TDA4VM: Compiler Placement of String Literals (.rodata.str)

Ali Mohamed

Part Number: TDA4VM

Tool/software:

Hello,

We are using the ti-arm-clang-3.2.0 compiler/toolchain for a project aimed

at Cortex-R5F/Armv7-R. Due to requirements, we need to map rodata.str1.* sections to different memory regions with varying attributes, such as cached vs. non-cached.

I have tried to do the following but have yet to be successful.


#pragma clang section data   = ".my_data"
#pragma clang section bss    = ".my_bss"
#pragma clang section text   = ".my_text"
#pragma clang section rodata = ".my_rodata"

static void foo(foo foo)
{
 ...
 const char[] foo = "Helllo World!";
 ...
}

#pragma clang section data   = ""
#pragma clang section bss    = ""
#pragma clang section text   = ""
#pragma clang section rodata = ""

The documentation doesn't say much

Best Regards,

Ali Mohamed

over 1 year ago

0 George Mock over 1 year ago

TI__Guru**** 251490 points

Is it practical to control it on a file by file basis? Don't use any compile options or pragmas. The control is implemented in the SECTIONS directive of the linker command file. For example ...

    rodata_strings1
    {
        f1.obj(.rodata.str1*)
        f2.obj(.rodata.str1*)
    } > SPECIAL_MEMORY1
    
    rodata_strings2
    {
        f3.obj(.rodata.str1*)
        f4.obj(.rodata.str1*)
    } > SPECIAL_MEMORY2

This collects all the strings from the object files f1.obj and f2.obj into an output section named rodata_strings1. It is allocated to a memory range named SPECIAL_MEMORY1. The output section rodata_string2 is similar, but for different files and a different memory range.

Thanks and regards,

-George

0 Ali Mohamed over 1 year ago in reply to George Mock

Prodigy 105 points

Hello George,

It will suffice for now as the files are limited; however, the underlying OS (an AUTOSAR BSW) is configuration-based and generates header files with pragmas.

Is there a possibility of enforcing the placement of rodata.str with pragmas as described above in the next increment?

Best regards,

Ali

+1 George Mock over 1 year ago in reply to Ali Mohamed

TI__Guru**** 251490 points

Ali Mohamed said:
Is there a possibility of enforcing the placement of rodata.str with pragmas as described above in the next increment?

I am unable to make any promises. But I did file EXT_EP-11829 to request a feature be added to the compiler. You are welcome to follow it with that link.

Thanks and regards,

-George

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TDA4VM: Compiler Placement of String Literals (.rodata.str)