fix: local.conf is overwritten on script invocation

Users expect local.conf to remain unchanged after it is created,
as this file is intended for their own custom modifications. To
support this behavior, the configuration generated from the kas
configuration files can be written to auto.conf instead of local.conf.

Signed-off-by: Abin Joseph <abinjose@qti.qualcomm.com>

Author: abinjose-qualcomm

setup-environment

@@ -110,7 +110,8 @@ for key, value in env_vars.items():
 
 cleanup() {
   [ -f .config.yaml ] && rm .config.yaml
-  unset MACHINE DISTRO KERNEL CONFIG_FILES SKIP_SETUP
+  [ -d "$KAS_BUILD_DIR" ] && rm -r "$KAS_BUILD_DIR"
+  unset MACHINE DISTRO KERNEL CONFIG_FILES SKIP_SETUP KAS_BUILD_DIR
 }
 
 init_env() {
@@ -130,6 +131,16 @@ init_env() {
     CONFIG_FILES="$CONFIG_FILES:$KERNEL"
   fi
 
+  # Temporary build directory should be in the same path
+  # to ensure bblayers.conf relative referencing is consistent
+  KAS_BUILD_DIR="$(mktemp -d -p "$PWD")" || \
+  {
+    cleanup
+    echo "ERROR: Failure while setting up temporary directory"
+    return 1
+  }
+  export KAS_BUILD_DIR
+
   # invoking kas shell should auto-generate BitBake configuration
   # based on the kas local_conf_header
   echo "INFO: Setting up bitbake configuration."
@@ -167,6 +178,18 @@ init_env() {
     return 1
   }
 
+  mkdir -p build/conf
+  # local.conf should be reserved for user specific changes.
+  # Use auto.conf for auto-generated configuration.
+  cp "$KAS_BUILD_DIR/conf/local.conf" build/conf/auto.conf
+  cp "$KAS_BUILD_DIR/conf/bblayers.conf" build/conf/bblayers.conf
+
+  # The local.conf file auto‑generated by oe-init-build-env overrides the
+  # MACHINE parameter defined in auto.conf. Create an empty local.conf to
+  # prevent it from being auto-generated. An existing local.conf should
+  # remain unchanged.
+  touch build/conf/local.conf
+
   echo "INFO: Cleaning up temporary contents."
   cleanup