contrib/loaders/flash/kinetis_ke/kinetis_ke_flash.s

   1 /***************************************************************************
   2  *   Copyright (C) 2015 by Ivan Meleca                                     *
   3  *   ivan@artekit.eu                                                       *
   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         /* Params:
  17          * r0 = flash destination address, status
  18          * r1 = longword count
  19          * r2 = workarea start address
  20          * r3 = workarea end address
  21          */
  22
  23         .text
  24         .cpu cortex-m0plus
  25         .code 16
  26         .thumb_func
  27
  28         .align  2
  29
  30         /* r5 = rp
  31          * r6 = wp, tmp
  32          * r7 = tmp
  33          */
  34
  35 wait_fifo:
  36         ldr     r6, [r2, #0]    /* read wp */
  37         cmp     r6, #0                  /* abort if wp == 0 */
  38         beq     exit
  39         ldr     r5, [r2, #4]    /* read rp */
  40         cmp     r5, r6                  /* wait until rp != wp */
  41         beq     wait_fifo
  42
  43         ldr             r6, fstat               /* Clear error flags */
  44         mov             r7, #48
  45         strb    r7, [r6]
  46
  47         ldr             r6, fccobix             /* FCCOBIX = 0 */
  48         mov             r7, #0
  49         strb    r7, [r6]
  50
  51         ldr     r6, fccobhi             /* Program FLASH command */
  52         mov             r7, #6                  /* FCCOBHI = 6 */
  53         strb    r7, [r6]
  54
  55         lsr             r7, r0, #16             /* FCCOBLO = flash destination address >> 16 */
  56         ldr             r6, fccoblo
  57         strb    r7, [r6]
  58
  59         ldr             r6, fccobix             /* Index for lower byte address bits[15:0] */
  60         mov             r7, #1
  61         strb    r7, [r6]                /* FCCOBIX = 1*/
  62
  63         uxtb    r7, r0                  /* Memory address bits[15:0] */
  64         ldr     r6, fccoblo
  65         strb    r7, [r6]                /* FCCOBLO = flash destination address */
  66
  67         lsr             r7, r0, #8
  68         ldr             r6, fccobhi
  69         strb    r7, [r6]                /* FCCOBHI = flash destination address >> 8 */
  70
  71         ldr             r6, fccobix             /* FCCOBIX = 2 */
  72         mov             r7, #2
  73         strb    r7, [r6]
  74
  75         ldrb    r7, [r5, #1]    /* FCCOBHI = rp >> 8 */
  76         ldr             r6, fccobhi
  77         strb    r7, [r6]
  78
  79         ldrb    r7, [r5]                /* FCCOBLO = rp */
  80         ldr     r6, fccoblo
  81         strb    r7, [r6]
  82
  83         ldr             r6, fccobix             /* FCCOBIX = 3 */
  84         mov             r7, #3
  85         strb    r7, [r6]
  86
  87         ldrb    r7, [r5, #3]    /* FCCOBHI = rp >> 24 */
  88         ldr             r6, fccobhi
  89         strb    r7, [r6]
  90
  91         ldrb    r7, [r5, #2]    /* FCCOBLO = rp >> 16 */
  92         ldr             r6, fccoblo
  93         strb    r7, [r6]
  94
  95         sub             r1, r1, #1              /* Two words (4 bytes) queued, decrement counter */
  96         add             r0, r0, #4              /* flash address += 4 */
  97         add             r5, r5, #4              /* rp += 4 */
  98
  99         cmp     r5, r3                  /* Wrap? */
 100         bcc     no_wrap
 101         mov     r5, r2
 102         add     r5, r5, #8
 103
 104 no_wrap:
 105         cmp             r1, #0                  /* Done? */
 106         beq             execute
 107
 108         ldr     r6, [r2, #0]    /* read wp */
 109         cmp     r6, r5
 110         beq             execute                 /* execute if rp == wp */
 111
 112         ldr             r6, fccobix             /* FCCOBIX = 4 */
 113         mov             r7, #4
 114         strb    r7, [r6]
 115
 116         ldrb    r7, [r5, #1]    /* FCCOBHI = rp >> 8 */
 117         ldr             r6, fccobhi
 118         strb    r7, [r6]
 119
 120         ldrb    r7, [r5]                /* FCCOBLO = rp */
 121         ldr     r6, fccoblo
 122         strb    r7, [r6]
 123
 124         ldr             r6, fccobix             /* FCCOBIX = 5 */
 125         mov             r7, #5
 126         strb    r7, [r6]
 127
 128         ldrb    r7, [r5, #3]    /* FCCOBHI = rp >> 24 */
 129         ldr             r6, fccobhi
 130         strb    r7, [r6]
 131
 132         ldrb    r7, [r5, #2]    /* FCCOBLO = rp >> 16 */
 133         ldr             r6, fccoblo
 134         strb    r7, [r6]
 135
 136         sub             r1, r1, #1              /* Two words (4 bytes) queued, decrement counter */
 137         add             r0, r0, #4              /* flash address += 4 */
 138         add             r5, r5, #4              /* rp += 4 */
 139
 140         cmp     r5, r3                  /* Wrap? */
 141         bcc     execute
 142         mov     r5, r2
 143         add     r5, r5, #8
 144
 145 execute:
 146         ldr             r6, fstat               /* Launch the command */
 147         mov             r7, #128
 148         strb    r7, [r6]
 149
 150 wait_busy:
 151         ldr             r6, fstat
 152         ldrb    r6, [r6]                /* Wait until finished */
 153         tst             r6, r7
 154         beq             wait_busy
 155
 156         mov             r7, #48                 /* Check error */
 157         tst             r6, r7
 158         bne             error
 159
 160         mov             r6, #0                  /* Clear error */
 161
 162         str     r5, [r2, #4]    /* Store rp */
 163
 164         cmp             r1, #0                  /* Done? */
 165         beq             done
 166         b               wait_fifo
 167
 168 error:
 169         mov             r0, #0
 170         str     r0, [r2, #4]    /* set rp = 0 on error */
 171
 172 done:
 173         mov             r0, r6                  /* Set result code */
 174         bkpt    #0
 175
 176         .align  2
 177 fstat:
 178         .word   0
 179 fccobix:
 180         .word   0
 181 fccobhi:
 182         .word   0
 183 fccoblo:
 184         .word   0