As I understand the marvell docs right you have to send the binary data not only once!
You have to send them repeatedly until you get the bootrom prompt.
Thats why I suggested kermit. With kermit you can write easily scripts doing exatly that.
Send data until you get some response.
Just my 2 ct
Did you try really sending the binary data?
What terminal programm did you use?
We created a file with a hex editor then sent it using a Hyperterminal.
Maybe you should give kermit a try. As far as I remeber you can write simple scripts with kermit and also transmit binary data very easily that way.
I'll give it a try with minicom.