flash/nor/stm32lx: fixed writes at high adapter speeds

The busy flag must be polled after each half-page write.
At low clock speeds, no issue is observed when the poll
is omitted, because the writes complete before the next
write begins. But at high clock speeds the subsequent
writes would overlap and cause the operation to fail.

The status polls are done on the target for efficiency,
since the half-pages are very small.

Change-Id: Ia1e9b4a6a71930549b3d84a902744ce6e596301b
Signed-off-by: Jimmy <nhminus@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/5598
Tested-by: jenkins
Reviewed-by: Jelle De Vleeschouwer
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-by: Andrzej Sierżęga <asier70@gmail.com>

diff --git a/contrib/loaders/flash/stm32/stm32lx.S b/contrib/loaders/flash/stm32/stm32lx.S
index bcae7a46cc4b5920dbddc39180d8bb75f1658754..7cfe48545215f4e6728faf43e1999c5c3eb48394 100644 (file)
--- a/contrib/loaders/flash/stm32/stm32lx.S
+++ b/contrib/loaders/flash/stm32/stm32lx.S
@@ -20,44 +20,61 @@
  *   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.,                                       *
- *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  ***************************************************************************/
 
-
        .text
        .syntax unified
        .cpu cortex-m0
        .thumb
 
 /*
+Parameters
        r0 - destination address
        r1 - source address
-       r2 - count
+       r2 - half pages
+       r3 - bytes per half page
+       r4 - flash base
+Variables
+       r0 - destination write pointer
+       r1 - source read pointer
+       r2 - source limit address
+       r3 - bytes per half page
+       r4 - flash base
+       r5 - pages left in current half page
+       r6 - temporary r/w
 */
 
+/* offsets of registers from flash reg base */
+#define STM32_FLASH_SR_OFFSET 0x18
+
        .thumb_func
        .global _start
 _start:
-       // r2 = source + count * 4
-       lsls    r2, r2, #2
-       adds    r2, r1, r2
+       // r2 = source + half pages * bytes per half page
+       muls r2, r2, r3
+       add r2, r1, r2
        // Go to compare
-       b       test_done
+       b test_done
+write_half_page:
+       // initialize pages left in current half page
+       mov r5, r3
 write_word:
        // load word from address in r1 and increase r1 by 4
-       ldmia r1!, {r3}
+       ldmia r1!, {r6}
        // store word to address in r0 and increase r0 by 4
-       stmia r0!, {r3}
+       stmia r0!, {r6}
+       // check for end of half page
+       subs r5, r5, #4
+       bne write_word
+wait_busy:
+       // read status register into r6, loop while bottom bit is set
+       ldr r6, [r4, #STM32_FLASH_SR_OFFSET]
+       lsls r6, r6, #31
+       bne wait_busy
 test_done:
-       // compare r1 and r2
+       // compare r1 and r2, loop if not equal
        cmp     r1, r2
-       // loop if not equal
-       bne     write_word
+       bne     write_half_page
 
        // Set breakpoint to exit
-       bkpt    #0x00
-
+       bkpt #0x00

diff --git a/contrib/loaders/flash/stm32/stm32lx.inc b/contrib/loaders/flash/stm32/stm32lx.inc
index eaaf1848aaae7be250cff623d355c3408b9ba272..668de2778714b88a783cfb9738b8908f0c0e4fc9 100644 (file)
--- a/contrib/loaders/flash/stm32/stm32lx.inc
+++ b/contrib/loaders/flash/stm32/stm32lx.inc
@@ -1,2 +1,3 @@
 /* Autogenerated with ../../../../src/helper/bin2char.sh */
-0x92,0x00,0x8a,0x18,0x01,0xe0,0x08,0xc9,0x08,0xc0,0x91,0x42,0xfb,0xd1,0x00,0xbe,
+0x5a,0x43,0x0a,0x44,0x07,0xe0,0x1d,0x46,0x40,0xc9,0x40,0xc0,0x04,0x3d,0xfb,0xd1,
+0xa6,0x69,0xf6,0x07,0xfc,0xd1,0x91,0x42,0xf5,0xd1,0x00,0xbe,

diff --git a/src/flash/nor/stm32lx.c b/src/flash/nor/stm32lx.c
index 488dc978a54d42df00c434a7ec937005bb8248ba..12211960643591844d76c9232ad4ecc0bc7cf34e 100644 (file)
--- a/src/flash/nor/stm32lx.c
+++ b/src/flash/nor/stm32lx.c
@@ -425,12 +425,12 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
        struct stm32lx_flash_bank *stm32lx_info = bank->driver_priv;
 
        uint32_t hp_nb = stm32lx_info->part_info.page_size / 2;
-       uint32_t buffer_size = 16384;
+       uint32_t buffer_size = (16384 / hp_nb) * hp_nb; /* must be multiple of hp_nb */
        struct working_area *write_algorithm;
        struct working_area *source;
        uint32_t address = bank->base + offset;
 
-       struct reg_param reg_params[3];
+       struct reg_param reg_params[5];
        struct armv7m_algorithm armv7m_info;
 
        int retval = ERROR_OK;
@@ -440,6 +440,10 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
        };
 
        /* Make sure we're performing a half-page aligned write. */
+       if (offset % hp_nb) {
+               LOG_ERROR("The offset must be %" PRIu32 "B-aligned but it is %" PRIi32 "B)", hp_nb, offset);
+               return ERROR_FAIL;
+       }
        if (count % hp_nb) {
                LOG_ERROR("The byte count must be %" PRIu32 "B-aligned but count is %" PRIu32 "B)", hp_nb, count);
                return ERROR_FAIL;
@@ -476,6 +480,9 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
 
                        LOG_WARNING("no large enough working area available, can't do block memory writes");
                        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+               } else {
+                       /* Make sure we're still asking for an integral number of half-pages */
+                       buffer_size -= buffer_size % hp_nb;
                }
        }
 
@@ -484,6 +491,8 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
        init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);
        init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);
        init_reg_param(&reg_params[2], "r2", 32, PARAM_OUT);
+       init_reg_param(&reg_params[3], "r3", 32, PARAM_OUT);
+       init_reg_param(&reg_params[4], "r4", 32, PARAM_OUT);
 
        /* Enable half-page write */
        retval = stm32lx_enable_write_half_page(bank);
@@ -494,6 +503,8 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
                destroy_reg_param(&reg_params[0]);
                destroy_reg_param(&reg_params[1]);
                destroy_reg_param(&reg_params[2]);
+               destroy_reg_param(&reg_params[3]);
+               destroy_reg_param(&reg_params[4]);
                return retval;
        }
 
@@ -524,8 +535,12 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
                buf_set_u32(reg_params[0].value, 0, 32, address);
                /* The source address of the copy (R1) */
                buf_set_u32(reg_params[1].value, 0, 32, source->address);
-               /* The length of the copy (R2) */
-               buf_set_u32(reg_params[2].value, 0, 32, this_count / 4);
+               /* The number of half pages to copy (R2) */
+               buf_set_u32(reg_params[2].value, 0, 32, this_count / hp_nb);
+               /* The size in byes of a half page (R3) */
+               buf_set_u32(reg_params[3].value, 0, 32, hp_nb);
+               /* The flash base address (R4) */
+               buf_set_u32(reg_params[4].value, 0, 32, stm32lx_info->flash_base);
 
                /* 5: Execute the bunch of code */
                retval = target_run_algorithm(target, 0, NULL,
@@ -593,6 +608,8 @@ static int stm32lx_write_half_pages(struct flash_bank *bank, const uint8_t *buff
        destroy_reg_param(&reg_params[0]);
        destroy_reg_param(&reg_params[1]);
        destroy_reg_param(&reg_params[2]);
+       destroy_reg_param(&reg_params[3]);
+       destroy_reg_param(&reg_params[4]);
 
        return retval;
 }