image: add KERNEL_SIZE to the default device vars

This reverts commit ec37a56587 and fixes
the underlying issue.

include/image.mk

@@ -369,7 +369,7 @@ define Device/Init
 endef
 
 DEFAULT_DEVICE_VARS := \
-  DEVICE_NAME KERNEL KERNEL_INITRAMFS KERNEL_INITRAMFS_IMAGE \
+  DEVICE_NAME KERNEL KERNEL_INITRAMFS KERNEL_SIZE KERNEL_INITRAMFS_IMAGE \
   DEVICE_DTS DEVICE_DTS_DIR BOARD_NAME CMDLINE \
   UBOOTENV_IN_UBI KERNEL_IN_UBI \
   BLOCKSIZE PAGESIZE SUBPAGESIZE VID_HDR_OFFSET \

target/linux/ar71xx/image/generic.mk

@@ -410,7 +410,7 @@ define Device/NBG6616
   CMDLINE += mem=128M
   IMAGES := sysupgrade.bin
   KERNEL := kernel-bin | patch-cmdline | lzma | uImage lzma | jffs2 boot/vmlinux.lzma.uImage
-  IMAGE/sysupgrade.bin = append-kernel $$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
+  IMAGE/sysupgrade.bin = append-kernel $$$$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
   # We cannot currently build a factory image. It is the sysupgrade image
   # prefixed with a header (which is actually written into the MTD device).
   # The header is 2kiB and is filled with 0xff. The format seems to be:
@@ -443,7 +443,7 @@ define Device/c-55
   KERNEL_SIZE = 2048k
   IMAGE_SIZE = 15872k
   MTDPARTS = spi0.0:256k(u-boot)ro,128k(u-boot-env)ro,2048k(kernel),13824k(rootfs),13824k(opt)ro,2624k(failsafe)ro,64k(art)ro,15872k@0x60000(firmware)
-  IMAGE/sysupgrade.bin = append-kernel $$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
+  IMAGE/sysupgrade.bin = append-kernel $$$$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
 endef
 
 TARGET_DEVICES += c-55

target/linux/ar71xx/image/ubnt.mk

@@ -261,7 +261,7 @@ define Device/ubnt-uap-pro
   DEVICE_PROFILE := UBNT UAPPRO
   KERNEL := kernel-bin | patch-cmdline | lzma | uImage lzma | jffs2 kernel0
   IMAGES := sysupgrade.bin factory.bin
-  IMAGE/sysupgrade.bin = append-kernel $$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
+  IMAGE/sysupgrade.bin = append-kernel $$$$(KERNEL_SIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
   IMAGE/factory.bin = $$(IMAGE/sysupgrade.bin) | mkubntimage2
 endef
 

target/linux/ipq806x/image/Makefile

@@ -41,7 +41,6 @@ define Device/Default
 	KERNEL_INITRAMFS_PREFIX := $$(IMG_PREFIX)-$(1)-initramfs
 	KERNEL_PREFIX := $$(IMAGE_PREFIX)
 endef
-DEVICE_VARS += KERNEL_SIZE
 
 define Device/LegacyImage
 	KERNEL_SUFFIX := -uImage

target/linux/kirkwood/image/Makefile

@@ -10,7 +10,6 @@ NAND_BLOCKSIZE := 2048-128k
 include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/image.mk
 
-DEVICE_VARS += KERNEL_SIZE
 KERNEL_LOADADDR:=0x8000
 TARGET_DEVICES = linksys-audi linksys-viper dockstar goflexnet goflexhome
 

target/linux/mvebu/image/Makefile

@@ -12,8 +12,6 @@ include $(INCLUDE_DIR)/image.mk
 
 KERNEL_LOADADDR := 0x00008000
 
-DEVICE_VARS += KERNEL_SIZE
-
 define Build/dtb
         $(call Image/BuildDTB,$(DTS_DIR)/$(DEVICE_DTS).dts,$@.dtb)
 endef

target/linux/oxnas/image/Makefile

@@ -10,7 +10,7 @@ include $(INCLUDE_DIR)/image.mk
 
 UBIFS_OPTS = -m 2048 -e 126KiB -c 4096
 
-DEVICE_VARS += DTS KERNEL_SIZE UBIFS_OPTS
+DEVICE_VARS += DTS UBIFS_OPTS
 
 KERNEL_LOADADDR := 0x60008000
 

target/linux/ramips/image/Makefile

@@ -22,7 +22,7 @@ define Image/Build/Initramfs
 	$(call Image/Build/Profile/$(PROFILE),initramfs)
 endef
 
-DEVICE_VARS += DTS IMAGE_SIZE KERNEL_SIZE
+DEVICE_VARS += DTS IMAGE_SIZE
 
 loadaddr-y := 0x80000000
 loadaddr-$(CONFIG_TARGET_ramips_rt288x) := 0x88000000