TMS320F2800156-Q1: data_section

Hi,

Our expert is OOO today due to optional holiday in TI India office. Please expect a reply early next week.

Meanwhile, please check if using #pragma RETAIN and #pragma DATA_SECTION directives helps resolve the issue:
#pragma DATA_SECTION allocation order in shared memory

https://downloads.ti.com/docs/esd/SPRU514/the-retain-pragma-stdz0558146.html

hi

#pragma RETAIN can soloved the data function.

but  when i used code_section ,myfunc() is not called.

#program code_section (myfunc,"myfunc_address")

void myfunc(void)

{ 

func1();

func2();

}

when i changed the  content of myfunc()(delte func2()),the hex is the same ,why?

hi

i undertand.

#pragma code_section (myfunc,"myfunc_address")

#pragma RETAIN 

void myfunc(void)

{ 

func1();

}

when i changed the  content of myfunc(),the hex is still the same ,why?

#pragma RETAIN (myfunc)

Hi Youjun,

Are you using COFF or EABI?

Thanks,

Ira

hi

i used EABI mode

Hi Youjun,

Can you try to declare the function with the retain attribute?

void __attribute__((retain)) myfunc(void)

{
  //add your function definition here

}

Thanks,

Ira

hi

Still the same result.

hi

this optimization setting  affect it？

Can you turn optimization off and try?

Thanks,

Ira

hi

I turn optimization off ,when i changed the  content of myfunc(),the hex is changed.

when i  turn optimization on,How to prevent it from being optimized?

Can you try the following methods?

1. Can you try used + retain

void __attribute__((used, retain)) myfunc(void)
{
// your function body
}

2. If that does not work then can you try this 

Go to project properties -> c2000 Linker -> Miscellaneous Options -> Eliminate sections not needed in the executable (--unused_section_elimination) -> OFF

Go to project properties -> c2000 linker -> symbol management -> Specify symbols/sections to be retained by linker (--retain) -> Add your symbol here based on the flag definition in CCS

Thanks,

Ira

hi

How was this image created？

It will appear if you hover on the + symbol in the --retain flag field in the new CCS (after version 20.x). Since you are using the older CCS, it will not appear. Either way can you try to add the flag based on the info provided by me in the image. 

Did the (used, retain) option work?

Thanks,

Ira

hi

Did the (used, retain) option work?----NO

my ccs(ver12.8.1)

Can you try adding your function name to the retain field using the + symbol? Also can you tell me which compiler version you're using?

Thanks,

Ira

hi

compiler version:

Can you try adding your function name to the retain field using the + symbol?

Is this the way to operate?

Can you try

#ifdef __TI_EABI__
#pragma RETAIN(myfunc)
#endif
__attribute__((used)) void myfunc(void)
{
    func1();
}

Verify the function appears in the .obj file — use the ofd2000 utility (or check the .map file) to confirm myfunc exists in the compiled object. If it's absent there, the problem is compiler-level, and no linker flag will help.

Go to the generated .map file and check which section _myfunc falls in, add that section to the --retain field
The syntax would typically be: --retain=*.obj(.text:myfunc) which means "retain the .text:myfunc section from any object file."

NOTE - Ensure myfunc is not static — a static function with no callers in the same translation unit can be removed by the compiler itself.

Thanks,
Ira