[openwrt/openwrt] image: add CONFIG_EXTRA_IMAGE_NAME

[LEDE Commits]

ynezz pushed a commit to openwrt/openwrt.git, branch openwrt-25.12:
https://git.openwrt.org/74c8435ebde1b8b104fcbff6a2c918051c561660

commit 74c8435ebde1b8b104fcbff6a2c918051c561660
Author: David Woodhouse <dwmw2 at infradead.org>
AuthorDate: Sat Nov 29 16:18:26 2025 +0000

    image: add CONFIG_EXTRA_IMAGE_NAME
    
    This allows an optional tag to be put in the .config file which is
    included in the filename of the resulting images, so it's easier to
    build images with different functionality for the same target hardware.
    
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
    Link: https://github.com/openwrt/openwrt/pull/20984
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
    (cherry picked from commit 24b8db118b6c84b92d17f969794b2bd6d73b8cdc)
---
 include/image.mk                   | 3 +++
 package/base-files/image-config.in | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/image.mk b/include/image.mk
index 0fbaf66dd1..38005b2ab2 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -41,6 +41,9 @@ KDIR=$(KERNEL_BUILD_DIR)
 KDIR_TMP=$(KDIR)/tmp
 DTS_DIR:=$(LINUX_DIR)/arch/$(LINUX_KARCH)/boot/dts
 
+ifeq ($(EXTRA_IMAGE_NAME),)
+EXTRA_IMAGE_NAME:=$(call qstrip,$(CONFIG_EXTRA_IMAGE_NAME))
+endif
 IMG_PREFIX_EXTRA:=$(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))-)
diff --git a/package/base-files/image-config.in b/package/base-files/image-config.in
index f1439550b0..5c3e157846 100644
--- a/package/base-files/image-config.in
+++ b/package/base-files/image-config.in
@@ -5,6 +5,14 @@
 # See /LICENSE for more information.
 #
 
+config EXTRA_IMAGE_NAME
+	string
+	prompt "Extra image filename" if IMAGEOPT
+	default ""
+	help
+		Add this to the output image filenames, to distinguish between
+		different builds for the same hardware type.
+
 config TARGET_DEFAULT_LAN_IP_FROM_PREINIT
 	bool "Use preinit IP configuration as default LAN IP" if IMAGEOPT
 	default n