This is a quick status update on my attempts to run the latest SeaBIOS
on the Acer c720 chromebook (aka Google peppy). In brief, the latest
SeaBIOS runs well on the c720, and it also enables booting from SD
cards (which oddly doesn't seem to work in the version of seabios
shipped with the c720).
At this point, I've only upgrading SeaBIOS. I haven't updated the
version of coreboot in the c720.
For those interested in reproducing, it will require the very latest
seabios from the git repo. Because only a small portion of the flash
is used for seabios and that portion is in a non-standard location,
the new seabios CONFIG_CBFS_LOCATION config option needs to be set to
0xffe00000 and some additional steps are needed to build the final
rom. I've attached a script with the steps I run to build and install
seabios for the c720 (based on instructions from Stefan Reinauer).
In some initial tests, I can install and run Fedora on the c720, but
there are some quirks. Suspend/resume is quirky (very slow to
resume), the touchpad isn't working (needs a driver), and the keyboard
mappings seem to be a little quirky. I don't think this is seabios
related though. Also, systems using syslinux for a boot loader don't
like the fact that the c720 reserves chunks of memory under 16Meg
(which requires setting an explicit "mem=1600m" in the kernel boot
parameters), however that doesn't seem to be a problem once the OS in
installed (and no longer uses syslinux).
The seabios xhci testing branch does detect the xhci controller.
However, the current c720 boot code maps all the xhci devices to an
ehci controller. I'm going to see if I can convince the boot code to
map the devices back to the xhci controller so that I can test the
seabios code on the Haswell xhci controller.
-Kevin