AnsweredAssumed Answered

GCC based Linker file for the STM32F0

Question asked by halherta on Jun 26, 2012
Latest reply on Jun 26, 2012 by Clive One
Hello all I just wrote a simple linker file to be used in the gcc environment. One of my goals was to define a stack and heap section in the linker file. The linker file is provided below. It seems to compile with a simple led blinky project for the STM32F0.
In the linker file I included the preinit, init and fini sections to make the linker compatible with C++. I did see in some linker files an .arm.extab section. Does anyone know the purpose of this section ? Please feel free to provide me with any other feedback on the linker file.

Thank you!

/******************************************************************************
 ******************************************************************************/
 
/* Entry Point */
ENTRY(Reset_Handler)
 
/* Specify the memory areas */
MEMORY
{
  FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 0x10000 /*64K*/
  RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 0x02000 /*8K*/
}
 
/* define stack size and heap size here */
stack_size = 1024;
heap_size = 256;
 
/* define beginning and ending of stack */
_stack_end = ORIGIN(RAM)+LENGTH(RAM);
_stack_begin = _stack_end - stack_size;
 
 
/* Define output sections */
SECTIONS
{
  /* The startup code goes first into FLASH */
  .isr_vector :
  {
    . = ALIGN(4);
    KEEP(*(.isr_vector)) /* Startup code */
    . = ALIGN(4);
  } >FLASH
 
  /* The program code and other data goes into FLASH */
  .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 (*(.init))
    KEEP (*(.fini))
 
    . = ALIGN(4);
    _etext = .;        /* define a global symbols at end of code */
  } >FLASH
 
  .preinit_array     :
  {
    PROVIDE_HIDDEN (__preinit_array_start = .);
    KEEP (*(.preinit_array*))
    PROVIDE_HIDDEN (__preinit_array_end = .);
  } >FLASH
  .init_array :
  {
    PROVIDE_HIDDEN (__init_array_start = .);
    KEEP (*(SORT(.init_array.*)))
    KEEP (*(.init_array*))
    PROVIDE_HIDDEN (__init_array_end = .);
  } >FLASH
  .fini_array :
  {
    PROVIDE_HIDDEN (__fini_array_start = .);
    KEEP (*(.fini_array*))
    KEEP (*(SORT(.fini_array.*)))
    PROVIDE_HIDDEN (__fini_array_end = .);
  } >FLASH
 
  /* used by the startup to initialize data */
  _sidata = .;
 
  /* Initialized data sections goes into RAM, load LMA copy after code */
  .data : AT ( _sidata )
  {
    . = ALIGN(4);
    _sdata = .;        /* create a global symbol at data start */
    *(.data)           /* .data sections */
    *(.data*)          /* .data* sections */
 
    . = ALIGN(4);
    _edata = .;        /* define a global symbol at data end */
  } >RAM
 
  /* Uninitialized data section */
  . = ALIGN(4);
  .bss :
  {
    /* This is used by the startup in order to initialize the .bss secion */
    _sbss = .;         /* define a global symbol at bss start */
    __bss_start__ = _sbss;
    *(.bss)
    *(.bss*)
    *(COMMON)
 
    . = ALIGN(4);
    _ebss = .;         /* define a global symbol at bss end */
    __bss_end__ = _ebss;
  } >RAM
 
. = ALIGN(4);
.heap :
{
_heap_start = .;
. = . + heap_size;
} > RAM
 
. = ALIGN(4);
. = _stack_begin;
.stack :
{
 
. = . + stack_size;
} > RAM
 
 
}

Outcomes