diff options
Diffstat (limited to 'contrib/loaders/flash/stm32x.s')
| -rw-r--r-- | contrib/loaders/flash/stm32x.s | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/contrib/loaders/flash/stm32x.s b/contrib/loaders/flash/stm32x.s index dcf2b83c..6cf9f579 100644 --- a/contrib/loaders/flash/stm32x.s +++ b/contrib/loaders/flash/stm32x.s @@ -19,7 +19,10 @@ ***************************************************************************/ .text - .arm + .syntax unified + .thumb + .thumb_func + .global write /* r0 - source address @@ -27,26 +30,27 @@ r2 - count (halfword-16bit) r3 - result r4 - temp - r5 - 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_CR - ldr r5, STM32_FLASH_SR - mov r3, #1 - str r3, [r4, #0] - ldrh r3, [r0], #2 - strh r3, [r1], #2 + 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, [r5, #0] - tst r3, #0x01 - beq busy - tst r3, #0x14 - bne exit - subs r2, r2, #1 - bne write + 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 #0 + bkpt #0x00 -STM32_FLASH_CR: .word 0x40022010 -STM32_FLASH_SR: .word 0x4002200C +STM32_FLASH_BASE: .word 0x40022000 /* base address of FLASH struct */ |