ;;
+        -b|--base)
+            base="$2"
+            shift 2
+            ;;
+        -c|--changes)
+	    changes="$changes $2"
+            shift 2
+            ;;
+        -o|--output)
+            output="$2"
+            shift 2
+            ;;
+        *)
+            usage
+            exit 1
+            ;;
     esac
 done
 
-if [ -z $output ] || [ -z $changes ] || [ -z $output ]; then
-        usage
-        exit 1
+if [ -z "$base" ] || [ -z "$changes" ] || [ -z "$output" ]; then
+    usage
+    exit 1
 fi
 
 if [ ! -x "$MERGE_CONFIG" ]; then
@@ -71,10 +74,13 @@ if [ ! -x "$MERGE_CONFIG" ]; then
 fi
 
 check_file "$base" "Base config"
-check_file "$changes" "Changes config"
+for change in $changes; do
+    check_file "$change" "Changes config"
+done
 
 TMPDIR=`mktemp -d`
 $MERGE_CONFIG -O "$TMPDIR" "$base" "$changes"
+
 O="$TMPDIR" make savedefconfig
 mv "$TMPDIR"/defconfig "$output"
 rm -r "$TMPDIR"