diff options
Diffstat (limited to 'contrib/loaders/flash/stm32/stm32h7x.S')
-rw-r--r-- | contrib/loaders/flash/stm32/stm32h7x.S | 73 |
1 files changed, 40 insertions, 33 deletions
diff --git a/contrib/loaders/flash/stm32/stm32h7x.S b/contrib/loaders/flash/stm32/stm32h7x.S index beb8fdbd..a4317229 100644 --- a/contrib/loaders/flash/stm32/stm32h7x.S +++ b/contrib/loaders/flash/stm32/stm32h7x.S @@ -25,29 +25,35 @@ * Code limitations: * The workarea must have size multiple of 4 bytes, since R/W * operations are all at 32 bits. - * The workarea must be big enough to contain 32 bytes of data, - * thus the minimum size is (rp, wp, data) = 4 + 4 + 32 = 40 bytes. + * The workarea must be big enough to contain rp, wp and data, thus the minumum + * workarea size is: min_wa_size = sizeof(rp, wp, data) = 4 + 4 + sizeof(data). + * - for 0x450 devices: sizeof(data) = 32 bytes, thus min_wa_size = 40 bytes. + * - for 0x480 devices: sizeof(data) = 16 bytes, thus min_wa_size = 24 bytes. * To benefit from concurrent host write-to-buffer and target * write-to-flash, the workarea must be way bigger than the minimum. - */ + * + * To avoid confusions the write word size is got from .block_size member of + * struct stm32h7x_part_info defined in stm32h7x.c +*/ /* * Params : * r0 = workarea start, status (out) * r1 = workarea end * r2 = target address - * r3 = count (256 bit words) - * r4 = flash reg base + * r3 = count (of write words) + * r4 = size of write word + * r5 = flash reg base * * Clobbered: - * r5 - rp - * r6 - wp, status, tmp - * r7 - loop index, tmp + * r6 - rp + * r7 - wp, status, tmp + * r8 - loop index, tmp */ #define STM32_FLASH_CR_OFFSET 0x0C /* offset of CR register in FLASH struct */ #define STM32_FLASH_SR_OFFSET 0x10 /* offset of SR register in FLASH struct */ -#define STM32_CR_PROG 0x00000032 /* PSIZE64 | PG */ +#define STM32_CR_PROG 0x00000002 /* PG */ #define STM32_SR_QW_MASK 0x00000004 /* QW */ #define STM32_SR_ERROR_MASK 0x07ee0000 /* DBECCERR | SNECCERR | RDSERR | RDPERR | OPERR | INCERR | STRBERR | PGSERR | WRPERR */ @@ -55,54 +61,55 @@ .thumb_func .global _start _start: - ldr r5, [r0, #4] /* read rp */ + ldr r6, [r0, #4] /* read rp */ wait_fifo: - ldr r6, [r0, #0] /* read wp */ - cbz r6, exit /* abort if wp == 0, status = 0 */ - subs r6, r6, r5 /* number of bytes available for read in r6 */ + ldr r7, [r0, #0] /* read wp */ + cbz r7, exit /* abort if wp == 0, status = 0 */ + subs r7, r7, r6 /* number of bytes available for read in r7 */ ittt mi /* if wrapped around */ - addmi r6, r1 /* add size of buffer */ - submi r6, r0 - submi r6, #8 - cmp r6, #32 /* wait until 32 bytes are available */ + addmi r7, r1 /* add size of buffer */ + submi r7, r0 + submi r7, #8 + cmp r7, r4 /* wait until data buffer is full */ bcc wait_fifo - mov r6, #STM32_CR_PROG - str r6, [r4, #STM32_FLASH_CR_OFFSET] + mov r7, #STM32_CR_PROG + str r7, [r5, #STM32_FLASH_CR_OFFSET] - mov r7, #8 /* program by 8 words = 32 bytes */ + mov r8, #4 + udiv r8, r4, r8 /* number of words is size of write word devided by 4*/ write_flash: dsb - ldr r6, [r5], #0x04 /* read one word from src, increment ptr */ - str r6, [r2], #0x04 /* write one word to dst, increment ptr */ + ldr r7, [r6], #0x04 /* read one word from src, increment ptr */ + str r7, [r2], #0x04 /* write one word to dst, increment ptr */ dsb - cmp r5, r1 /* if rp >= end of buffer ... */ + cmp r6, r1 /* if rp >= end of buffer ... */ it cs - addcs r5, r0, #8 /* ... then wrap at buffer start */ - subs r7, r7, #1 /* decrement loop index */ + addcs r6, r0, #8 /* ... then wrap at buffer start */ + subs r8, r8, #1 /* decrement loop index */ bne write_flash /* loop if not done */ busy: - ldr r6, [r4, #STM32_FLASH_SR_OFFSET] - tst r6, #STM32_SR_QW_MASK + ldr r7, [r5, #STM32_FLASH_SR_OFFSET] + tst r7, #STM32_SR_QW_MASK bne busy /* operation in progress, wait ... */ - ldr r7, =STM32_SR_ERROR_MASK - tst r6, r7 + ldr r8, =STM32_SR_ERROR_MASK + tst r7, r8 bne error /* fail... */ - str r5, [r0, #4] /* store rp */ + str r6, [r0, #4] /* store rp */ subs r3, r3, #1 /* decrement count */ bne wait_fifo /* loop if not done */ b exit error: - movs r7, #0 - str r7, [r0, #4] /* set rp = 0 on error */ + movs r8, #0 + str r8, [r0, #4] /* set rp = 0 on error */ exit: - mov r0, r6 /* return status in r0 */ + mov r0, r7 /* return status in r0 */ bkpt #0x00 .pool |