Compiler data location management

brucebowling — Tue, 06 Dec 2016 19:33:31 GMT

I am using the S32DS tool with the KEAZ128 device, and I am creating a large number of display bitmap images. loading these in as static initialized data variables is causing issue, it appears the compiler/linker is not loading these in flash. I am receiving the following error:

xxxx.elf section `.data' will not fit in region `SRAM'

I want to specify that these data should be within section FLASH_2 section. I am trying to use pragmas to specify the placement but they are not working as far as I can tell. I am using the format:

#pragma arm section rodata

to place in section .rodata which is part of FLASH_2 definition in the linker file. FLASH_2 has a length of 0x1FBF0 which should be plenty of space.

Any documents, etc that I should be reviewing about placement of static defined variables?

Re: Compiler data location management

stanish — Tue, 06 Dec 2016 22:49:31 GMT

Hi Bruce,

I'd recommend you to declare these bitmaps as constant instead of static variables e.g.:

const unsigned char BitMapImage[] = {0,1,2,3,4};‍

BitMapImage will be placed into .rodata

if you want to have them in a custom flash section you should adjust your linker file (.ld)

KEA.ld:

...
.text :
 {
 . = ALIGN(4);
 *(.text) /* .text sections (code) */
 *(.text*) /* .text* sections (code) */
 *(.rodata) /* .rodata sections (constants, strings, etc.) */
 *(.rodata*) /* .rodata* sections (constants, strings, etc.) */
 *(.glue_7) /* glue arm to thumb code */
 *(.glue_7t) /* glue thumb to arm code */
 *(.eh_frame)
 KEEP(*(.my_bitmap_flash)) /* bitmap flash section*/
 KEEP (*(.init))
 KEEP (*(.fini))
 . = ALIGN(4);
 } > FLASH_2
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

source file:

__attribute__((section(".my_bitmap_flash")))
const unsigned char BitMapImage[] = {0,1,2,3,4};‍‍

Hope it helps.

Stan

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Compiler data location management

Re: Compiler data location management