[OpenBIOS] [Qemu-devel] Re: [PATCHv8 00/16] boot order specification

[Blue Swirl]

2010/12/11 Gleb Natapov <gleb at redhat.com>:
> On Sat, Dec 11, 2010 at 08:02:23PM +0200, Gleb Natapov wrote:
>> On Sat, Dec 11, 2010 at 05:19:01PM +0000, Blue Swirl wrote:
>> > >>                                                 What should we do with
>> > >> ata-2 at 600 vs drive at 1?
>> > > There is no available IDE OF binding spec, so I when with the way
>> > > OpenBIOS reports ata on qemu-x86. I have no idea what 600 in ata-2 at 600
>> > > may mean, but looking at g3_beige_300.html there is no such node there
>> > > and looking at any other device tree in http://penguinppc.org/historical/dev-trees-html/
>> > > I haven't found one that use this kind of addressing for pci-ata.
>> > > http://penguinppc.org/historical/dev-trees-html/g3bw_400.html for
>> > > instance has pci at 80000000/pci-bridge at d/pci-ata at 1/ata-4. ata-2 at 600 kind of
>> > > addressing is used by devices on mac-io bus which I do not think we
>> > > emulate in qemu. So it looks like OpneBIOS is wrong here.
>> >
>> > We have PMAC IDE, but this device is CMD646, so mac-io bus addressing
>> > rules should not be used.
>> >
>> So you agree that OpenBIOS is wrong here?
>>
>> > In this tree there are two disks connected to CMD646, named
>> > /pci at 80000000/pci-bridge at d/pci-ata at 1/ata-4/disk and
>> > /pci at 80000000/pci-bridge at d/pci-ata at 1/ata-4/disk at 1:
>> > http://penguinppc.org/historical/dev-trees-html/g4_pci_350.html
>> You are saying that qemu creates paths like:
>> /grackle at fec00000/ide at 3/drive at 1/disk at 0
>> /grackle at fec00000/ide at 3/drive at 1/disk at 1
>>
>> I do not understand why qemu creates node drive at 1. It should be drive at 0
>> according to the code. I'll look at why unit-address is incorrect for
>> the node. But assuming that this problem is fixed then paths created by
>> qemu is very similar to the paths in g4_pci_350.html. It looks like in
>> g4_pci_350.html they omit unit address if it is zero.
>>
> Ah the problem is that we have not qdevified mac io bus. Since first to
> ide disks are automatically attached to mac-io bus device paths for them
> are incorrect. Next two ide devices will be attached to CMD646 and qemu
> will generate correct device paths for them:
>
> qemu-system-ppc -drive if=none,id=hda,file=/dev/null -device ide-drive,drive=hda,bootindex=1
> -drive if=none,id=cd,file=/dev/null -device ide-drive,drive=cd,bootindex=0 -nographic -drive
> if=none,id=hdb,file=/dev/null -device ide-drive,drive=hdb,bus=ide.0,bootindex=2 -drive
> if=none,id=hdc,file=/dev/null -device ide-drive,drive=hdc,bus=ide.0,bootindex=3
> adding '/grackle at fec00000/ide at 3/drive at 1/disk at 1' at index 0
> adding '/grackle at fec00000/ide at 3/drive at 1/disk at 0' at index 1
> adding '/grackle at fec00000/ide at 3/drive at 0/disk at 0' at index 2
> adding '/grackle at fec00000/ide at 3/drive at 0/disk at 1' at index 3

But why is the path almost the same as CMD646, shouldn't 'ide at 3' be
different since the PCI device is not the same?

> So the fix is to qdevify mac io bus.

OK.