PowerPC bare

[Joel Sherrill]

Stephen Holford wrote:
> 
> Hi
> 
> I've been trying to build a bare BSP build for powerpc (8260 and 860)  using
> the README instructions in the bare bsp directory. However, the 8260 and 860
> libcpu code seems to be dependent on header files provided by bsp specific
> code. And, the file cpu.h is provided from within libbsp, rather than from
> within c/src/exec/score/cpu as with other processors. Has anyone managed to
> create a powerpc bare build?  Is cleaning this up being worked on right now
> in conjunction with multi-libbing rtems?

Eventually the multilib'ing effort will get to the PowerPC and result in
something
better than the bare bsp.  The "BSP Kit" will contain (more or less)
libbsp,
libchip, and libcpu.  These would be configured and built separately
from RTEMS
itself.  At the moment, the PowerPC is the last port with some work
required
to be multilibable.  Because it contains the two exception processing
models,
it has conflicting definitions in places like rtems/score/cpu.h that
can't be
resolved unless you know the exception model.  You can't know the
exception model
until you know the CPU model and you can't know the precise RTEMS CPU
model
in the multilibable side.

So yes .. eventually the PowerPC will be built multilib and a BSP Kit
will exist.
This will probably result in the bare BSP being buildable for the
PowerPC.
But at the current time, this effort is taking place at its own pace
given that
it is being done as volunteer/unsponsored effort.

If you want to do something short-term, then I recommend putting your
BSP in
the tree and building it there.  Or hacking the score/cpu/powerpc so the
new
exception processing stuff in libbsp is there for you locally since that
is
the model used for 8xx and 8xxx cpu models.  Or sponsoring the effort to
address the remaining multilibable issues in the PPC port.

> Thanks,
> 
> Steve Holford
> 
> ----------------------------------------------------------------
> Stephen F. Holford, P.Eng.
> Wescam
> (905) 633-4000 x2119

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
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