From e7385853e45b8352a073de40252df21e43d2aec3 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Mon, 14 Dec 2020 14:45:36 +0200
Subject: kbuild: Add options to selectively compile kernel components

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 kbuild.sh | 54 ++++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 12 deletions(-)

diff --git a/kbuild.sh b/kbuild.sh
index 3776e72..7d857df 100755
--- a/kbuild.sh
+++ b/kbuild.sh
@@ -35,12 +35,16 @@ usage() {
 	echo   ""
 	echo   "Supported options:"
 	echo   "--bootloader file	Boot loader file (CrOS images only)"
+	echo   "--build components	List of components to build: image, modules, dt (default: all)"
 	echo   "--cmdline		Command line arguments file (CrOS images only)"
 	echo   "--config		Run menuconfig"
 	echo   "--deb			Create Debian packages"
 	echo   "--defconfig file	Generate a new .config with defaults from file"
 	echo   "--doc[=dir]		Compile the documentation (for the specified dir only)"
 	echo   "-h, --help		Print this help text"
+	echo   "--no-dt			Don't compile the device trees"
+	echo   "--no-image		Don't compile the kernel image"
+	echo   "--no-modules		Don't compile the kernel modules"
 	echo   "--			End options parsing, next argument is the platform"
 	echo   ""
 	echo   "Supported platforms:"
@@ -49,10 +53,11 @@ usage() {
 	done
 }
 
-do_compile_doc=0
+declare -A do_build
 do_menu_config=0
 do_package_deb=0
 opt_bootloader=
+opt_build="image,modules,dt"
 opt_cmdline_file=
 opt_defconfig=
 opt_doc_dirs='.'
@@ -71,6 +76,10 @@ while [[ $# != 0 ]] ; do
 			fi
 			shift
 			;;
+		--build)
+			opt_build="$1"
+			shift
+			;;
 		--cmdline)
 			opt_cmdline_file=$1
 			if [[ ! -r $opt_cmdline_file ]] ; then
@@ -94,10 +103,10 @@ while [[ $# != 0 ]] ; do
 			shift
 			;;
 		--doc)
-			do_compile_doc=1
+			do_build[doc]=1
 			;;
 		--doc=*)
-			do_compile_doc=1
+			do_build[doc]=1
 			opt_doc_dirs="${option/--doc=/}"
 			;;
 		-h|--help)
@@ -121,6 +130,19 @@ while [[ $# != 0 ]] ; do
 	esac
 done
 
+IFS=',' read -r -a opt_build <<< "$opt_build"
+for component in ${opt_build[@]} ; do
+	case $component in
+	dt|image|modules)
+		do_build[$component]=1
+		;;
+	*)
+		echo "Invalid build component ${component}"
+		exit 1
+		;;
+	esac
+done
+
 #
 # Platform
 #
@@ -205,7 +227,7 @@ fi
 # Compile documentation if requested
 #
 
-if [[ $do_compile_doc == 1 ]] ; then
+if [[ ${do_build[doc]} == 1 ]] ; then
 	(
 	if [[ ! -f $PWD/output/doc/bin/activate ]] ; then
 		virtualenv $PWD/output/doc
@@ -224,15 +246,19 @@ fi
 #
 
 kernel_dtbs=
-for dtb in $dtbs ; do
-	dtb=${dtb/:*/}
-	kernel_dtbs="$kernel_dtbs $dtb"
-done
+if [[ ${do_build[dtbs]} == 1 ]] ; then
+	for dtb in $dtbs ; do
+		dtb=${dtb/:*/}
+		kernel_dtbs="$kernel_dtbs $dtb"
+	done
+fi
 
-$pmake $kbuild_options KCFLAGS="$kcflags" $image_kernel $kernel_dtbs
+if [[ ${do_build[image]} == 1 ]] ; then
+	$pmake $kbuild_options KCFLAGS="$kcflags" $image_kernel $kernel_dtbs
+fi
 
 grep 'CONFIG_MODULES=y' $output_dir/.config > /dev/null && modules=modules
-if [[ x$modules == xmodules ]] ; then
+if [[ x$modules == xmodules ]] && [[ ${do_build[modules]} == 1 ]]; then
 	$pmake $kbuild_options KCFLAGS="$kcflags" $modules
 fi
 
@@ -277,6 +303,10 @@ copy_dtbs() {
 	local dest_dir=$1
 	local dtb
 
+	if [[ ${do_build[dtbs]} != 1 ]] ; then
+		return
+	fi
+
 	if [[ $_image_type == FIT || $_image_type == CrOS ]] ; then
 		return
 	fi
@@ -301,7 +331,7 @@ if [[ $_image_type != CrOS && -d "$tftp_dir" ]] ; then
 	copy_dtbs $tftp_dir/
 fi
 
-if [[ x$modules == xmodules ]] ; then
+if [[ x$modules == xmodules ]] && [[ ${do_build[modules]} == 1 ]]; then
 	mod_path=${target_dir:-$output_dir/modules}
 	mkdir -p $mod_path
 	$pmake INSTALL_MOD_PATH=$mod_path modules_install
@@ -320,7 +350,7 @@ fi
 #
 
 echo "Kernel image available in ${_image_file}"
-if [[ x$modules == xmodules ]] ; then
+if [[ x$modules == xmodules ]] && [[ ${do_build[modules]} == 1 ]]; then
 	echo "Kernel modules installed to $mod_path/lib/modules/$version"
 fi
 echo "Build $version completed at $(date)"
-- 
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