If you really don't want allocations to happen in a certain area, have you tried "reserving" it by doing the allocation before the other (smaller) allocations? If you need that space temporarily, you can still try to assign memory from the "reserved" space temporarily, effectively implementing your own memory management.
A really naive solution, but it might work.
This is what I have tried:
- Reserve large block temporarly
- Do smaller things
- Free large block for large allocation
- Allocate large block (done unter the hood by std::make_unique<>())
- SOME RTOS/IDF RELATED DYNAMIC ALLOCATIONS MAY OCCUR?!?!
- Free large block (destroy unique_ptr object)
- SOME RTOS/IDF RELATED DYNAMIC ALLOCATIONS MAY OCCUR?!?!
- Try to reallocate the large block with std::make_unique<>() -> error large block is not available any more
It seems that whatever dynamic allocation stuff is going on in between, maybe from RTOS and/or IDF somehow shrinks the heap area which contains the large block so that eventually one can't allocate the large contiguous block anymore.
If one could tell malloc to allocate first from D/IRAM as priority, then maybe the large block (DRAM) stays untouched.
Hmm, not an easy one, I guess...
