Is there a way to programmatically change the stack size in Contiki?
I know on Linux systems I'm able to call:
ulimit -s SIZE
But I'm currently using Contiki as a flashed binary, and don't really have access to a traditional terminal. I've tried executing the command from C using system() and popen() calls to no avail.
Perhaps there's a CFLAG or LDFLAG I can leverage? Or modifying something in the makefile?
FYI I'm flashing the binary to a Texas Instruments cc2650, which has a 32 bit processor.
CC2650 does not have a MPU (Memory Protection Unit), which implies that no one checks for the boundaries of the stack region during runtime, which in turn implies that there is no way to "reserve" stack in the same sense that stack memory is reserved on Linux.
Essentially, if you keep allocating new things on stack, the stack will keep to grow even after it reaches other memory regions - usually the .data region, which contains dynamically allocated memory, if any, and static/global variables. The growth of stack will corrupt the memory in those other regions in a way that you might even fail to notice, leading to hard-to-find bugs.
There are a couple of things to do. One is to reserve bigger stack memory during compile time. This will not limit the stack region, but will limit the extent of the data region. To do that, change the CC2650 linker script in cpu/cc26xx-cc13xx/cc26xx.ld:
_Min_Stack_Size = 0x100; /* 256 bytes by default for the stack */
The other thing is to use Contiki-NG recent revisions, which have built-in stackoverflow checks. There is still no way to change the stack region size during runtime, but you will get an error if stack overflow happens.