barebox: add option to specify config fragments

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

boot/barebox/Config.in

@@ -91,6 +91,12 @@ config BR2_TARGET_BAREBOX_CUSTOM_CONFIG_FILE
 	help
 	  Path to the barebox configuration file
 
+config BR2_TARGET_BAREBOX_CONFIG_FRAGMENT_FILES
+	string "Additional configuration fragment files"
+	help
+	  A space-separated list of configuration fragment files,
+	  that will be merged to the main Barebox configuration file.
+
 config BR2_TARGET_BAREBOX_BAREBOXENV
 	bool "bareboxenv tool in target"
 	help

boot/barebox/barebox.mk

@@ -64,6 +64,7 @@ BAREBOX_SOURCE_CONFIG = $(call qstrip,$(BR2_TARGET_BAREBOX_CUSTOM_CONFIG_FILE))
 endif
 
 BAREBOX_KCONFIG_FILE = $(BAREBOX_SOURCE_CONFIG)
+BAREBOX_KCONFIG_FRAGMENT_FILES = $(call qstrip,$(BR2_TARGET_BAREBOX_CONFIG_FRAGMENT_FILES))
 BAREBOX_KCONFIG_EDITORS = menuconfig xconfig gconfig nconfig
 BAREBOX_KCONFIG_OPTS = $(BAREBOX_MAKE_FLAGS)