build: support adding version code to file names (FS#323)

Now that the VERSION_NUMBER variable holds the human friendly name and not
the commit ID anymore, we need to support adding the revision ID as well.

Introduce a new config variable CONFIG_VERSION_CODE_FILENAMES which, if set,
causes the resulting file names to contain a commit ID designation as printed
by scripts/getver.sh.

Also sanitize the input variables to ensure that the resulting strings are
lowercased and no not contain spaces.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

include/image.mk

@@ -40,9 +40,11 @@ KDIR=$(KERNEL_BUILD_DIR)
 KDIR_TMP=$(KDIR)/tmp
 DTS_DIR:=$(LINUX_DIR)/arch/$(LINUX_KARCH)/boot/dts
 
-EXTRA_NAME_SANITIZED=$(call sanitize,$(EXTRA_IMAGE_NAME))
+IMG_PREFIX_EXTRA:=$(if $(EXTRA_IMAGE_NAME),$(call sanitize,$(EXTRA_IMAGE_NAME))-)
+IMG_PREFIX_VERNUM:=$(if $(CONFIG_VERSION_FILENAMES),$(call sanitize,$(VERSION_NUMBER))-)
+IMG_PREFIX_VERCODE:=$(if $(CONFIG_VERSION_CODE_FILENAMES),$(call sanitize,$(VERSION_CODE))-)
 
-IMG_PREFIX:=$(VERSION_DIST_SANITIZED)-$(if $(CONFIG_VERSION_FILENAMES),$(VERSION_NUMBER)-)$(if $(EXTRA_NAME_SANITIZED),$(EXTRA_NAME_SANITIZED)-)$(BOARD)$(if $(SUBTARGET),-$(SUBTARGET))
+IMG_PREFIX:=$(VERSION_DIST_SANITIZED)-$(IMG_PREFIX_VERNUM)$(IMG_PREFIX_VERCODE)$(IMG_PREFIX_EXTRA)$(BOARD)$(if $(SUBTARGET),-$(SUBTARGET))
 
 MKFS_DEVTABLE_OPT := -D $(INCLUDE_DIR)/device_table.txt
 

package/base-files/image-config.in

@@ -258,6 +258,15 @@ if VERSIONOPT
 		help
 			Enable this to include the version number in firmware image, SDK-
 			and Image Builder archive file names
+
+	config VERSION_CODE_FILENAMES
+		bool
+		prompt "Revision code in filenames"
+		default y
+		help
+			Enable this to include the revision identifier or the configured
+			version code into the firmware image, SDK- and Image Builder archive
+			file names
 endif