"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 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)

[Petter Myhre]

If I set ASMFLAGS += -D__HEAP_SIZE=0 I get:

.heap           0x2000e1e8        0x0
                0x2000e1e8                __end__ = .
                0x2000e1e8                end = __end__
 *(.heap*)
 .heap          0x2000e1e8        0x0 _build/gcc_startup_nrf52.o
                0x2000e1e8                __HeapLimit = .

.stack_dummy    0x2000e1e8     0x1200
 *(.stack*)
 .stack         0x2000e1e8     0x1200 _build/gcc_startup_nrf52.o
                0x20010000                __StackTop = (ORIGIN (RAM) + 0xd800)
                0x2000ee00                __StackLimit = (__StackTop - SIZEOF (.stack_dummy))
                0x20010000                PROVIDE (__stack, __StackTop)
                0x00000001                ASSERT ((__StackLimit >= __HeapLimit), region RAM overflowed with stack)

[Petter Myhre]

I'm testing with \examples\iot\mqtt\subscriber\boards\pca10040\armgcc

[Jawad]

Thanks Petter, I changed the heap to zero and I dont get the region RAM overflowed with stack anymore but now I am facing another issue. While running mqtt I can only do a fixed number (15) of mqtt publish or subscribe requests and then mqtt stops responding to received messages. I am suspecting this as a memory issue where stack pointer reaches an undefined location. Do you have any suggestion to debug such an issue while the project is running? Thanks a lot

[Petter Myhre]

Great! I converted my comment to an answer, please consider accepting it by clicking the grey circle next to it. If you have unrelated questions please add them separately, so you should add a new question.

[Jawad]

Hi Petter, I have posted the issue as a new question here. Could you please comment there about what should I do?