Any known compiler issues for CPU32? (stack corruption problem)

Matthew J Fletcher amimjf at
Wed Feb 27 23:52:25 UTC 2002

On Wednesday 27 Feb 2002 6:51 pm, Mike Panetta wrote:
> Are there any known compiler issues when generating CPU32 code with the
> rtems binutils-2.11.2-1 or the rtems gcc2.95.3newlib1.9.0-3?  I am
> getting stack corruption on one machine, that I am not on another, both
> m68k, but one is 68030 and the other is 68332 based.  I do not think the
> corruption is occuring in BSP specific code, and since the RTEMS main
> code works on one machine and not the other, I am beginning to suspect
> the compiler.  So if anyone has had problems with the above compiler on
> a CPU32 based machine, or just know (because they are intimate with the
> compiler) that there are bugs with it for CPU32, please tell me :)  If
> anyone has an idea on how I could track down this stack corruption
> problem, I would love that kind of info too :)

i might be stupid here, but your not trying to run 68332 (i.e cpu32), code
on the not-totaly-cpu32, 68030 are you ?,.. i doubt it but what the hell,..

ok, when i was developing on 68331's we never had these problems but
we did patch gcc 2.95.3 with a special inturrupt patch that fixed problems,
with restoring regiesters (like stack pointers), after a context switch,.

here is the link,..

> So far, all I know, is somewhere before the code gets to Init() (in
> hello sample) the stack gets messed so bad that the stack pointer is
> pointing to an address over 5000 bytes above the top of the stack!  

ok, so thats before inturrupts have even been enabled (i think), so its
probably not the above.

> addition the frame pointer has been set to 0 (is that ok?). Its fine at
> boot_card(), and its fine at console_initialize() (a bsp specific
> routine in this case), but between console_initialize() and Init() it
> goes south.  I have stepped through all the code in console_initialize,
> and the stack seems fine in there too. Maybe this is just me not quite
> understanding how RTEMS initializes the stack for a process...  I do
> know, that if I let the program run without any breakpoints, it goes
> wild and overwrites itself...  Isn't that generally an indication of
> stack corruption?

is something just blowing the stack ?, do you have enough configured
is trickey to really work out how much you need, but doubleing it is
a good idea. 

i also seem to remember (but cant be sure), that rtems is running in 
priverlaged mode at this point, is it possible that come code is stomping
the stack pointer ? - ive seen stranger.


Matthew J Fletcher		amimjf at
Software Engineering		Matthew.Fletcher at			ICQ amimjf 44193496
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