contrib/loaders/flash/str9x.s

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2010 by Spencer Oliver                                  *
   5  *   spen@spen-soft.co.uk                                                  *
   6  ***************************************************************************/
   7
   8         .text
   9         .arm
  10         .arch armv5t
  11
  12         .section .init
  13 /*
  14         r0 source address (in)
  15         r1 target address (in)
  16         r2 word count (in)
  17         r3 result (out)
  18 */
  19
  20 write:
  21         bic             r4, r1, #3                      /* word address */
  22         mov             r3, #0x40                       /* write command */
  23         strh    r3, [r4, #0]
  24         ldrh    r3, [r0], #2            /* read data */
  25         strh    r3, [r1], #2            /* write data */
  26         mov             r3, #0x70                       /* status command */
  27         strh    r3, [r4, #0]
  28 busy:
  29         ldrb    r3, [r4, #0]            /* status */
  30         tst     r3, #0x80
  31         beq     busy
  32         mov             r5, #0x50                       /* clear status command */
  33         strh    r5, [r4, #0]
  34         mov             r5, #0xFF                       /* read array */
  35         strh    r5, [r4, #0]
  36         tst             r3, #0x12
  37         bne             exit
  38         subs    r2, r2, #1                      /* decrement word count */
  39         bne     write
  40 exit:
  41         bkpt    #0
  42
  43         .end