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

Blue Swirl blauwirbel at gmail.com
Sun Dec 20 18:02:05 CET 2009

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.

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