Fix support for single-bank stm32l4 processors
[fw/openocd] / src / flash / nor / stm32l4x.c
index 42e90bc746adc3de045b8da4d1c38dd7bf6e237a..7d1e4298406d0c0b2af50f6d4739d3b456752a77 100644 (file)
@@ -13,8 +13,7 @@
  *   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.                                        *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  ***************************************************************************/
 
 #ifdef HAVE_CONFIG_H
 
 /* STM32L4xxx series for reference.
  *
- * RM0351
- * http://www.st.com/st-web-ui/static/active/en/resource/technical/document/reference_manual/DM00083560.pdf
+ * RM0351 (STM32L4x5/STM32L4x6)
+ * http://www.st.com/resource/en/reference_manual/dm00083560.pdf
  *
- * STM32L476RG Datasheet (for erase timing)
- * http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00108832.pdf
+ * RM0394 (STM32L43x/44x/45x/46x)
+ * http://www.st.com/resource/en/reference_manual/dm00151940.pdf
+ *
+ * RM0432 (STM32L4R/4Sxx)
+ * http://www.st.com/resource/en/reference_manual/dm00310109.pdf
  *
+ * STM32L476RG Datasheet (for erase timing)
+ * http://www.st.com/resource/en/datasheet/stm32l476rg.pdf
  *
- * The device has normally two banks, but on 512 and 256 kiB devices an
- * option byte is available to map all sectors to the first bank.
+ * The RM0351 devices have normally two banks, but on 512 and 256 kiB devices
+ * an option byte is available to map all sectors to the first bank.
  * Both STM32 banks are treated as one OpenOCD bank, as other STM32 devices
  * handlers do!
  *
+ * RM0394 devices have a single bank only.
+ *
+ * RM0432 devices have single and dual bank operating modes.
+ * The FLASH size is 1Mbyte or 2Mbyte.
+ * Bank page (sector) size is 4Kbyte (dual mode) or 8Kbyte (single mode).
+ *
+ * Bank mode is controlled by two different bits in option bytes register.
+ * In 2M FLASH devices bit 22 (DBANK) controls Dual Bank mode.
+ * In 1M FLASH devices bit 21 (DB1M) controls Dual Bank mode.
+ *
  */
 
 /* Erase time can be as high as 25ms, 10x this and assume it's toast... */
@@ -54,8 +68,8 @@
 #define STM32_FLASH_CR      0x40022014
 #define STM32_FLASH_OPTR    0x40022020
 #define STM32_FLASH_WRP1AR  0x4002202c
-#define STM32_FLASH_WRP2AR  0x40022030
-#define STM32_FLASH_WRP1BR  0x4002204c
+#define STM32_FLASH_WRP1BR  0x40022030
+#define STM32_FLASH_WRP2AR  0x4002204c
 #define STM32_FLASH_WRP2BR  0x40022050
 
 /* FLASH_CR register bits */
 #define FLASH_CR_BKER  (1 << 11)
 #define FLASH_MER2     (1 << 15)
 #define FLASH_STRT     (1 << 16)
+#define FLASH_OPTSTRT  (1 << 17)
 #define FLASH_EOPIE    (1 << 24)
 #define FLASH_ERRIE    (1 << 25)
+#define FLASH_OBLLAUNCH (1 << 27)
 #define FLASH_OPTLOCK  (1 << 30)
 #define FLASH_LOCK     (1 << 31)
 
@@ -77,7 +93,7 @@
 #define FLASH_BSY      (1 << 16)
 /* Fast programming not used => related errors not used*/
 #define FLASH_PGSERR   (1 << 7) /* Programming sequence error */
-#define FLASH_SIZERR   (1 << 6) /* Size  error */
+#define FLASH_SIZERR   (1 << 6) /* Size error */
 #define FLASH_PGAERR   (1 << 5) /* Programming alignment error */
 #define FLASH_WRPERR   (1 << 4) /* Write protection error */
 #define FLASH_PROGERR  (1 << 3) /* Programming error */
 
 /* STM32_FLASH_OBR bit definitions (reading) */
 
-#define OPT_DUALBANK   21      /* dual flash bank only */
+#define OPT_DBANK_LE_1M (1 << 21)      /* dual bank for devices up to 1M flash */
+#define OPT_DBANK_GE_2M (1 << 22)      /* dual bank for devices with 2M flash */
 
 /* register unlock keys */
 
 #define OPTKEY1        0x08192A3B
 #define OPTKEY2        0x4C5D6E7F
 
+#define RDP_LEVEL_0       0xAA
+#define RDP_LEVEL_1       0xBB
+#define RDP_LEVEL_2       0xCC
+
 
 /* other registers */
 #define DBGMCU_IDCODE  0xE0042000
 #define FLASH_SIZE_REG 0x1FFF75E0
 
-struct stm32l4_options {
-       uint8_t RDP;
-       uint16_t bank_b_start;
-       uint8_t user_options;
-       uint8_t wpr1a_start;
-       uint8_t wpr1a_end;
-       uint8_t wpr1b_start;
-       uint8_t wpr1b_end;
-       uint8_t wpr2a_start;
-       uint8_t wpr2a_end;
-       uint8_t wpr2b_start;
-       uint8_t wpr2b_end;
-    /* Fixme: Handle PCROP */
-};
-
 struct stm32l4_flash_bank {
-       struct stm32l4_options option_bytes;
+       uint16_t bank2_start;
        int probed;
 };
 
@@ -184,6 +190,8 @@ static int stm32l4_wait_status_busy(struct flash_bank *bank, int timeout)
 
        /* Clear but report errors */
        if (status & FLASH_ERROR) {
+               if (retval == ERROR_OK)
+                       retval = ERROR_FAIL;
                /* If this operation fails, we ignore it and report the original
                 * retval
                 */
@@ -260,97 +268,80 @@ static int stm32l4_unlock_option_reg(struct target *target)
        return ERROR_OK;
 }
 
-static int stm32l4_read_options(struct flash_bank *bank)
+static int stm32l4_read_option(struct flash_bank *bank, uint32_t address, uint32_t* value)
 {
-       uint32_t optiondata;
-       struct stm32l4_flash_bank *stm32l4_info = NULL;
        struct target *target = bank->target;
+       return target_read_u32(target, address, value);
+}
 
-       stm32l4_info = bank->driver_priv;
+static int stm32l4_write_option(struct flash_bank *bank, uint32_t address, uint32_t value, uint32_t mask)
+{
+       struct target *target = bank->target;
+       uint32_t optiondata;
 
-       /* read current option bytes */
-       int retval = target_read_u32(target, STM32_FLASH_OPTR, &optiondata);
+       int retval = target_read_u32(target, address, &optiondata);
        if (retval != ERROR_OK)
                return retval;
 
-       stm32l4_info->option_bytes.user_options = (optiondata >> 8) & 0x3ffff;
-       stm32l4_info->option_bytes.RDP = optiondata & 0xff;
-
-       retval = target_read_u32(target, STM32_FLASH_WRP1AR, &optiondata);
+       retval = stm32l4_unlock_reg(target);
        if (retval != ERROR_OK)
                return retval;
-       stm32l4_info->option_bytes.wpr1a_start =  optiondata         & 0xff;
-       stm32l4_info->option_bytes.wpr1a_end   = (optiondata >> 16)  & 0xff;
 
-       retval = target_read_u32(target, STM32_FLASH_WRP2AR, &optiondata);
+       retval = stm32l4_unlock_option_reg(target);
        if (retval != ERROR_OK)
                return retval;
-       stm32l4_info->option_bytes.wpr2a_start =  optiondata         & 0xff;
-       stm32l4_info->option_bytes.wpr2a_end   = (optiondata >> 16)  & 0xff;
 
-       retval = target_read_u32(target, STM32_FLASH_WRP1BR, &optiondata);
+       optiondata = (optiondata & ~mask) | (value & mask);
+
+       retval = target_write_u32(target, address, optiondata);
        if (retval != ERROR_OK)
                return retval;
-       stm32l4_info->option_bytes.wpr1b_start =  optiondata         & 0xff;
-       stm32l4_info->option_bytes.wpr1b_end   = (optiondata >> 16)  & 0xff;
 
-       retval = target_read_u32(target, STM32_FLASH_WRP2BR, &optiondata);
+       retval = target_write_u32(target, stm32l4_get_flash_reg(bank, STM32_FLASH_CR), FLASH_OPTSTRT);
        if (retval != ERROR_OK)
                return retval;
-       stm32l4_info->option_bytes.wpr2b_start =  optiondata         & 0xff;
-       stm32l4_info->option_bytes.wpr2b_end   = (optiondata >> 16)  & 0xff;
-
-       if (stm32l4_info->option_bytes.RDP != 0xAA)
-               LOG_INFO("Device Security Bit Set");
-
-       return ERROR_OK;
-}
-
-static int stm32l4_write_options(struct flash_bank *bank)
-{
-       struct stm32l4_flash_bank *stm32l4_info = NULL;
-       struct target *target = bank->target;
-       uint32_t optiondata;
-
-       stm32l4_info = bank->driver_priv;
-
-       (void) optiondata;
-       (void) stm32l4_info;
 
-       int retval = stm32l4_unlock_option_reg(target);
+       retval = stm32l4_wait_status_busy(bank, FLASH_ERASE_TIMEOUT);
        if (retval != ERROR_OK)
                return retval;
-       /* FIXME: Implement Option writing!*/
-       return ERROR_OK;
+
+       return retval;
 }
 
 static int stm32l4_protect_check(struct flash_bank *bank)
 {
        struct stm32l4_flash_bank *stm32l4_info = bank->driver_priv;
-
-       /* read write protection settings */
-       int retval = stm32l4_read_options(bank);
-       if (retval != ERROR_OK) {
-               LOG_DEBUG("unable to read option bytes");
-               return retval;
-       }
+       uint32_t wrp1ar, wrp1br, wrp2ar, wrp2br;
+       stm32l4_read_option(bank, STM32_FLASH_WRP1AR, &wrp1ar);
+       stm32l4_read_option(bank, STM32_FLASH_WRP1BR, &wrp1br);
+       stm32l4_read_option(bank, STM32_FLASH_WRP2AR, &wrp2ar);
+       stm32l4_read_option(bank, STM32_FLASH_WRP2BR, &wrp2br);
+
+       const uint8_t wrp1a_start = wrp1ar & 0xFF;
+       const uint8_t wrp1a_end = (wrp1ar >> 16) & 0xFF;
+       const uint8_t wrp1b_start = wrp1br & 0xFF;
+       const uint8_t wrp1b_end = (wrp1br >> 16) & 0xFF;
+       const uint8_t wrp2a_start = wrp2ar & 0xFF;
+       const uint8_t wrp2a_end = (wrp2ar >> 16) & 0xFF;
+       const uint8_t wrp2b_start = wrp2br & 0xFF;
+       const uint8_t wrp2b_end = (wrp2br >> 16) & 0xFF;
 
        for (int i = 0; i < bank->num_sectors; i++) {
-               if (i < stm32l4_info->option_bytes.bank_b_start) {
-                       if (((i >= stm32l4_info->option_bytes.wpr1a_start) &&
-                                (i <= stm32l4_info->option_bytes.wpr1a_end)) ||
-                               ((i >= stm32l4_info->option_bytes.wpr2a_start) &&
-                                (i <= stm32l4_info->option_bytes.wpr2a_end)))
+               if (i < stm32l4_info->bank2_start) {
+                       if (((i >= wrp1a_start) &&
+                                (i <= wrp1a_end)) ||
+                               ((i >= wrp1b_start) &&
+                                (i <= wrp1b_end)))
                                bank->sectors[i].is_protected = 1;
                        else
                                bank->sectors[i].is_protected = 0;
                } else {
                        uint8_t snb;
-                       snb = i - stm32l4_info->option_bytes.bank_b_start + 256;
-                       if (((snb >= stm32l4_info->option_bytes.wpr1b_start) &&
-                                (snb <= stm32l4_info->option_bytes.wpr1b_end)) ||
-                               ((snb >= stm32l4_info->option_bytes.wpr2b_start) &&
-                                (snb <= stm32l4_info->option_bytes.wpr2b_end)))
+                       snb = i - stm32l4_info->bank2_start;
+                       if (((snb >= wrp2a_start) &&
+                                (snb <= wrp2a_end)) ||
+                               ((snb >= wrp2b_start) &&
+                                (snb <= wrp2b_end)))
                                bank->sectors[i].is_protected = 1;
                        else
                                bank->sectors[i].is_protected = 0;
@@ -383,7 +374,7 @@ static int stm32l4_erase(struct flash_bank *bank, int first, int last)
        1. Check that no Flash memory operation is ongoing by
        checking the BSY bit in the FLASH_SR register
        2. Set the PER bit and select the page and bank
-          you wish to erase  in the FLASH_CR register
+          you wish to erase in the FLASH_CR register
        3. Set the STRT bit in the FLASH_CR register
        4. Wait for the BSY bit to be cleared
         */
@@ -393,9 +384,9 @@ static int stm32l4_erase(struct flash_bank *bank, int first, int last)
                uint32_t erase_flags;
                erase_flags = FLASH_PER | FLASH_STRT;
 
-               if  (i >= stm32l4_info->option_bytes.bank_b_start) {
+               if (i >= stm32l4_info->bank2_start) {
                        uint8_t snb;
-                       snb = (i - stm32l4_info->option_bytes.bank_b_start) + 256;
+                       snb = i - stm32l4_info->bank2_start;
                        erase_flags |= snb << FLASH_PAGE_SHIFT | FLASH_CR_BKER;
                } else
                        erase_flags |= i << FLASH_PAGE_SHIFT;
@@ -429,20 +420,29 @@ static int stm32l4_protect(struct flash_bank *bank, int set, int first, int last
                return ERROR_TARGET_NOT_HALTED;
        }
 
-       /* read protection settings */
-       int retval = stm32l4_read_options(bank);
-       if (retval != ERROR_OK) {
-               LOG_DEBUG("unable to read option bytes");
-               return retval;
+       int ret = ERROR_OK;
+       /* Bank 2 */
+       uint32_t reg_value = 0xFF; /* Default to bank un-protected */
+       if (last >= stm32l4_info->bank2_start) {
+               if (set == 1) {
+                       uint8_t begin = first > stm32l4_info->bank2_start ? first : 0x00;
+                       reg_value = ((last & 0xFF) << 16) | begin;
+               }
+
+               ret = stm32l4_write_option(bank, STM32_FLASH_WRP2AR, reg_value, 0xffffffff);
        }
+       /* Bank 1 */
+       reg_value = 0xFF; /* Default to bank un-protected */
+       if (first < stm32l4_info->bank2_start) {
+               if (set == 1) {
+                       uint8_t end = last >= stm32l4_info->bank2_start ? 0xFF : last;
+                       reg_value = (end << 16) | (first & 0xFF);
+               }
 
-       (void)stm32l4_info;
-       /* FIXME: Write First and last in a valid WRPxx_start/end combo*/
-       retval = stm32l4_write_options(bank);
-       if (retval != ERROR_OK)
-               return retval;
+               ret = stm32l4_write_option(bank, STM32_FLASH_WRP1AR, reg_value, 0xffffffff);
+       }
 
-       return ERROR_OK;
+       return ret;
 }
 
 /* Count is in halfwords */
@@ -458,18 +458,8 @@ static int stm32l4_write_block(struct flash_bank *bank, const uint8_t *buffer,
        struct armv7m_algorithm armv7m_info;
        int retval = ERROR_OK;
 
-       /* See contrib/loaders/flash/stm32l4x.S for source and
-        * hints how to generate the data!
-        */
-
        static const uint8_t stm32l4_flash_write_code[] = {
-               0xd0, 0xf8, 0x00, 0x80, 0xb8, 0xf1, 0x00, 0x0f, 0x1e, 0xd0, 0x45, 0x68,
-               0xb8, 0xeb, 0x05, 0x06, 0x07, 0x2e, 0xf5, 0xd3, 0xdf, 0xf8, 0x34, 0x60,
-               0x66, 0x61, 0xf5, 0xe8, 0x02, 0x67, 0xe2, 0xe8, 0x02, 0x67, 0xbf, 0xf3,
-               0x4f, 0x8f, 0x26, 0x69, 0x16, 0xf4, 0x80, 0x3f, 0xfb, 0xd1, 0x16, 0xf0,
-               0xfa, 0x0f, 0x07, 0xd1, 0x8d, 0x42, 0x28, 0xbf, 0x00, 0xf1, 0x08, 0x05,
-               0x45, 0x60, 0x01, 0x3b, 0x13, 0xb1, 0xdd, 0xe7, 0x00, 0x21, 0x41, 0x60,
-               0x30, 0x46, 0x00, 0xbe, 0x01, 0x00, 0x00, 0x00
+#include "../../../contrib/loaders/flash/stm32/stm32l4x.inc"
        };
 
        if (target_alloc_working_area(target, sizeof(stm32l4_flash_write_code),
@@ -481,8 +471,10 @@ static int stm32l4_write_block(struct flash_bank *bank, const uint8_t *buffer,
        retval = target_write_buffer(target, write_algorithm->address,
                        sizeof(stm32l4_flash_write_code),
                        stm32l4_flash_write_code);
-       if (retval != ERROR_OK)
+       if (retval != ERROR_OK) {
+               target_free_working_area(target, write_algorithm);
                return retval;
+       }
 
        /* memory buffer */
        while (target_alloc_working_area_try(target, buffer_size, &source) !=
@@ -493,7 +485,7 @@ static int stm32l4_write_block(struct flash_bank *bank, const uint8_t *buffer,
                         * buffer, free the algorithm */
                        target_free_working_area(target, write_algorithm);
 
-                       LOG_WARNING("no large enough working area available, can't do block memory writes");
+                       LOG_WARNING("large enough working area not available, can't do block memory writes");
                        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
                }
        }
@@ -599,6 +591,7 @@ static int stm32l4_probe(struct flash_bank *bank)
        struct stm32l4_flash_bank *stm32l4_info = bank->driver_priv;
        int i;
        uint16_t flash_size_in_kb = 0xffff;
+       uint16_t max_flash_size_in_kb;
        uint32_t device_id;
        uint32_t options;
        uint32_t base_address = 0x08000000;
@@ -613,51 +606,119 @@ static int stm32l4_probe(struct flash_bank *bank)
 
        /* set max flash size depending on family */
        switch (device_id & 0xfff) {
+       case 0x470:
+               max_flash_size_in_kb = 2048;
+               break;
+       case 0x461:
        case 0x415:
+               max_flash_size_in_kb = 1024;
+               break;
+       case 0x462:
+               max_flash_size_in_kb = 512;
+               break;
+       case 0x435:
+               max_flash_size_in_kb = 256;
                break;
        default:
-               LOG_WARNING("Cannot identify target as a STM32L4 family.");
+               LOG_WARNING("Cannot identify target as an STM32L4 family device.");
                return ERROR_FAIL;
        }
 
        /* get flash size from target. */
        retval = target_read_u16(target, FLASH_SIZE_REG, &flash_size_in_kb);
 
-       /* get options to for DUAL BANK. */
-       retval = target_read_u32(target, STM32_FLASH_OPTR, &options);
-
-       /* only devices with < 1024 kiB may be set to single bank dual banks */
-       if ((flash_size_in_kb == 1024) || !(options & OPT_DUALBANK))
-               stm32l4_info->option_bytes.bank_b_start = 256;
-       else
-               stm32l4_info->option_bytes.bank_b_start = flash_size_in_kb << 9;
+       /* failed reading flash size or flash size invalid (early silicon),
+        * default to max target family */
+       if (retval != ERROR_OK || flash_size_in_kb == 0xffff || flash_size_in_kb == 0) {
+               LOG_WARNING("STM32 flash size failed, probe inaccurate - assuming %dk flash",
+                       max_flash_size_in_kb);
+               flash_size_in_kb = max_flash_size_in_kb;
+       }
 
        LOG_INFO("flash size = %dkbytes", flash_size_in_kb);
 
-       /* did we assign flash size? */
+       /* did we assign flash size? */
        assert((flash_size_in_kb != 0xffff) && flash_size_in_kb);
 
-       /* calculate numbers of pages */
-       int num_pages = flash_size_in_kb / 2;
+       /* get options for DUAL BANK. */
+       retval = target_read_u32(target, STM32_FLASH_OPTR, &options);
 
-       /* check that calculation result makes sense */
-       assert(num_pages > 0);
+       if (retval != ERROR_OK)
+               return retval;
+
+       int num_pages = 0;
+       int page_size = 0;
+
+       switch (device_id & 0xfff) {
+               case 0x470:
+                       /* L4R/S have 1M or 2M FLASH and dual/single bank mode.
+                        * Page size is 4K or 8K.*/
+                       if (flash_size_in_kb == 2048) {
+                               stm32l4_info->bank2_start = 256;
+                               if (options & OPT_DBANK_GE_2M) {
+                                       page_size = 4096;
+                                       num_pages = 512;
+                               } else {
+                                       page_size = 8192;
+                                       num_pages = 256;
+                               }
+                               break;
+                       }
+                       if (flash_size_in_kb == 1024) {
+                               stm32l4_info->bank2_start = 128;
+                               if (options & OPT_DBANK_LE_1M) {
+                                       page_size = 4096;
+                                       num_pages = 256;
+                               } else {
+                                       page_size = 8192;
+                                       num_pages = 128;
+                               }
+                               break;
+                       }
+                       /* Invalid FLASH size for this device. */
+                       LOG_WARNING("Invalid flash size for STM32L4+ family device.");
+                       return ERROR_FAIL;
+               case 0x461:
+               case 0x415:
+                       /* These are dual-bank devices, we need to check the OPT_DBANK_LE_1M bit here */
+                       page_size = 2048;
+                       num_pages = flash_size_in_kb / 2;
+                       /* check that calculation result makes sense */
+                       assert(num_pages > 0);
+                       if ((flash_size_in_kb == 1024) || !(options & OPT_DBANK_LE_1M))
+                               stm32l4_info->bank2_start = 256;
+                       else
+                               stm32l4_info->bank2_start = num_pages / 2;
+                       break;
+               case 0x462:
+               case 0x435:
+               default:
+                       /* These are single-bank devices */
+                       page_size = 2048;
+                       num_pages = flash_size_in_kb / 2;
+                       /* check that calculation result makes sense */
+                       assert(num_pages > 0);
+                       stm32l4_info->bank2_start = UINT16_MAX;
+                       break;
+       }
 
+       /* Release sector table if allocated. */
        if (bank->sectors) {
                free(bank->sectors);
                bank->sectors = NULL;
        }
 
+       /* Set bank configuration and construct sector table. */
        bank->base = base_address;
-       bank->size = num_pages * (1 << 11);
+       bank->size = num_pages * page_size;
        bank->num_sectors = num_pages;
        bank->sectors = malloc(sizeof(struct flash_sector) * num_pages);
        if (!bank->sectors)
                return ERROR_FAIL; /* Checkme: What better error to use?*/
 
        for (i = 0; i < num_pages; i++) {
-               bank->sectors[i].offset = i << 11;
-               bank->sectors[i].size = 1 << 11;
+               bank->sectors[i].offset = i * page_size;
+               bank->sectors[i].size = page_size;
                bank->sectors[i].is_erased = -1;
                bank->sectors[i].is_protected = 1;
        }
@@ -685,7 +746,7 @@ static int get_stm32l4_info(struct flash_bank *bank, char *buf, int buf_size)
        if (retval != ERROR_OK)
                return retval;
 
-       uint16_t device_id = dbgmcu_idcode & 0xffff;
+       uint16_t device_id = dbgmcu_idcode & 0xfff;
        uint8_t rev_id = dbgmcu_idcode >> 28;
        uint8_t rev_minor = 0;
        int i;
@@ -700,8 +761,24 @@ static int get_stm32l4_info(struct flash_bank *bank, char *buf, int buf_size)
        const char *device_str;
 
        switch (device_id) {
-       case 0x6415:
-               device_str = "STM32L4xx";
+       case 0x470:
+               device_str = "STM32L4R/4Sxx";
+               break;
+
+       case 0x461:
+               device_str = "STM32L496/4A6";
+               break;
+
+       case 0x415:
+               device_str = "STM32L475/476/486";
+               break;
+
+       case 0x462:
+               device_str = "STM32L45x/46x";
+               break;
+
+       case 0x435:
+               device_str = "STM32L43x/44x";
                break;
 
        default:
@@ -715,89 +792,6 @@ static int get_stm32l4_info(struct flash_bank *bank, char *buf, int buf_size)
        return ERROR_OK;
 }
 
-COMMAND_HANDLER(stm32l4_handle_lock_command)
-{
-       struct target *target = NULL;
-       struct stm32l4_flash_bank *stm32l4_info = NULL;
-
-       if (CMD_ARGC < 1)
-               return ERROR_COMMAND_SYNTAX_ERROR;
-
-       struct flash_bank *bank;
-       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
-       if (ERROR_OK != retval)
-               return retval;
-
-       stm32l4_info = bank->driver_priv;
-       target = bank->target;
-
-       if (target->state != TARGET_HALTED) {
-               LOG_ERROR("Target not halted");
-               return ERROR_TARGET_NOT_HALTED;
-       }
-
-       if (stm32l4_read_options(bank) != ERROR_OK) {
-               command_print(CMD_CTX, "%s failed to read options",
-                                         bank->driver->name);
-               return ERROR_OK;
-       }
-
-       /* set readout protection */
-       stm32l4_info->option_bytes.RDP = 0;
-
-       if (stm32l4_write_options(bank) != ERROR_OK) {
-               command_print(CMD_CTX, "%s failed to lock device", bank->driver->name);
-               return ERROR_OK;
-       }
-
-       command_print(CMD_CTX, "%s locked", bank->driver->name);
-
-       return ERROR_OK;
-}
-
-COMMAND_HANDLER(stm32l4_handle_unlock_command)
-{
-       struct target *target = NULL;
-       struct stm32l4_flash_bank *stm32l4_info = NULL;
-
-       if (CMD_ARGC < 1)
-               return ERROR_COMMAND_SYNTAX_ERROR;
-
-       struct flash_bank *bank;
-       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
-       if (ERROR_OK != retval)
-               return retval;
-
-       stm32l4_info = bank->driver_priv;
-       target = bank->target;
-
-       if (target->state != TARGET_HALTED) {
-               LOG_ERROR("Target not halted");
-               return ERROR_TARGET_NOT_HALTED;
-       }
-
-       if (stm32l4_read_options(bank) != ERROR_OK) {
-               command_print(CMD_CTX, "%s failed to read options", bank->driver->name);
-               return ERROR_OK;
-       }
-
-       /* clear readout protection and complementary option bytes
-        * this will also force a device unlock if set */
-       stm32l4_info->option_bytes.RDP = 0xAA;
-
-       if (stm32l4_write_options(bank) != ERROR_OK) {
-               command_print(CMD_CTX, "%s failed to unlock device",
-                                         bank->driver->name);
-               return ERROR_OK;
-       }
-
-       command_print(CMD_CTX, "%s unlocked.\n"
-                       "INFO: a reset or power cycle is required "
-                       "for the new settings to take effect.", bank->driver->name);
-
-       return ERROR_OK;
-}
-
 static int stm32l4_mass_erase(struct flash_bank *bank, uint32_t action)
 {
        int retval;
@@ -841,7 +835,7 @@ COMMAND_HANDLER(stm32l4_handle_mass_erase_command)
        uint32_t action;
 
        if (CMD_ARGC < 1) {
-               command_print(CMD_CTX, "stm32x mass_erase <STM32L4 bank>");
+               command_print(CMD_CTX, "stm32l4x mass_erase <STM32L4 bank>");
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
@@ -857,14 +851,151 @@ COMMAND_HANDLER(stm32l4_handle_mass_erase_command)
                for (i = 0; i < bank->num_sectors; i++)
                        bank->sectors[i].is_erased = 1;
 
-               command_print(CMD_CTX, "stm32x mass erase complete");
+               command_print(CMD_CTX, "stm32l4x mass erase complete");
        } else {
-               command_print(CMD_CTX, "stm32x mass erase failed");
+               command_print(CMD_CTX, "stm32l4x mass erase failed");
+       }
+
+       return retval;
+}
+
+COMMAND_HANDLER(stm32l4_handle_option_read_command)
+{
+       if (CMD_ARGC < 2) {
+               command_print(CMD_CTX, "stm32l4x option_read <STM32L4 bank> <option_reg offset>");
+               return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
+       struct flash_bank *bank;
+       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
+       if (ERROR_OK != retval)
+               return retval;
+
+       uint32_t reg_addr = STM32_FLASH_BASE;
+       uint32_t value = 0;
+
+       reg_addr += strtoul(CMD_ARGV[1], NULL, 16);
+
+       retval = stm32l4_read_option(bank, reg_addr, &value);
+       if (ERROR_OK != retval)
+               return retval;
+
+       command_print(CMD_CTX, "Option Register: <0x%" PRIx32 "> = 0x%" PRIx32 "", reg_addr, value);
+
+       return retval;
+}
+
+COMMAND_HANDLER(stm32l4_handle_option_write_command)
+{
+       if (CMD_ARGC < 3) {
+               command_print(CMD_CTX, "stm32l4x option_write <STM32L4 bank> <option_reg offset> <value> [mask]");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       struct flash_bank *bank;
+       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
+       if (ERROR_OK != retval)
+               return retval;
+
+       uint32_t reg_addr = STM32_FLASH_BASE;
+       uint32_t value = 0;
+       uint32_t mask = 0xFFFFFFFF;
+
+       reg_addr += strtoul(CMD_ARGV[1], NULL, 16);
+       value = strtoul(CMD_ARGV[2], NULL, 16);
+       if (CMD_ARGC > 3)
+               mask = strtoul(CMD_ARGV[3], NULL, 16);
+
+       command_print(CMD_CTX, "%s Option written.\n"
+                               "INFO: a reset or power cycle is required "
+                               "for the new settings to take effect.", bank->driver->name);
+
+       retval = stm32l4_write_option(bank, reg_addr, value, mask);
+       return retval;
+}
+
+COMMAND_HANDLER(stm32l4_handle_option_load_command)
+{
+       if (CMD_ARGC < 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       struct flash_bank *bank;
+       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
+       if (ERROR_OK != retval)
+               return retval;
+
+       struct target *target = bank->target;
+
+       retval = stm32l4_unlock_reg(target);
+       if (ERROR_OK != retval)
+               return retval;
+
+       retval = stm32l4_unlock_option_reg(target);
+       if (ERROR_OK != retval)
+               return retval;
+
+       /* Write the OBLLAUNCH bit in CR -> Cause device "POR" and option bytes reload */
+       retval = target_write_u32(target, stm32l4_get_flash_reg(bank, STM32_FLASH_CR), FLASH_OBLLAUNCH);
+
+       command_print(CMD_CTX, "stm32l4x option load (POR) completed.");
        return retval;
 }
 
+COMMAND_HANDLER(stm32l4_handle_lock_command)
+{
+       struct target *target = NULL;
+
+       if (CMD_ARGC < 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       struct flash_bank *bank;
+       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
+       if (ERROR_OK != retval)
+               return retval;
+
+       target = bank->target;
+
+       if (target->state != TARGET_HALTED) {
+               LOG_ERROR("Target not halted");
+               return ERROR_TARGET_NOT_HALTED;
+       }
+
+       /* set readout protection level 1 by erasing the RDP option byte */
+       if (stm32l4_write_option(bank, STM32_FLASH_OPTR, 0, 0x000000FF) != ERROR_OK) {
+               command_print(CMD_CTX, "%s failed to lock device", bank->driver->name);
+               return ERROR_OK;
+       }
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(stm32l4_handle_unlock_command)
+{
+       struct target *target = NULL;
+
+       if (CMD_ARGC < 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       struct flash_bank *bank;
+       int retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
+       if (ERROR_OK != retval)
+               return retval;
+
+       target = bank->target;
+
+       if (target->state != TARGET_HALTED) {
+               LOG_ERROR("Target not halted");
+               return ERROR_TARGET_NOT_HALTED;
+       }
+
+       if (stm32l4_write_option(bank, STM32_FLASH_OPTR, RDP_LEVEL_0, 0x000000FF) != ERROR_OK) {
+               command_print(CMD_CTX, "%s failed to unlock device", bank->driver->name);
+               return ERROR_OK;
+       }
+
+       return ERROR_OK;
+}
+
 static const struct command_registration stm32l4_exec_command_handlers[] = {
        {
                .name = "lock",
@@ -887,6 +1018,27 @@ static const struct command_registration stm32l4_exec_command_handlers[] = {
                .usage = "bank_id",
                .help = "Erase entire flash device.",
        },
+       {
+               .name = "option_read",
+               .handler = stm32l4_handle_option_read_command,
+               .mode = COMMAND_EXEC,
+               .usage = "bank_id reg_offset",
+               .help = "Read & Display device option bytes.",
+       },
+       {
+               .name = "option_write",
+               .handler = stm32l4_handle_option_write_command,
+               .mode = COMMAND_EXEC,
+               .usage = "bank_id reg_offset value mask",
+               .help = "Write device option bit fields with provided value.",
+       },
+       {
+               .name = "option_load",
+               .handler = stm32l4_handle_option_load_command,
+               .mode = COMMAND_EXEC,
+               .usage = "bank_id",
+               .help = "Force re-load of device options (will cause device reset).",
+       },
        COMMAND_REGISTRATION_DONE
 };
 
@@ -914,4 +1066,5 @@ struct flash_driver stm32l4x_flash = {
        .erase_check = default_flash_blank_check,
        .protect_check = stm32l4_protect_check,
        .info = get_stm32l4_info,
+       .free_driver_priv = default_flash_free_driver_priv,
 };