board/arm/oc8n/libs/ldscripts/at91sam7.ld-flash

   1 /* ****************************************************************************************************** */
   2 /*   demo_at91sam7_blink_flash.cmd                      LINKER  SCRIPT                                                */
   3 /*                                                                                                        */
   4 /*                                                                                                        */
   5 /*   The Linker Script defines how the code and data emitted by the GNU C compiler and assembler are      */
   6 /*   to be loaded into memory (code goes into FLASH, variables go into RAM).                                              */
   7 /*                                                                                                        */
   8 /*   Any symbols defined in the Linker Script are automatically global and available to the rest of the   */
   9 /*   program.                                                                                             */
  10 /*                                                                                                        */
  11 /*   To force the linker to use this LINKER SCRIPT, just add the -T demo_at91sam7_blink_flash.cmd         */
  12 /*   directive to the linker flags in the makefile. For example,                                          */
  13 /*                                                                                                        */
  14 /*                      LFLAGS  =  -Map main.map -nostartfiles -T demo_at91sam7_blink_flash.cmd                   */
  15 /*                                                                                                        */
  16 /*                                                                                                        */
  17 /*   The order that the object files are listed in the makefile determines what .text section is          */
  18 /*   placed first.                                                                                        */
  19 /*                                                                                                        */
  20 /*   For example:  $(LD) $(LFLAGS) -o main.out  crt.o main.o lowlevelinit.o                               */
  21 /*                                                                                                        */
  22 /*                         crt.o is first in the list of objects, so it will be placed at address 0x00000000      */
  23 /*                                                                                                        */
  24 /*                                                                                                        */
  25 /*   The top of the stack (_stack_end) is (last_byte_of_ram +1) - 4                                                   */
  26 /*                                                                                                        */
  27 /*   Therefore:   _stack_end = (0x00020FFFF + 1) - 4  =  0x00021000 - 4  =  0x0020FFFC                    */
  28 /*                                                                                                        */
  29 /*   Note that this symbol (_stack_end) is automatically GLOBAL and will be used by the crt.s             */
  30 /*   startup assembler routine to specify all stacks for the various ARM modes                            */
  31 /*                                                                                                        */
  32 /*                              MEMORY MAP                                                                */
  33 /*                      |                                 |                                               */
  34 /*            .-------->|---------------------------------|0x00210000                                     */
  35 /*            .         |                                 |0x0020FFFC  <---------- _stack_end             */
  36 /*            .         |    UDF Stack  16 bytes          |                                               */
  37 /*            .         |                                 |                                               */
  38 /*            .         |---------------------------------|0x0020FFEC                                     */
  39 /*            .         |                                 |                                               */
  40 /*            .         |    ABT Stack  16 bytes          |                                               */
  41 /*            .         |                                 |                                               */
  42 /*            .         |---------------------------------|0x0020FFDC                                     */
  43 /*            .         |                                 |                                               */
  44 /*            .         |                                 |                                               */
  45 /*            .         |    FIQ Stack  128 bytes         |                                               */
  46 /*            .         |                                 |                                               */
  47 /*            .         |                                 |                                               */
  48 /*           RAM        |---------------------------------|0x0020FF5C                                     */
  49 /*            .         |                                 |                                               */
  50 /*            .         |                                 |                                               */
  51 /*            .         |    IRQ Stack  128 bytes         |                                               */
  52 /*            .         |                                 |                                               */
  53 /*            .         |                                 |                                               */
  54 /*            .         |---------------------------------|0x0020FEDC                                     */
  55 /*            .         |                                 |                                               */
  56 /*            .         |    SVC Stack  16 bytes          |                                               */
  57 /*            .         |                                 |                                               */
  58 /*            .         |---------------------------------|0x0020FECC                                     */
  59 /*            .         |                                 |                                                       */
  60 /*            .         |     stack area for user program |                                               */
  61 /*            .         |                                 |                                               */
  62 /*            .         |                                 |                                               */
  63 /*            .         |                                 |                                               */
  64 /*            .         |          free ram               |                                               */
  65 /*            .         |                                 |                                               */
  66 /*            .         |.................................|0x002006D8 <---------- _bss_end                */
  67 /*            .         |                                 |                                               */
  68 /*            .         |  .bss   uninitialized variables |                                               */
  69 /*            .         |.................................|0x002006D0 <---------- _bss_start, _edata      */
  70 /*            .         |                                 |                                               */
  71 /*            .         |  .data  initialized variables   |                                               */
  72 /*            .         |                                 |                                               */
  73 /*            .-------->|_________________________________|0x00200000                                     */
  74 /*                                                                                                        */
  75 /*                                                                                                        */
  76 /*            .-------->|---------------------------------|0x00100000                                     */
  77 /*            .         |                                 |                                               */
  78 /*            .         |                                 |                                               */
  79 /*            .         |         free flash              |                                               */
  80 /*            .         |                                 |                                               */
  81 /*            .         |                                 |                                               */
  82 /*            .         |.................................|0x000006D0 <---------- _bss_start, _edata      */
  83 /*            .         |                                 |                                               */
  84 /*            .         |  .data  initialized variables   |                                               */
  85 /*            .         |                                 |                                               */
  86 /*            .         |---------------------------------|0x000006C4 <----------- _etext                 */
  87 /*            .         |                                 |                                               */
  88 /*            .         |            C code               |                                               */
  89 /*            .         |                                 |                                               */
  90 /*            .         |                                 |                                               */
  91 /*            .         |---------------------------------|0x00000118  main()                             */
  92 /*            .         |                                 |                                               */
  93 /*            .         |    Startup Code  (crt.s)        |                                               */
  94 /*            .         |         (assembler)             |                                               */
  95 /*            .         |                                 |                                               */
  96 /*            .         |---------------------------------|0x00000020                                     */
  97 /*            .         |                                 |                                               */
  98 /*            .         | Interrupt Vector Table          |                                               */
  99 /*            .         |          32 bytes               |                                               */
 100 /*            .-------->|---------------------------------|0x00000000 _vec_reset                            *
 101 /*                                                                                                        */
 102 /*                                                                                                        */
 103 /*  Author:  James P. Lynch                                                                               */
 104 /*                                                                                                        */
 105 /* ****************************************************************************************************** */
 106
 107
 108 /* identify the Entry Point  (_vec_reset is defined in file crt.s)  */
 109 ENTRY(_vec_reset)
 110
 111 /* specify the LPC2106 memory areas  */
 112
 113 /* if you find this file hard to understand, this may help: http://www.gnu.org/software/binutils/manual/ld-2.9.1/html_chapter/ld_3.html#SEC5 */
 114
 115 MEMORY
 116 {
 117         flash   : ORIGIN = 0,          LENGTH = 256K    /* FLASH EPROM          */
 118         ram             : ORIGIN = 0x00200000, LENGTH = 64K     /* static RAM area      */
 119 }
 120
 121
 122 /* define a global symbol _stack_end  (see analysis in annotation above) */
 123 _stack_end = 0x20FFFC;
 124
 125 /* now define the output sections  */
 126 SECTIONS
 127 {
 128         . = 0;                                                          /* set location counter to address zero  */
 129
 130         .zeropage :
 131         {
 132                 *(.zeropage)                    /* the .zeropage section put at the beginning  */
 133         } > flash
 134
 135         .text :                                                         /* collect all sections that should go into FLASH after startup  */
 136         {
 137                 *(.text)                                                /* all .text sections (code)  */
 138                 *(.rodata)                                              /* all .rodata sections (constants, strings, etc.)  */
 139                 *(.rodata*)                                             /* all .rodata* sections (constants, strings, etc.)  */
 140                 *(.glue_7)                                              /* all .glue_7 sections  (no idea what these are) */
 141                 *(.glue_7t)                                             /* all .glue_7t sections (no idea what these are) */
 142                 _etext = .;                                             /* define a global symbol _etext just after the last code byte */
 143         } >flash                                                        /* put all the above into FLASH */
 144
 145         .data :                                                         /* collect all initialized .data sections that go into RAM  */
 146         {
 147                 _data = .;                                              /* create a global symbol marking the start of the .data section  */
 148                 *(.data)                                                /* all .data sections  */
 149                 _edata = .;                                             /* define a global symbol marking the end of the .data section  */
 150         } >ram AT >flash                                /* put all the above into RAM (but load the LMA initializer copy into FLASH)  */
 151
 152         .bss :                                                          /* collect all uninitialized .bss sections that go into RAM  */
 153         {
 154                 _bss_start = .;                                 /* define a global symbol marking the start of the .bss section */
 155                 *(.bss)                                                 /* all .bss sections  */
 156         } >ram                                                          /* put all the above in RAM (it will be cleared in the startup code */
 157
 158         . = ALIGN(4);                                           /* advance location counter to the next 32-bit boundary */
 159         _bss_end = . ;                                          /* define a global symbol marking the end of the .bss section */
 160 }
 161         _end = .;                                                       /* define a global symbol marking the end of application RAM */
 162         PROVIDE (end = .);