linking warning: section spans page boundary: not allowed before CPU revision 3.0

Ah, yes.  Apparently I need to brush up on my math skills.  No wonder my numbers confused you.

Unfortunately if you need/want a heap greater than 64K words there is no obvious easy way to do it.  The heap allocator in the runtime support cannot use a memory chunk that crosses a page boundary, so 64K is the max.

You could (with a good deal of effort) re-work the existing heap allocator (or start from scratch) to implement an allocator that can deal with a larger heap.  malloc and friends are the in the runtime support file memory.c.  The source is distributed in the file rtssrc.zip.

Hi Yuhua,

1. C5510 always uses only a CPU revision 2 (2.2 or 2.21 I believe).  Only the more recent C55x devices (5505, 5504, 5515, ...) use CPU 3.x.  Unfortunately the 64K limit on the size of the heap still exists on rev 3 CPUs.  The intention was to update the allocator to support the more flexible rules of the rev 3 CPU, but as yet that has not been done, I think largely becuase typcial users have not been big users of the heap.

2. A number of bad things are possible.  Generally the heap allocator will behave in erratic an unpredictable ways.  Some examples: If the allocator manages to return a memory chunk that straddles a page boundary, code trying to index into that chunk will access the wrong addresses for the index values that would be expected to be on the "next" page.  Once the allocator starts utilizing the memory on a second page, it is likely to break its own internal data structures that maintain the free list.  It would be unusual for this warning to be safely ignored.  (I'm kind of wondering why we did not make it an error.)  I suppose if malloc never actually allocated any of the memory on the "other" page, things would work OK, but of course then there was no reason to make the heap that big in the first place.