Problem with the stack on m68k
Wed May 17 11:43:00 GMT 2000
Noah Aklilu wrote:
> I writing code for a 68306 board using m68k cross compiler,
> and I was getting bus and address errors from my code, not always
> in the same location. It seems to be related to problems with the
> stack, I have noticed that the compiler allocates portions of the
> stack using "link" (e.g. link a6,#$FFEF) to create space for
> variables. How does one control the maximum stack size?
> Some of the errors seem to be related to corrupt files being
> read back from the variable spaced allocated with "link". I
> have tested my memory to make sure it is fine.
> Having written a few perl programs lately, my main function
> ended up being a little large (about 200 lines). As a result it seems
> to allocate a large chunk of (about 0xffff) of the stack as variable
> space. I have another
> program that I tested and it is much smaller (about 20 lines)
> and it runs to finish without any problems.
> I want to check another thing. When calling assembly routines
> from c code, my routine assumes the first value it pops from the
> stack is the return address, and the next two values, its input
> parameters. So I pop off the return address, save it in a0 (which I
> believe I can use as scratch space), and push it back onto the
> stack before returning using rts.
Is your called function popping the passed arguments off the stack?
In the standard C calling interface, it is the caller's responsibility
to clean arguments off the stack. If your subroutine doesn't return the
stack pointer where the calling function expects, things will break.
Want more information? See the CrossGCC FAQ, http://www.objsw.com/CrossGCC/
Want to unsubscribe? Send a note to firstname.lastname@example.org
More information about the crossgcc