[SeaBIOS] [PATCH v3 4/6] pci: init boot devices only on address space shortage

[Gerd Hoffmann]

On 07/05/11 18:23, Michael S. Tsirkin wrote:
> On Tue, Jul 05, 2011 at 05:27:03PM +0200, Gerd Hoffmann wrote:
>> Try to handle address space shortage by skipping any device
>> which isn't essential for boot.
>>
>> Signed-off-by: Gerd Hoffmann<kraxel at redhat.com>
>
> At least in a virt setup, it's much easier to debug
> things if boot just fails. Partial boot could be an option I guess.

Yea, I think that is pretty much the fundamental question.  Does it make 
sense to try boot up even if we can't fit some devices into the pci 
memory hole.

At least linux guests will try to map devices below the pci memory hole 
in case seabios didn't assign an address.  Of course this works only if 
the guest hasn't too much memory so there is some free space between end 
of ram and the start of the pci memory hole.

> We usually have a list of bootable devices we got from qemu -
> want to use that?

Why?  seabios knows itself which devices it can use to boot.  Also the 
list from qemu is incomplete, the boot menu can have more entries than 
what we get passed in from qemu as boot order list.

cheers,
   Gerd