[gPXE] [PATCH] [pciextra] Restore the PCI COMMAND register after writing to the BARs

[Stefan Hajnoczi]

On Tue, Feb 9, 2010 at 5:30 PM, Bernhard Kohl <bernhard.kohl at nsn.com> wrote:
> I tried both the older qemu-kvm Bochs BIOS and the latest SeaBIOS.
> For both the error occurred with PCIAPI_PCBIOS and worked well with
> PCIAPI_DIRECT.

Thank you for running these tests.  I think this has narrowed down the problem.

PCIAPI_DIRECT talks straight to the hardware to access PCI config
space.  PCIAPI_PCBIOS calls into the BIOS in order to access PCI
config space.  We need to look at what Bochs BIOS and SeaBIOS are
doing.

> I could not make it booting from the physical machine. It is an
> HP ProLiant BL460c-G6 Blade. After printing the following 3 lines
> it stops and reboots after 5 seconds. The same gpxe.iso image
> boots in a qemu-kvm VM without problems. But I think this
> test is not really necessary as the problem is related to the QEMU BIOS.
>
> ISOLINUX 3.75 2009-04-16 ETCD Copyright (C) 1994-2009 H. Peter Anvin et al
> Etherboot ISO boot image generated by geniso
> Loading gpxe.krn.....ready.

This looks like an unrelated problem.  Are you using BIOS serial
console redirection?  The following AMI BIOS bug has recently been
reported:

http://support.etherboot.org/index.php?do=details&task_id=67

I would like for the ISO boot properly on your system.  If you have
time we can debug this issue, too.

Stefan