[source] image.mk: add support for specifying the VID header offset for UBI

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=9a50a213d225263985eef5a4ab7870ff2c0925cf

commit 9a50a213d225263985eef5a4ab7870ff2c0925cf
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Jul 20 08:46:08 2016 +0200

    image.mk: add support for specifying the VID header offset for UBI
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/image-commands.mk | 1 +
 include/image.mk          | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/image-commands.mk b/include/image-commands.mk
index 1128aea..fc36509 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -107,6 +107,7 @@ define Build/append-ubi
 		$@.tmp \
 		-p $(BLOCKSIZE) -m $(PAGESIZE) \
 		$(if $(SUBPAGESIZE),-s $(SUBPAGESIZE)) \
+		$(if $(VID_HDR_OFFSET),-O $(VID_HDR_OFFSET)) \
 		$(UBINIZE_OPTS)
 	cat $@.tmp >> $@
 	rm $@.tmp
diff --git a/include/image.mk b/include/image.mk
index b24ba1c..3891787 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -295,6 +295,7 @@ define Device/Init
   BLOCKSIZE :=
   PAGESIZE :=
   SUBPAGESIZE :=
+  VID_HDR_OFFSET :=
   UBINIZE_OPTS := -E 5
   MKUBIFS_OPTS :=
 
@@ -310,7 +311,7 @@ DEFAULT_DEVICE_VARS := \
   DEVICE_NAME KERNEL KERNEL_INITRAMFS KERNEL_INITRAMFS_IMAGE \
   DEVICE_DTS DEVICE_DTS_DIR \
   UBOOTENV_IN_UBI KERNEL_IN_UBI \
-  BLOCKSIZE PAGESIZE SUBPAGESIZE \
+  BLOCKSIZE PAGESIZE SUBPAGESIZE VID_HDR_OFFSET \
   UBINIZE_OPTS
 
 define Device/ExportVar