How can I access linker file keywords in my C code?

[juliusjai]

Hi,

I'm using MPC5744P MCU and S32DS IDE.

I need to access the range of allocated Stack memory after compilation.

My linker file includes the keywords:

.stack (NOLOAD) : ALIGN(16)
{
_stack_end = . ;
. += __STACK_SIZE ;
_stack_addr = . ;
__SP_INIT = . ;
. += 4;
} > m_data

How can I access _stack_end and _stack_addr in my C source code?

I will be using these addresses to monitor stack overflow/underflow during runtime.

Thanks in advance.

Julius

[BlackNight · Accepted solution]

Hi Julius,

see Accessing GNU Linker Script Symbols from C/C++ | MCU on Eclipse 

I hope this helps,

Erich

[juliusjai]

Hi Erich,

Thank you very much. This is very helpful.

By the way, I'm using a 32-bit MPC5744P MCU.

Which should be the correct type of extern?

extern unsigned int _stack_end?

Or

extern unsigned long _stack_end?

Thanks again!

Julius

[BlackNight]

Hi Julius,

the type really does not matter, because the linker does not know about types. All what the linker knows and provides you is an address (or to the essence a number). So you can use whatever makes sense in your application.

Because your stack entries are 32bit, you probably want to use uint32_t as you don't know how many bits int or long can have.

I hope this helps,

Erich

[juliusjai]

Hi Erich,

Thank you very much. This is now clear.

Julius