Change serial speed on raspberry pi?

[Adam McDougall]

I have been experimenting and googling for at least a half hour but am
getting seemingly nowhere.  Is it possible to make a raspberry pi with a
serial adapter board run at a speed less than 115200?  I am getting
serial corruption during uboot and after the system has booted.  My
usual instinct is to try a slower speed but I have no idea how.  I'd
like it to work for the uboot environment as well as after the kernel.
I should try the FreeBSD side of it but I need to switch tasks right
now.  Can anyone give me a hint?  Is it compiled into uboot?  Thanks.

I have:
http://www.52pi.com/en/raspberry-pi/56-original-raspberry-pi-bb-plus-accessories-rpi-uart-expand-module-uart-extend-board-.html?

I've tried both I got, on two different pis, with different serial
adapters and cables.