contrib/loaders/flash/kinetis/kinetis_flash.s

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2015 by Ivan Meleca                                     *
   5  *   ivan@artekit.eu                                                       *
   6  *                                                                         *
   7  *   Copyright (C) 2016 by Tomas Vanek                                     *
   8  *   vanekt@fbl.cz                                                         *
   9  ***************************************************************************/
  10
  11         /* Params:
  12          * r0 = flash destination address in/out
  13          * r1 = longword count
  14          * r2 = workarea start address
  15          * r3 = workarea end address
  16          * r4 = FTFx base
  17          */
  18
  19         .text
  20         .cpu cortex-m0plus
  21         .code 16
  22         .thumb_func
  23
  24         .align  2
  25
  26         /* r5 = rp
  27          * r6 = wp, tmp
  28          * r7 = tmp
  29          */
  30
  31         /* old longword algo: 6.680 KiB/s @ adapter_khz 2000
  32          * this async algo: 19.808 KiB/s @ adapter_khz 2000
  33          */
  34
  35 FTFx_FSTAT =    0
  36 FTFx_FCCOB3 =   4
  37 FTFx_FCCOB0 =   7
  38 FTFx_FCCOB7 =   8
  39
  40 wait_fifo:
  41         ldr     r6, [r2, #0]    /* read wp */
  42         cmp     r6, #0          /* abort if wp == 0 */
  43         beq     exit
  44
  45         ldr     r5, [r2, #4]    /* read rp */
  46         cmp     r5, r6          /* wait until rp != wp */
  47         beq     wait_fifo
  48
  49         str     r0, [r4, #FTFx_FCCOB3] /* set flash address */
  50         mov     r7, #6
  51         strb    r7, [r4, #FTFx_FCCOB0] /* flash command */
  52
  53         ldr     r7, [r5]        /* set longword data = *rp */
  54         str     r7, [r4, #FTFx_FCCOB7]
  55
  56         mov     r7, #128
  57         strb    r7, [r4, #FTFx_FSTAT]
  58
  59         add     r5, #4          /* rp += 4 */
  60         cmp     r5, r3          /* Wrap? */
  61         bcc     no_wrap
  62         mov     r5, r2
  63         add     r5, #8
  64
  65 no_wrap:
  66         str     r5, [r2, #4]    /* Store rp */
  67
  68 wait_ccif:
  69         ldr     r6, [r2, #0]    /* read wp */
  70         cmp     r6, #0          /* abort if wp == 0 */
  71         beq     exit
  72
  73         ldrb    r6, [r4, #FTFx_FSTAT]
  74         tst     r6, r7
  75         beq     wait_ccif
  76
  77         mov     r7, #0x70
  78         tst     r6, r7
  79         bne     error
  80
  81         add     r0, #4          /* flash address += 4, do not increment before err check */
  82
  83         sub     r1, #1          /* word_count-- */
  84         cmp     r1, #0
  85         bne     wait_fifo
  86         b       exit
  87
  88 error:
  89         mov     r5, #0
  90         str     r5, [r2, #4]    /* set rp = 0 on error */
  91
  92 exit:
  93         bkpt    #0