tinyriscv-openocd/contrib/loaders/flash/stm32l4x.S

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/***************************************************************************
* Copyright (C) 2010 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
* Copyright (C) 2011 Øyvind Harboe *
* oyvind.harboe@zylin.com *
* *
* Copyright (C) 2015 Uwe Bonnes *
* bon@elektron.ikp.physik.tu-darmstadt.de *
* *
* 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. *
***************************************************************************/
.text
.syntax unified
.cpu cortex-m4
.thumb
.thumb_func
/* To assemble:
* arm-none-eabi-gcc -c stm32l4x.S
*
* To disassemble:
* arm-none-eabi-objdump -o stm32l4x.o
*
* To generate binary file:
* arm-none-eabi-objcopy -O binary stm32l4x.o stm32l4_flash_write_code.bin
*
* To generate include file:
* xxd -i stm32l4_flash_write_code.bin
*/
/*
* Params :
* r0 = workarea start, status (out)
* r1 = workarea end
* r2 = target address
* r3 = count (64bit words)
* r4 = flash base
*
* Clobbered:
* r6 - temp
* r7 - rp
* r8 - wp, tmp
*/
#define STM32_FLASH_CR_OFFSET 0x14 /* offset of CR register in FLASH struct */
#define STM32_FLASH_SR_OFFSET 0x10 /* offset of SR register in FLASH struct */
wait_fifo:
ldr r8, [r0, #0] /* read wp */
cmp r8, #0 /* abort if wp == 0 */
beq exit
ldr r7, [r0, #4] /* read rp */
subs r6, r8, r7 /* number of bytes available for read in r6*/
cmp r6, #7 /* wait until 8 bytes are available */
bcc wait_fifo
ldr r6, STM32_PROG
str r6, [r4, #STM32_FLASH_CR_OFFSET]
ldr r6, [r7], #0x04 /* read one word from src, increment ptr */
str r6, [r2], #0x04 /* write one word to dst, increment ptr */
ldr r6, [r7], #0x04 /* read one word from src, increment ptr */
str r6, [r2], #0x04 /* write one word to dst, increment ptr */
dsb
busy:
ldr r6, [r4, #STM32_FLASH_SR_OFFSET]
tst r6, #0x10000 /* BSY (bit16) == 1 => operation in progress */
bne busy /* wait more... */
tst r6, #0xfa /* PGSERR | PGPERR | PGAERR | WRPERR | PROGERR*/
bne error /* fail... */
cmp r7, r1 /* wrap rp at end of buffer */
it cs
addcs r7, r0, #8 /* skip loader args */
str r7, [r0, #4] /* store rp */
subs r3, r3, #1 /* decrement dword count */
cbz r3, exit /* loop if not done */
b wait_fifo
error:
movs r1, #0
str r1, [r0, #4] /* set rp = 0 on error */
exit:
mov r0, r6 /* return status in r0 */
bkpt #0x00
STM32_PROG: .word 0x1 /* PG */