Here’s a quick HOWTO for updating a Soekris net4801 BIOS using cu(1) and lsx(1) from comms/lrzsz under FreeBSD.
First, establish contact to the BIOS using something like ‘cu -l /dev/ttyU0 -s 19200’ adjusted to fit the device node and speed used in your setup. Then follow these steps:
Ctrl+Pto enter the Soekris BIOS monitor
If the XMODEM transfer was successful, continue with the following steps:
~.to exit cu(1)
That’s it! The BIOS should now be updated :)