contrib/loaders/flash/armv7m_io.s

   1 /***************************************************************************
   2  *   Copyright (C) 2013 by Henrik Nilsson                                  *
   3  *   henrik.nilsson@bytequest.se                                           *
   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         .syntax unified
  23         .arch armv7-m
  24         .thumb
  25         .thumb_func
  26
  27         .align 4
  28
  29 /* Inputs:
  30  *  r0  buffer address
  31  *  r1  NAND data address (byte wide)
  32  *  r2  buffer length
  33  */
  34 read:
  35         ldrb    r3, [r1]
  36         strb    r3, [r0], #1
  37         subs    r2, r2, #1
  38         bne             read
  39
  40 done_read:
  41         bkpt #0
  42
  43         .align 4
  44
  45 /* Inputs:
  46  *  r0  NAND data address (byte wide)
  47  *  r1  buffer address
  48  *  r2  buffer length
  49  */
  50 write:
  51         ldrb    r3, [r1], #1
  52         strb    r3, [r0]
  53         subs    r2, r2, #1
  54         bne             write
  55
  56 done_write:
  57         bkpt #0
  58
  59         .end
  60