[U-Boot] U-Boot / Coreboot integration

[Graeme Russ]

Hi Simon,

On Wed, Oct 24, 2012 at 12:48 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Graeme,
>
> On Mon, Oct 22, 2012 at 11:41 PM, Graeme Russ <graeme.russ at gmail.com> wrote:
>> Hi Simon

[snip]

>> The x86 kernel doesn't yet support FDT as far as I am aware. I just want to
>> make sure we follow a path that won't lead to huge rework in the future. I
>> think I will raise it on LKML and see what is going on.
>
> I believe it does. Perhaps I should turn it on to make sure...

I quick Google seems to confirm, but I really don't know what the
Linux kernel pulls out of the device tree for x86. For example, does
it pull out PCI Memory, I/O, and IRQ assignments?

>>> We can certainly instruct Coreboot to load U-Boot wherever it likes.
>>> But I believe we need to relocate U-Boot to the top of memory (isn't
>>> that just a requirement of U-Boot on all archs?). Your plan makes
>>> sense to me - I agree sub-option 1 is good.
>>
>> Ok. I'll have a look at what would be involved in implementing the.kernel
>> style 'relocate in place'
>
> OK. Also from my point of view, while omitting a copy is nice and
> clean, it isn't a huge deal in terms of boot time.

Every ms counts :) And for me, life is generally easier if things
aren't jumping all over the place.

>>> On the patches side, I have another series ready to go, so will send
>>> it soon. Does everything look reasonable so far?
>>
>> Yes, but I have not had a chance to have a close look at them (family
>> commitments). Let me know if you want some priority applied.
>
> Only that if there are any red flags I would like to know before continuing.

No red flags so far. With x86 being so small (coreboot being the only
active platform) you pretty much have carte blanch over x86 :)

But as has been seen by others, be careful about breaking non-x86 builds.

Regards,

Graeme