gcc __attribute__ section 지정으로 직접 변수 기록될 영역 고정하기

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http://www.mikrocontroller.net/attachment/143228/stm32_flash.ld

/*

*****************************************************************************

**

**  File        : stm32_flash.ld

**

**  Abstract    : Linker script for STM32F207 Device with

**                1MByte FLASH, 128KByte SRAM

**

**                Set heap size, stack size and stack location according

**                to application requirements.

**

**                Set memory bank area and size if external memory is used.

**

**  Target      : STMicroelectronics STM32

**

**  Environment : Eclipse with CDT plugin and GCC compiler from CodeSourcery

**

** Author           Date        Comment

**~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**    T.Kamenicky      24/06/11    Upravil kod stazen z netu

** T.Kamenicky 13/10/11 Predelal na STM32F2

** T.Kamenicky 29/11/11    Pridal podporu externi SRAM

**

*****************************************************************************

*/

/* Entry Point */

/* This define entry point for linker, this address is used for CPU too as absolute first function */

ENTRY(Reset_Handler)

/* Highest address of the user mode stack, _estack is end of stack */

_estack = 0x20020000;    /* end of 128K RAM */

/* Generate a link error if heap and stack don't fit into RAM */

/* Heap is zero because we use own malloc implementation. The amount of heap is calculated 

 * from free space after compilation, see last section for RAM area */

_Min_Heap_Size = 0x0;      /* required amount of heap  */

/* This stack is used for main function. If FreeRTOS is used this stack is used by OS itself. */

/* The size of stack for tasks is defined in freertos config file and when creating the task. */

_Min_Stack_Size = 0x600; /* required amount of stack */

/* Specify the memory areas */

MEMORY

{

  FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 1022K  /* This is main program area */

  FACTORY_VAR(rx) : ORIGIN = 0x080FF800, LENGTH = 2K  /* This area is used for factory values, such as MAC address, ID...etc */

  RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 128K        /* This is RAM area */

  FSMC_SRAM (rx)  : ORIGIN = 0x64000000, LENGTH = 2048K       /* This is useful for external memory, like thru FSMC peripheral */

}

/* 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 */

    KEEP (*(.init))

    KEEP (*(.fini))

     . = ALIGN(4);

    _etext = .;        /* define a global symbols at end of code */

  } >FLASH

  /* .ARM.extab names a section that contains exception unwinding information.  See EHABI for details. */

  /* .ARM.exidx names a section that contains index entries for section unwinding.  See EHABI for details. */

   .ARM.extab   : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH

    .ARM : {

    __exidx_start = .;

      *(.ARM.exidx*)

      __exidx_end = .;

    } >FLASH

  /* Is used for compiler information, which is located only in elf file */

  .ARM.attributes 0 : { *(.ARM.attributes) }

  /* Those sections is used for initializing dynamic objects used in C++ */

 .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 as memory location to initialize data */

  /* from this point the content of flash is copied to ram */

  _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

  _SRAM_data = _sidata + _edata - _sdata;

  /* Second part of inicialized section goes into SRAM conected thru FSMC */

  /* FSMC_SRAM section, code must be located here explicitly            */

  /* unsigned long int __attribute__ ((section (".sram_data"))) my_initialized_number = 0xAABBCCDD; */

  .fsmc_sram_data : AT ( _SRAM_data )

  {

  . = ALIGN(4);

    _iSRAM_data = .;        

    *(.sram_data)      

    *(.sram_data*)

    

    . = ALIGN(4);

    _iSRAM_data_end = .;   

  } >FSMC_SRAM

  

  .fsmc_sram_bss : AT ( _iSRAM_data_end )

  {

    _iSRAM_null_data = .;       

    *(.sram_bss)

    *(.sram_bss*)

    

    . = ALIGN(4);

    _iSRAM_null_data_end = .;

  } >FSMC_SRAM

  

  .fsmc_sram_perma : AT ( _iSRAM_null_data_end )

  {

    _iSRAM_perma_data = .;       

    *(.sram_perma)

    *(.sram_perma*)

    

    . = ALIGN(4);

    _iSRAM_perma_data_end = .;

  } >FSMC_SRAM

  

   /* Uninitialized data section */

  . = ALIGN(4);

  

  .bss : AT ( _edata )

  {

    /* 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

  

  /* Those numbers are used for SRAM init */

  PROVIDE ( _linker_sram_start = _iSRAM_data );

  PROVIDE ( _linker_sram_data_end = _iSRAM_data_end );

  PROVIDE ( _linker_sram_end = _iSRAM_null_data_end );

  PROVIDE ( _linker_sram_inits = _SRAM_data );

  

  /* Those numbers are used for malloc and sbrk functions */

  PROVIDE ( _linker_memory_start = _sdata );

  PROVIDE ( _linker_heap_start = _ebss );

  PROVIDE ( _linker_heap_end = (_estack - _Min_Stack_Size) );

  PROVIDE ( _linker_memory_end = _estack );

  PROVIDE ( _end = _ebss );

   /* User_heap_stack section, used to check that there is enough RAM left */

  ._user_heap_stack : AT ( _linker_heap_end )

  {

    . = ALIGN(4);

    . = . + _Min_Heap_Size;

    . = . + _Min_Stack_Size;

    . = ALIGN(4);

  } >RAM

 /* FLASH memory area for factory default values                          */

  /* Example of usage: extern int foo(void) __attribute__ ((section (".fvtext"))); */

  /* unsigned long int my_factory_number_changed_in_production = 0xAABBCCDD __attribute__ ((section (".fvrodata"))); */ 

  .factory_values :

  {

    . = ALIGN(4);

    *(.fvtext)        /* .fvtext sections (code) */

    *(.fvtext*)       /* .fvtext* sections (code)  */

    *(.fvrodata)      /* read-only data (constants) */

    *(.fvrodata*)

    . = ALIGN(4);

  } >FACTORY_VAR

  /* Remove information from the standard libraries */

  /DISCARD/ :

  {

    libc.a ( * )

    libm.a ( * )

    libgcc.a ( * )

  }

}