ar71xx: Add support for Mikrotik RB SXT 2nD r3

The Mikrotik RouterBOARD SXT 2nD r3 is an outdoor WiFi AP / CPE
with a single 2.4 GHz radio and a 100 Mbps Ethernet port.
The device similar to the SXT 2nD r2, but it has SPI NOR flash instead
of NAND flash.

Hardware
--------
CPU:   Atheros AR9344 (600 MHz)
RAM:   64 MiB
FLASH: 16 MiB SPI NOR W25Q128
ETH:   1x 100 Mbps Atheros AG71xx
WiFi: 2T2R 802.11b/g/n (ath9k)
Power: Passive PoE 8-30 V

Installation instructions:

1. Boot openwrt-ar71xx-mikrotik-vmlinux-initramfs.elf using a
   DHCP+TFTP server.
2. Erase the "firmware" partition using the mtd command. This should
   no longer be required once this patch is merged.
3. Use sysupgrade to install to flash. The file
   openwrt-ar71xx-mikrotik-rb-nor-flash-16M-squashfs-sysupgrade.bin
   should be used.

Signed-off-by: Xavier Douville <github@douville.org>

target/linux/ar71xx/base-files/etc/board.d/02_network

@@ -110,6 +110,7 @@ ar71xx_setup_interfaces()
 	rb-lhg-5nd|\
 	rb-mapl-2nd|\
 	rb-sxt2n|\
+	rb-sxt-2nd-r3|\
 	rb-sxt5n|\
 	rb-wap-2nd|\
 	rb-wapr-2nd|\

target/linux/ar71xx/base-files/etc/diag.sh

@@ -381,6 +381,7 @@ get_status_led() {
 	rb-lhg-5nd|\
 	rb-map-2nd|\
 	rb-mapl-2nd|\
+	rb-sxt-2nd-r3|\
 	rb-wap-2nd|\
 	rb-wapr-2nd)
 		status_led="rb:green:user"

target/linux/ar71xx/base-files/lib/ar71xx.sh

@@ -1119,6 +1119,9 @@ ar71xx_board_detect() {
 	*"RouterBOARD mAP L-2nD")
 		name="rb-mapl-2nd"
 		;;
+	*"RouterBOARD SXT 2nD r3")
+		name="rb-sxt-2nd-r3"
+		;;
 	*"RouterBOARD SXT Lite2")
 		name="rb-sxt2n"
 		;;

target/linux/ar71xx/base-files/lib/upgrade/platform.sh

@@ -730,6 +730,7 @@ platform_check_image() {
 	rb-lhg-5nd|\
 	rb-map-2nd|\
 	rb-mapl-2nd|\
+	rb-sxt-2nd-r3|\
 	rb-wap-2nd|\
 	rb-wapg-5hact2hnd|\
 	rb-wapr-2nd)
@@ -758,6 +759,7 @@ platform_pre_upgrade() {
 	rb-lhg-5nd|\
 	rb-map-2nd|\
 	rb-mapl-2nd|\
+	rb-sxt-2nd-r3|\
 	rb-wap-2nd|\
 	rb-wapg-5hact2hnd|\
 	rb-wapr-2nd)

target/linux/ar71xx/files/arch/mips/ath79/Kconfig.openwrt

@@ -1188,6 +1188,7 @@ config ATH79_MACH_RBSPI
 	  MikroTik RouterBOARD Powerbox
 	  MikroTik RouterBOARD LHG 5
 	  MikroTik RouterBOARD cAP (EXPERIMENTAL)
+	  MikroTik RouterBOARD SXT Lite 2 r3
 	  MikroTik RouterBOARD wAP
 	  MikroTik RouterBOARD wAP R-2nD
 

target/linux/ar71xx/image/mikrotik.mk

@@ -46,7 +46,7 @@ define Device/rb-nor-flash-16M
   DEVICE_PACKAGES := rbcfg rssileds -nand-utils kmod-ledtrig-gpio
   IMAGE_SIZE := 16000k
   KERNEL_INSTALL := 1
-  SUPPORTED_DEVICES := rb-750-r2 rb-750up-r2 rb-750p-pbr2 rb-911-2hn rb-911-5hn rb-931-2nd rb-941-2nd rb-951ui-2nd rb-952ui-5ac2nd rb-962uigs-5hact2hnt rb-lhg-5nd rb-map-2nd rb-mapl-2nd rb-wap-2nd rb-wapr-2nd
+  SUPPORTED_DEVICES := rb-750-r2 rb-750up-r2 rb-750p-pbr2 rb-911-2hn rb-911-5hn rb-931-2nd rb-941-2nd rb-951ui-2nd rb-952ui-5ac2nd rb-962uigs-5hact2hnt rb-lhg-5nd rb-map-2nd rb-mapl-2nd rb-wap-2nd rb-wapr-2nd rb-sxt-2nd-r3
   IMAGE/sysupgrade.bin := append-kernel | kernel2minor -s 1024 -e | pad-to $$$$(BLOCKSIZE) | \
 	append-rootfs | pad-rootfs | append-metadata | check-size $$$$(IMAGE_SIZE)
 endef