flash: add stm32f2x async flash loader

[openocd.git] / contrib / loaders / flash / stm32f2x.S

diff --git a/contrib/loaders/flash/stm32f2x.S b/contrib/loaders/flash/stm32f2x.S
index 49c821b6060e0838e8fab19d4f952afd78c7838a..7ac5e3c0669daef7440de5fb4ff26130af98434e 100644 (file)
--- a/contrib/loaders/flash/stm32f2x.S
+++ b/contrib/loaders/flash/stm32f2x.S
@@ -21,43 +21,60 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
-
-// Build : arm-eabi-gcc -c stm32f2xxx.S
        .text
        .syntax unified
        .cpu cortex-m3
        .thumb
        .thumb_func
-       .global write
 
 /*
-       r0 - source address
-       r1 - target address
-       r2 - count (halfword-16bit)
-       r3 - result out
-       r4 - flash base
-*/
+ * Params :
+ * r0 = workarea start, status (out)
+ * r1 = workarea end
+ * r2 = target address
+ * r3 = count (16bit words)
+ * r4 = flash base
+ *
+ * Clobbered:
+ * r6 - temp
+ * r7 - rp
+ * r8 - wp, tmp
+ */
 
 #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 */
+#define STM32_FLASH_SR_OFFSET  0x0c                    /* offset of SR register in FLASH struct */
 
-write:
+wait_fifo:
+       ldr     r8, [r0, #0]    /* read wp */
+       cmp     r8, #0                  /* abort if wp == 0 */
+       beq     exit
+       ldr     r7, [r0, #4]    /* read rp */
+       cmp     r7, r8                  /* wait until rp != wp */
+       beq     wait_fifo
 
-write_half_word:
-       ldr             r3, STM32_PROG16
-       str             r3, [r4, #STM32_FLASH_CR_OFFSET]
-       ldrh    r3, [r0], #0x02                                         /* read one half-word from src, increment ptr */
-       strh    r3, [r1], #0x02                                         /* write one half-word from src, increment ptr */
+       ldr             r6, STM32_PROG16
+       str             r6, [r4, #STM32_FLASH_CR_OFFSET]
+       ldrh    r6, [r7], #0x02                                         /* read one half-word from src, increment ptr */
+       strh    r6, [r2], #0x02                                         /* write one half-word from src, increment ptr */
 busy:
-       ldr     r3, [r4, #STM32_FLASH_SR_OFFSET]
-       tst     r3, #0x10000                                            /* BSY (bit0) == 1 => operation in progress */
-       beq     busy                                                            /* wait more... */
-       tst             r3, #0xf0                                                       /* PGSERR | PGPERR | PGAERR | WRPERR */
-       bne             exit                                                            /* fail... */
-       subs    r2, r2, #0x01                                           /* decrement counter */
-       bne             write_half_word                                         /* write next half-word if anything left */
+       ldr     r6, [r4, #STM32_FLASH_SR_OFFSET]
+       tst     r6, #0x10000                                            /* BSY (bit16) == 1 => operation in progress */
+       bne     busy                                                            /* wait more... */
+       tst             r6, #0xf0                                                       /* PGSERR | PGPERR | PGAERR | WRPERR */
+       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 halfword 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_PROG16: .word 0x101                                              /* PG | PSIZE_16*/
+STM32_PROG16: .word 0x101      /* PG | PSIZE_16*/