Enabling SeaBIOS

[Matthias Apitz]

Hello,

I'm running FreeBSD 11CURRENT on an Acer C720 Chromebook which uses
Coreboot and SeaBIOS to boot from SSD. Before installing FreeBSD I
switched Coreboot to boot to SeaBIOS as default as described here:
https://wiki.archlinux.org/index.php/Chromebook#Enabling_SeaBIOS

I plan to install a 2nd C720 and my question is if tools mentioned in this
page are available as source too to see if I could use them from within
FreeBSD, or if there is any other method to make this switch without
ChromeOS or without making a Linux USB bootkey.

Thanks

matthias

[Julius Werner]

All ChromiumOS firmware components and support tools are open source
(minus vendor blobs on certain platforms). The 'crossystem' and
'futility' (which contains 'gbb_utility' which is called by the
set_gbb_flags.sh script) tools are part of
https://chromium.googlesource.com/chromiumos/platform/vboot_reference/+/mast...
.

set_gbb_flash.sh ultimately calls flashrom to update flags in the ROM,
which should hopefully "just work" under FreeBSD (assuming flashrom's
FreeBSD support is as good as the README suggests). 'crossystem
dev_boot_legacy=1' ultimately writes to CMOS on the C720 through
/dev/nvram, which seems to exist on FreeBSD so if you're lucky it will
also just work. (Note that if you were using an ARM Chromebook
instead, it would need to write to the embedded controller and you'd
be out of luck unless you wanted to port the (also open-source)
drivers for that.)