contrib/loaders/flash/armv7m_io.s

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2013 by Henrik Nilsson                                  *
   5  *   henrik.nilsson@bytequest.se                                           *
   6  ***************************************************************************/
   7
   8         .text
   9         .syntax unified
  10         .arch armv7-m
  11         .thumb
  12         .thumb_func
  13
  14         .align 4
  15
  16 /* Inputs:
  17  *  r0  buffer address
  18  *  r1  NAND data address (byte wide)
  19  *  r2  buffer length
  20  */
  21 read:
  22         ldrb    r3, [r1]
  23         strb    r3, [r0], #1
  24         subs    r2, r2, #1
  25         bne             read
  26
  27 done_read:
  28         bkpt #0
  29
  30         .align 4
  31
  32 /* Inputs:
  33  *  r0  NAND data address (byte wide)
  34  *  r1  buffer address
  35  *  r2  buffer length
  36  */
  37 write:
  38         ldrb    r3, [r1], #1
  39         strb    r3, [r0]
  40         subs    r2, r2, #1
  41         bne             write
  42
  43 done_write:
  44         bkpt #0
  45
  46         .end