TFTP from server 192.168.31.100; our IP address is 192.168.31.101
Filename 'miwifi_ra69_firmware_45a77_1.0.18.bin'.
here's all you need -^
set your PC to IP 192.168.31.100, start a TFTP server, and serve the image using filename miwifi_ra69_firmware_45a77_1.0.18.bin.
Don't forget to disable any firewall you might have running on the system hosting the TFTP.
I think you kick of the DL and boot by simply typing bootm on the console.
you can do a dry run without doing all the initial work, just to see what it says.