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  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  19  ***************************************************************************/
  20
  21         .text
  22         .arm
  23         .arch armv5t
  24
  25         .section .init
  26 /*
  27         r0 source address (in)
  28         r1 target address (in)
  29         r2 word count (in)
  30         r3 result (out)
  31 */
  32
  33 write:
  34         bic             r4, r1, #3                      /* word address */
  35         mov             r3, #0x40                       /* write command */
  36         strh    r3, [r4, #0]
  37         ldrh    r3, [r0], #2            /* read data */
  38         strh    r3, [r1], #2            /* write data */
  39         mov             r3, #0x70                       /* status command */
  40         strh    r3, [r4, #0]
  41 busy:
  42         ldrb    r3, [r4, #0]            /* status */
  43         tst     r3, #0x80
  44         beq     busy
  45         mov             r5, #0x50                       /* clear status command */
  46         strh    r5, [r4, #0]
  47         mov             r5, #0xFF                       /* read array */
  48         strh    r5, [r4, #0]
  49         tst             r3, #0x12
  50         bne             exit
  51         subs    r2, r2, #1                      /* decremment word count */
  52         bne     write
  53 exit:
  54         bkpt    #0
  55
  56         .end