ipq40xx: add support for EnGenius EAP1300

ipq40xx: add support for EnGenius EAP1300

SOC:    IPQ4018 / QCA Dakota
CPU:    Quad-Core ARMv7 Processor rev 5 (v7l) Cortex-A7
DRAM:   256 MiB
NOR:    32 MiB
ETH:    Qualcomm Atheros QCA8072
WLAN1:  Qualcomm Atheros QCA4018 2.4GHz 802.11bgn 2:2x2
WLAN2:  Qualcomm Atheros QCA4018 5GHz 802.11a/n/ac 2:2x2
INPUT:  RESET Button
LEDS:   Power, LAN, MESH, WLAN 2.4GHz, WLAN 5GHz

1. Load Ramdisk via U-Boot

To set up the flash memory environment, do the following:
a. As a preliminary step, ensure that the board console port is connected to the PC using these RS232 parameters:
   * 115200bps
   * 8N1
b. Confirm that the PC is connected to the board using one of the Ethernet ports. Set a static ip 192.168.99.8 for Ethernet that connects to board. The PC must have a TFTP server launched and listening on the interface to which the board is connected. At this stage power up the board and, after a few seconds, press 4 and then any key during the countdown.

U-BOOT> set serverip 192.168.99.8 && set ipaddr 192.168.99.9 && tftpboot 0x84000000 openwrt.itb && bootm

2. Load image via GUI

a. Upgrade EAP1300 to FW v3.5.3.2
In the GUI, System Manager > Firmware > Firmware Upgrade, to do upgrade.
b. Transfer to OpenWrt from EnGenius.
In Firmware Upgrade page, to upgrade yours openwrt-ipq40xx-engenius_eap1300-squashfs-sysupgrade.bin.

3. Revert to EnGenius EAP1300
To flash openwrt-ipq40xx-engenius_eap1300-squashfs-factory.bin by using sysupgrade command and "DO NOT" keep configuration.
$ sysupgrade –n openwrt-ipq40xx-engenius_eap1300-squashfs-factory.bin

Signed-off-by: Steven Lin <steven.lin@senao.com>