- /* Read the RDP byte and check if it is 0xAA */
- uint8_t rdp;
- retval = target_read_u32(target, FLASH_OBR, ®32);
- if (retval != ERROR_OK)
- return retval;
- rdp = reg32 & 0xFF;
- if (rdp != 0xAA) {
- /*
- * Unlocking the option byte is done by unlocking the PECR, then
- * by writing the 2 option byte keys to OPTKEYR
- */
-
- /* To unlock the PECR write the 2 PEKEY to the PEKEYR register */
- retval = target_write_u32(target, FLASH_PEKEYR, PEKEY1);
- if (retval != ERROR_OK)
- return retval;
-
- retval = target_write_u32(target, FLASH_PEKEYR, PEKEY2);
- if (retval != ERROR_OK)
- return retval;
-
- /* Make sure it worked */
- retval = target_read_u32(target, FLASH_PECR, ®32);
- if (retval != ERROR_OK)
- return retval;
-
- if (reg32 & FLASH_PECR__PELOCK)
- return ERROR_FLASH_OPERATION_FAILED;
-
- retval = target_write_u32(target, FLASH_OPTKEYR, OPTKEY1);
- if (retval != ERROR_OK)
- return retval;
- retval = target_write_u32(target, FLASH_OPTKEYR, OPTKEY2);
- if (retval != ERROR_OK)
- return retval;
+ /* Get the flash size from target. 0x427 and 0x436 devices use a
+ * different location for the Flash Size register, please see RM0038 r8 or
+ * newer. */
+ if ((device_id & 0xfff) == 0x427 || (device_id & 0xfff) == 0x436 ||
+ (device_id & 0xfff) == 0x437)
+ retval = target_read_u16(target, F_SIZE_MP, &flash_size_in_kb);
+ else
+ retval = target_read_u16(target, F_SIZE, &flash_size_in_kb);
+
+ /* 0x436 devices report their flash size as a 0 or 1 code indicating 384K
+ * or 256K, respectively. Please see RM0038 r8 or newer and refer to
+ * section 30.1.1. */
+ if (retval == ERROR_OK && (device_id & 0xfff) == 0x436) {
+ if (flash_size_in_kb == 0)
+ flash_size_in_kb = 384;
+ else if (flash_size_in_kb == 1)
+ flash_size_in_kb = 256;
+ }