Re: [SeaBIOS] [PATCHv6 00/16] boot order specification

Gleb Natapov
2010-11-28T19:52:31Z

On Sun, Nov 28, 2010 at 08:11:45PM +0100, Peter Stuge wrote:
> Peter Stuge wrote:
> > Specifying boot device using PCI BDF is a great example of using
> > common structured data. That BDF exists both in machine and firmware
> > data models.
>
> Gleb Natapov wrote:
> > Bus numbers are assigned by a guest. Qemu knows nothing about them,
> > so it specify device path by topology.
>
> Quite. By BDF I of course mean topology. ;)
>
Ah, then we are in violent agreement :)

> The BDF itself is not much better than a BBS concept, since only the
> firmware knows the details.
>
Yeap.

> But the topology is common, even if bus number differs between
> machine and firmware.
>
Correct.

> How is the topology structured? I'm not sure that firmware can use a
> "slot" number. Device number on the bus works, is that what you mean?
>
To specify device path to PCI card using topology one needs to specify
slot.fn of all pci-to-pci buses from pci host controller to pci device
in question.

--
Gleb.