Re: EFI and ACPI

[Sheda <shedatc%gmail.com@localhost>]

On Fri, Jan 22, 2016 at 1:46 AM, Christos Zoulas <christos%astron.com@localhost> wrote:
> In article <CALokOgxnvQkF8y_ZddBch4kjxQKztarfFOuCyetj_J4oLFhQ+Q%mail.gmail.com@localhost>,
> Sheda  <shedatc%gmail.com@localhost> wrote:
>>The patch (grub-knetbsd-efi-systbl.patch) I submitted to the GRUB team
>>in 2014 was commited. So it would be great to integrate its
>>NetBSD-counterpart (efi.patch) or at least discuss it.
>>The problem this patches solve consist in booting NetBSD/amd64 on an
>>EFI machine via GRUB because, AFAIK, there's no alternative.
>
> You mean this patch:
> https://mail-index.netbsd.org/tech-kern/2014/05/22/msg017119.html

Yes, the NetBSD-part of this patch as the GRUB-part was committed.

> How can we test this?

You should attempt to boot NetBSD with an EFI with no Compatibility
Support Module (CSM) enabled. Doing that should result in the kernel
being unable to locate the ACPI tables. AFAIK, that's where GRUB
become the only option: install GRUB with EFI support and attempt to
boot NetBSD using the knetbsd command. The patch should do 2 things:
- make the kernel support a new parameter, BTINFO_EFI, that is
expected to be the physical address of the EFI System Table;
- and use this information to locate the ACPI tables.

Sheda