EFI e820 map handling

EFI e820 map handling

[Andi Kleen]

Hallo,

I thought a bit about the zero page problem. I really would prefer to not
having it used in a boot loader right now because it's not extensible anymore
when external users start (ab)using it.

When I asked for separate EFI->e820 functions I was really thinking
of the kernel to do the conversion; not the boot loader.

Could you move that code into the kernel early boot code please? 
e.g. on x86-64 it could be in head64.c.  It could stuff the result
into the zero page to pass it cleanly on without special cases later.

On i386 a head32.c that runs before start_kernel() could be also 
introduced for this.

As long as it's localized there it is fine.

This would also allow to define new private e820 types and extend
the string decoding in e820; so that dmesg will correctly contain

EFI: ....

instead of

BIOS-e820: ... 

Thanks,

-Andi
 

Re: EFI e820 map handling

[Yinghai Lu]

On 8/9/07, Andi Kleen <ak@suse.de> wrote:
>
> Hallo,
>
> I thought a bit about the zero page problem. I really would prefer to not
> having it used in a boot loader right now because it's not extensible anymore
> when external users start (ab)using it.
>
> When I asked for separate EFI->e820 functions I was really thinking
> of the kernel to do the conversion; not the boot loader.
>
> Could you move that code into the kernel early boot code please?
> e.g. on x86-64 it could be in head64.c.  It could stuff the result
> into the zero page to pass it cleanly on without special cases later.
>
> On i386 a head32.c that runs before start_kernel() could be also
> introduced for this.
>
> As long as it's localized there it is fine.
>
> This would also allow to define new private e820 types and extend
> the string decoding in e820; so that dmesg will correctly contain
>
> EFI: ....
>
> instead of
>
> BIOS-e820: ...
>

How about elilo to load freebsd or opensolaris?

YH

Re: EFI e820 map handling

[Andi Kleen]

> How about elilo to load freebsd or opensolaris?

I don't know. How is that related? The current lilo can't load them either.
Supposedly they could write their own EFI boot loaders

-Andi

Re: EFI e820 map handling

[huang ying]

On 8/9/07, Andi Kleen <ak@suse.de> wrote:
> I thought a bit about the zero page problem. I really would prefer to not
> having it used in a boot loader right now because it's not extensible anymore
> when external users start (ab)using it.

I think there is more to be discussed than just EFI->e820 conversion.
We can discuss them in another thread.

Best Regards,
Huang Ying