add optional padding for x86 grub images (useful for running jffs2 images in qemu)

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@6359 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/x86-2.6/image/Config.in

@@ -4,6 +4,10 @@ config X86_GRUB_IMAGES
     depends TARGET_ROOTFS_EXT2FS || TARGET_ROOTFS_JFFS2
     default y
 
+config X86_GRUB_IMAGES_PAD
+	bool "Pad GRUB images to filesystem size (for JFFS2)"
+	depends X86_GRUB_IMAGES
+
 config X86_GRUB_BAUDRATE
     int "Serial port baud rate"
     depends X86_GRUB_IMAGES

target/linux/x86-2.6/image/Makefile

@@ -44,7 +44,7 @@ ifeq ($(CONFIG_X86_GRUB_IMAGES),y)
 		-e 's#@CMDLINE@#$(strip $(call Image/cmdline/$(1))) $(CONFIG_X86_GRUB_BOOTOPTS)#g' \
 		-e 's#@BAUDRATE@#$(CONFIG_X86_GRUB_BAUDRATE)#g' \
 		./grub/menu.lst > $(KDIR)/root.grub/boot/grub/menu.lst
-	PATH="$(STAGING_DIR)/usr/sbin:$(STAGING_DIR)/bin:$(PATH)" ./gen_image.sh $(BIN_DIR)/openwrt-$(BOARD)-$(KERNEL)-$(1).image $(CONFIG_X86_GRUB_KERNELPART) $(KDIR)/root.grub $(CONFIG_TARGET_ROOTFS_FSPART) $(KDIR)/root.$(1)
+	PADDING="$(CONFIG_X86_GRUB_IMAGES_PAD)" PATH="$(STAGING_DIR)/usr/sbin:$(STAGING_DIR)/bin:$(PATH)" ./gen_image.sh $(BIN_DIR)/openwrt-$(BOARD)-$(KERNEL)-$(1).image $(CONFIG_X86_GRUB_KERNELPART) $(KDIR)/root.grub $(CONFIG_TARGET_ROOTFS_FSPART) $(KDIR)/root.$(1)
   endef
 endif
 

target/linux/x86-2.6/image/gen_image.sh

@@ -23,11 +23,13 @@ set `ptgen -o "$OUTPUT" -h $head -s $sect -p ${KERNELSIZE}m -p ${ROOTFSSIZE}m`
 
 KERNELOFFSET="$(($1 / 512))"
 ROOTFSOFFSET="$(($2 / 512))"
+ROOTFSSIZE="$(( ($3 - $2) / 512))"
 
 BLOCKS="$((($ROOTFSOFFSET - $KERNELOFFSET) / 2 - 1))"
 
 genext2fs -d "$KERNELDIR" -b "$BLOCKS" "$OUTPUT.kernel"
 dd if="$OUTPUT.kernel" of="$OUTPUT" bs=512 seek="$KERNELOFFSET" conv=notrunc
+[ -n "$PADDING" ] && dd if=/dev/zero of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc count="$ROOTFSSIZE"
 dd if="$ROOTFSIMAGE" of="$OUTPUT" bs=512 seek="$ROOTFSOFFSET" conv=notrunc
 #rm -f "$OUTPUT.kernel"