TP link MR3220 status, boot from flash via u-boot question

[Milan Obuch]

Hi,

I am working with cheap TP-link router, MR3220, current feature
and status summary is

UART (console) works.
GPIO works.
USB works.
Ethernet works, both interfaces.
Switch connected to the second ethernet interface is not yet tested.
SPI flash works.
PCI seems to be working too.
Wifi needs some attachment code patch.  

I am going to prepare summary of patches against -current necessary to
make this work somewhere, if anybody is interested meanwhile, just ask
me.

I am able to build kernel with root fs mounted via NFS, put on USB
flash or md image embedded into kernel, but still need to download it
into device via TFTP.

MR3220 has u-boot, I found in OpenWRT repository utilities page at
https://dev.openwrt.org/browser/trunk/tools/firmware-utils/src and
there mktplinkfw.c source, which builds and creates images, but it does
not work for me yet. Actually, for building images mips on i386 I
replaced some byteswap macro with ntohl call as a quick hack, which
seems to produce correct results, at least I can inspect images from
TP-link (original firmware) and OpenWRT (replacement), both showing
correct (reasonable, at least) entries for load address etc, but my
image does not start correctly...

Has anybody any experience with firmware images for TP-link's devices
or any idea how could this be debugged? All I got is just a message
telling 'Starting...' or some such, which tells me nothing :(

Regards,
Milan