Re: [Qemu-devel] [PATCH 1/2] Allow QEMUMachine to override reset sequencing

[David Gibson]

On Thu, Aug 02, 2012 at 05:17:27PM +0200, Paolo Bonzini wrote:
> Il 02/08/2012 05:50, Benjamin Herrenschmidt ha scritto:
> > 
> >> >  This sort of stuff is either
> >> > (1) hard coded in a firmware/flashrom or (2) built dynamically in
> >> > firmware.  Let's not pretend like we're doing this because it's needed
> >> > for real hardware.
> > Doesn't matter, we do things like -kernel which means pre-loading the
> > kernel from qemu, even on x86. That doesn't match real HW either, but
> > it's convenient to have. But overall there are real HW reasons to
> > control the reset as well so the hook makes sense both ways.
> 
> On x86 we do not pre-load the kernel.  Neither the kernel/initramfs and
> the option ROM that loads the kernel are written in memory, they are
> passed to the guest via fw_cfg.  Then the option ROM is loaded by the
> BIOS, and loads the kernel/initramfs.

On x86 (or rather PC platform), yes.  But spapr is far from the only
one to load the kernel images direct into RAM - arm_load_kernel() does
it too, so does milkymist, sun4[mu] and a bunch of others.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson