AM2634: How to build data (.c and .h) without main function?

Abdelrhman Afifi

Part Number: AM2634

Hello,

I have some post-build data and I need it to be at a certain place inside the memory.

The linker generates this error

Is there a specific linker flag to build this kind of data?

Yours,
Afifi

over 2 years ago

0 QJ Wang over 2 years ago

TI__Guru**** 199106 points

Hi Afifi,

You could use the section attributes and an linker cmd script to define the desired address for that section:

__attribute__((section("main_section"))) int main() {
  printf("hello\n");
  return 0;
}


Linker cmd:

SECTIONS                    /* SECTIONS directive    */
{

    main_section: > SPECIFIC_MEM

or use the location attribute to place the symble or function to a absolute address:

for example:

__attribute__((location(0x2001))) int main() {
  printf("Good morning, Afifi.\n");
  return 0;
}

0 QJ Wang over 2 years ago

TI__Guru**** 199106 points

Hi Afifi,

Before you can run a C/C++ program, you have to create the C/C++ run-time environment. The C/C++ boot routine performs this task using a function called c_int00 (or _c_int00). The c_int00 or _c_int00 is declared and defined in boot.asm or boot.c in run-time support library.

This startup function performs any needed auto-initialization and system setup, then calls the user’s main() function. So the main() function is needed in your project.

0 Abdelrhman Afifi over 2 years ago in reply to QJ Wang

Intellectual 415 points

Thanks for your help, but this is not the point.

I want to build somehow like calibration data, without any function(even the main).

Thanks,

0 QJ Wang over 2 years ago in reply to Abdelrhman Afifi

TI__Guru**** 199106 points

It is not practical to put your data in a separate project. One way you can try is to place your calibration data at a specified location in a flash (e.g. NOR flash), and modify you code project to read the calibration data from the specified location in the flash.

0 Abdelrhman Afifi over 2 years ago in reply to QJ Wang

Intellectual 415 points

Thanks,

I think you did not get the point.

I have some data which will be downloaded on the ECU through the software download process.
This data should be in hex format, so I want to build this data (some arrays for example) without any code to be executed.

In most compilers, there is a linker flag like LINKONLY which just compile and link the .o files without building it like software with code to be executed.

Yours,

0 QJ Wang over 2 years ago in reply to Abdelrhman Afifi

TI__Guru**** 199106 points

Hi Afifi,

I don't know how to compile/link a project with data arrays only. The entry point is always required when linking the object files. I will post this kind of question to CCS/Compiler E2E forum to get suggestions.

0 Abdelrhman Afifi over 2 years ago in reply to QJ Wang

Intellectual 415 points

Okay, thanks for your help.

Just update me if you find a solution.

0 Abdelrhman Afifi over 2 years ago in reply to QJ Wang

Intellectual 415 points

I made a workaround to have my data only built, I compiled the .text, .data, and .stack in a separate section. Then I cropped the hex file to have my data only.

But it will be better to compile it directly without this workaround.