[LinuxBIOS] Add support for the AMD SimNow (TM) simulator

[Jordan Crouse]

On 09/11/07 12:46 -0700, Myles Watson wrote:
> On 11/9/07, Jordan Crouse <jordan.crouse at amd.com> wrote:
> > By popular request, this is a patch to buildrom adding support for
> > the AMD SimNow simulator.  Basically, it patches LinuxBIOS to work
> > around a few SimNow related quirks that are currently in the
> > public version of SimNow.  The quirks themselves have been reported,
> > and hopefully will be fixed in future releases.
> >
> > What is SimNow, and why does it rock, you might ask?  SimNow (TM) is
> > a processor simulator that we have developed at AMD.  Its a great way
> > to simulate the processor / chipset boot process and develop LinuxBIOS
> > and payloads, because it features an integrated debugger, and its easy
> > to fix when you brick the thing (just hit reset).  There is a public
> > version here:
> >
> > http://developer.amd.com/simnow.jsp
> >
> > For the more commercial customers out there, there is also a NDA
> > version that has support for more processors (contact your friendly
> > AMD representative for more information).  I'll put this information
> > on the wiki as well, for posterity.
> >
> > Myles and other SimNow users - let me know if this works.
> 
> It doesn't work for me yet.
> 1. It still resets (I comment out the actual soft reset, not the
> needs_reset calculation when I do it)

It will reset once - it shouldn't reset repeatedly (doesn't on my
test setup).  I haven't tried the public version yet, I'll do that.
The issue is on the non-coherent devices - the coherent ones should
optimize correctly - if they don't, thats a way bigger problem.

> 2. You modify generic-linuxbios.mk instead of a specific one for the
> target (see my earlier patch)
> 3.  I'd like it if it depended on either serengeti-cheetah config
> option (also in the earlier patch)

Yes - I haven't refactored against your previous patch.  Its still
in my queue.

> I haven't run into the other issues (beside the reset), so I don't
> know how to test them.

If it boots quickly, then you don't hit the other problem.  If the
thing grinds to a halt then you hit it.

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.