Re: [PATCH v5 0/3] x86: make rsdp address accessible via boot params

From: Ingo Molnar
Date: Wed Oct 10 2018 - 03:19:26 EST



* Juergen Gross <jgross@xxxxxxxx> wrote:

> You can just dive into the discussion we had back in February:

That was half a year and a thousand commits ago! ;-)

> https://lore.kernel.org/lkml/20180213163244.j2zuxyhs4kbfhwgj@xxxxxxxxx/
>
> The scheme I have used in V5 of the series is the one you agreed to use
> back then.
>
> A quick summary of the problem you mentioned:
>
> There are some downstream variants of grub2 with a patch breaking the
> boot protocol by writing garbage past the end of setup_header. Adding
> a new field at the end of setup_header (here: rsdp_address) resulted in
> those grub2 variants clobbering the preset value of 0.
>
> The solution is to let grub2 report back the used boot protocol version
> with setting a flag "I am reporting back my version". The kernel now is
> capable to know which fields of setup_header are known to grub2 and can
> act accordingly.
>
> The related grub2 patch series is under review right now.

Ok, that's reassuring - that's all the context I needed.

Would it help grub2 review+integration if we applied this to -tip and staged
it there until the Grub patches are accepted, or can I consider those changes
as grub2 upstream accepted?

I'd like to help make it happen, let me know what the best route is.

Thanks,

Ingo