On Thu, Nov 26, 2009 at 11:35:52PM +0100, Sebastian Herbszt wrote: > Maybe the expansion rom bar can be used for pci devices like on real > hardware. The bios will check it and load the rom itself instead of > relying on qemu to do the job.
SeaBIOS can pull roms from pci space today. Long term, I would prefer to see qemu use this. > If a soft reset is requested with the goal of a transition from > protected to real mode and the bios is reloaded, it should not do > any harm because the internal device states are kept and the cmos > still has the correct shutdown status code for the transition. SeaBIOS stores internal state in the f-segment - it wont function properly if that state is cleared. (For example, disk read requests will fail, e820 requests will fail, etc.) >Bochs > bios doesn't rely on shadowing so none of its internal state is lost > either, but the created tables (smbios, mp table, etc.) will be > gone. Clearing the tables is also broken (though less likely to be noticed). In a nutshell, qemu can't reset the f-segment and expect a resume operation to work. As Gleb pointed out though, it seems this use case is more theoretical than practical, so worrying about this may not be productive. -Kevin
