ecosflash/flash.S

   1 /*
   2 #####ECOSGPLCOPYRIGHTBEGIN####
   3 ## -------------------------------------------
   4 ## This file is part of eCos, the Embedded Configurable Operating System.
   5 ## Copyright (C) 2008 Øyvind Harboe
   6 ##
   7 ## eCos is free software; you can redistribute it and/or modify it under
   8 ## the terms of the GNU General Public License as published by the Free
   9 ## Software Foundation; either version 2 or (at your option) any later version.
  10 ##
  11 ## eCos is distributed in the hope that it will be useful, but WITHOUT ANY
  12 ## WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 ## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 ## for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License along
  17 ## with eCos; if not, write to the Free Software Foundation, Inc.,
  18 ## 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  19 ##
  20 ## As a special exception, if other files instantiate templates or use macros
  21 ## or inline functions from this file, or you compile this file and link it
  22 ## with other works to produce a work based on this file, this file does not
  23 ## by itself cause the resulting work to be covered by the GNU General Public
  24 ## License. However the source code for this file must still be made available
  25 ## in accordance with section (3) of the GNU General Public License.
  26 ##
  27 ## This exception does not invalidate any other reasons why a work based on
  28 ## this file might be covered by the GNU General Public License.
  29 ## -------------------------------------------
  30 #####ECOSGPLCOPYRIGHTEND####
  31 */
  32
  33 /*
  34         Jump table for flash driver
  35
  36         Registers in ARM callling convention is to place args in registers
  37         starting at r0.
  38
  39         So for:
  40
  41         void foo(int a, int b, int c).
  42
  43         a=r0
  44         b=r1
  45         c=r2
  46
  47
  48 */
  49         .global _stack_base
  50         .global _stack_start
  51         .global _workarea
  52         .global _start
  53         .global _start_bss_clear
  54 _start:
  55         // offset=0
  56         // int erase(void *address, int len)
  57         ldr     sp,=_stack_start
  58         bl erase
  59         nop // Stop CPU here using hw breakpoint
  60
  61         // offset=0xc
  62         // int program(void *buffer, void *address, int len)
  63         ldr     sp,=_stack_start
  64         bl program
  65         nop // Stop CPU here using hw breakpoint
  66
  67         // offset=0x18
  68         ldr     r0,=_workarea
  69         nop // Stop CPU here using hw breakpoint
  70
  71         // offset=0x20
  72         // int init() - returns error message if the flash chip can't be detected
  73         ldr     sp,=_stack_start
  74         bl init
  75         nop // Stop CPU here using hw breakpoint
  76
  77     .section ".bss"
  78     .balign 4
  79 _stack_base:
  80         .rept 4096
  81         .byte 0
  82         .endr
  83 _stack_start:
  84     .balign 4
  85 _workarea:
  86         .rept 8192
  87         .byte 0
  88         .endr
  89         // NB!!! we clear bss while the stack is in use, so we start BSS clearing here !!! :-)
  90 _start_bss_clear: