[SeaBIOS] [PATCH v2 9/9] seabios: Build the dsdt separately

[Laszlo Ersek]

(CC'ing Jordan, the TianoCore/OvmfPkg maintainer)

On 10/10/12 09:29, Paolo Bonzini wrote:
> Il 10/10/2012 09:14, Gerd Hoffmann ha scritto:
>>   Hi,
>>
>>> Instead of moving just the dsdt to qemu, though, can we move all acpi
>>> tables into qemu?  Moving just the dsdt can lead to conflicts with the
>>> generated ssdt code and potentially some of the other acpi tables.
>>
>> For now the plan is to keep the dsdt in the seabios git repo, but
>> install them next to bios.bin, then have qemu pick the correct one
>> depending on the machine type.
>>
>>> The only seabios acpi dependency that pops into mind is the memory
>>> addresses of the acpi tables themselves.
>>
>> There is also the BDAT in the SSDT and the patching logic ...
> 
> The patching logic can be moved to QEMU with no problems.  The BDAT
> perhaps could be replaced with a Package and Index().
> 
> I think there's no urgency to move ACPI tables to QEMU, but it would be
> a useful cleanup if somebody has the time to do it.  It would improve
> the degree to which compatibility machine types can mimic old versions
> of QEMU, too.
> 
> The important thing is that it can be done incrementally.  Even the SSDT
> can be split in multiple tables, one built by QEMU and one built by SeaBIOS.
> 
> Laszlo has been forward-porting some SeaBIOS changes to TianoCore.  When
> he gets to the remaining bells-and-whistles (mostly hotplug and S3/S4),
> perhaps he could instead add the fwcfg interface to TianoCore and move
> them from SeaBIOS to QEMU.  IIUC it's just a sequence of
> 
>    uint16_t len;
>    uint8_t  table[];
> 
> structs, it shouldn't take long to add it.

Good idea. See the following edk2-devel messages from April 2012:

http://sourceforge.net/mailarchive/message.php?msg_id=29200341
http://sourceforge.net/mailarchive/message.php?msg_id=29200817

I added this to my todo list. I don't know when I'll get to it, so if
someone needs it urgently, please go ahead. (Especially the
seabios->qemu move could be implemented while I'm slacking off :))

Thanks,
Laszlo