[coreboot] CBFS searches in Coreboot and SeaBIOS

[Stefan Reinauer]

On Sep 26, 2009, at 2:41, Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net 
 > wrote:

> On 25.09.2009 20:04, Myles Watson wrote:
>> On Fri, Sep 25, 2009 at 11:57 AM, Stefan Reinauer <stepan at coresystems.de 
>> >wrote:
>>
>>> But your reasons are very sound. It's quite a lot of cbfs  
>>> accesses, and
>>> generally I guess walking the device tree (in coreboot it's even a
>>> memory op, and not a pci config space op) is cheaper than walking  
>>> all of
>>> the rom all of the time..
>>>
>>
>> It's not a show-stopper for me, but I thought I'd bring it up when  
>> I came to
>> it.
>>
>
> Given that ages ago my proposal to add caching for LAR entries was
> rejected (and I don't think positions have changed since then), LAR/ 
> CBFS
> walking will stay somewhat expensive. You could build a special-case
> cache of LAR entries for PCI option ROMs and hope nobody remembers the
> original rejections. It would definitely speed up things a lot, while
> saving you the trouble of changing the current option ROM init model.
>

I don't think we do have a problem just yet... Let's not add another  
layer of complexity to fight the one that *might* be there... For now  
the biggest waste of time is just extensive while uninformative  
because repetetive serial  output.

Stefan

> Regards,
> Carl-Daniel
>
> -- 
> http://www.hailfinger.org/
>
>