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/***************************************************************************
* Copyright (C) 2017 by Texas Instruments, Inc. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
/* Params:
* r0 = buffer start address (in)
* r1 = flash destination address (in)
* r2 = number of words to write (in/out)
*/
.text
.cpu cortex-m4
.code 16
.thumb
.syntax unified
.align 2
/* r3 = scratchpad
* r4 = buffer word counter
* r10 = flash programming key
* r11 = base FWB address
* r12 = base flash regs address
*/
start:
ldr r10, =0xa4420001 /* flash programming key */
ldr r11, =0x400fd100 /* base of FWB */
ldr r12, =0x400fd000 /* base of flash regs */
and r3, r1, #0x7f /* is the dest address 32 word aligned? */
cmp r3, #0
bne program_word /* if not aligned do one word at a time */
/* program using the write buffers */
program_buffer:
mov r4, #0 /* start the buffer word counter at 0 */
str r1, [r12] /* store the dest addr in FMA */
fill_buffer:
ldr r3, [r0] /* get the word to write to FWB */
str r3, [r11] /* store the word in the FWB */
add r11, r11, #4 /* increment the FWB pointer */
add r0, r0, #4 /* increment the source pointer */
sub r2, r2, #1 /* decrement the total word counter */
add r4, r4, #1 /* increment the buffer word counter */
add r1, r1, #4 /* increment the dest pointer */
cmp r2, #0 /* is the total word counter now 0? */
beq buffer_ready /* go to end if total word counter is 0 */
cmp r4, #32 /* is the buffer word counter now 32? */
bne fill_buffer /* go to continue to fill buffer */
buffer_ready:
str r10, [r12, #0x20] /* store the key and write bit to FMC2 */
wait_buffer_done:
ldr r3, [r12, #0x20] /* read FMC2 */
tst r3, #1 /* see if the write bit is cleared */
bne wait_buffer_done /* go to read FMC2 if bit not cleared */
cmp r2, #0 /* is the total word counter now 0? */
bne start /* go if there is more to program */
b exit
/* program just one word */
program_word:
str r1, [r12] /* store the dest addr in FMA */
ldr r3, [r0] /* get the word to write to FMD */
str r3, [r12, #0x4] /* store the word in FMD */
str r10, [r12, #0x8] /* store the key and write bit to FMC */
wait_word_done:
ldr r3, [r12, #0x8] /* read FMC */
tst r3, #1 /* see if the write bit is cleared */
bne wait_word_done /* go to read FMC if bit not cleared */
sub r2, r2, #1 /* decrement the total word counter */
add r0, r0, #4 /* increment the source pointer */
add r1, r1, #4 /* increment the dest pointer */
cmp r2, #0 /* is the total word counter now 0 */
bne start /* go if there is more to program */
/* end */
exit:
bkpt #0
bkpt #1
b exit
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