ath79: add support for Netgear WNDR4300

This patch adds ath79 support for Netgear WNDR4300.
Router was previously supported by ar71xx target only.
Note: device requires 'ar934x-nand' driver in kernel.

Specification
=============
  * Description: Netgear WNDR4300
  * Loader: U-boot
  * SOC: Atheros AR9344 (560 MHz)
  * RAM: 128 MiB
  * Flash: 128 MiB (NAND)
	- U-boot binary: 256 KiB
	- U-boot environment: 256 KiB
	- ART: 256 KiB
	- POT: 512 KiB
	- Language: 2 MiB
	- Config: 512 KiB
	- Traffic Meter: 3 MiB
	- Firmware: 25 MiB
	- ART Backup: 256 KiB
	- Reserved: 96 MiB
  * Ethernet: 5 x 10/100/1000 (4 x LAN, 1 x WAN) (AR8327)
  * Wireless:
	- 2.4 GHz b/g/n (internal)
	- 5 GHz a/n (AR9580)
  * USB: yes, 1 x USB 2.0
  * Buttons:
	- Reset
	- WiFi (rfkill)
	- WPS
  * LEDs:
	- Power (amber/green)
	- WAN (amber/green)
	- WLAN 2G (green)
	- WLAN 5G (blue)
	- 4 x LAN (amber/green)
	- USB (green)
	- WPS (amber/green)
  * UART: 4-pin connector JP1, 3.3V (Vcc, TX, RX, GND), 115200 8N1
  * Power supply: DC 12V 2.5A
  * MAC addresses: LAN=WLAN2G on case label, WAN +1, WLAN5G +2

Installation
============
  * TFTP recovery
  * TFTP via U-boot prompt
  * sysupgrade
  * Web interface

Note about partitioning: firmware partition offset (0x6c0000) is
hardcoded into vendor's u-boot, so this partition cannot be moved
and resized to include Netgear-specific flash areas (pot, language,
config, traffic_meter) not used by OpenWrt.

Test build configuration
========================
CONFIG_TARGET_ath79=y
CONFIG_TARGET_ath79_nand=y
CONFIG_TARGET_ath79_nand_DEVICE_netgear_wndr4300=y
CONFIG_ALL_KMODS=y
CONFIG_DEVEL=y
CONFIG_CCACHE=y
CONFIG_COLLECT_KERNEL_DEBUG=y
CONFIG_IMAGEOPT=y

Signed-off-by: Michal Cieslakiewicz <michal.cieslakiewicz@wp.pl>

target/linux/ath79/image/Makefile

@@ -77,6 +77,7 @@ include ./generic-ubnt.mk
 endif
 ifeq ($(SUBTARGET),nand)
 include ./nand.mk
+include ./nand-netgear.mk
 endif
 ifeq ($(SUBTARGET),tiny)
 include ./tiny.mk

target/linux/ath79/image/nand-netgear.mk

@@ -0,0 +1,34 @@
+include ./common-netgear.mk	# for netgear-uImage
+
+# (pad-offset 129 = 2 * uimage_header + 0xff)
+define Device/netgear_ath79_nand
+  DEVICE_VENDOR := NETGEAR
+  DEVICE_PACKAGES := kmod-usb2 kmod-usb-ledtrig-usbport
+  KERNEL_SIZE := 2048k
+  BLOCKSIZE := 128k
+  PAGESIZE := 2048
+  IMAGE_SIZE := 25600k
+  KERNEL := kernel-bin | append-dtb | lzma -d20 | \
+	pad-offset $$(KERNEL_SIZE) 129 | \
+	netgear-uImage lzma | append-string -e '\xff' | \
+	append-uImage-fakehdr filesystem $$(NETGEAR_KERNEL_MAGIC)
+  KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma -d20 | \
+	netgear-uImage lzma
+  IMAGES := ubi-sysupgrade.bin ubi-factory.img
+  IMAGE/ubi-factory.img := append-kernel | append-ubi | netgear-dni | \
+	check-size $$$$(IMAGE_SIZE)
+  IMAGE/ubi-sysupgrade.bin := sysupgrade-tar | append-metadata | \
+	check-size $$$$(IMAGE_SIZE)
+  UBINIZE_OPTS := -E 5
+endef
+
+define Device/netgear_wndr4300
+  ATH_SOC := ar9344
+  DEVICE_MODEL := WNDR4300
+  NETGEAR_KERNEL_MAGIC := 0x33373033
+  NETGEAR_BOARD_ID := WNDR4300
+  NETGEAR_HW_ID := 29763948+0+128+128+2x2+3x3
+  SUPPORTED_DEVICES += wndr4300
+  $(Device/netgear_ath79_nand)
+endef
+TARGET_DEVICES += netgear_wndr4300