How to specify the order of sections in link command file?

Leo Cheng

Hi,

Below is the link command file. I want to put all r and rx code sections, like interrupt, text, const, init table at the beginning of CODE_DATA_MEMORY, then put all rw data sections behind code section. Now the problem is linking will fail. What is the problem? Why it fail?

If move .cinit out of code_section, just use,

.cinit > CODE_DATA_MEMORY

then the .cinit will be located behind of data_section, this is not what I want.

error #10247-D: creating output section ".cinit" without a SECTIONS specification

MEMORY
{
   CODE_DATA_MEMORY  : org = CODE_DATA_MEM_ADDR,     len = CODE_DATA_MEM_LEN
}

SECTIONS
{
   code_section :
   {
      *(.intvecs)
      *(.text)
      *(.const)
      *(.cinit)
   } > CODE_DATA_MEM_ADDR

   data_section :
   {
      bss_start = .;
      *(.bss)
      bss_end = .;
      
      *(.data)
      *(.cio)
      *(.sysmem)
      
      __stack_start = .;
      *(.stack)
      __stack_end = .;
      __STACK_SIZE = __stack_end - __stack_start + 1;
            
   } > CODE_DATA_MEMORY
}

over 4 years ago

0 Kier over 4 years ago

Mastermind 9130 points

You can control the order with the GROUP directive.

https://software-dl.ti.com/ccs/esd/documents/sdto_cgt_Linker-Command-File-Primer.html

+1 George Mock over 4 years ago

TI__Guru**** 249860 points

Unfortunately, the only solution is to create two separate memory ranges. All the initialized sections, like .text, go into one memory range. All the uninitialized sections, like .data, go into the other memory range.

For example ...

MEMORY
{
   /* Change to match your system */
   INITIALIZED     : o = 0x1000, l = 0x3000
   NOT_INITIALIZED : o = 0x4000, l = 0x3000
}

SECTIONS
{
    .intvecs > INITIALIZED
    .text    > INITIALIZED
    .const   > INITIALIZED
    .cinit   > INITIALIZED

    .bss     > NOT_INITIALIZED, START(bss_start), END(bss_end)
    .data    > NOT_INITIALIZED
    .cio     > NOT_INITIALIZED
    .sysmem  > NOT_INITIALIZED
    .stack   > NOT_INITIALIZED, START(__stack_start), END(__stack_end)
}

/* Do not overwrite __STACK_SIZE that is created by default */
__MY_STACK_SIZE = __stack_end - __stack_start + 1;

Note the linker creates a symbol named __STACK_SIZE by default. You are welcome to create a similar symbol, but it has to have a different name.

If you want to make the INITIALIZED memory range just big enough to fit those sections ... Unfortunately, the only way to do it is with trial and error. If you use this method, give it a bit more memory than absolutely required, so you have some room for the sections to get bigger.

Thanks and regards,

-George

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How to specify the order of sections in link command file?