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

[Alexander Graf]

On 06.04.2013, at 22:07, Edgar E. Iglesias wrote:

> On Sat, Apr 06, 2013 at 01:38:52PM +0200, Alexander Graf wrote:
>> 
>> On 06.04.2013, at 13:27, Peter Maydell wrote:
>> 
>>> On 6 April 2013 10:07, Alexander Graf <address@hidden> wrote:
>>>> On ARM, look at highbank. Because we're not running we're lacking
>>>> a monitor mode blob that provides sys calls for flushing caches.
>>>> Thus today the highbank machine doesn't boot anymore with Linux.
>>>> If we ran firmware like the real board, that would provide for the
>>>> sys call.
>>> 
>>> We also flat out don't implement enough monitor mode to allow
>>> a hypothetical firmware blob to work.
>> 
>> Why don't we implement enough monitor mode? Because we're not running 
>> firmware :). It's a chicken and egg thing. Bottom line is that Linux validly 
>> expects that firmware exists. If we don't run firmware, we diverge, thus we 
>> potentially break.
> 
> 
> Hi guys, A question -  For linux kernels that depend on preivous stages to 
> setup
> HW state. What is the prefered way to handle it?
> 
> In particular, if the boot loader chain depends on for example a boot rom
> that is not Open Source. Is providing a QEMU specific loader in pc-bios/ a 
> good
> option?

That's pretty much what we do for all PPC machines that do execute firmware, 
yes :). Just make sure to license your own firmware code under an open source 
license.


Alex