[openwrt/openwrt] build: image: add UBIFS kernel packer

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/da3261e57cf33d6804222c614c77e13fdb32cf95

commit da3261e57cf33d6804222c614c77e13fdb32cf95
Author: Robert Marko <robimarko at gmail.com>
AuthorDate: Sun Apr 18 19:05:47 2021 +0200

    build: image: add UBIFS kernel packer
    
    This allows packing the kernel into UBIFS like newer
    MikroTik NAND devices require.
    
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 include/image-commands.mk | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/image-commands.mk b/include/image-commands.mk
index 91865e1e7e..23c7bd6133 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -27,6 +27,15 @@ define Build/append-kernel
 	dd if=$(IMAGE_KERNEL) >> $@
 endef
 
+define Build/package-kernel-ubifs
+	mkdir $@.kernelubifs
+	cp $@ $@.kernelubifs/kernel
+	$(STAGING_DIR_HOST)/bin/mkfs.ubifs \
+		$(KERNEL_UBIFS_OPTS) \
+		-r $@.kernelubifs $@
+	rm -r $@.kernelubifs
+endef
+
 define Build/append-image
 	dd if=$(BIN_DIR)/$(DEVICE_IMG_PREFIX)-$(1) >> $@
 endef