diff options
Diffstat (limited to 'contrib/loaders/flash/stm32x.S')
-rw-r--r-- | contrib/loaders/flash/stm32x.S | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/contrib/loaders/flash/stm32x.S b/contrib/loaders/flash/stm32x.S new file mode 100644 index 00000000..7269e799 --- /dev/null +++ b/contrib/loaders/flash/stm32x.S @@ -0,0 +1,57 @@ +/*************************************************************************** + * 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 */ |