This implementation doesn't have any major deviations from the other EFI
ports. I've copied the boilerplate from arm and arm64.
I've tested this with the following boot flows:
OpenSBI (M-mode) -> u-boot (S-mode) -> loader.efi -> FreeBSD
OpenSBI (M-mode) -> u-boot (S-mode) -> boot1.efi -> loader.efi -> FreeBSD
Due to the way that u-boot handles secondary CPUs, OpenSBI >= v0.7 is required,
as the HSM extension is needed to bring them up explicitly. Because of this,
using BBL as the SBI implementation will not be possible. Additionally, there
are a few recent u-boot changes that are required as well, all of which will be
present in the upcoming v2020.07 release.
Looks good: emaste
Differential Revision: https://reviews.freebsd.org/D25135
The location of the device-tree blob is passed to the kernel by the
previous booting stage (i.e. BBL or OpenSBI). Currently, we leave it
untouched and mark the 1MB of memory holding it as unavailable.
Instead, do what is done by other fake_preload_metadata() routines and
copy to the DTB to KVA space. This is more in line with what loader(8)
will provide us in the future, and it allows us to reclaim the hole in
physical memory.
Reviewed by: markj, kp (earlier version)
Differential Revision: https://reviews.freebsd.org/D24152
