ramips: build factory images for Netgear EX2700

This patch adds support for building factory and sysupgrade images
for the Netgear EX2700 that don't require modification of u-boot
environment variables.

The bootloader on this device expects the kernel partition to end
on a 64k block boundary. The last 64 byte of the kernel partition
must contain a valid uImage header - in the stock firmware, this is
the uImage header of the root filesystem. For this patch, we're using
the uImage header of a 0 byte partition (ex2700-fakeroot.uImage).

Signed-off-by: Joseph C. Lehner <joseph.c.lehner@gmail.com>

SVN-Revision: 48771

target/linux/ramips/image/Makefile

@@ -912,8 +912,34 @@ endif
 # MT7620A Profiles
 #
 
+# $(1): (ignored)
+# $(2): lowercase board name
+# $(3): uppercase board name (must match DTS filename w/o extension)
+# $(4): erase block size
+# $(5): hardware id for mkdniimg
+# $(6): maximum image size
+define BuildFirmware/Netgear/squashfs
+	$(call PatchKernelLzmaDtb,$(2),$(3))
+	# Pad kernel to eraseblock boundary, minus 2 uImage headers (=128 bytes):
+	# bs = (eraseblock * (1 + (128 + kernelsize)/eraseblock)) - 128
+	dd if=$(KDIR)/vmlinux-$(2).bin.lzma \
+		of=$(KDIR)/vmlinux-$(2).bin.lzma.tmp \
+		bs=`expr \( $(4) \* \( 1 + \( 128 + \`wc -c < $(KDIR)/vmlinux-$(2).bin.lzma\` \) / $(4) \) \) - 128` \
+		count=1 conv=sync
+
+	$(call MkImage,lzma,$(KDIR)/vmlinux-$(2).bin.lzma.tmp,$(KDIR)/vmlinux-$(2).uImage)
+	cat ex2700-fakeroot.uImage >> $(KDIR)/vmlinux-$(2).uImage
+	$(call MkImageSysupgrade/squashfs,squashfs,$(2),$(6))
+
+	$(STAGING_DIR_HOST)/bin/mkdniimg \
+		-B $(3) -H $(5) -v OpenWrt \
+		-i $(call imgname,squashfs,$(2))-sysupgrade.bin \
+		-o $(call imgname,squashfs,$(2))-factory.bin
+endef
+
 Image/Build/Profile/E1700=$(call BuildFirmware/UMedia/$(1),$(1),e1700,E1700,0x013326)
-Image/Build/Profile/EX2700=$(call BuildFirmware/Default4M/$(1),$(1),ex2700,EX2700)
+ex2700_mtd_size=3866624
+Image/Build/Profile/EX2700=$(call BuildFirmware/Netgear/$(1),$(1),ex2700,EX2700,65536,29764623+4+0+32+2x2+0,$(ex2700_mtd_size))
 Image/Build/Profile/MT7620a=$(call BuildFirmware/Default8M/$(1),$(1),mt7620a,MT7620a)
 Image/Build/Profile/MT7620a_MT7610e=$(call BuildFirmware/Default8M/$(1),$(1),mt7620a_mt7610e,MT7620a_MT7610e)
 Image/Build/Profile/MT7620a_MT7530=$(call BuildFirmware/Default8M/$(1),$(1),mt7620a_mt7530,MT7620a_MT7530)