ft2232_spi.c - flashprog - Gitiles

 /*
  * This file is part of the flashrom project.
  *
  * Copyright (C) 2009 Paul Fox <pgf@laptop.org>
  * Copyright (C) 2009, 2010 Carl-Daniel Hailfinger
  *
  * 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; version 2 of the License.
  *
  * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */

 #if CONFIG_FT2232_SPI == 1

 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include "flash.h"
 #include "chipdrivers.h"
 #include "programmer.h"
 #include "spi.h"
 #include <ftdi.h>

 #define FTDI_VID		0x0403
 #define FTDI_FT2232H_PID	0x6010
 #define FTDI_FT4232H_PID	0x6011
 #define AMONTEC_JTAGKEY_PID	0xCFF8

 const struct usbdev_status devs_ft2232spi[] = {
 	{FTDI_VID, FTDI_FT2232H_PID, OK, "FTDI", "FT2232H"},
 	{FTDI_VID, FTDI_FT4232H_PID, OK, "FTDI", "FT4232H"},
 	{FTDI_VID, AMONTEC_JTAGKEY_PID, OK, "Amontec", "JTAGkey"},
 	{},
 };

 /*
  * The 'H' chips can run internally at either 12MHz or 60MHz.
  * The non-H chips can only run at 12MHz.
  */
 #define CLOCK_5X 1

 /*
  * In either case, the divisor is a simple integer clock divider.
  * If CLOCK_5X is set, this divisor divides 30MHz, else it divides 6MHz.
  */
 #define DIVIDE_BY 3  /* e.g. '3' will give either 10MHz or 2MHz SPI clock. */

 #define BITMODE_BITBANG_NORMAL	1
 #define BITMODE_BITBANG_SPI	2

 /* Set data bits low-byte command:
  *  value: 0x08  CS=high, DI=low, DO=low, SK=low
  *    dir: 0x0b  CS=output, DI=input, DO=output, SK=output
  *
  * JTAGkey(2) needs to enable its output via Bit4 / GPIOL0
  *  value: 0x18  OE=high, CS=high, DI=low, DO=low, SK=low
  *    dir: 0x1b  OE=output, CS=output, DI=input, DO=output, SK=output
  */
 static uint8_t cs_bits = 0x08;
 static uint8_t pindir = 0x0b;
 static struct ftdi_context ftdic_context;

 static const char *get_ft2232_devicename(int ft2232_vid, int ft2232_type)
 {
 	int i;
 	for (i = 0; devs_ft2232spi[i].vendor_name != NULL; i++) {
 		if ((devs_ft2232spi[i].device_id == ft2232_type)
 			&& (devs_ft2232spi[i].vendor_id == ft2232_vid))
 				return devs_ft2232spi[i].device_name;
 	}
 	return "unknown device";
 }

 static const char *get_ft2232_vendorname(int ft2232_vid, int ft2232_type)
 {
 	int i;
 	for (i = 0; devs_ft2232spi[i].vendor_name != NULL; i++) {
 		if ((devs_ft2232spi[i].device_id == ft2232_type)
 			&& (devs_ft2232spi[i].vendor_id == ft2232_vid))
 				return devs_ft2232spi[i].vendor_name;
 	}
 	return "unknown vendor";
 }

 static int send_buf(struct ftdi_context *ftdic, const unsigned char *buf,
 		    int size)
 {
 	int r;
 	r = ftdi_write_data(ftdic, (unsigned char *) buf, size);
 	if (r < 0) {
 		msg_perr("ftdi_write_data: %d, %s\n", r,
 				ftdi_get_error_string(ftdic));
 		return 1;
 	}
 	return 0;
 }

 static int get_buf(struct ftdi_context *ftdic, const unsigned char *buf,
 		   int size)
 {
 	int r;
 	r = ftdi_read_data(ftdic, (unsigned char *) buf, size);
 	if (r < 0) {
 		msg_perr("ftdi_read_data: %d, %s\n", r,
 				ftdi_get_error_string(ftdic));
 		return 1;
 	}
 	return 0;
 }

 int ft2232_spi_init(void)
 {
 	int f;
 	struct ftdi_context *ftdic = &ftdic_context;
 	unsigned char buf[512];
 	int ft2232_vid = FTDI_VID;
 	int ft2232_type = FTDI_FT4232H_PID;
 	enum ftdi_interface ft2232_interface = INTERFACE_B;
 	char *arg;

 	arg = extract_programmer_param("type");
 	if (arg) {
 		if (!strcasecmp(arg, "2232H"))
 			ft2232_type = FTDI_FT2232H_PID;
 		else if (!strcasecmp(arg, "4232H"))
 			ft2232_type = FTDI_FT4232H_PID;
 		else if (!strcasecmp(arg, "jtagkey")) {
 			ft2232_type = AMONTEC_JTAGKEY_PID;
 			ft2232_interface = INTERFACE_A;
 			cs_bits = 0x18;
 			pindir = 0x1b;
 		}
 		else {
 			msg_perr("Error: Invalid device type specified.\n");
 			free(arg);
 			return 1;
 		}
 	}
 	free(arg);
 	arg = extract_programmer_param("port");
 	if (arg) {
 		switch (toupper(*arg)) {
 		case 'A':
 			ft2232_interface = INTERFACE_A;
 			break;
 		case 'B':
 			ft2232_interface = INTERFACE_B;
 			break;
 		default:
 			msg_perr("Error: Invalid port/interface specified.\n");
 			free(arg);
 			return 1;
 		}
 	}
 	free(arg);
 	msg_pdbg("Using device type %s %s ",
 		 get_ft2232_vendorname(ft2232_vid, ft2232_type),
 		 get_ft2232_devicename(ft2232_vid, ft2232_type));
 	msg_pdbg("interface %s\n",
 		 (ft2232_interface == INTERFACE_A) ? "A" : "B");

 	if (ftdi_init(ftdic) < 0) {
 		msg_perr("ftdi_init failed\n");
 		return EXIT_FAILURE; // TODO
 	}

 	f = ftdi_usb_open(ftdic, FTDI_VID, ft2232_type);

 	if (f < 0 && f != -5) {
 		msg_perr("Unable to open FTDI device: %d (%s)\n", f,
 				ftdi_get_error_string(ftdic));
 		exit(-1); // TODO
 	}

 	if (ftdi_set_interface(ftdic, ft2232_interface) < 0) {
 		msg_perr("Unable to select interface: %s\n",
 				ftdic->error_str);
 	}

 	if (ftdi_usb_reset(ftdic) < 0) {
 		msg_perr("Unable to reset FTDI device\n");
 	}

 	if (ftdi_set_latency_timer(ftdic, 2) < 0) {
 		msg_perr("Unable to set latency timer\n");
 	}

 	if (ftdi_write_data_set_chunksize(ftdic, 512)) {
 		msg_perr("Unable to set chunk size\n");
 	}

 	if (ftdi_set_bitmode(ftdic, 0x00, BITMODE_BITBANG_SPI) < 0) {
 		msg_perr("Unable to set bitmode to SPI\n");
 	}

 #if CLOCK_5X
 	msg_pdbg("Disable divide-by-5 front stage\n");
 	buf[0] = 0x8a;		/* Disable divide-by-5. */
 	if (send_buf(ftdic, buf, 1))
 		return -1;
 #define MPSSE_CLK 60.0

 #else

 #define MPSSE_CLK 12.0

 #endif
 	msg_pdbg("Set clock divisor\n");
 	buf[0] = 0x86;		/* command "set divisor" */
 	/* valueL/valueH are (desired_divisor - 1) */
 	buf[1] = (DIVIDE_BY - 1) & 0xff;
 	buf[2] = ((DIVIDE_BY - 1) >> 8) & 0xff;
 	if (send_buf(ftdic, buf, 3))
 		return -1;

 	msg_pdbg("SPI clock is %fMHz\n",
 		 (double)(MPSSE_CLK / (((DIVIDE_BY - 1) + 1) * 2)));

 	/* Disconnect TDI/DO to TDO/DI for loopback. */
 	msg_pdbg("No loopback of TDI/DO TDO/DI\n");
 	buf[0] = 0x85;
 	if (send_buf(ftdic, buf, 1))
 		return -1;

 	msg_pdbg("Set data bits\n");
 	buf[0] = SET_BITS_LOW;
 	buf[1] = cs_bits;
 	buf[2] = pindir;
 	if (send_buf(ftdic, buf, 3))
 		return -1;

 	// msg_pdbg("\nft2232 chosen\n");

 	buses_supported = CHIP_BUSTYPE_SPI;
 	spi_controller = SPI_CONTROLLER_FT2232;

 	return 0;
 }

 int ft2232_spi_send_command(unsigned int writecnt, unsigned int readcnt,
 		const unsigned char *writearr, unsigned char *readarr)
 {
 	struct ftdi_context *ftdic = &ftdic_context;
 	static unsigned char *buf = NULL;
 	/* failed is special. We use bitwise ops, but it is essentially bool. */
 	int i = 0, ret = 0, failed = 0;
 	int bufsize;
 	static int oldbufsize = 0;

 	if (writecnt > 65536 || readcnt > 65536)
 		return SPI_INVALID_LENGTH;

 	/* buf is not used for the response from the chip. */
 	bufsize = max(writecnt + 9, 260 + 9);
 	/* Never shrink. realloc() calls are expensive. */
 	if (bufsize > oldbufsize) {
 		buf = realloc(buf, bufsize);
 		if (!buf) {
 			msg_perr("Out of memory!\n");
 			exit(1);
 		}
 		oldbufsize = bufsize;
 	}

 	/*
 	 * Minimize USB transfers by packing as many commands as possible
 	 * together. If we're not expecting to read, we can assert CS#, write,
 	 * and deassert CS# all in one shot. If reading, we do three separate
 	 * operations.
 	 */
 	msg_pspew("Assert CS#\n");
 	buf[i++] = SET_BITS_LOW;
 	buf[i++] = 0 & ~cs_bits; /* assertive */
 	buf[i++] = pindir;

 	if (writecnt) {
 		buf[i++] = 0x11;
 		buf[i++] = (writecnt - 1) & 0xff;
 		buf[i++] = ((writecnt - 1) >> 8) & 0xff;
 		memcpy(buf + i, writearr, writecnt);
 		i += writecnt;
 	}

 	/*
 	 * Optionally terminate this batch of commands with a
 	 * read command, then do the fetch of the results.
 	 */
 	if (readcnt) {
 		buf[i++] = 0x20;
 		buf[i++] = (readcnt - 1) & 0xff;
 		buf[i++] = ((readcnt - 1) >> 8) & 0xff;
 		ret = send_buf(ftdic, buf, i);
 		failed = ret;
 		/* We can't abort here, we still have to deassert CS#. */
 		if (ret)
 			msg_perr("send_buf failed before read: %i\n",
 				ret);
 		i = 0;
 		if (ret == 0) {
 			/*
 			 * FIXME: This is unreliable. There's no guarantee that
 			 * we read the response directly after sending the read
 			 * command. We may be scheduled out etc.
 			 */
 			ret = get_buf(ftdic, readarr, readcnt);
 			failed |= ret;
 			/* We can't abort here either. */
 			if (ret)
 				msg_perr("get_buf failed: %i\n", ret);
 		}
 	}

 	msg_pspew("De-assert CS#\n");
 	buf[i++] = SET_BITS_LOW;
 	buf[i++] = cs_bits;
 	buf[i++] = pindir;
 	ret = send_buf(ftdic, buf, i);
 	failed |= ret;
 	if (ret)
 		msg_perr("send_buf failed at end: %i\n", ret);

 	return failed ? -1 : 0;
 }

 int ft2232_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len)
 {
 	/* Maximum read length is 64k bytes. */
 	return spi_read_chunked(flash, buf, start, len, 64 * 1024);
 }

 int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len)
 {
 	return spi_write_chunked(flash, buf, start, len, 256);
 }

 void print_supported_usbdevs(const struct usbdev_status *devs)
 {
 	int i;

 	for (i = 0; devs[i].vendor_name != NULL; i++) {
 		msg_pinfo("%s %s [%04x:%04x]%s\n", devs[i].vendor_name,
 			  devs[i].device_name, devs[i].vendor_id,
 			  devs[i].device_id,
 			  (devs[i].status == NT) ? " (untested)" : "");
 	}
 }

 #endif
	/*
	* This file is part of the flashrom project.
	*
	* Copyright (C) 2009 Paul Fox <pgf@laptop.org>
	* Copyright (C) 2009, 2010 Carl-Daniel Hailfinger
	*
	* 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; version 2 of the License.
	*
	* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#if CONFIG_FT2232_SPI == 1

	#include <stdio.h>
	#include <stdint.h>
	#include <string.h>
	#include <stdlib.h>
	#include <ctype.h>
	#include "flash.h"
	#include "chipdrivers.h"
	#include "programmer.h"
	#include "spi.h"
	#include <ftdi.h>

	#define FTDI_VID 0x0403
	#define FTDI_FT2232H_PID 0x6010
	#define FTDI_FT4232H_PID 0x6011
	#define AMONTEC_JTAGKEY_PID 0xCFF8

	const struct usbdev_status devs_ft2232spi[] = {
	{FTDI_VID, FTDI_FT2232H_PID, OK, "FTDI", "FT2232H"},
	{FTDI_VID, FTDI_FT4232H_PID, OK, "FTDI", "FT4232H"},
	{FTDI_VID, AMONTEC_JTAGKEY_PID, OK, "Amontec", "JTAGkey"},
	{},
	};

	/*
	* The 'H' chips can run internally at either 12MHz or 60MHz.
	* The non-H chips can only run at 12MHz.
	*/
	#define CLOCK_5X 1

	/*
	* In either case, the divisor is a simple integer clock divider.
	* If CLOCK_5X is set, this divisor divides 30MHz, else it divides 6MHz.
	*/
	#define DIVIDE_BY 3 /* e.g. '3' will give either 10MHz or 2MHz SPI clock. */

	#define BITMODE_BITBANG_NORMAL 1
	#define BITMODE_BITBANG_SPI 2

	/* Set data bits low-byte command:
	* value: 0x08 CS=high, DI=low, DO=low, SK=low
	* dir: 0x0b CS=output, DI=input, DO=output, SK=output
	*
	* JTAGkey(2) needs to enable its output via Bit4 / GPIOL0
	* value: 0x18 OE=high, CS=high, DI=low, DO=low, SK=low
	* dir: 0x1b OE=output, CS=output, DI=input, DO=output, SK=output
	*/
	static uint8_t cs_bits = 0x08;
	static uint8_t pindir = 0x0b;
	static struct ftdi_context ftdic_context;

	static const char *get_ft2232_devicename(int ft2232_vid, int ft2232_type)
	{
	int i;
	for (i = 0; devs_ft2232spi[i].vendor_name != NULL; i++) {
	if ((devs_ft2232spi[i].device_id == ft2232_type)
	&& (devs_ft2232spi[i].vendor_id == ft2232_vid))
	return devs_ft2232spi[i].device_name;
	}
	return "unknown device";
	}

	static const char *get_ft2232_vendorname(int ft2232_vid, int ft2232_type)
	{
	int i;
	for (i = 0; devs_ft2232spi[i].vendor_name != NULL; i++) {
	if ((devs_ft2232spi[i].device_id == ft2232_type)
	&& (devs_ft2232spi[i].vendor_id == ft2232_vid))
	return devs_ft2232spi[i].vendor_name;
	}
	return "unknown vendor";
	}

	static int send_buf(struct ftdi_context ftdic, const unsigned char buf,
	int size)
	{
	int r;
	r = ftdi_write_data(ftdic, (unsigned char *) buf, size);
	if (r < 0) {
	msg_perr("ftdi_write_data: %d, %s\n", r,
	ftdi_get_error_string(ftdic));
	return 1;
	}
	return 0;
	}

	static int get_buf(struct ftdi_context ftdic, const unsigned char buf,
	int size)
	{
	int r;
	r = ftdi_read_data(ftdic, (unsigned char *) buf, size);
	if (r < 0) {
	msg_perr("ftdi_read_data: %d, %s\n", r,
	ftdi_get_error_string(ftdic));
	return 1;
	}
	return 0;
	}

	int ft2232_spi_init(void)
	{
	int f;
	struct ftdi_context *ftdic = &ftdic_context;
	unsigned char buf[512];
	int ft2232_vid = FTDI_VID;
	int ft2232_type = FTDI_FT4232H_PID;
	enum ftdi_interface ft2232_interface = INTERFACE_B;
	char *arg;

	arg = extract_programmer_param("type");
	if (arg) {
	if (!strcasecmp(arg, "2232H"))
	ft2232_type = FTDI_FT2232H_PID;
	else if (!strcasecmp(arg, "4232H"))
	ft2232_type = FTDI_FT4232H_PID;
	else if (!strcasecmp(arg, "jtagkey")) {
	ft2232_type = AMONTEC_JTAGKEY_PID;
	ft2232_interface = INTERFACE_A;
	cs_bits = 0x18;
	pindir = 0x1b;
	}
	else {
	msg_perr("Error: Invalid device type specified.\n");
	free(arg);
	return 1;
	}
	}
	free(arg);
	arg = extract_programmer_param("port");
	if (arg) {
	switch (toupper(*arg)) {
	case 'A':
	ft2232_interface = INTERFACE_A;
	break;
	case 'B':
	ft2232_interface = INTERFACE_B;
	break;
	default:
	msg_perr("Error: Invalid port/interface specified.\n");
	free(arg);
	return 1;
	}
	}
	free(arg);
	msg_pdbg("Using device type %s %s ",
	get_ft2232_vendorname(ft2232_vid, ft2232_type),
	get_ft2232_devicename(ft2232_vid, ft2232_type));
	msg_pdbg("interface %s\n",
	(ft2232_interface == INTERFACE_A) ? "A" : "B");

	if (ftdi_init(ftdic) < 0) {
	msg_perr("ftdi_init failed\n");
	return EXIT_FAILURE; // TODO
	}

	f = ftdi_usb_open(ftdic, FTDI_VID, ft2232_type);

	if (f < 0 && f != -5) {
	msg_perr("Unable to open FTDI device: %d (%s)\n", f,
	ftdi_get_error_string(ftdic));
	exit(-1); // TODO
	}

	if (ftdi_set_interface(ftdic, ft2232_interface) < 0) {
	msg_perr("Unable to select interface: %s\n",
	ftdic->error_str);
	}

	if (ftdi_usb_reset(ftdic) < 0) {
	msg_perr("Unable to reset FTDI device\n");
	}

	if (ftdi_set_latency_timer(ftdic, 2) < 0) {
	msg_perr("Unable to set latency timer\n");
	}

	if (ftdi_write_data_set_chunksize(ftdic, 512)) {
	msg_perr("Unable to set chunk size\n");
	}

	if (ftdi_set_bitmode(ftdic, 0x00, BITMODE_BITBANG_SPI) < 0) {
	msg_perr("Unable to set bitmode to SPI\n");
	}

	#if CLOCK_5X
	msg_pdbg("Disable divide-by-5 front stage\n");
	buf[0] = 0x8a; /* Disable divide-by-5. */
	if (send_buf(ftdic, buf, 1))
	return -1;
	#define MPSSE_CLK 60.0

	#else

	#define MPSSE_CLK 12.0

	#endif
	msg_pdbg("Set clock divisor\n");
	buf[0] = 0x86; /* command "set divisor" */
	/* valueL/valueH are (desired_divisor - 1) */
	buf[1] = (DIVIDE_BY - 1) & 0xff;
	buf[2] = ((DIVIDE_BY - 1) >> 8) & 0xff;
	if (send_buf(ftdic, buf, 3))
	return -1;

	msg_pdbg("SPI clock is %fMHz\n",
	(double)(MPSSE_CLK / (((DIVIDE_BY - 1) + 1) * 2)));

	/* Disconnect TDI/DO to TDO/DI for loopback. */
	msg_pdbg("No loopback of TDI/DO TDO/DI\n");
	buf[0] = 0x85;
	if (send_buf(ftdic, buf, 1))
	return -1;

	msg_pdbg("Set data bits\n");
	buf[0] = SET_BITS_LOW;
	buf[1] = cs_bits;
	buf[2] = pindir;
	if (send_buf(ftdic, buf, 3))
	return -1;

	// msg_pdbg("\nft2232 chosen\n");

	buses_supported = CHIP_BUSTYPE_SPI;
	spi_controller = SPI_CONTROLLER_FT2232;

	return 0;
	}

	int ft2232_spi_send_command(unsigned int writecnt, unsigned int readcnt,
	const unsigned char writearr, unsigned char readarr)
	{
	struct ftdi_context *ftdic = &ftdic_context;
	static unsigned char *buf = NULL;
	/* failed is special. We use bitwise ops, but it is essentially bool. */
	int i = 0, ret = 0, failed = 0;
	int bufsize;
	static int oldbufsize = 0;

	if (writecnt > 65536 \|\| readcnt > 65536)
	return SPI_INVALID_LENGTH;

	/* buf is not used for the response from the chip. */
	bufsize = max(writecnt + 9, 260 + 9);
	/* Never shrink. realloc() calls are expensive. */
	if (bufsize > oldbufsize) {
	buf = realloc(buf, bufsize);
	if (!buf) {
	msg_perr("Out of memory!\n");
	exit(1);
	}
	oldbufsize = bufsize;
	}

	/*
	* Minimize USB transfers by packing as many commands as possible
	* together. If we're not expecting to read, we can assert CS#, write,
	* and deassert CS# all in one shot. If reading, we do three separate
	* operations.
	*/
	msg_pspew("Assert CS#\n");
	buf[i++] = SET_BITS_LOW;
	buf[i++] = 0 & ~cs_bits; /* assertive */
	buf[i++] = pindir;

	if (writecnt) {
	buf[i++] = 0x11;
	buf[i++] = (writecnt - 1) & 0xff;
	buf[i++] = ((writecnt - 1) >> 8) & 0xff;
	memcpy(buf + i, writearr, writecnt);
	i += writecnt;
	}

	/*
	* Optionally terminate this batch of commands with a
	* read command, then do the fetch of the results.
	*/
	if (readcnt) {
	buf[i++] = 0x20;
	buf[i++] = (readcnt - 1) & 0xff;
	buf[i++] = ((readcnt - 1) >> 8) & 0xff;
	ret = send_buf(ftdic, buf, i);
	failed = ret;
	/* We can't abort here, we still have to deassert CS#. */
	if (ret)
	msg_perr("send_buf failed before read: %i\n",
	ret);
	i = 0;
	if (ret == 0) {
	/*
	* FIXME: This is unreliable. There's no guarantee that
	* we read the response directly after sending the read
	* command. We may be scheduled out etc.
	*/
	ret = get_buf(ftdic, readarr, readcnt);
	failed \|= ret;
	/* We can't abort here either. */
	if (ret)
	msg_perr("get_buf failed: %i\n", ret);
	}
	}

	msg_pspew("De-assert CS#\n");
	buf[i++] = SET_BITS_LOW;
	buf[i++] = cs_bits;
	buf[i++] = pindir;
	ret = send_buf(ftdic, buf, i);
	failed \|= ret;
	if (ret)
	msg_perr("send_buf failed at end: %i\n", ret);

	return failed ? -1 : 0;
	}

	int ft2232_spi_read(struct flashchip flash, uint8_t buf, int start, int len)
	{
	/* Maximum read length is 64k bytes. */
	return spi_read_chunked(flash, buf, start, len, 64 * 1024);
	}

	int ft2232_spi_write_256(struct flashchip flash, uint8_t buf, int start, int len)
	{
	return spi_write_chunked(flash, buf, start, len, 256);
	}

	void print_supported_usbdevs(const struct usbdev_status *devs)
	{
	int i;

	for (i = 0; devs[i].vendor_name != NULL; i++) {
	msg_pinfo("%s %s [%04x:%04x]%s\n", devs[i].vendor_name,
	devs[i].device_name, devs[i].vendor_id,
	devs[i].device_id,
	(devs[i].status == NT) ? " (untested)" : "");
	}
	}

	#endif