Re: [Qemu-devel] Re: [PATCHv2 0/8 RFC] boot order specification

[Gleb Natapov <gleb@redhat.com>]

On Thu, Nov 04, 2010 at 10:24:45AM +0100, Markus Armbruster wrote:
> Gleb Natapov <gleb@redhat.com> writes:
> 
> > On Sun, Oct 31, 2010 at 06:25:53PM -0400, Kevin O'Connor wrote:
> >> On Sun, Oct 31, 2010 at 01:40:01PM +0200, Gleb Natapov wrote:
> >> > This is current sate of the patch series for people to comment on.
> >> > I tried to use open firmware naming scheme to specify device path names.
> >> > 
> >> > The patch series produce names like these:
> >> > for pci machine:
> >> > /pci@i0cf8/pci-isa-bridge@1/fdc@03f1/floppy@0
> >> > /pci@i0cf8/pci-isa-bridge@1/fdc@03f1/floppy@1
> >> > /pci@i0cf8/ata@1,1/ata-disk@1:0
> >> > /pci@i0cf8/ata@1,1/ata-disk@1:1
> >> > /pci@i0cf8/virtio-blk@3/virtio-disk@0
> >> > /pci@i0cf8/ethernet@4/ethernet-phy@0
> >> > /pci@i0cf8/ethernet@5/ethernet-phy@0
> >> > 
> >> > for isa machine:
> >> > adding '/isa/fdc@03f1/floppy@0' at index 2
> >> > adding '/isa/fdc@03f1/floppy@1' at index 1
> >> > adding '/isa/ata@0170/ata-disk@0:0' at index 0
> >> > adding '/isa/ata@0170/ata-disk@0:1' at index 3
> >> 
> >> Hi Gleb,
> >> 
> >> How will USB drives be identified?
> >> 
> > USB bus has Open Firmware binding. I haven't look at the spec yet, but it
> > should be easy.
> >
> >> I'm not sure how SeaBIOS will be able to line up something like
> >> "/pci@i0cf8/ethernet@4/ethernet-phy@0" to an optionrom BEV.  Also, if
> >> there is an optionrom with BCVs (eg, a scsi card), I'm not sure how
> >> that would that would be identified.
> >
> > The way to parse  "/pci@i0cf8/ethernet@4/ethernet-phy@0" is this: each
> > element (between /.../) consist of node-name@unit-address. node-name
> > describes device/bus. unit-address is a device address on preceding node.
> > So pci@i0cf8 tells us that this is pci bus accessible through io
> > register 0x0cf8, ethernet@4 tells us that this is ethernet device in pci
> > slot 4 function 0, (ata@1,1 means ata device in slot 1 function 1).
> 
> Aren't "ethernet" and "ata" redundant there?
> 
In case of PCI bus yes. If parent bus does not allow to query device
type they are not.

--
			Gleb.