[SeaBIOS] [Qemu-devel] [RFC PATCH] Distinguish between reset types

Laszlo Ersek lersek at redhat.com
Wed Feb 20 16:18:10 CET 2013


On 02/19/13 23:45, David Woodhouse wrote:

> I'm beginning to wish I'd just ignored the fact that
> we need a properly working "soft" reset to get back from 286 protected
> mode to real mode, and wired up the damn PAM reset unconditionally. I'm
> not convinced that the protected->real mode transition will work for
> anyone anyway.

I believe currently we must be somewhere "between" soft reset & hard
reset. I estimate getting closer to a well-emulated hard reset is more
important than getting closer to a soft one. If you were to extend the
i440FX reset handler so that it unconditionally resets the PAMs, I'd
give my Rb. (Take it for what it's worth :))

The long-term solution covering all targets is being designed, but a
quick shortcut would be nice, and not only for CSM development /
testing. (I gather qemu_prep_reset() in SeaBIOS would not have had to be
written that way, for example.) For CSM stuff we can still carry private
qemu patches of course...

Thanks
Laszlo



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