RAM Section allocated by Linker

RE: RAM Section allocated by Linker

Einar Thorsrud — Mon, 01 Feb 2021 09:24:09 GMT

Ah, I see. I have not been able to find an answer to that. Have you tried asking Segger (either private support or on their forum)? I would expect they should be able to answer quickly.

RE: RAM Section allocated by Linker

WesC — Fri, 29 Jan 2021 13:46:56 GMT

How do I set an upper limit on the size of the section in order to prevent linking when the config data area gets larger than 4096?

the “size” attribute won’t work for this application because it sets the size of the section being created to a fixed value.

I hope this doesn’t confuse things, but this is how I do it for the GNU linker (ld) in a .ld file:

   /*///////////////////////////////////////////////////////////////////////////*/
   /* .cnfig_data must fit into one flash block (4K) including the 2-byte CRC-16 */
   /*///////////////////////////////////////////////////////////////////////////*/
   .cnfig_data :
   {
                _start_of_cnfig_data = .;
                *(.cnfig_data)
                *(.cnfig_data.*)
                _end_of_cnfig_data = .;
   } > SRAM1

   _size_of_cnfig_data = _end_of_cnfig_data - _start_of_cnfig_data;
   ASSERT( _size_of_cnfig_data <= 4094, ".cnfig_data cannot exceed 4094 bytes")

   /*///////////////////////////////////////////////////////////////////////////*/

RE: RAM Section allocated by Linker

Einar Thorsrud — Thu, 28 Jan 2021 14:20:01 GMT

Hi,

This thread on the Segger forum shows how to place data at a specific location (both in flash and RAM). That does not show how to specify size, but it is described in the linker documentation here.