riscv-openocd/contrib/loaders/flash/stm32x.S

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/***************************************************************************
* Copyright (C) 2010 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
* 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, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
.text
.syntax unified
.cpu cortex-m3
.thumb
.thumb_func
.global write
/*
r0 - source address
r1 - target address
r2 - count (halfword-16bit)
r3 - result
r4 - temp
*/
#define STM32_FLASH_CR_OFFSET 0x10 /* offset of CR register in FLASH struct */
#define STM32_FLASH_SR_OFFSET 0x0c /* offset of CR register in FLASH struct */
write:
ldr r4, STM32_FLASH_BASE
write_half_word:
movs r3, #0x01
str r3, [r4, #STM32_FLASH_CR_OFFSET] /* PG (bit0) == 1 => flash programming enabled */
ldrh r3, [r0], #0x02 /* read one half-word from src, increment ptr */
strh r3, [r1], #0x02 /* write one half-word from src, increment ptr */
busy:
ldr r3, [r4, #STM32_FLASH_SR_OFFSET]
tst r3, #0x01 /* BSY (bit0) == 1 => operation in progress */
beq busy /* wait more... */
tst r3, #0x14 /* PGERR (bit2) == 1 or WRPRTERR (bit4) == 1 => error */
bne exit /* fail... */
subs r2, r2, #0x01 /* decrement counter */
bne write_half_word /* write next half-word if anything left */
exit:
bkpt #0x00
STM32_FLASH_BASE: .word 0x40022000 /* base address of FLASH struct */