[SeaBIOS] [Qemu-devel] [PATCH 1/2] pci: Automatically patch PCI device id in PCI ROM
anthony at codemonkey.ws
Mon Oct 18 20:39:38 CEST 2010
On 10/18/2010 05:09 AM, Gerd Hoffmann wrote:
> On 10/15/10 23:05, Anthony Liguori wrote:
>> On 10/15/2010 03:51 PM, Stefan Weil wrote:
>>> PCI device with different device ids sometimes share
>>> the same rom code. Only the device id and the checksum
>>> differ in a boot rom for such devices.
>> BTW, SeaBIOS doesn't reject ROMs when they're loaded via rombar, only
>> when they're loaded via romfile.
> SeaBIOS rejects them when loaded from the rom bar and doesn't reject
> them when loaded via fw_cfg.
What I meant was, rombar=0 in qdev. Sometimes my fingers don't work the
same way my brain does :-)
> Using the rom bar is the prefered way though, fw_cfg is only there for
> compatibility with older versions.
>> Maybe it's better to use fw_cfg to explicitly tell SeaBIOS to ignore the
>> PCI device id in the rom header for a certain device?
> Patching the rom is fine IMHO. Why create + use a separate
> communication path when we can use a much simpler approach?
How does this interact with PCI device passthrough?
We clearly can't patch in that case whereas if we had a hint to SeaBIOS,
it would still work.
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