contrib/loaders/flash/cc3220sf/cc3220sf.s

   1 /***************************************************************************
   2  *   Copyright (C) 2017 by Texas Instruments, Inc.                         *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  16  ***************************************************************************/
  17
  18         /* Params:
  19          * r0 = buffer start address (in)
  20          * r1 = flash destination address (in)
  21          * r2 = number of words to write (in/out)
  22          */
  23
  24         .text
  25         .cpu cortex-m4
  26         .code 16
  27         .thumb
  28         .syntax unified
  29
  30         .align 2
  31
  32         /* r3 = scratchpad
  33          * r4 = buffer word counter
  34          * r10 = flash programming key
  35          * r11 = base FWB address
  36          * r12 = base flash regs address
  37          */
  38
  39 start:
  40         ldr     r10, =0xa4420001        /* flash programming key */
  41         ldr     r11, =0x400fd100        /* base of FWB */
  42         ldr     r12, =0x400fd000        /* base of flash regs */
  43         and     r3, r1, #0x7f           /* is the dest address 32 word aligned? */
  44         cmp     r3, #0
  45         bne     program_word            /* if not aligned do one word at a time */
  46
  47         /* program using the write buffers */
  48 program_buffer:
  49         mov     r4, #0                          /* start the buffer word counter at 0 */
  50         str     r1, [r12]                       /* store the dest addr in FMA */
  51 fill_buffer:
  52         ldr     r3, [r0]                        /* get the word to write to FWB */
  53         str     r3, [r11]                       /* store the word in the FWB */
  54         add     r11, r11, #4            /* increment the FWB pointer */
  55         add     r0, r0, #4                      /* increment the source pointer */
  56         sub     r2, r2, #1                      /* decrement the total word counter */
  57         add     r4, r4, #1                      /* increment the buffer word counter */
  58         add     r1, r1, #4                      /* increment the dest pointer */
  59         cmp     r2, #0                          /* is the total word counter now 0? */
  60         beq     buffer_ready            /* go to end if total word counter is 0 */
  61         cmp     r4, #32                         /* is the buffer word counter now 32? */
  62         bne     fill_buffer                     /* go to continue to fill buffer */
  63 buffer_ready:
  64         str     r10, [r12, #0x20]       /* store the key and write bit to FMC2 */
  65 wait_buffer_done:
  66         ldr     r3, [r12, #0x20]        /* read FMC2 */
  67         tst     r3, #1                          /* see if the write bit is cleared */
  68         bne     wait_buffer_done        /* go to read FMC2 if bit not cleared */
  69         cmp     r2, #0                          /* is the total word counter now 0? */
  70         bne     start                           /* go if there is more to program */
  71         b       exit
  72
  73         /* program just one word */
  74 program_word:
  75         str     r1, [r12]                       /* store the dest addr in FMA */
  76         ldr     r3, [r0]                        /* get the word to write to FMD */
  77         str     r3, [r12, #0x4]         /* store the word in FMD */
  78         str     r10, [r12, #0x8]        /* store the key and write bit to FMC */
  79 wait_word_done:
  80         ldr     r3, [r12, #0x8]         /* read FMC */
  81         tst     r3, #1                          /* see if the write bit is cleared */
  82         bne     wait_word_done          /* go to read FMC if bit not cleared */
  83         sub     r2, r2, #1                      /* decrement the total word counter */
  84         add     r0, r0, #4                      /* increment the source pointer */
  85         add     r1, r1, #4                      /* increment the dest pointer */
  86         cmp     r2, #0                          /* is the total word counter now 0 */
  87         bne     start                           /* go if there is more to program */
  88
  89         /* end */
  90 exit:
  91         bkpt    #0
  92         bkpt    #1
  93         b       exit