/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   Copyright (C) 2011 Øyvind Harboe                                      *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   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, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "imp.h"
#include <helper/binarybuffer.h>
#include <target/algorithm.h>
#include <target/armv7m.h>

/* Regarding performance:
 *
 * Short story - it might be best to leave the performance at
 * current levels.
 *
 * You may see a jump in speed if you change to using
 * 32bit words for the block programming.
 *
 * Its a shame you cannot use the double word as its
 * even faster - but you require external VPP for that mode.
 *
 * Having said all that 16bit writes give us the widest vdd
 * operating range, so may be worth adding a note to that effect.
 *
 */

/* Danger!!!! The STM32F1x and STM32F2x series actually have
 * quite different flash controllers.
 *
 * What's more scary is that the names of the registers and their
 * addresses are the same, but the actual bits and what they do are
 * can be very different.
 *
 * To reduce testing complexity and dangers of regressions,
 * a seperate file is used for stm32fx2x.
 *
 * Sector sizes in kiBytes:
 * 1 MiByte part with 4 x 16, 1 x 64, 7 x 128.
 * 1.5 MiByte part with 4 x 16, 1 x 64, 11 x 128.
 * 2 MiByte part with 4 x 16, 1 x 64, 7 x 128, 4 x 16, 1 x 64, 7 x 128.
 * 1 MiByte STM32F42x/43x part with DB1M Option set:
 *                    4 x 16, 1 x 64, 3 x 128, 4 x 16, 1 x 64, 3 x 128.
 *
 * STM32F7[2|3]
 * 512 kiByte part with 4 x 16, 1 x 64, 3 x 128.
 *
 * STM32F7[4|5]
 * 1 MiByte part with 4 x 32, 1 x 128, 3 x 256.
 *
 * STM32F7[6|7]
 * 1 MiByte part in single bank mode with 4 x 32, 1 x 128, 3 x 256.
 * 1 MiByte part in dual-bank mode two banks with 4 x 16, 1 x 64, 3 x 128 each.
 * 2 MiByte part in single-bank mode with 4 x 32, 1 x 128, 7 x 256.
 * 2 MiByte part in dual-bank mode two banks with 4 x 16, 1 x 64, 7 x 128 each.
 *
 * Protection size is sector size.
 *
 * Tested with STM3220F-EVAL board.
 *
 * STM32F4xx series for reference.
 *
 * RM0090
 * http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf
 *
 * PM0059
 * www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/
 * PROGRAMMING_MANUAL/CD00233952.pdf
 *
 * STM32F7xx series for reference.
 *
 * RM0385
 * http://www.st.com/web/en/resource/technical/document/reference_manual/DM00124865.pdf
 *
 * RM0410
 * http://www.st.com/resource/en/reference_manual/dm00224583.pdf
 *
 * RM0430
 * http://www.st.com/resource/en/reference_manual/dm00305666.pdf
 *
 * RM0431
 * http://www.st.com/resource/en/reference_manual/dm00305990.pdf
 *
 * STM32F1x series - notice that this code was copy, pasted and knocked
 * into a stm32f2x driver, so in case something has been converted or
 * bugs haven't been fixed, here are the original manuals:
 *
 * RM0008 - Reference manual
 *
 * RM0042, the Flash programming manual for low-, medium- high-density and
 * connectivity line STM32F10x devices
 *
 * PM0068, the Flash programming manual for XL-density STM32F10x devices.
 *
 */

/* Erase time can be as high as 1000ms, 10x this and it's toast... */
#define FLASH_ERASE_TIMEOUT 10000
#define FLASH_WRITE_TIMEOUT 5

/* Mass erase time can be as high as 32 s in x8 mode. */
#define FLASH_MASS_ERASE_TIMEOUT 33000

#define STM32_FLASH_BASE    0x40023c00
#define STM32_FLASH_ACR     0x40023c00
#define STM32_FLASH_KEYR    0x40023c04
#define STM32_FLASH_OPTKEYR 0x40023c08
#define STM32_FLASH_SR      0x40023c0C
#define STM32_FLASH_CR      0x40023c10
#define STM32_FLASH_OPTCR   0x40023c14
#define STM32_FLASH_OPTCR1  0x40023c18
#define STM32_FLASH_OPTCR2  0x40023c1c

/* FLASH_CR register bits */
#define FLASH_PG       (1 << 0)
#define FLASH_SER      (1 << 1)
#define FLASH_MER      (1 << 2)		/* MER/MER1 for f76x/77x */
#define FLASH_MER1     (1 << 15)	/* MER2 for f76x/77x, confusing ... */
#define FLASH_STRT     (1 << 16)
#define FLASH_PSIZE_8  (0 << 8)
#define FLASH_PSIZE_16 (1 << 8)
#define FLASH_PSIZE_32 (2 << 8)
#define FLASH_PSIZE_64 (3 << 8)
/* The sector number encoding is not straight binary for dual bank flash. */
#define FLASH_SNB(a)   ((a) << 3)
#define FLASH_LOCK     (1 << 31)

/* FLASH_SR register bits */
#define FLASH_BSY      (1 << 16)
#define FLASH_PGSERR   (1 << 7) /* Programming sequence error */
#define FLASH_PGPERR   (1 << 6) /* Programming parallelism error */
#define FLASH_PGAERR   (1 << 5) /* Programming alignment error */
#define FLASH_WRPERR   (1 << 4) /* Write protection error */
#define FLASH_OPERR    (1 << 1) /* Operation error */

#define FLASH_ERROR (FLASH_PGSERR | FLASH_PGPERR | FLASH_PGAERR | FLASH_WRPERR | FLASH_OPERR)

/* STM32_FLASH_OPTCR register bits */
#define OPTCR_LOCK     (1 << 0)
#define OPTCR_START    (1 << 1)
#define OPTCR_NDBANK   (1 << 29)	/* not dual bank mode */
#define OPTCR_DB1M     (1 << 30)	/* 1 MiB devices dual flash bank option */
#define OPTCR_SPRMOD   (1 << 31)	/* switches PCROPi/nWPRi interpretation */

/* STM32_FLASH_OPTCR2 register bits */
#define OPTCR2_PCROP_RDP	(1 << 31)	/* erase PCROP zone when decreasing RDP */

/* register unlock keys */
#define KEY1           0x45670123
#define KEY2           0xCDEF89AB

/* option register unlock key */
#define OPTKEY1        0x08192A3B
#define OPTKEY2        0x4C5D6E7F

struct stm32x_options {
	uint8_t RDP;
	uint16_t user_options;	/* bit 0-7 usual options, bit 8-11 extra options */
	uint32_t protection;
	uint32_t boot_addr;
	uint32_t optcr2_pcrop;
};

struct stm32x_flash_bank {
	struct stm32x_options option_bytes;
	int probed;
	bool has_large_mem;		/* F42x/43x/469/479/7xx in dual bank mode */
	bool has_extra_options; /* F42x/43x/469/479/7xx */
	bool has_boot_addr;     /* F7xx */
	bool has_optcr2_pcrop;	/* F72x/73x */
	int protection_bits;	/* F413/423 */
	uint32_t user_bank_size;
};

/* flash bank stm32x <base> <size> 0 0 <target#>
 */
FLASH_BANK_COMMAND_HANDLER(stm32x_flash_bank_command)
{
	struct stm32x_flash_bank *stm32x_info;

	if (CMD_ARGC < 6)
		return ERROR_COMMAND_SYNTAX_ERROR;

	stm32x_info = malloc(sizeof(struct stm32x_flash_bank));
	bank->driver_priv = stm32x_info;

	stm32x_info->probed = 0;
	stm32x_info->user_bank_size = bank->size;

	return ERROR_OK;
}

static inline int stm32x_get_flash_reg(struct flash_bank *bank, uint32_t reg)
{
	return reg;
}

static inline int stm32x_get_flash_status(struct flash_bank *bank, uint32_t *status)
{
	struct target *target = bank->target;
	return target_read_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_SR), status);
}

static int stm32x_wait_status_busy(struct flash_bank *bank, int timeout)
{
	struct target *target = bank->target;
	uint32_t status;
	int retval = ERROR_OK;

	/* wait for busy to clear */
	for (;;) {
		retval = stm32x_get_flash_status(bank, &status);
		if (retval != ERROR_OK)
			return retval;
		LOG_DEBUG("status: 0x%" PRIx32 "", status);
		if ((status & FLASH_BSY) == 0)
			break;
		if (timeout-- <= 0) {
			LOG_ERROR("timed out waiting for flash");
			return ERROR_FAIL;
		}
		alive_sleep(1);
	}


	if (status & FLASH_WRPERR) {
		LOG_ERROR("stm32x device protected");
		retval = ERROR_FAIL;
	}

	/* 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
		 */
		target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_SR),
				status & FLASH_ERROR);
	}
	return retval;
}

static int stm32x_unlock_reg(struct target *target)
{
	uint32_t ctrl;

	/* first check if not already unlocked
	 * otherwise writing on STM32_FLASH_KEYR will fail
	 */
	int retval = target_read_u32(target, STM32_FLASH_CR, &ctrl);
	if (retval != ERROR_OK)
		return retval;

	if ((ctrl & FLASH_LOCK) == 0)
		return ERROR_OK;

	/* unlock flash registers */
	retval = target_write_u32(target, STM32_FLASH_KEYR, KEY1);
	if (retval != ERROR_OK)
		return retval;

	retval = target_write_u32(target, STM32_FLASH_KEYR, KEY2);
	if (retval != ERROR_OK)
		return retval;

	retval = target_read_u32(target, STM32_FLASH_CR, &ctrl);
	if (retval != ERROR_OK)
		return retval;

	if (ctrl & FLASH_LOCK) {
		LOG_ERROR("flash not unlocked STM32_FLASH_CR: %" PRIx32, ctrl);
		return ERROR_TARGET_FAILURE;
	}

	return ERROR_OK;
}

static int stm32x_unlock_option_reg(struct target *target)
{
	uint32_t ctrl;

	int retval = target_read_u32(target, STM32_FLASH_OPTCR, &ctrl);
	if (retval != ERROR_OK)
		return retval;

	if ((ctrl & OPTCR_LOCK) == 0)
		return ERROR_OK;

	/* unlock option registers */
	retval = target_write_u32(target, STM32_FLASH_OPTKEYR, OPTKEY1);
	if (retval != ERROR_OK)
		return retval;

	retval = target_write_u32(target, STM32_FLASH_OPTKEYR, OPTKEY2);
	if (retval != ERROR_OK)
		return retval;

	retval = target_read_u32(target, STM32_FLASH_OPTCR, &ctrl);
	if (retval != ERROR_OK)
		return retval;

	if (ctrl & OPTCR_LOCK) {
		LOG_ERROR("options not unlocked STM32_FLASH_OPTCR: %" PRIx32, ctrl);
		return ERROR_TARGET_FAILURE;
	}

	return ERROR_OK;
}

static int stm32x_read_options(struct flash_bank *bank)
{
	uint32_t optiondata;
	struct stm32x_flash_bank *stm32x_info = NULL;
	struct target *target = bank->target;

	stm32x_info = bank->driver_priv;

	/* read current option bytes */
	int retval = target_read_u32(target, STM32_FLASH_OPTCR, &optiondata);
	if (retval != ERROR_OK)
		return retval;

    /* caution: F2 implements 5 bits (WDG_SW only)
     * whereas F7 6 bits (IWDG_SW and WWDG_SW) in user_options */
	stm32x_info->option_bytes.user_options = optiondata & 0xfc;
	stm32x_info->option_bytes.RDP = (optiondata >> 8) & 0xff;
	stm32x_info->option_bytes.protection =
		(optiondata >> 16) & (~(0xffff << stm32x_info->protection_bits) & 0xffff);

	if (stm32x_info->has_extra_options) {
		/* F42x/43x/469/479 and 7xx have up to 4 bits of extra options */
		stm32x_info->option_bytes.user_options |= (optiondata >> 20) &
			((0xf00 << (stm32x_info->protection_bits - 12)) & 0xf00);
	}

	if (stm32x_info->has_large_mem || stm32x_info->has_boot_addr) {
		retval = target_read_u32(target, STM32_FLASH_OPTCR1, &optiondata);
		if (retval != ERROR_OK)
			return retval;

		/* FLASH_OPTCR1 has quite diffent meanings ... */
		if (stm32x_info->has_boot_addr) {
			/* for F7xx it contains boot0 and boot1 */
			stm32x_info->option_bytes.boot_addr = optiondata;
		} else {
			/* for F42x/43x/469/479 it contains 12 additional protection bits */
			stm32x_info->option_bytes.protection |= (optiondata >> 4) & 0x00fff000;
		}
	}

	if (stm32x_info->has_optcr2_pcrop) {
		retval = target_read_u32(target, STM32_FLASH_OPTCR2, &optiondata);
		if (retval != ERROR_OK)
			return retval;

		stm32x_info->option_bytes.optcr2_pcrop = optiondata;
		if (stm32x_info->has_optcr2_pcrop &&
			(stm32x_info->option_bytes.optcr2_pcrop & ~OPTCR2_PCROP_RDP)) {
			LOG_INFO("PCROP Engaged");
		}
	} else {
		stm32x_info->option_bytes.optcr2_pcrop = 0x0;
	}

	if (stm32x_info->option_bytes.RDP != 0xAA)
		LOG_INFO("Device Security Bit Set");

	return ERROR_OK;
}

static int stm32x_write_options(struct flash_bank *bank)
{
	struct stm32x_flash_bank *stm32x_info = NULL;
	struct target *target = bank->target;
	uint32_t optiondata, optiondata2;

	stm32x_info = bank->driver_priv;

	int retval = stm32x_unlock_option_reg(target);
	if (retval != ERROR_OK)
		return retval;

	/* rebuild option data */
	optiondata = stm32x_info->option_bytes.user_options & 0xfc;
	optiondata |= stm32x_info->option_bytes.RDP << 8;
	optiondata |= (stm32x_info->option_bytes.protection &
		(~(0xffff << stm32x_info->protection_bits))) << 16;

	if (stm32x_info->has_extra_options) {
		/* F42x/43x/469/479 and 7xx have up to 4 bits of extra options */
		optiondata |= (stm32x_info->option_bytes.user_options &
			((0xf00 << (stm32x_info->protection_bits - 12)) & 0xf00)) << 20;
	}

	if (stm32x_info->has_large_mem || stm32x_info->has_boot_addr) {
		if (stm32x_info->has_boot_addr) {
			/* F7xx uses FLASH_OPTCR1 for boot0 and boot1 ... */
			optiondata2 = stm32x_info->option_bytes.boot_addr;
		} else {
			/* F42x/43x/469/479 uses FLASH_OPTCR1 for additional protection bits */
			optiondata2 = (stm32x_info->option_bytes.protection & 0x00fff000) << 4;
		}

		retval = target_write_u32(target, STM32_FLASH_OPTCR1, optiondata2);
		if (retval != ERROR_OK)
			return retval;
	}

	/* program extra pcrop register */
	if (stm32x_info->has_optcr2_pcrop) {
		retval = target_write_u32(target, STM32_FLASH_OPTCR2,
			stm32x_info->option_bytes.optcr2_pcrop);
		if (retval != ERROR_OK)
			return retval;
	}

	/* program options */
	retval = target_write_u32(target, STM32_FLASH_OPTCR, optiondata);
	if (retval != ERROR_OK)
		return retval;

	/* start programming cycle */
	retval = target_write_u32(target, STM32_FLASH_OPTCR, optiondata | OPTCR_START);
	if (retval != ERROR_OK)
		return retval;

	/* wait for completion, this might trigger a security erase and take a while */
	retval = stm32x_wait_status_busy(bank, FLASH_MASS_ERASE_TIMEOUT);
	if (retval != ERROR_OK)
		return retval;

	/* relock registers */
	retval = target_write_u32(target, STM32_FLASH_OPTCR, optiondata | OPTCR_LOCK);
	if (retval != ERROR_OK)
		return retval;

	return ERROR_OK;
}

static int stm32x_protect_check(struct flash_bank *bank)
{
	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
	struct flash_sector *prot_blocks;
	int num_prot_blocks;

	/* read write protection settings */
	int retval = stm32x_read_options(bank);
	if (retval != ERROR_OK) {
		LOG_DEBUG("unable to read option bytes");
		return retval;
	}

	if (bank->prot_blocks) {
		num_prot_blocks = bank->num_prot_blocks;
		prot_blocks = bank->prot_blocks;
	} else {
		num_prot_blocks = bank->num_sectors;
		prot_blocks = bank->sectors;
	}

	for (int i = 0; i < num_prot_blocks; i++)
		prot_blocks[i].is_protected =
			~(stm32x_info->option_bytes.protection >> i) & 1;

	return ERROR_OK;
}

static int stm32x_erase(struct flash_bank *bank, int first, int last)
{
	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
	struct target *target = bank->target;
	int i;

	assert((0 <= first) && (first <= last) && (last < bank->num_sectors));

	if (bank->target->state != TARGET_HALTED) {
		LOG_ERROR("Target not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	int retval;
	retval = stm32x_unlock_reg(target);
	if (retval != ERROR_OK)
		return retval;

	/*
	Sector Erase
	To erase a sector, follow the procedure below:
	1. Check that no Flash memory operation is ongoing by checking the BSY bit in the
	  FLASH_SR register
	2. Set the SER bit and select the sector
	  you wish to erase (SNB) in the FLASH_CR register
	3. Set the STRT bit in the FLASH_CR register
	4. Wait for the BSY bit to be cleared
	 */

	for (i = first; i <= last; i++) {
		int snb;
		if (stm32x_info->has_large_mem && i >= 12)
			snb = (i - 12) | 0x10;
		else
			snb = i;

		retval = target_write_u32(target,
				stm32x_get_flash_reg(bank, STM32_FLASH_CR), FLASH_SER | FLASH_SNB(snb) | FLASH_STRT);
		if (retval != ERROR_OK)
			return retval;

		retval = stm32x_wait_status_busy(bank, FLASH_ERASE_TIMEOUT);
		if (retval != ERROR_OK)
			return retval;

		bank->sectors[i].is_erased = 1;
	}

	retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR), FLASH_LOCK);
	if (retval != ERROR_OK)
		return retval;

	return ERROR_OK;
}

static int stm32x_protect(struct flash_bank *bank, int set, int first, int last)
{
	struct target *target = bank->target;
	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;

	if (target->state != TARGET_HALTED) {
		LOG_ERROR("Target not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	/* read protection settings */
	int retval = stm32x_read_options(bank);
	if (retval != ERROR_OK) {
		LOG_DEBUG("unable to read option bytes");
		return retval;
	}

	for (int i = first; i <= last; i++) {
		if (set)
			stm32x_info->option_bytes.protection &= ~(1 << i);
		else
			stm32x_info->option_bytes.protection |= (1 << i);
	}

	retval = stm32x_write_options(bank);
	if (retval != ERROR_OK)
		return retval;

	return ERROR_OK;
}

static int stm32x_write_block(struct flash_bank *bank, const uint8_t *buffer,
		uint32_t offset, uint32_t count)
{
	struct target *target = bank->target;
	uint32_t buffer_size = 16384;
	struct working_area *write_algorithm;
	struct working_area *source;
	uint32_t address = bank->base + offset;
	struct reg_param reg_params[5];
	struct armv7m_algorithm armv7m_info;
	int retval = ERROR_OK;

	static const uint8_t stm32x_flash_write_code[] = {
#include "../../../contrib/loaders/flash/stm32/stm32f2x.inc"
	};

	if (target_alloc_working_area(target, sizeof(stm32x_flash_write_code),
			&write_algorithm) != ERROR_OK) {
		LOG_WARNING("no working area available, can't do block memory writes");
		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
	}

	retval = target_write_buffer(target, write_algorithm->address,
			sizeof(stm32x_flash_write_code),
			stm32x_flash_write_code);
	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) != ERROR_OK) {
		buffer_size /= 2;
		if (buffer_size <= 256) {
			/* we already allocated the writing code, but failed to get a
			 * 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");
			return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
		}
	}

	armv7m_info.common_magic = ARMV7M_COMMON_MAGIC;
	armv7m_info.core_mode = ARM_MODE_THREAD;

	init_reg_param(&reg_params[0], "r0", 32, PARAM_IN_OUT);		/* buffer start, status (out) */
	init_reg_param(&reg_params[1], "r1", 32, PARAM_OUT);		/* buffer end */
	init_reg_param(&reg_params[2], "r2", 32, PARAM_OUT);		/* target address */
	init_reg_param(&reg_params[3], "r3", 32, PARAM_OUT);		/* count (halfword-16bit) */
	init_reg_param(&reg_params[4], "r4", 32, PARAM_OUT);		/* flash base */

	buf_set_u32(reg_params[0].value, 0, 32, source->address);
	buf_set_u32(reg_params[1].value, 0, 32, source->address + source->size);
	buf_set_u32(reg_params[2].value, 0, 32, address);
	buf_set_u32(reg_params[3].value, 0, 32, count);
	buf_set_u32(reg_params[4].value, 0, 32, STM32_FLASH_BASE);

	retval = target_run_flash_async_algorithm(target, buffer, count, 2,
			0, NULL,
			5, reg_params,
			source->address, source->size,
			write_algorithm->address, 0,
			&armv7m_info);

	if (retval == ERROR_FLASH_OPERATION_FAILED) {
		LOG_ERROR("error executing stm32x flash write algorithm");

		uint32_t error = buf_get_u32(reg_params[0].value, 0, 32) & FLASH_ERROR;

		if (error & FLASH_WRPERR)
			LOG_ERROR("flash memory write protected");

		if (error != 0) {
			LOG_ERROR("flash write failed = %08" PRIx32, error);
			/* Clear but report errors */
			target_write_u32(target, STM32_FLASH_SR, error);
			retval = ERROR_FAIL;
		}
	}

	target_free_working_area(target, source);
	target_free_working_area(target, write_algorithm);

	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;
}

static int stm32x_write(struct flash_bank *bank, const uint8_t *buffer,
		uint32_t offset, uint32_t count)
{
	struct target *target = bank->target;
	uint32_t words_remaining = (count / 2);
	uint32_t bytes_remaining = (count & 0x00000001);
	uint32_t address = bank->base + offset;
	uint32_t bytes_written = 0;
	int retval;

	if (bank->target->state != TARGET_HALTED) {
		LOG_ERROR("Target not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	if (offset & 0x1) {
		LOG_WARNING("offset 0x%" PRIx32 " breaks required 2-byte alignment", offset);
		return ERROR_FLASH_DST_BREAKS_ALIGNMENT;
	}

	retval = stm32x_unlock_reg(target);
	if (retval != ERROR_OK)
		return retval;

	/* multiple half words (2-byte) to be programmed? */
	if (words_remaining > 0) {
		/* try using a block write */
		retval = stm32x_write_block(bank, buffer, offset, words_remaining);
		if (retval != ERROR_OK) {
			if (retval == ERROR_TARGET_RESOURCE_NOT_AVAILABLE) {
				/* if block write failed (no sufficient working area),
				 * we use normal (slow) single dword accesses */
				LOG_WARNING("couldn't use block writes, falling back to single memory accesses");
			}
		} else {
			buffer += words_remaining * 2;
			address += words_remaining * 2;
			words_remaining = 0;
		}
	}

	if ((retval != ERROR_OK) && (retval != ERROR_TARGET_RESOURCE_NOT_AVAILABLE))
		return retval;

	/*
	Standard programming
	The Flash memory programming sequence is as follows:
	1. Check that no main Flash memory operation is ongoing by checking the BSY bit in the
	  FLASH_SR register.
	2. Set the PG bit in the FLASH_CR register
	3. Perform the data write operation(s) to the desired memory address (inside main
	  memory block or OTP area):
	– – Half-word access in case of x16 parallelism
	– Word access in case of x32 parallelism
	–
	4.
	Byte access in case of x8 parallelism
	Double word access in case of x64 parallelism
	Wait for the BSY bit to be cleared
	*/
	while (words_remaining > 0) {
		uint16_t value;
		memcpy(&value, buffer + bytes_written, sizeof(uint16_t));

		retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR),
				FLASH_PG | FLASH_PSIZE_16);
		if (retval != ERROR_OK)
			return retval;

		retval = target_write_u16(target, address, value);
		if (retval != ERROR_OK)
			return retval;

		retval = stm32x_wait_status_busy(bank, FLASH_WRITE_TIMEOUT);
		if (retval != ERROR_OK)
			return retval;

		bytes_written += 2;
		words_remaining--;
		address += 2;
	}

	if (bytes_remaining) {
		retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR),
				FLASH_PG | FLASH_PSIZE_8);
		if (retval != ERROR_OK)
			return retval;
		retval = target_write_u8(target, address, buffer[bytes_written]);
		if (retval != ERROR_OK)
			return retval;

		retval = stm32x_wait_status_busy(bank, FLASH_WRITE_TIMEOUT);
		if (retval != ERROR_OK)
			return retval;
	}

	return target_write_u32(target, STM32_FLASH_CR, FLASH_LOCK);
}

static int setup_sector(struct flash_bank *bank, int start, int num, int size)
{

	for (int i = start; i < (start + num) ; i++) {
		assert(i < bank->num_sectors);
		bank->sectors[i].offset = bank->size;
		bank->sectors[i].size = size;
		bank->size += bank->sectors[i].size;
	    LOG_DEBUG("sector %d: %dkBytes", i, size >> 10);
	}

	return start + num;
}

static void setup_bank(struct flash_bank *bank, int start,
	uint16_t flash_size_in_kb, uint16_t max_sector_size_in_kb)
{
	int remain;

	start = setup_sector(bank, start, 4, (max_sector_size_in_kb / 8) * 1024);
	start = setup_sector(bank, start, 1, (max_sector_size_in_kb / 2) * 1024);

	/* remaining sectors all of size max_sector_size_in_kb */
	remain = (flash_size_in_kb / max_sector_size_in_kb) - 1;
	start = setup_sector(bank, start, remain, max_sector_size_in_kb * 1024);
}

static int stm32x_get_device_id(struct flash_bank *bank, uint32_t *device_id)
{
	/* this checks for a stm32f4x errata issue where a
	 * stm32f2x DBGMCU_IDCODE is incorrectly returned.
	 * If the issue is detected target is forced to stm32f4x Rev A.
	 * Only effects Rev A silicon */

	struct target *target = bank->target;
	uint32_t cpuid;

	/* read stm32 device id register */
	int retval = target_read_u32(target, 0xE0042000, device_id);
	if (retval != ERROR_OK)
		return retval;

	if ((*device_id & 0xfff) == 0x411) {
		/* read CPUID reg to check core type */
		retval = target_read_u32(target, 0xE000ED00, &cpuid);
		if (retval != ERROR_OK)
			return retval;

		/* check for cortex_m4 */
		if (((cpuid >> 4) & 0xFFF) == 0xC24) {
			*device_id &= ~((0xFFFF << 16) | 0xfff);
			*device_id |= (0x1000 << 16) | 0x413;
			LOG_INFO("stm32f4x errata detected - fixing incorrect MCU_IDCODE");
		}
	}
	return retval;
}

static int stm32x_probe(struct flash_bank *bank)
{
	struct target *target = bank->target;
	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
	int i, num_prot_blocks;
	uint16_t flash_size_in_kb;
	uint32_t flash_size_reg = 0x1FFF7A22;
	uint16_t max_sector_size_in_kb = 128;
	uint16_t max_flash_size_in_kb;
	uint32_t device_id;
	uint32_t base_address = 0x08000000;

	stm32x_info->probed = 0;
	stm32x_info->has_large_mem = false;
	stm32x_info->has_boot_addr = false;
	stm32x_info->has_extra_options = false;
	stm32x_info->has_optcr2_pcrop = false;
	stm32x_info->protection_bits = 12;		/* max. number of nWRPi bits (in FLASH_OPTCR !!!) */
	num_prot_blocks = 0;

	if (bank->sectors) {
		free(bank->sectors);
		bank->num_sectors = 0;
		bank->sectors = NULL;
	}

	if (bank->prot_blocks) {
		free(bank->prot_blocks);
		bank->num_prot_blocks = 0;
		bank->prot_blocks = NULL;
	}

	/* read stm32 device id register */
	int retval = stm32x_get_device_id(bank, &device_id);
	if (retval != ERROR_OK)
		return retval;
	LOG_INFO("device id = 0x%08" PRIx32 "", device_id);
	device_id &= 0xfff;		/* only bits 0-11 are used further on */

	/* set max flash size depending on family, id taken from AN2606 */
	switch (device_id) {
	case 0x411: /* F20x/21x */
	case 0x413: /* F40x/41x */
		max_flash_size_in_kb = 1024;
		break;

	case 0x419: /* F42x/43x */
	case 0x434: /* F469/479 */
		stm32x_info->has_extra_options = true;
		max_flash_size_in_kb = 2048;
		break;

	case 0x423:	/* F401xB/C */
		max_flash_size_in_kb = 256;
		break;

	case 0x421:	/* F446 */
	case 0x431: /* F411 */
	case 0x433: /* F401xD/E */
	case 0x441: /* F412 */
		max_flash_size_in_kb = 512;
		break;

	case 0x458: /* F410 */
		max_flash_size_in_kb = 128;
		break;

	case 0x449:	/* F74x/75x */
		max_flash_size_in_kb = 1024;
		max_sector_size_in_kb = 256;
		flash_size_reg = 0x1FF0F442;
		stm32x_info->has_extra_options = true;
		stm32x_info->has_boot_addr = true;
		break;

	case 0x451:	/* F76x/77x */
		max_flash_size_in_kb = 2048;
		max_sector_size_in_kb = 256;
		flash_size_reg = 0x1FF0F442;
		stm32x_info->has_extra_options = true;
		stm32x_info->has_boot_addr = true;
		break;

	case 0x452:	/* F72x/73x */
		max_flash_size_in_kb = 512;
		flash_size_reg = 0x1FF07A22;	/* yes, 0x1FF*0*7A22, not 0x1FF*F*7A22 */
		stm32x_info->has_extra_options = true;
		stm32x_info->has_boot_addr = true;
		stm32x_info->has_optcr2_pcrop = true;
		break;

	case 0x463:	/* F413x/423x */
		max_flash_size_in_kb = 1536;
		stm32x_info->has_extra_options = true;
		stm32x_info->protection_bits = 15;
		num_prot_blocks = 15;
		break;

	default:
		LOG_WARNING("Cannot identify target as a STM32 family.");
		return ERROR_FAIL;
	}

	/* get flash size from target. */
	retval = target_read_u16(target, flash_size_reg, &flash_size_in_kb);

	/* 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;
	}

	/* if the user sets the size manually then ignore the probed value
	 * this allows us to work around devices that have a invalid flash size register value */
	if (stm32x_info->user_bank_size) {
		LOG_INFO("ignoring flash probed value, using configured bank size");
		flash_size_in_kb = stm32x_info->user_bank_size / 1024;
	}

	LOG_INFO("flash size = %dkbytes", flash_size_in_kb);

	/* did we assign flash size? */
	assert(flash_size_in_kb != 0xffff);

	/* F42x/43x/469/479 1024 kiByte devices have a dual bank option */
	if ((device_id == 0x419) || (device_id == 0x434)) {
		uint32_t optiondata;
		retval = target_read_u32(target, STM32_FLASH_OPTCR, &optiondata);
		if (retval != ERROR_OK) {
			LOG_DEBUG("unable to read option bytes");
			return retval;
		}
		if ((flash_size_in_kb > 1024) || (optiondata & OPTCR_DB1M)) {
			stm32x_info->has_large_mem = true;
			LOG_INFO("Dual Bank %d kiB STM32F42x/43x/469/479 found", flash_size_in_kb);
		} else {
			stm32x_info->has_large_mem = false;
			LOG_INFO("Single Bank %d kiB STM32F42x/43x/469/479 found", flash_size_in_kb);
		}
	}

	/* F76x/77x devices have a dual bank option */
	if (device_id == 0x451) {
		uint32_t optiondata;
		retval = target_read_u32(target, STM32_FLASH_OPTCR, &optiondata);
		if (retval != ERROR_OK) {
			LOG_DEBUG("unable to read option bytes");
			return retval;
		}
		if (optiondata & OPTCR_NDBANK) {
			stm32x_info->has_large_mem = false;
			LOG_INFO("Single Bank %d kiB STM32F76x/77x found", flash_size_in_kb);
		} else {
			stm32x_info->has_large_mem = true;
			max_sector_size_in_kb >>= 1; /* sector size divided by 2 in dual-bank mode */
			LOG_INFO("Dual Bank %d kiB STM32F76x/77x found", flash_size_in_kb);
		}
	}

	/* calculate numbers of pages */
	int num_pages = flash_size_in_kb / max_sector_size_in_kb
		+ (stm32x_info->has_large_mem ? 8 : 4);

	bank->base = base_address;
	bank->num_sectors = num_pages;
	bank->sectors = malloc(sizeof(struct flash_sector) * num_pages);
	for (i = 0; i < num_pages; i++) {
		bank->sectors[i].is_erased = -1;
		bank->sectors[i].is_protected = 0;
	}
	bank->size = 0;
	LOG_DEBUG("allocated %d sectors", num_pages);

	/* F76x/77x in dual bank mode */
	if ((device_id == 0x451) && stm32x_info->has_large_mem)
		num_prot_blocks = num_pages >> 1;

	if (num_prot_blocks) {
		bank->prot_blocks = malloc(sizeof(struct flash_sector) * num_prot_blocks);
		for (i = 0; i < num_prot_blocks; i++)
			bank->prot_blocks[i].is_protected = 0;
		LOG_DEBUG("allocated %d prot blocks", num_prot_blocks);
	}

	if (stm32x_info->has_large_mem) {
		/* dual-bank */
		setup_bank(bank, 0, flash_size_in_kb >> 1, max_sector_size_in_kb);
		setup_bank(bank, num_pages >> 1, flash_size_in_kb >> 1,
			max_sector_size_in_kb);

		/* F767x/F77x in dual mode, one protection bit refers to two adjacent sectors */
		if (device_id == 0x451) {
			for (i = 0; i < num_prot_blocks; i++) {
				bank->prot_blocks[i].offset = bank->sectors[i << 1].offset;
				bank->prot_blocks[i].size = bank->sectors[i << 1].size
						+ bank->sectors[(i << 1) + 1].size;
			}
		}
	} else {
		/* single-bank */
		setup_bank(bank, 0, flash_size_in_kb, max_sector_size_in_kb);

		/* F413/F423, sectors 14 and 15 share one common protection bit */
		if (device_id == 0x463) {
			for (i = 0; i < num_prot_blocks; i++) {
				bank->prot_blocks[i].offset = bank->sectors[i].offset;
				bank->prot_blocks[i].size = bank->sectors[i].size;
			}
			bank->prot_blocks[num_prot_blocks - 1].size <<= 1;
		}
	}
	bank->num_prot_blocks = num_prot_blocks;
	assert((bank->size >> 10) == flash_size_in_kb);

	stm32x_info->probed = 1;
	return ERROR_OK;
}

static int stm32x_auto_probe(struct flash_bank *bank)
{
	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
	if (stm32x_info->probed)
		return ERROR_OK;
	return stm32x_probe(bank);
}

static int get_stm32x_info(struct flash_bank *bank, char *buf, int buf_size)
{
	uint32_t dbgmcu_idcode;

	/* read stm32 device id register */
	int retval = stm32x_get_device_id(bank, &dbgmcu_idcode);
	if (retval != ERROR_OK)
		return retval;

	uint16_t device_id = dbgmcu_idcode & 0xfff;
	uint16_t rev_id = dbgmcu_idcode >> 16;
	const char *device_str;
	const char *rev_str = NULL;

	switch (device_id) {
	case 0x411:
		device_str = "STM32F2xx";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;

		case 0x2000:
			rev_str = "B";
			break;

		case 0x1001:
			rev_str = "Z";
			break;

		case 0x2001:
			rev_str = "Y";
			break;

		case 0x2003:
			rev_str = "X";
			break;

		case 0x2007:
			rev_str = "1";
			break;

		case 0x200F:
			rev_str = "V";
			break;

		case 0x201F:
			rev_str = "2";
			break;
		}
		break;

	case 0x413:
	case 0x419:
	case 0x434:
		device_str = "STM32F4xx";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;

		case 0x1001:
			rev_str = "Z";
			break;

		case 0x1003:
			rev_str = "Y";
			break;

		case 0x1007:
			rev_str = "1";
			break;

		case 0x2001:
			rev_str = "3";
			break;
		}
		break;

	case 0x421:
		device_str = "STM32F446";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;
		}
		break;

	case 0x423:
	case 0x431:
	case 0x433:
	case 0x458:
	case 0x441:
		device_str = "STM32F4xx (Low Power)";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;

		case 0x1001:
			rev_str = "Z";
			break;

		case 0x2000:
			rev_str = "B";
			break;

		case 0x3000:
			rev_str = "C";
			break;
		}
		break;

	case 0x449:
		device_str = "STM32F7[4|5]x";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;

		case 0x1001:
			rev_str = "Z";
			break;
		}
		break;

	case 0x451:
		device_str = "STM32F7[6|7]x";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;
		case 0x1001:
			rev_str = "Z";
			break;
		}
		break;

	case 0x452:
		device_str = "STM32F7[2|3]x";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;
		}
		break;

	case 0x463:
		device_str = "STM32F4[1|2]3";

		switch (rev_id) {
		case 0x1000:
			rev_str = "A";
			break;
		}
		break;

	default:
		snprintf(buf, buf_size, "Cannot identify target as a STM32F2/4/7\n");
		return ERROR_FAIL;
	}

	if (rev_str != NULL)
		snprintf(buf, buf_size, "%s - Rev: %s", device_str, rev_str);
	else
		snprintf(buf, buf_size, "%s - Rev: unknown (0x%04x)", device_str, rev_id);

	return ERROR_OK;
}

COMMAND_HANDLER(stm32x_handle_lock_command)
{
	struct target *target = NULL;
	struct stm32x_flash_bank *stm32x_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;

	stm32x_info = bank->driver_priv;
	target = bank->target;

	if (target->state != TARGET_HALTED) {
		LOG_INFO("Target not halted");
		/* return ERROR_TARGET_NOT_HALTED; */
	}

	if (stm32x_read_options(bank) != ERROR_OK) {
		command_print(CMD_CTX, "%s failed to read options", bank->driver->name);
		return ERROR_OK;
	}

	/* set readout protection */
	stm32x_info->option_bytes.RDP = 0;

	if (stm32x_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(stm32x_handle_unlock_command)
{
	struct target *target = NULL;
	struct stm32x_flash_bank *stm32x_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;

	stm32x_info = bank->driver_priv;
	target = bank->target;

	if (target->state != TARGET_HALTED) {
		LOG_INFO("Target not halted");
		/* return ERROR_TARGET_NOT_HALTED; */
	}

	if (stm32x_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 */
	stm32x_info->option_bytes.RDP = 0xAA;
	if (stm32x_info->has_optcr2_pcrop) {
		stm32x_info->option_bytes.optcr2_pcrop = OPTCR2_PCROP_RDP | (~1U << bank->num_sectors);
	}

	if (stm32x_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 stm32x_mass_erase(struct flash_bank *bank)
{
	int retval;
	uint32_t flash_mer;
	struct target *target = bank->target;
	struct stm32x_flash_bank *stm32x_info = NULL;

	if (target->state != TARGET_HALTED) {
		LOG_ERROR("Target not halted");
		return ERROR_TARGET_NOT_HALTED;
	}

	stm32x_info = bank->driver_priv;

	retval = stm32x_unlock_reg(target);
	if (retval != ERROR_OK)
		return retval;

	/* mass erase flash memory */
	if (stm32x_info->has_large_mem)
		flash_mer = FLASH_MER | FLASH_MER1;
	else
		flash_mer = FLASH_MER;

	retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR), flash_mer);
	if (retval != ERROR_OK)
		return retval;
	retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR),
		flash_mer | FLASH_STRT);
	if (retval != ERROR_OK)
		return retval;

	retval = stm32x_wait_status_busy(bank, FLASH_MASS_ERASE_TIMEOUT);
	if (retval != ERROR_OK)
		return retval;

	retval = target_write_u32(target, stm32x_get_flash_reg(bank, STM32_FLASH_CR), FLASH_LOCK);
	if (retval != ERROR_OK)
		return retval;

	return ERROR_OK;
}

COMMAND_HANDLER(stm32x_handle_mass_erase_command)
{
	int i;

	if (CMD_ARGC < 1) {
		command_print(CMD_CTX, "stm32x mass_erase <bank>");
		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;

	retval = stm32x_mass_erase(bank);
	if (retval == ERROR_OK) {
		/* set all sectors as erased */
		for (i = 0; i < bank->num_sectors; i++)
			bank->sectors[i].is_erased = 1;

		command_print(CMD_CTX, "stm32x mass erase complete");
	} else {
		command_print(CMD_CTX, "stm32x mass erase failed");
	}

	return retval;
}

COMMAND_HANDLER(stm32f2x_handle_options_read_command)
{
	int retval;
	struct flash_bank *bank;
	struct stm32x_flash_bank *stm32x_info = NULL;

	if (CMD_ARGC != 1) {
		command_print(CMD_CTX, "stm32f2x options_read <bank>");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
	if (ERROR_OK != retval)
		return retval;

	retval = stm32x_read_options(bank);
	if (ERROR_OK != retval)
		return retval;

	stm32x_info = bank->driver_priv;
	if (stm32x_info->has_extra_options) {
		if (stm32x_info->has_boot_addr) {
			uint32_t boot_addr = stm32x_info->option_bytes.boot_addr;

			command_print(CMD_CTX, "stm32f2x user_options 0x%03X,"
				" boot_add0 0x%04X, boot_add1 0x%04X",
				stm32x_info->option_bytes.user_options,
				boot_addr & 0xffff, (boot_addr & 0xffff0000) >> 16);
			if (stm32x_info->has_optcr2_pcrop) {
				command_print(CMD_CTX, "stm32f2x optcr2_pcrop 0x%08X",
						stm32x_info->option_bytes.optcr2_pcrop);
			}
		} else {
			command_print(CMD_CTX, "stm32f2x user_options 0x%03X",
				stm32x_info->option_bytes.user_options);
		}
	} else {
		command_print(CMD_CTX, "stm32f2x user_options 0x%02X",
			stm32x_info->option_bytes.user_options);

	}

	return retval;
}

COMMAND_HANDLER(stm32f2x_handle_options_write_command)
{
	int retval;
	struct flash_bank *bank;
	struct stm32x_flash_bank *stm32x_info = NULL;
	uint16_t user_options, boot_addr0, boot_addr1, options_mask;

	if (CMD_ARGC < 1) {
		command_print(CMD_CTX, "stm32f2x options_write <bank> ...");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
	if (ERROR_OK != retval)
		return retval;

	retval = stm32x_read_options(bank);
	if (ERROR_OK != retval)
		return retval;

	stm32x_info = bank->driver_priv;
	if (stm32x_info->has_boot_addr) {
		if (CMD_ARGC != 4) {
			command_print(CMD_CTX, "stm32f2x options_write <bank> <user_options>"
				" <boot_addr0> <boot_addr1>");
			return ERROR_COMMAND_SYNTAX_ERROR;
		}
		COMMAND_PARSE_NUMBER(u16, CMD_ARGV[2], boot_addr0);
		COMMAND_PARSE_NUMBER(u16, CMD_ARGV[3], boot_addr1);
		stm32x_info->option_bytes.boot_addr = boot_addr0 | (((uint32_t) boot_addr1) << 16);
	} else {
		if (CMD_ARGC != 2) {
			command_print(CMD_CTX, "stm32f2x options_write <bank> <user_options>");
			return ERROR_COMMAND_SYNTAX_ERROR;
		}
	}

	COMMAND_PARSE_NUMBER(u16, CMD_ARGV[1], user_options);
	options_mask = !stm32x_info->has_extra_options ? ~0xfc :
		~(((0xf00 << (stm32x_info->protection_bits - 12)) | 0xff) & 0xffc);
	if (user_options & options_mask) {
		command_print(CMD_CTX, "stm32f2x invalid user_options");
		return ERROR_COMMAND_ARGUMENT_INVALID;
	}

	stm32x_info->option_bytes.user_options = user_options;

	if (stm32x_write_options(bank) != ERROR_OK) {
		command_print(CMD_CTX, "stm32f2x failed to write options");
		return ERROR_OK;
	}

	/* switching between single- and dual-bank modes requires re-probe */
	/* ... and reprogramming of whole flash */
	stm32x_info->probed = 0;

	command_print(CMD_CTX, "stm32f2x write options complete.\n"
				"INFO: a reset or power cycle is required "
				"for the new settings to take effect.");
	return retval;
}

COMMAND_HANDLER(stm32f2x_handle_optcr2_write_command)
{
	int retval;
	struct flash_bank *bank;
	struct stm32x_flash_bank *stm32x_info = NULL;
	uint32_t optcr2_pcrop;

	if (CMD_ARGC != 2) {
		command_print(CMD_CTX, "stm32f2x optcr2_write <bank> <optcr2_value>");
		return ERROR_COMMAND_SYNTAX_ERROR;
	}

	retval = CALL_COMMAND_HANDLER(flash_command_get_bank, 0, &bank);
	if (ERROR_OK != retval)
		return retval;

	stm32x_info = bank->driver_priv;
	if (!stm32x_info->has_optcr2_pcrop) {
		command_print(CMD_CTX, "no optcr2 register");
		return ERROR_COMMAND_ARGUMENT_INVALID;
	}

	command_print(CMD_CTX, "INFO: To disable PCROP, set PCROP_RDP"
				" with PCROPi bits STILL SET, then\nlock device and"
				" finally unlock it. Clears PCROP and mass erases flash.");

	retval = stm32x_read_options(bank);
	if (ERROR_OK != retval)
		return retval;

	COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], optcr2_pcrop);
	stm32x_info->option_bytes.optcr2_pcrop = optcr2_pcrop;

	if (stm32x_write_options(bank) != ERROR_OK) {
		command_print(CMD_CTX, "stm32f2x failed to write options");
		return ERROR_OK;
	}

	command_print(CMD_CTX, "stm32f2x optcr2_write complete.");
	return retval;
}

static const struct command_registration stm32x_exec_command_handlers[] = {
	{
		.name = "lock",
		.handler = stm32x_handle_lock_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id",
		.help = "Lock entire flash device.",
	},
	{
		.name = "unlock",
		.handler = stm32x_handle_unlock_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id",
		.help = "Unlock entire protected flash device.",
	},
	{
		.name = "mass_erase",
		.handler = stm32x_handle_mass_erase_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id",
		.help = "Erase entire flash device.",
	},
	{
		.name = "options_read",
		.handler = stm32f2x_handle_options_read_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id",
		.help = "Read and display device option bytes.",
	},
	{
		.name = "options_write",
		.handler = stm32f2x_handle_options_write_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id user_options [ boot_add0 boot_add1 ]",
		.help = "Write option bytes",
	},
	{
		.name = "optcr2_write",
		.handler = stm32f2x_handle_optcr2_write_command,
		.mode = COMMAND_EXEC,
		.usage = "bank_id optcr2",
		.help = "Write optcr2 word",
	},

	COMMAND_REGISTRATION_DONE
};

static const struct command_registration stm32x_command_handlers[] = {
	{
		.name = "stm32f2x",
		.mode = COMMAND_ANY,
		.help = "stm32f2x flash command group",
		.usage = "",
		.chain = stm32x_exec_command_handlers,
	},
	COMMAND_REGISTRATION_DONE
};

struct flash_driver stm32f2x_flash = {
	.name = "stm32f2x",
	.commands = stm32x_command_handlers,
	.flash_bank_command = stm32x_flash_bank_command,
	.erase = stm32x_erase,
	.protect = stm32x_protect,
	.write = stm32x_write,
	.read = default_flash_read,
	.probe = stm32x_probe,
	.auto_probe = stm32x_auto_probe,
	.erase_check = default_flash_blank_check,
	.protect_check = stm32x_protect_check,
	.info = get_stm32x_info,
	.free_driver_priv = default_flash_free_driver_priv,
};
