ecosflash/flash.S

   1 /***************************************************************************
   2  *   Copyright (C) 2008 Øyvind Harboe                                      *
   3  *   oyvind.harboe@zylin.com                                               *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 /*
  21         Jump table for flash driver
  22
  23         Registers in ARM callling convention is to place args in registers
  24         starting at r0.
  25
  26         So for:
  27
  28         void foo(int a, int b, int c).
  29
  30         a=r0
  31         b=r1
  32         c=r2
  33
  34
  35 */
  36         .global _stack_base
  37         .global _stack_start
  38         .global _workarea
  39         .global _start
  40         .global _start_bss_clear
  41 _start:
  42         // offset=0
  43         // int erase(void *address, int len)
  44         ldr     sp,=_stack_start
  45         bl erase
  46         nop // Stop CPU here using hw breakpoint
  47
  48         // offset=0xc
  49         // int program(void *buffer, void *address, int len)
  50         ldr     sp,=_stack_start
  51         bl program
  52         nop // Stop CPU here using hw breakpoint
  53
  54         // offset=0x18
  55         ldr     r0,=_workarea
  56         nop // Stop CPU here using hw breakpoint
  57
  58         // offset=0x20
  59         // int init() - returns error message if the flash chip can't be detected
  60         ldr     sp,=_stack_start
  61         bl init
  62         nop // Stop CPU here using hw breakpoint
  63
  64     .section ".bss"
  65     .balign 4
  66 _stack_base:
  67         .rept 4096
  68         .byte 0
  69         .endr
  70 _stack_start:
  71     .balign 4
  72 _workarea:
  73         .rept 8192
  74         .byte 0
  75         .endr
  76         // NB!!! we clear bss while the stack is in use, so we start BSS clearing here !!! :-)
  77 _start_bss_clear: