Region RAM overflowed with stack, when upgrading SEGGER RTT

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Elm — Wed, 18 May 2016 12:43:42 GMT

I found the problem. A typo. An uninitialized buffer (.bss) of size 2048 had become 20148. This explains why "section .bss will not fit in region RAM"

Sorry for taking your time.

Elm

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Elm — Wed, 18 May 2016 12:02:55 GMT

Strange enough, when I add -D__HEAP_SIZE=512 -D__STACK_SIZE=8192 to CFLAGS, ASMFLAGS and LDFLAGS, there is no change in the error printout. I am unable to explain this, mainly due to my limited competence in linkers and ARM memory usage. Any help would be appreciated!

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Elm — Wed, 18 May 2016 12:00:03 GMT

I am aware of these variables. I have increased some of them, as the debug output is quite elaborate, and smaller buffers do not work; some printouts become truncated. Thanks anyway!

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Christopher — Tue, 17 May 2016 20:39:04 GMT

RTT can be configured, especially the amount of RAM you want to allocated for RTT. Please have a look at these constants in your code:

#define SEGGER_RTT_MAX_NUM_UP_BUFFERS
#define SEGGER_RTT_MAX_NUM_DOWN_BUFFERS
#define BUFFER_SIZE_UP
#define BUFFER_SIZE_DOWN
#define SEGGER_RTT_PRINTF_BUFFER_SIZE

Try to reduce the number of buffers and the size of them. I do not know what the default values are in your RTT version, maybe it was tuned for a 32k RAM IC version.

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Elm — Tue, 17 May 2016 14:14:15 GMT

I guess debug strings occupy both RAM and flash memory. Flash because they need to survive power cycling, RAM because you can modify them. Is there a possibility to make the compiler (gcc) save strings only in flash (for strings that need not be modified?) Can the static keyword accomplish that?

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Wojtek — Tue, 17 May 2016 14:12:41 GMT

Is it possible that previously you had debugging turned off? Or did you use it by uart? Maybe before these strings were not allocated. But they probably should go to ROM memory, not RAM, so that is probably not the case. although i don't know your memory settings.

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Elm — Tue, 17 May 2016 14:10:30 GMT

The program is riddled with debugging strings. But why would just replacing the RTT source files make the RAM size almost 7kB larger?

RE: Region RAM overflowed with stack, when upgrading SEGGER RTT

Wojtek — Tue, 17 May 2016 13:42:02 GMT

Is it possible that debugging strings could take that memory? you can check .map file.