Porting Fiasco+L4re to DaVinci DA850 - prefetch abort in sigma0

[Peter Howard]

On Wed, 2014-05-14 at 02:00 +0200, Adam Lackorzynski wrote:
> Hi,
> 
> On Tue May 13, 2014 at 16:48:58 +1000, Peter Howard wrote:
> > I'm trying to port Fiasco to the DA850.  I'm basing this on the
> > 2014022818 snapshot.  I've gotten to the point where I've modified the
> > configuration for both fiasco and l4re, added the BSP and bootstrap
> > platform files, and added the extra drivers I need to get started.  I
> > can build an image to load on the machine and it boots through the
> > kernel fine.  Then it tries to run sigma0 and gets a prefetch abort:
> > 
> > EXCEPTION: prefetch abort pfa=c0090100, error=0033000d                         
> > R[0]: c0002000 00000000 00000000 00000000  00000000 00000000 00000000 00000000 
> > R[8]: 00000000 00000000 00000000 00000000  00000000 c1013de4 04080124 c0090100 
> > 
> > (note, I'm including the full boot output at the end of the email)
> > 
> > The address, c0090100, is correct as the entry point for sigma0.
> > 
> > Now, if I'm reading the FSR right, that's indicating a permission error
> > on the section.  But nothing I've added/changed has anything to do with
> > the MMU/mapping.  As far as I can see, that's all straight armv5 code,
> > with nothing special to the board (which uses an arm926ejs core).
> > 
> > So any idea why sigma0 would be getting mappings with the wrong
> > permission?
> 
> Since RAM starts at 3GB physically, I'm wondering whether you set the
> 'kern_start_0xd' preprocessor tag in your Modules bsp-file
> (PREPROCESS_PARTS += kern_start_0xd)?
> 

Wasn't aware I needed that tag.  Adding it solved the problem.

Thanks!