On 19/07/18 09:10, Thomas Huth wrote:
On 18.07.2018 23:13, Mark Cave-Ayland wrote:
Hi all,
Following on from a couple of patches I've previously posted to the
mailing list at
https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've
made some good progress with trying to add bootindex support to OpenBIOS
but I'm stuck with generating the IDE device paths from QEMU.
According to OpenBIOS the device path for a cdrom on a sun4u machine
should be:
/pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0
whereas with my working patchset I'm currently generating:
/pci@1fe,0/pci@1,1/ide@3/drive@1
The issue is that the drive@1 part is being generated by the IDE drive
device attached to the IDE bus in hw/ide/qdev.c, and so I think I need
to override idebus_get_fw_dev_path() to manually generate the remainder
of the path including both the controller and the correctly named drive
node.
One option may be to consider subclassing IDEBus and overriding
idebus_get_fw_dev_path() there, but the cmd646 device is a child of
TYPE_PCI_IDE which has its own internal IDEBus and so it seems
overriding it is impossible.
Can anyone point me in the right direction as to how to generate the
correct fw path for IDE devices in the above format for sun4u machines?
Not sure if it is of any help, but the pseries machine is also rewriting
the device paths for the device tree: See function spapr_get_fw_dev_path
in hw/ppc/spapr.c.
Ah I see - this is very useful indeed, as it seemingly allows all the fw
paths to be managed in a single place without having to add Bus support.
Thanks for the reference!
ATB,
Mark.
