Kick for a long lost topic

Allthough Archos / Rockbox communicate through the serial port at 9600 baud to be compatible with the original remote.
For a specific project I would like to change the baudrate to 38400 baud.
Can this be done by just changing the serial.c ?
Or does this involve somewhat more work ?
Also SoftTX, is there a proper way to test this ? Does it require a cable to the PC with a proper MAX3232 'dongle' ?