Re: [Qemu-devel] [PATCH 3/3] PPC PReP: can run without bios image

[Scott Wood <scottwood@freescale.com>]

On 04/06/2013 04:01:32 AM, Alexander Graf wrote:
> 
> 
> Am 06.04.2013 um 01:00 schrieb Scott Wood <scottwood@freescale.com>:
> 
> > On 04/04/2013 06:59:24 AM, Alexander Graf wrote:
> >> On 04.04.2013, at 13:53, Andreas Färber wrote:
> >> > For PReP, Fabien has not stated what his use case actually is (in
> >> > particular which hardware?), so it's hard for me to comment on  
> what the
> >> > hardware actually does and I thus won't accept random changes  
> just
> >> > because they happen to be in Leon3 code. There's nothing  
> conceptually
> >> > wrong with loading ELF code so I'm positive we will find a  
> solution to
> >> > accommodate all use cases in some way. :)
> >> I think it makes a lot of sense to support loading -kernel as an  
> ELF binary. I don't think it's a good idea to allow -kernel without  
> any BIOS. We do that on the e500 machines and so far it's mostly hurt  
> us.
> >
> > If by "mostly hurt us" you mean allowed things to work without  
> having to do a bunch of hacking to create a paravirt U-Boot and/or  
> implement a bunch of emulation that we don't really need otherwise.
> 
> I mean that we lack compatibility. The less we diverge from what  
> users are used to, the better usability becomes for users.
> 
> Just try to run *BSD on e500. Good luck ;)

It should be fine (or at least fixable without too much hassle) if the  
particular BSD complies with ePAPR.  I don't know the status of it, but  
Googling suggests that there's at least been effort to do this for  
FreeBSD.

If someone wants to implement an e500 boot mode other than ePAPR, they  
can -- I don't see how having the ePAPR option hurts that.

-Scott