The xHCI patches were removed because they caused issues
on Sandybridge-based Dell Latitude laptops. See:
https://codeberg.org/libreboot/lbmk/issues/216
The issue was not reported elsewhere, but we still don't
need xHCI support in Canoeboot's GRUB because none of the
available coreboot targets have xHCI support. However, we
may want it in the future and it helps to keep Canoeboot
in sync with Libreboot (this patch is adapted from lbmk).
Each given coreboot target can say which GRUB tree to use
by setting this in target.cfg:
grubtree="xhci"
In the above example, the "xhci" tree would be used. Some
generic GRUB config has been moved to config/data/grub/
and config/grub/ now looks like config/coreboot/ - also,
the grub.cfg file (named "payload" in each tree) is copied
to the GRUB source tree as ".config", then added to GRUB's
memdisk in the same way, as grub.cfg.
Several other design changes had to be made because of this:
* grub.cfg in memdisk no longer automatically jumps to one
in CBFS, but now shows a menuentry for it if available
* Certain commands in script/trees are disabled for GRUB,
such as *config make commands.
* gnulib is now defined in config/submodule/grub/, instead
of config/git/grub - and this mitigates an existing bug
where downloading gnulib first would make grub no longer
possible to download in lbmk.
There is another reason for merging this design change from
lbmk, and that reasoning also applies to lbmk. Specifically:
This change will enable per-board GRUB optimisation in the
future. For example, we hardcode what partitions and LVMs
GRUB scans because * is slow on ICH7-based machines, due
to GRUB's design. On other machines, * is reasonably fast,
for automatically enumerating the list of devices for boot.
Use of * (and other wildcards) could enable our GRUB payload
to automatically boot more distros, with minimal fuss. This
can be done at a later date, in subsequent revisions.
Signed-off-by: Leah Rowe <leah@libreboot.org>