contrib/loaders/flash/sim3x.s

   1 /***************************************************************************
   2  *   Copyright (C) 2014 by Ladislav Bábel                                  *
   3  *   ladababel@seznam.cz                                                   *
   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
  16 #define INITIAL_UNLOCK    0x5A
  17 #define MULTIPLE_UNLOCK   0xF2
  18
  19 #define FLASHCTRL_KEY     0x4002E0C0
  20 #define FLASHCTRL_CONFIG  0x4002E000
  21 #define FLASHCTRL_WRADDR  0x4002E0A0
  22 #define FLASHCTRL_WRDATA  0x4002E0B0
  23 #define BUSYF             0x00100000
  24
  25
  26                 /* Write the initial unlock value to KEY (0xA5) */
  27                 movs    r6, #INITIAL_UNLOCK
  28                 str     r6, [r0, #FLASHCTRL_KEY]
  29
  30                 /* Write the multiple unlock value to KEY (0xF2) */
  31                 movs    r6, #MULTIPLE_UNLOCK
  32                 str     r6, [r0, #FLASHCTRL_KEY]
  33
  34 wait_fifo:
  35                 ldr     r6, [r2, #0]
  36                 cmp         r6, #0
  37                 beq     exit
  38                 ldr     r5, [r2, #4]
  39                 cmp     r5, r6
  40                 beq     wait_fifo
  41
  42                 /* wait for BUSYF flag */
  43 wait_busy1:
  44                 ldr     r6, [r0, #FLASHCTRL_CONFIG]
  45                 tst     r6, #BUSYF
  46                 bne     wait_busy1
  47
  48                 /* Write the destination address to WRADDR */
  49                 str     r4, [r0, #FLASHCTRL_WRADDR]
  50
  51                 /* Write the data half-word to WRDATA in right-justified format */
  52                 ldrh    r6, [r5]
  53                 str     r6, [r0, #FLASHCTRL_WRDATA]
  54
  55                 adds    r5, #2
  56                 adds    r4, #2
  57
  58                 /* wrap rp at end of buffer */
  59                 cmp     r5, r3
  60                 bcc     no_wrap
  61                 mov     r5, r2
  62                 adds    r5, #8
  63
  64 no_wrap:
  65                 str     r5, [r2, #4]
  66                 subs    r1, r1, #1
  67                 cmp     r1, #0
  68                 beq     exit
  69                 b       wait_fifo
  70
  71 exit:
  72                 movs    r6, #MULTIPLE_LOCK
  73                 str     r6, [r0, #FLASHCTRL_KEY]
  74
  75                 /* wait for BUSYF flag */
  76 wait_busy2:
  77                 ldr     r6, [r0, #FLASHCTRL_CONFIG]
  78                 tst     r6, #BUSYF
  79                 bne     wait_busy2
  80
  81                 bkpt    #0