contrib/loaders/flash/str9x.s

   1 /***************************************************************************
   2  *   Copyright (C) 2010 by Spencer Oliver                                  *
   3  *   spen@spen-soft.co.uk                                                  *
   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         .text
  22         .arm
  23         .section .init
  24 /*
  25         r0 source address (in)
  26         r1 target address (in)
  27         r2 word count (in)
  28         r3 result (out)
  29 */
  30
  31 write:
  32         bic             r4, r1, #3                      /* word address */
  33         mov             r3, #0x40                       /* write command */
  34         strh    r3, [r4, #0]
  35         ldrh    r3, [r0], #2            /* read data */
  36         strh    r3, [r1], #2            /* write data */
  37         mov             r3, #0x70                       /* status command */
  38         strh    r3, [r4, #0]
  39 busy:
  40         ldrb    r3, [r4, #0]            /* status */
  41         tst     r3, #0x80
  42         beq     busy
  43         mov             r5, #0x50                       /* clear status command */
  44         strh    r5, [r4, #0]
  45         mov             r5, #0xFF                       /* read array */
  46         strh    r5, [r4, #0]
  47         tst             r3, #0x12
  48         bne             exit
  49         subs    r2, r2, #1                      /* decremment word count */
  50         bne     write
  51 exit:
  52         bkpt    #0
  53
  54         .end