CCSv6.1.3 MSP430 GCC Stack Size

Michael Machate

Prodigy 40 points

I need to change the stack size of a MSP430 project.

Is there a parameter in the CCS Studio for the MSP430 GNU GCC to change the stack size?

over 9 years ago

0 friedl over 9 years ago

Intellectual 900 points

AFAIK, there is no such parameter.
The stack size is just the remaining RAM = RAM-size - variables - heap (if used, eg. by printf, ...)

0 Michael Machate over 9 years ago in reply to friedl

Prodigy 40 points

Has the heap size a fix number or is it calculated at compile time?

0 friedl over 9 years ago in reply to Michael Machate

Intellectual 900 points

It is not calculated, as said before it is just the RAM that is left over by the variables and possibly the Heap (if used).

Because the Heap is dynamic by nature you'd have to find the remaining stack space during runtime, eg. by using "stack painting" before "main()".

E.g. from http://stackoverflow.com/questions/389219/how-to-determine-maximum-stack-usage

Jack Ganssle says more than just that. I think that was just his intro one-liner. 
From his book, 2nd edition, p. 250: "Since few programmers have a reasonable 
way to determine maximum stack requirements, always assume your estimates 
will be incorrect. For each stack in the system, make sure the initialization code fills 
the entire amount of memory allocated to the stack with the value 0x55. Later, when 
debugging, you can view the stack and detect stack overflows by seeing no blocks 
of 0x55 in that region..." – Craig McQueen Nov 18 '09 at 23:51

0 friedl over 9 years ago in reply to friedl

Intellectual 900 points

I personally use this code snippet:

#include <stdint.h>

// import GCC symbols
extern uint8_t __noinit_end;	// end of data, as defined in linker script
extern uint8_t __stack;		// start of stack, defined by the init code

#define	STACK_INIT_VAL		0xAA

/********************************************************************
 *
 * AUTO INITIALIZATION of stack with default value
 *
 *******************************************************************/
void stackInit(void) __attribute__ ((naked));
void stackInit(void) __attribute__ ((used));
void stackInit(void) __attribute__ ((section (".crt_0050stack_init")));
void stackInit(void)
{
	register uint8_t *stack = &__noinit_end;

	/* write default value to whole stack space */
	do {
		*(stack++) = STACK_INIT_VAL;
	} while (stack <= &__stack);
}

0 Michael Machate over 9 years ago in reply to friedl

Prodigy 40 points

Hi Friedl
Thank you so much. Your code snippet works very well and helps me to analyze the stack usage.

0 Michael Machate over 9 years ago in reply to Michael Machate

Prodigy 40 points

mcuoneclipse.com/.../

0 Nick de Smith over 8 years ago in reply to friedl

Intellectual 775 points

Hi - Is there a variant of this code for TI's MSP430 compiler or IAR?

Thanks

Nick

0 Nick de Smith over 8 years ago in reply to Nick de Smith

Intellectual 775 points

I tried using the above code in CSS 7 with the TI compiler, and __noinit_end and __stack are undefined...

Also, why use the specific section: ".crt_0050stack_init"

Anyone got any more thoughts on this?

Thanks...

0 friedl over 8 years ago in reply to Nick de Smith

Intellectual 900 points

Hi!

Nick de Smith said:
I tried using the above code in CSS 7 with the TI compiler, and __noinit_end and __stack are undefined...

This is for GCC only!

For the TI compiler please have a look into the .cmd linker script and the .map file created.

AFAIK you might need to use "_stack" instead of "__noinit_end" and "__STACK_END" instead of "__stack", but I haven't tried.

Nick de Smith said:
Also, why use the specific section: ".crt_0050stack_init"
Anyone got any more thoughts on this?

This section, when using GCC, is used to include this code very early during system startup, way before main() executes.

Referring to [PDF] MSP430 Optimizing C/C++ Compiler User's Guide - Texas Instruments, section 6.9 "System Initialization", you might need to change this into "_c_int01". Check the .map file created before and afterwards.

You might as well change the "void stackInit(void) __attribute__ ((naked));" line into a FUNC_IS_PURE pragma - see 5.11.13 in said manual.

0 Nick de Smith over 8 years ago in reply to friedl

Intellectual 775 points

I eventually wrote this properly for IAR and CCS:
e2e.ti.com/.../580473

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CCSv6.1.3 MSP430 GCC Stack Size