RE: [PATCH 0/3] Enable Option ROM support in Guest BIOS

[Akio Takebe <takebe_akio@jp.fujitsu.com>]

Hi, Shan-san

I read option ROM from /sys/devices/pci0000\:00/<BDF>/rom like the below.
1. echo 1 > /sys/devices/pci0000\:00/0000\:00\:01.0/0000\:01\:00.0/rom
2. dd if=/sys/devices/pci0000\:00/0000\:00\:01.0/0000\:01\:00.0/rom of=
rom.data

The rom didn't have any contents.

Best Regards,

Akio Takebe

>Takebe San,
>
>For the empty option ROM case, do you mean that you can not see any contents 
>by reading the PCI expansion ROM bar address? Or they are indeed empty?
>I have met a problem when developing the patches; I can not read any contents 
>from expansion ROM bar. I wonder whether they are the same problem.
>
>Shan Haitao
>
>-----Original Message-----
>From: Akio Takebe [mailto:takebe_akio@jp.fujitsu.com] 
>Sent: 2008年11月25日 8:35
>To: Shan, Haitao; 'Keir Fraser'
>Cc: 'xen-devel@lists.xensource.com'
>Subject: Re: [Xen-devel] [PATCH 0/3] Enable Option ROM support in Guest BIOS
>
>Hi, Shan
>
>>
>>Note: There is no support for booting from SCSI disk now. Since guest BIOS 
>>lacks support for that. Please see the comments below.
>>//--------------------------------------------------------------------------
>>// BIOS Boot Specification 1.0.1 compatibility
>>//
>>// Very basic support for the BIOS Boot Specification, which allows 
>>expansion
>>// ROMs to register themselves as boot devices, instead of just stealing the
>>// INT 19h boot vector.
>>//
>>// This is a hack: to do it properly requires a proper PnP BIOS and we 
>>aren't
>>// one; we just lie to the option ROMs to make them behave correctly.
>>// We also don't support letting option ROMs register as bootable disk
>>// drives (BCVs), only as bootable devices (BEVs).
>>//
>>// http://www.phoenix.com/en/Customer+Services/White+Papers-Specs/pc+
>>industry
>>+specifications.htm
>>//--------------------------------------------------------------------------
>>
>We have also worked for enabling option ROM.
>I and Kouya made the patch for supporting BCV. And we could boot HVM 
>guest from SAN storage. (please see my presentation of XenSummit Tokyo)
>
>I'll check your patch and remake the patch soon.
>
>BTW, I found some problems, they are:
>- Some device require services that are not supported by ROMBIOS.
>  (I think updating ROMBIOS to the latest bochs is better.)
>- Some devcies have empty option ROM or option ROM for EFI.
>  (e.g. NIC cards)
>
>Best Regards,
>
>Akio Takebe