[SeaBIOS] [Qemu-devel] [PATCH 1/8] Support PCI based option rom loading

Alexander Graf agraf at suse.de
Sun Dec 20 18:18:46 CET 2009

On 20.12.2009, at 18:02, Blue Swirl wrote:

> On Sun, Dec 20, 2009 at 3:34 PM, Anthony Liguori <anthony at codemonkey.ws> wrote:
>> Blue Swirl wrote:
>>> On Fri, Dec 18, 2009 at 11:01 AM, Gerd Hoffmann <kraxel at redhat.com> wrote:
>>>> From: Anthony Liguori <aliguori at us.ibm.com>
>>>> Currently, we preload option roms into the option rom space in memory.
>>>>  This
>>>> prevents DDIM from functioning correctly which severely limits the number
>>>> of roms we can support.
>>>> This patch introduces a pci_add_option_rom() which registers the
>>>> PCI_ROM_ADDRESS bar which points to our option rom.  It also converts
>>>> over
>>>> the cirrus vga adapter, the rtl8139, virtio, and the e1000 to use this
>>>> new mechanism.
>>> This means that the VGA roms are now visible for all targets, not just
>>> when rom_enable_driver_roms is true. I'm not opposing this, but it may
>>> create regressions.
>> This is pretty normal on bare metal though, no?  I thought a lot of non-x86
>> systems actually use x86 emulators specifically to enable support for these
>> roms.
> I think so too, but ROM loading was first introduced with
> rom_enable_driver_roms mechanism just for cases like this.
> But if there are no regressions, rom_enable_driver_roms mechanism
> could be removed.

Don't macs usually have a powerpc vgabios?

I don't think we'd introduce regressions, just something you wouldn't find in a real machine. But then again the mac target isn't exactly that close to real hw anyways ...


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