From f5cab4828c9eb81eaaf3b0526ea4babb695e2290 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 17 Jan 2015 21:19:24 +0000
Subject: [PATCH] build: add image makefile helper function for pading with an
 offset

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 44012
---
 include/image.mk | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/image.mk b/include/image.mk
index e64020132f..06feef5516 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -307,6 +307,17 @@ define Build/pad-rootfs
 	$(call prepare_generic_squashfs,$@)
 endef
 
+define Build/pad-offset
+	let \
+		size="$$(stat -c%s $@)" \
+		pad="$(word 1, $(1))" \
+		offset="$(word 2, $(1))" \
+		pad="(pad - ((size + offset) % pad)) % pad" \
+		newsize='size + pad'; \
+		dd if=$@ of=$@.new bs=$$newsize count=1 conv=sync
+	mv $@.new $@
+endef
+
 define Build/check-size
 	@[ $$(($(subst k,* 1024,$(subst m, * 1024k,$(1))))) -gt "$$(stat -c%s $@)" ] || { \
 		echo "WARNING: Image file $@ is too big"; \