stm32x: add support for STM32F20x

ready for wider testing and comments on basic erase + programming.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

4 files changed, 778 insertions, 0 deletions

diff --git a/contrib/loaders/flash/stm32f2xxx.S b/contrib/loaders/flash/stm32f2xxx.S
new file mode 100644
index 00000000..49c821b6
--- /dev/null
+++ b/contrib/loaders/flash/stm32f2xxx.S
@@ -0,0 +1,63 @@
+/***************************************************************************
+ *   Copyright (C) 2010 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, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   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
+*/
+
+#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 */
+
+write:
+
+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 */
+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 */
+exit:
+	bkpt	#0x00
+
+
+STM32_PROG16: .word 0x101 						/* PG | PSIZE_16*/
diff --git a/src/flash/nor/Makefile.am b/src/flash/nor/Makefile.am
index 42707e00..95bd313d 100644
--- a/src/flash/nor/Makefile.am
+++ b/src/flash/nor/Makefile.am
@@ -25,6 +25,7 @@ NOR_DRIVERS = \
 	stmsmi.c \
 	stellaris.c \
 	stm32x.c \
+	stm32f2xxx.c \
 	str7x.c \
 	str9x.c \
 	str9xpec.c \
diff --git a/src/flash/nor/drivers.c b/src/flash/nor/drivers.c
index f4479f6c..5489419f 100644
--- a/src/flash/nor/drivers.c
+++ b/src/flash/nor/drivers.c
@@ -33,6 +33,7 @@ extern struct flash_driver aduc702x_flash;
 extern struct flash_driver stellaris_flash;
 extern struct flash_driver str9xpec_flash;
 extern struct flash_driver stm32x_flash;
+extern struct flash_driver stm32xf2xxx_flash;
 extern struct flash_driver tms470_flash;
 extern struct flash_driver ecosflash_flash;
 extern struct flash_driver ocl_flash;
@@ -60,6 +61,7 @@ static struct flash_driver *flash_drivers[] = {
 	&stellaris_flash,
 	&str9xpec_flash,
 	&stm32x_flash,
+	&stm32xf2xxx_flash,
 	&tms470_flash,
 	&ecosflash_flash,
 	&ocl_flash,
diff --git a/src/flash/nor/stm32f2xxx.c b/src/flash/nor/stm32f2xxx.c
new file mode 100644
index 00000000..2ccf5317
--- /dev/null
+++ b/src/flash/nor/stm32f2xxx.c
@@ -0,0 +1,712 @@
+/***************************************************************************
+ *   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, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+#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 STM32F1xxxx and STM32F2xxxx 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 stm32fx2222.
+ *
+ * 1mByte part with 4 x 16, 1 x 64, 7 x 128kBytes sectors
+ *
+ * What's the protection page size???
+ *
+ * Tested with STM3220F-EVAL board.
+ *
+ * STM32F21xx series for reference.
+ *
+ * RM0033
+ * http://www.st.com/internet/mcu/product/250192.jsp
+ *
+ * PM0059
+ * www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/PROGRAMMING_MANUAL/CD00233952.pdf
+ *
+ * STM32F1xxx series - notice that this code was copy, pasted and knocked
+ * into a stm32f2xxx 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 STM32F10xxx devices
+ *
+ * PM0068, the Flash programming manual for XL-density STM32F10xxx 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
+
+
+#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_OBR		0x40023c1C
+
+
+
+/* option byte location */
+
+#define STM32_OB_RDP		0x1FFFF800
+#define STM32_OB_USER		0x1FFFF802
+#define STM32_OB_DATA0		0x1FFFF804
+#define STM32_OB_DATA1		0x1FFFF806
+#define STM32_OB_WRP0		0x1FFFF808
+#define STM32_OB_WRP1		0x1FFFF80A
+#define STM32_OB_WRP2		0x1FFFF80C
+#define STM32_OB_WRP3		0x1FFFF80E
+
+/* FLASH_CR register bits */
+
+#define FLASH_PG		(1 << 0)
+#define FLASH_SER		(1 << 1)
+#define FLASH_MER		(1 << 2)
+#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)
+#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_OBR bit definitions (reading) */
+
+#define OPT_ERROR		0
+#define OPT_READOUT		1
+#define OPT_RDWDGSW		2
+#define OPT_RDRSTSTOP	3
+#define OPT_RDRSTSTDBY	4
+#define OPT_BFB2		5	/* dual flash bank only */
+
+/* register unlock keys */
+
+#define KEY1			0x45670123
+#define KEY2			0xCDEF89AB
+
+struct stm32x_flash_bank
+{
+	struct working_area *write_algorithm;
+	int probed;
+};
+
+
+/* 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)
+	{
+		LOG_WARNING("incomplete flash_bank stm32x configuration");
+		return ERROR_FLASH_BANK_INVALID;
+	}
+
+	stm32x_info = malloc(sizeof(struct stm32x_flash_bank));
+	bank->driver_priv = stm32x_info;
+
+	stm32x_info->write_algorithm = NULL;
+	stm32x_info->probed = 0;
+
+	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 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)
+{
+	/* unlock flash registers */
+	int 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;
+	return ERROR_OK;
+}
+
+static int stm32x_protect_check(struct flash_bank *bank)
+{
+	return ERROR_OK;
+}
+
+static int stm32x_erase(struct flash_bank *bank, int first, int last)
+{
+	struct target *target = bank->target;
+	int i;
+
+	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 (out of the 12 sectors in the main memory block)
+	  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++)
+	{
+		retval = target_write_u32(target,
+				stm32x_get_flash_reg(bank, STM32_FLASH_CR), FLASH_SER | FLASH_SNB(i) | 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)
+{
+	return ERROR_OK;
+}
+
+static int stm32x_write_block(struct flash_bank *bank, uint8_t *buffer,
+		uint32_t offset, uint32_t count)
+{
+	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
+	struct target *target = bank->target;
+	uint32_t buffer_size = 16384;
+	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;
+
+	/* see contib/loaders/flash/stm32x.s for src */
+
+	static const uint16_t stm32x_flash_write_code_16[] = {
+//	00000000 <write>:
+	   0x4b07, //     	ldr	r3, [pc, #28]	(20 <STM32_PROG16>)
+	   0x6123,  //    	str	r3, [r4, #16]
+       0xf830, 0x3b02, 	//ldrh.w	r3, [r0], #2
+       0xf821, 0x3b02, 	//strh.w	r3, [r1], #2
+
+	//0000000c <busy>:
+	0x68e3,      	//ldr	r3, [r4, #12]
+0xf413, 0x3f80, // 	tst.w	r3, #65536	; 0x10000
+0xd0fb,      	//beq.n	c <busy>
+0xf013, 0x0ff0, 	//tst.w	r3, #240	; 0xf0
+0xd101,      	//bne.n	1e <exit>
+0x3a01,      	//subs	r2, #1
+0xd1f0,      	//bne.n	0 <write>
+	            	   	//0000001e <exit>:
+	0xbe00, //      	bkpt	0x0000
+
+	//00000020 <STM32_PROG16>:
+	0x0101, 0x0000, // 	.word	0x00000101
+
+	};
+
+	// Flip endian
+	uint8_t stm32x_flash_write_code[sizeof(stm32x_flash_write_code_16)*2];
+	for (unsigned i = 0; i < sizeof(stm32x_flash_write_code_16) / 2; i++)
+	{
+		stm32x_flash_write_code[i*2 + 0] = stm32x_flash_write_code_16[i] & 0xff;
+		stm32x_flash_write_code[i*2 + 1] = (stm32x_flash_write_code_16[i] >> 8) & 0xff;
+	}
+
+	if (target_alloc_working_area(target, sizeof(stm32x_flash_write_code),
+			&stm32x_info->write_algorithm) != ERROR_OK)
+	{
+		LOG_WARNING("no working area available, can't do block memory writes");
+		return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+	};
+
+	if ((retval = target_write_buffer(target, stm32x_info->write_algorithm->address,
+			sizeof(stm32x_flash_write_code),
+			(uint8_t*)stm32x_flash_write_code)) != ERROR_OK)
+		return retval;
+
+	/* memory buffer */
+	while (target_alloc_working_area_try(target, buffer_size, &source) != ERROR_OK)
+	{
+		buffer_size /= 2;
+		if (buffer_size <= 256)
+		{
+			/* if we already allocated the writing code, but failed to get a
+			 * buffer, free the algorithm */
+			if (stm32x_info->write_algorithm)
+				target_free_working_area(target, stm32x_info->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 = ARMV7M_MODE_ANY;
+
+	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_IN_OUT);
+	init_reg_param(&reg_params[4], "r4", 32, PARAM_OUT);
+
+	while (count > 0)
+	{
+		uint32_t thisrun_count = (count > (buffer_size / 2)) ?
+				(buffer_size / 2) : count;
+
+		if ((retval = target_write_buffer(target, source->address,
+				thisrun_count * 2, buffer)) != ERROR_OK)
+			break;
+
+		buf_set_u32(reg_params[0].value, 0, 32, source->address);
+		buf_set_u32(reg_params[1].value, 0, 32, address);
+		buf_set_u32(reg_params[2].value, 0, 32, thisrun_count);
+		// R3 is a return value only
+		buf_set_u32(reg_params[4].value, 0, 32, STM32_FLASH_BASE);
+
+		if ((retval = target_run_algorithm(target, 0, NULL,
+				sizeof(reg_params) / sizeof(*reg_params),
+				reg_params,
+				stm32x_info->write_algorithm->address,
+				0,
+				10000, &armv7m_info)) != ERROR_OK)
+		{
+			LOG_ERROR("error executing stm32x flash write algorithm");
+			break;
+		}
+
+		uint32_t error = buf_get_u32(reg_params[3].value, 0, 32) & FLASH_ERROR;
+
+		if (error & FLASH_WRPERR)
+		{
+			LOG_ERROR("flash memory write protected");
+		}
+
+		if (error != 0)
+		{
+			LOG_ERROR("flash write failed = %08x", error);
+			/* Clear but report errors */
+			target_write_u32(target, STM32_FLASH_SR, error);
+			retval = ERROR_FAIL;
+			break;
+		}
+
+		buffer += thisrun_count * 2;
+		address += thisrun_count * 2;
+		count -= thisrun_count;
+	}
+
+	target_free_working_area(target, source);
+	target_free_working_area(target, stm32x_info->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, 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 */
+		if ((retval = stm32x_write_block(bank, buffer, offset, words_remaining)) != 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 void setup_sector(struct flash_bank *bank, int start, int num, int size)
+{
+	for (int i = start; i < (start + num) ; i++)
+	{
+		bank->sectors[i].offset = bank->size;
+		bank->sectors[i].size = size;
+		bank->size += bank->sectors[i].size;
+	}
+}
+
+static int stm32x_probe(struct flash_bank *bank)
+{
+	struct target *target = bank->target;
+	struct stm32x_flash_bank *stm32x_info = bank->driver_priv;
+	int i;
+	uint16_t num_pages;
+	uint32_t device_id;
+	uint32_t base_address = 0x08000000;
+
+	stm32x_info->probed = 0;
+
+	/* read stm32 device id register */
+	int retval = target_read_u32(target, 0xE0042000, &device_id);
+	if (retval != ERROR_OK)
+		return retval;
+	LOG_INFO("device id = 0x%08" PRIx32 "", device_id);
+
+	/* get flash size from target. */
+	retval = target_read_u16(target, 0x1FFFF7E0, &num_pages);
+	if (retval != ERROR_OK)
+	{
+		LOG_WARNING("failed reading flash size, default to max target family");
+		/* failed reading flash size, default to max target family */
+		num_pages = 0xffff;
+	}
+
+	if ((device_id & 0x7ff) != 0x411)
+	{
+		LOG_WARNING("Cannot identify target as a STM32 family, try the other STM32 drivers.");
+		return ERROR_FAIL;
+	}
+
+	/* sectors sizes vary, handle this in a different code path
+	 * than the rest.
+	 */
+	// Uhhh.... what to use here?
+
+	/* calculate numbers of pages*/
+	num_pages = 4 + 1 + 7;
+
+	if (bank->sectors)
+	{
+		free(bank->sectors);
+		bank->sectors = NULL;
+	}
+
+	bank->base = base_address;
+	bank->num_sectors = num_pages;
+	bank->sectors = malloc(sizeof(struct flash_sector) * num_pages);
+
+	bank->size = 0;
+	setup_sector(bank, 0, 4, 16 * 1024);
+	setup_sector(bank, 4, 1, 64 * 1024);
+	setup_sector(bank, 4+1, 7, 128 * 1024);
+
+	for (i = 0; i < num_pages; i++)
+	{
+		bank->sectors[i].is_erased = -1;
+		bank->sectors[i].is_protected = 0;
+	}
+
+	LOG_INFO("flash size = %dkBytes", bank->size / 1024);
+
+	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)
+{
+	struct target *target = bank->target;
+	uint32_t device_id;
+	int printed;
+
+	/* read stm32 device id register */
+	int retval = target_read_u32(target, 0xE0042000, &device_id);
+	if (retval != ERROR_OK)
+		return retval;
+
+	if ((device_id & 0x7ff) == 0x411)
+	{
+		printed = snprintf(buf, buf_size, "stm32x (1mByte part) - Rev: ");
+		buf += printed;
+		buf_size -= printed;
+
+		switch (device_id >> 16)
+		{
+			case 0x1000:
+				snprintf(buf, buf_size, "A");
+				break;
+
+			case 0x2000:
+				snprintf(buf, buf_size, "B");
+				break;
+
+			case 0x1001:
+				snprintf(buf, buf_size, "Z");
+				break;
+
+			default:
+				snprintf(buf, buf_size, "unknown");
+				break;
+		}
+	}
+	else
+	{
+		snprintf(buf, buf_size, "Cannot identify target as a stm32x\n");
+		return ERROR_FAIL;
+	}
+
+	return ERROR_OK;
+}
+
+static const struct command_registration stm32x_exec_command_handlers[] = {
+	COMMAND_REGISTRATION_DONE
+};
+
+static const struct command_registration stm32x_command_handlers[] = {
+	{
+		.name = "stm32f2xxx",
+		.mode = COMMAND_ANY,
+		.help = "stm32f2xxx flash command group",
+		.chain = stm32x_exec_command_handlers,
+	},
+	COMMAND_REGISTRATION_DONE
+};
+
+struct flash_driver stm32xf2xxx_flash = {
+	.name = "stm32f2xxx",
+	.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_mem_blank_check,
+	.protect_check = stm32x_protect_check,
+	.info = get_stm32x_info,
+};