/** @page tplink-mr3020 TP-LINK MR3020 wireless router

The router has
@li Atheros ar9331 SoC;
@li 32 MiB SDRAM;
@li 4 MiB NOR type SPI Flash Memory;
@li RS232 serial interface (LV-TTL levels on board!);
@li 1 USB interface;
@li 1 Ethernet interfaces;
@li 802.11b/g/n (WiFi) interface;
@li LEDs & buttons.

The router uses U-Boot 1.1.4 as firmware.

Barebox can be started from U-Boot using tftp.
But you have to encode barebox image in a very special way.

First obtain 'lzma' and 'mktplinkfw' utilities.

The 'lzma' utility can be obtained in Debian/Ubuntu
distro by installing lzma package.

The 'mktplinkfw' utility can be obtained from openwrt, e.g.:

@verbatim
$ OWRTPREF=https://raw.githubusercontent.com/mirrors/openwrt/master
$ curl -OL $OWRTPREF/tools/firmware-utils/src/mktplinkfw.c \
        -OL $OWRTPREF/tools/firmware-utils/src/md5.c \
        -OL $OWRTPREF/tools/firmware-utils/src/md5.h
$ cc -o mktplinkfw mktplinkfw.c md5.c
@endverbatim

To convert your barebox.bin to U-Boot-loadable image (6F01A8C0.img)
use this command sequence:

@verbatim
$ lzma -c -k barebox.bin > barebox.lzma
$ ./FW/mktplinkfw -c -H 0x07200103 -W 1 -N TL-WR720N-v3 \
    -s -F 4Mlzma -k barebox.lzma -o 6F01A8C0.img
@endverbatim

You must setup tftp-server on host 192.168.0.1.
Put your 6F01A8C0.img to tftp-server directory
(usual /tftpboot or /srv/tftp).
Connect your board to your tftp-server network via Ethernet.

Next, setup network on MR3020 and run 6F01A8C0.img, e.g.:
@verbatim
hornet> set ipaddr 192.168.0.2
hornet> set serverip 192.168.0.1
hornet> tftpboot 0x81000000 6F01A8C0.img
hornet> bootm 0x81000000
@endverbatim

TP-LINK MR3020 links:
@li http://www.tp-link.com/en/products/details/?model=TL-MR3020
@li http://wiki.openwrt.org/toh/tp-link/tl-mr3020
@li https://wikidevi.com/wiki/TP-LINK_TL-MR3020

See also:
@li http://www.eeboard.com/wp-content/uploads/downloads/2013/08/AR9331.pdf
@li http://squonk42.github.io/TL-WR703N/

*/