"region RAM overflowed with stack" error while using TLS

[Jawad]

Hello everyone,

I am using nrf52832 with SDK version 11.0 for an IoT application. I am communicating with Atmel ATWINC 1500 module through SPI in order to connect to Wifi. First I faced memory issues using SPI which were fixed by setting heap size to 0 as suggested in this thread. Now when I enable TLS for mqtt communication I get region RAM overflowed with stack. I have tried changing stack to 16kB with heap as 0 and also tried with various other combinations of stack and heap but the error stays the same. My .map file,make file and startup file is attached for reference. I am not using any soft device so is there any way of making TLS work by utilizing maximum available RAM?

nrf52832_xxaa.map Makefile arm_startup_nrf52.s

[Petter Myhre]

I'm not sure why you are getting this assert. Have you seen this?

[Jawad]

Thanks Petter, I checked the link and it doesn't seem very relevant.

[Petter Myhre]

From your .map file it seems that heap is 0x200 not 0, and because (__StackLimit >= __HeapLimit) evaluates to 0 you get an assert.

[Jawad]

Hi Petter, Thanks a lot for the helpful feedback. Could you please elaborate where I can see the heap size in .map file and how can I modify heap size to 0? I am doing it this way in Makefile ASMFLAGS += -D__STACK_SIZE=8192 ASMFLAGS += -D__HEAP_SIZE=0 is it correct? Thanks

[Petter Myhre]

I don't have too much experience with gcc, but you can find it here:

.heap           0x2000fd40      0x200
                0x2000fd40                __end__ = .
                0x2000fd40                PROVIDE (end, .)
 *(.heap*)
 .heap          0x2000fd40      0x200 _build/gcc_startup_nrf52.o
                0x2000fd40                __HeapBase
                0x2000ff40                __HeapLimit = .

.stack_dummy    0x2000fd40     0x3c00
 *(.stack*)
 .stack         0x2000fd40     0x3c00 _build/gcc_startup_nrf52.o
                0x20010000                __StackTop = (ORIGIN (RAM) + LENGTH (RAM))
                0x2000c400                __StackLimit = (__StackTop - SIZEOF (.stack_dummy))
                0x20010000                PROVIDE (__stack, __StackTop)
                0x00000000                ASSERT ((__StackLimit >= __HeapLimit), region RAM overflowed with stack)