+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
/***************************************************************************
* Copyright (C) 2013 by Paul Fertser, fercerpav@gmail.com *
* *
* Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
* Based on at91rm9200.c (c) Anders Larsen *
* and RPi GPIO examples by Gert van Loo & Dom *
- * *
- * 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
#endif
#include <jtag/interface.h>
+#include <transport/transport.h>
#include "bitbang.h"
#include <sys/mman.h>
#define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
static int dev_mem_fd;
-static volatile uint32_t *pio_base;
+static volatile uint32_t *pio_base = MAP_FAILED;
+static volatile uint32_t *pads_base = MAP_FAILED;
-static int bcm2835gpio_read(void);
-static void bcm2835gpio_write(int tck, int tms, int tdi);
-static void bcm2835gpio_reset(int trst, int srst);
+static bb_value_t bcm2835gpio_read(void);
+static int bcm2835gpio_write(int tck, int tms, int tdi);
static int bcm2835_swdio_read(void);
static void bcm2835_swdio_drive(bool is_output);
+static int bcm2835gpio_swd_write(int swclk, int swdio);
static int bcm2835gpio_init(void);
static int bcm2835gpio_quit(void);
static struct bitbang_interface bcm2835gpio_bitbang = {
.read = bcm2835gpio_read,
.write = bcm2835gpio_write,
- .reset = bcm2835gpio_reset,
.swdio_read = bcm2835_swdio_read,
.swdio_drive = bcm2835_swdio_drive,
+ .swd_write = bcm2835gpio_swd_write,
.blink = NULL
};
static int swclk_gpio_mode;
static int swdio_gpio = -1;
static int swdio_gpio_mode;
+static int swdio_dir_gpio = -1;
+static int swdio_dir_gpio_mode;
/* Transition delay coefficients */
static int speed_coeff = 113714;
static int speed_offset = 28;
static unsigned int jtag_delay;
-static int bcm2835gpio_read(void)
+static int is_gpio_valid(int gpio)
+{
+ return gpio >= 0 && gpio <= 31;
+}
+
+static bb_value_t bcm2835gpio_read(void)
{
- return !!(GPIO_LEV & 1<<tdo_gpio);
+ return (GPIO_LEV & 1<<tdo_gpio) ? BB_HIGH : BB_LOW;
}
-static void bcm2835gpio_write(int tck, int tms, int tdi)
+static int bcm2835gpio_write(int tck, int tms, int tdi)
{
uint32_t set = tck<<tck_gpio | tms<<tms_gpio | tdi<<tdi_gpio;
uint32_t clear = !tck<<tck_gpio | !tms<<tms_gpio | !tdi<<tdi_gpio;
for (unsigned int i = 0; i < jtag_delay; i++)
asm volatile ("");
+
+ return ERROR_OK;
}
-static void bcm2835gpio_swd_write(int tck, int tms, int tdi)
+static int bcm2835gpio_swd_write(int swclk, int swdio)
{
- uint32_t set = tck<<swclk_gpio | tdi<<swdio_gpio;
- uint32_t clear = !tck<<swclk_gpio | !tdi<<swdio_gpio;
+ uint32_t set = swclk << swclk_gpio | swdio << swdio_gpio;
+ uint32_t clear = !swclk << swclk_gpio | !swdio << swdio_gpio;
GPIO_SET = set;
GPIO_CLR = clear;
for (unsigned int i = 0; i < jtag_delay; i++)
asm volatile ("");
+
+ return ERROR_OK;
}
/* (1) assert or (0) deassert reset lines */
-static void bcm2835gpio_reset(int trst, int srst)
+static int bcm2835gpio_reset(int trst, int srst)
{
uint32_t set = 0;
uint32_t clear = 0;
- if (trst_gpio > 0) {
+ if (is_gpio_valid(trst_gpio)) {
set |= !trst<<trst_gpio;
clear |= trst<<trst_gpio;
}
- if (srst_gpio > 0) {
+ if (is_gpio_valid(srst_gpio)) {
set |= !srst<<srst_gpio;
clear |= srst<<srst_gpio;
}
GPIO_SET = set;
GPIO_CLR = clear;
+
+ return ERROR_OK;
}
static void bcm2835_swdio_drive(bool is_output)
{
- if (is_output)
- OUT_GPIO(swdio_gpio);
- else
- INP_GPIO(swdio_gpio);
+ if (is_gpio_valid(swdio_dir_gpio)) {
+ if (is_output) {
+ GPIO_SET = 1 << swdio_dir_gpio;
+ OUT_GPIO(swdio_gpio);
+ } else {
+ INP_GPIO(swdio_gpio);
+ GPIO_CLR = 1 << swdio_dir_gpio;
+ }
+ } else {
+ if (is_output)
+ OUT_GPIO(swdio_gpio);
+ else
+ INP_GPIO(swdio_gpio);
+ }
}
static int bcm2835_swdio_read(void)
return ERROR_OK;
}
-static int is_gpio_valid(int gpio)
-{
- return gpio >= 0 && gpio <= 53;
-}
-
COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)
{
if (CMD_ARGC == 4) {
return ERROR_COMMAND_SYNTAX_ERROR;
}
- command_print(CMD_CTX,
+ command_print(CMD,
"BCM2835 GPIO config: tck = %d, tms = %d, tdi = %d, tdo = %d",
tck_gpio, tms_gpio, tdi_gpio, tdo_gpio);
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tck_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: tck = %d", tck_gpio);
+ command_print(CMD, "BCM2835 GPIO config: tck = %d", tck_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tms_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: tms = %d", tms_gpio);
+ command_print(CMD, "BCM2835 GPIO config: tms = %d", tms_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdo_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
+ command_print(CMD, "BCM2835 GPIO config: tdo = %d", tdo_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], tdi_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
+ command_print(CMD, "BCM2835 GPIO config: tdi = %d", tdi_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], srst_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: srst = %d", srst_gpio);
+ command_print(CMD, "BCM2835 GPIO config: srst = %d", srst_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], trst_gpio);
- command_print(CMD_CTX, "BCM2835 GPIO config: trst = %d", trst_gpio);
+ command_print(CMD, "BCM2835 GPIO config: trst = %d", trst_gpio);
return ERROR_OK;
}
return ERROR_COMMAND_SYNTAX_ERROR;
}
- command_print(CMD_CTX,
+ command_print(CMD,
"BCM2835 GPIO nums: swclk = %d, swdio = %d",
swclk_gpio, swdio_gpio);
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swclk_gpio);
- command_print(CMD_CTX, "BCM2835 num: swclk = %d", swclk_gpio);
+ command_print(CMD, "BCM2835 num: swclk = %d", swclk_gpio);
return ERROR_OK;
}
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_gpio);
- command_print(CMD_CTX, "BCM2835 num: swdio = %d", swdio_gpio);
+ command_print(CMD, "BCM2835 num: swdio = %d", swdio_gpio);
+ return ERROR_OK;
+}
+
+COMMAND_HANDLER(bcm2835gpio_handle_swd_dir_gpionum_swdio)
+{
+ if (CMD_ARGC == 1)
+ COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], swdio_dir_gpio);
+
+ command_print(CMD, "BCM2835 num: swdio_dir = %d", swdio_dir_gpio);
return ERROR_OK;
}
COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
}
+
+ command_print(CMD, "BCM2835 GPIO: speed_coeffs = %d, speed_offset = %d",
+ speed_coeff, speed_offset);
return ERROR_OK;
}
{
if (CMD_ARGC == 1)
COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
+
+ command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
+ bcm2835_peri_base);
return ERROR_OK;
}
-static const struct command_registration bcm2835gpio_command_handlers[] = {
+static const struct command_registration bcm2835gpio_subcommand_handlers[] = {
{
- .name = "bcm2835gpio_jtag_nums",
+ .name = "jtag_nums",
.handler = &bcm2835gpio_handle_jtag_gpionums,
.mode = COMMAND_CONFIG,
.help = "gpio numbers for tck, tms, tdi, tdo. (in that order)",
- .usage = "(tck tms tdi tdo)* ",
+ .usage = "[tck tms tdi tdo]",
},
{
- .name = "bcm2835gpio_tck_num",
+ .name = "tck_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_tck,
.mode = COMMAND_CONFIG,
.help = "gpio number for tck.",
+ .usage = "[tck]",
},
{
- .name = "bcm2835gpio_tms_num",
+ .name = "tms_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_tms,
.mode = COMMAND_CONFIG,
.help = "gpio number for tms.",
+ .usage = "[tms]",
},
{
- .name = "bcm2835gpio_tdo_num",
+ .name = "tdo_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_tdo,
.mode = COMMAND_CONFIG,
.help = "gpio number for tdo.",
+ .usage = "[tdo]",
},
{
- .name = "bcm2835gpio_tdi_num",
+ .name = "tdi_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_tdi,
.mode = COMMAND_CONFIG,
.help = "gpio number for tdi.",
+ .usage = "[tdi]",
},
{
- .name = "bcm2835gpio_swd_nums",
+ .name = "swd_nums",
.handler = &bcm2835gpio_handle_swd_gpionums,
.mode = COMMAND_CONFIG,
.help = "gpio numbers for swclk, swdio. (in that order)",
- .usage = "(swclk swdio)* ",
+ .usage = "[swclk swdio]",
},
{
- .name = "bcm2835gpio_swclk_num",
+ .name = "swclk_num",
.handler = &bcm2835gpio_handle_swd_gpionum_swclk,
.mode = COMMAND_CONFIG,
.help = "gpio number for swclk.",
+ .usage = "[swclk]",
},
{
- .name = "bcm2835gpio_swdio_num",
+ .name = "swdio_num",
.handler = &bcm2835gpio_handle_swd_gpionum_swdio,
.mode = COMMAND_CONFIG,
.help = "gpio number for swdio.",
+ .usage = "[swdio]",
},
{
- .name = "bcm2835gpio_srst_num",
+ .name = "swdio_dir_num",
+ .handler = &bcm2835gpio_handle_swd_dir_gpionum_swdio,
+ .mode = COMMAND_CONFIG,
+ .help = "gpio number for swdio direction control pin (set=output mode, clear=input mode)",
+ .usage = "[swdio_dir]",
+ },
+ {
+ .name = "srst_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_srst,
.mode = COMMAND_CONFIG,
.help = "gpio number for srst.",
+ .usage = "[srst]",
},
{
- .name = "bcm2835gpio_trst_num",
+ .name = "trst_num",
.handler = &bcm2835gpio_handle_jtag_gpionum_trst,
.mode = COMMAND_CONFIG,
.help = "gpio number for trst.",
+ .usage = "[trst]",
},
{
- .name = "bcm2835gpio_speed_coeffs",
+ .name = "speed_coeffs",
.handler = &bcm2835gpio_handle_speed_coeffs,
.mode = COMMAND_CONFIG,
.help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
+ .usage = "[SPEED_COEFF SPEED_OFFSET]",
},
{
- .name = "bcm2835gpio_peripheral_base",
+ .name = "peripheral_base",
.handler = &bcm2835gpio_handle_peripheral_base,
.mode = COMMAND_CONFIG,
.help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
+ .usage = "[base]",
},
COMMAND_REGISTRATION_DONE
};
+static const struct command_registration bcm2835gpio_command_handlers[] = {
+ {
+ .name = "bcm2835gpio",
+ .mode = COMMAND_ANY,
+ .help = "perform bcm2835gpio management",
+ .chain = bcm2835gpio_subcommand_handlers,
+ .usage = "",
+ },
+ COMMAND_REGISTRATION_DONE
+};
+
static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
-struct jtag_interface bcm2835gpio_interface = {
- .name = "bcm2835gpio",
+static struct jtag_interface bcm2835gpio_interface = {
.supported = DEBUG_CAP_TMS_SEQ,
.execute_queue = bitbang_execute_queue,
+};
+
+struct adapter_driver bcm2835gpio_adapter_driver = {
+ .name = "bcm2835gpio",
.transports = bcm2835_transports,
- .swd = &bitbang_swd,
- .speed = bcm2835gpio_speed,
- .khz = bcm2835gpio_khz,
- .speed_div = bcm2835gpio_speed_div,
.commands = bcm2835gpio_command_handlers,
+
.init = bcm2835gpio_init,
.quit = bcm2835gpio_quit,
+ .reset = bcm2835gpio_reset,
+ .speed = bcm2835gpio_speed,
+ .khz = bcm2835gpio_khz,
+ .speed_div = bcm2835gpio_speed_div,
+
+ .jtag_ops = &bcm2835gpio_interface,
+ .swd_ops = &bitbang_swd,
};
static bool bcm2835gpio_jtag_mode_possible(void)
return 1;
}
+static void bcm2835gpio_munmap(void)
+{
+ if (pio_base != MAP_FAILED) {
+ munmap((void *)pio_base, sysconf(_SC_PAGE_SIZE));
+ pio_base = MAP_FAILED;
+ }
+
+ if (pads_base != MAP_FAILED) {
+ munmap((void *)pads_base, sysconf(_SC_PAGE_SIZE));
+ pads_base = MAP_FAILED;
+ }
+}
+
static int bcm2835gpio_init(void)
{
bitbang_interface = &bcm2835gpio_bitbang;
LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
- if (bcm2835gpio_jtag_mode_possible()) {
- if (bcm2835gpio_swd_mode_possible())
- LOG_INFO("JTAG and SWD modes enabled");
- else
- LOG_INFO("JTAG only mode enabled (specify swclk and swdio gpio to add SWD mode)");
- if (!is_gpio_valid(trst_gpio) && !is_gpio_valid(srst_gpio)) {
- LOG_ERROR("Require at least one of trst or srst gpios to be specified");
- return ERROR_JTAG_INIT_FAILED;
- }
- } else if (bcm2835gpio_swd_mode_possible()) {
- LOG_INFO("SWD only mode enabled (specify tck, tms, tdi and tdo gpios to add JTAG mode)");
- } else {
- LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode and/or swclk and swdio gpio for SWD mode");
+ if (transport_is_jtag() && !bcm2835gpio_jtag_mode_possible()) {
+ LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
return ERROR_JTAG_INIT_FAILED;
}
- dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+ if (transport_is_swd() && !bcm2835gpio_swd_mode_possible()) {
+ LOG_ERROR("Require swclk and swdio gpio for SWD mode");
+ return ERROR_JTAG_INIT_FAILED;
+ }
+
+ dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
+ if (dev_mem_fd < 0) {
+ LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
+ dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+ }
if (dev_mem_fd < 0) {
- perror("open");
+ LOG_ERROR("open: %s", strerror(errno));
return ERROR_JTAG_INIT_FAILED;
}
MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
if (pio_base == MAP_FAILED) {
- perror("mmap");
+ LOG_ERROR("mmap: %s", strerror(errno));
close(dev_mem_fd);
return ERROR_JTAG_INIT_FAILED;
}
- static volatile uint32_t *pads_base;
pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
if (pads_base == MAP_FAILED) {
- perror("mmap");
+ LOG_ERROR("mmap: %s", strerror(errno));
+ bcm2835gpio_munmap();
close(dev_mem_fd);
return ERROR_JTAG_INIT_FAILED;
}
- /* set 16mA drive strength */
- pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000018 + 7;
+ close(dev_mem_fd);
+
+ /* set 4mA drive strength, slew rate limited, hysteresis on */
+ pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
- tdo_gpio_mode = MODE_GPIO(tdo_gpio);
- tdi_gpio_mode = MODE_GPIO(tdi_gpio);
- tck_gpio_mode = MODE_GPIO(tck_gpio);
- tms_gpio_mode = MODE_GPIO(tms_gpio);
- swclk_gpio_mode = MODE_GPIO(swclk_gpio);
- swdio_gpio_mode = MODE_GPIO(swdio_gpio);
/*
* Configure TDO as an input, and TDI, TCK, TMS, TRST, SRST
* as outputs. Drive TDI and TCK low, and TMS/TRST/SRST high.
*/
- INP_GPIO(tdo_gpio);
-
- GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio | 1<<swdio_gpio | 1<<swclk_gpio;
- GPIO_SET = 1<<tms_gpio;
-
- OUT_GPIO(tdi_gpio);
- OUT_GPIO(tck_gpio);
- OUT_GPIO(tms_gpio);
- OUT_GPIO(swclk_gpio);
- OUT_GPIO(swdio_gpio);
- if (trst_gpio != -1) {
- trst_gpio_mode = MODE_GPIO(trst_gpio);
- GPIO_SET = 1 << trst_gpio;
- OUT_GPIO(trst_gpio);
+ if (transport_is_jtag()) {
+ tdo_gpio_mode = MODE_GPIO(tdo_gpio);
+ tdi_gpio_mode = MODE_GPIO(tdi_gpio);
+ tck_gpio_mode = MODE_GPIO(tck_gpio);
+ tms_gpio_mode = MODE_GPIO(tms_gpio);
+
+ INP_GPIO(tdo_gpio);
+
+ GPIO_CLR = 1<<tdi_gpio | 1<<tck_gpio;
+ GPIO_SET = 1<<tms_gpio;
+
+ OUT_GPIO(tdi_gpio);
+ OUT_GPIO(tck_gpio);
+ OUT_GPIO(tms_gpio);
+
+ if (is_gpio_valid(trst_gpio)) {
+ trst_gpio_mode = MODE_GPIO(trst_gpio);
+ GPIO_SET = 1 << trst_gpio;
+ OUT_GPIO(trst_gpio);
+ }
+ }
+
+ if (transport_is_swd()) {
+ /* Make buffer an output before the GPIO connected to it */
+ if (is_gpio_valid(swdio_dir_gpio)) {
+ swdio_dir_gpio_mode = MODE_GPIO(swdio_dir_gpio);
+ GPIO_SET = 1 << swdio_dir_gpio;
+ OUT_GPIO(swdio_dir_gpio);
+ }
+
+ swclk_gpio_mode = MODE_GPIO(swclk_gpio);
+ swdio_gpio_mode = MODE_GPIO(swdio_gpio);
+
+ GPIO_CLR = 1<<swdio_gpio | 1<<swclk_gpio;
+
+ OUT_GPIO(swclk_gpio);
+ OUT_GPIO(swdio_gpio);
}
- if (srst_gpio != -1) {
+
+ if (is_gpio_valid(srst_gpio)) {
srst_gpio_mode = MODE_GPIO(srst_gpio);
GPIO_SET = 1 << srst_gpio;
OUT_GPIO(srst_gpio);
"tdo %d trst %d srst %d", tck_gpio_mode, tms_gpio_mode,
tdi_gpio_mode, tdo_gpio_mode, trst_gpio_mode, srst_gpio_mode);
- if (swd_mode) {
- bcm2835gpio_bitbang.write = bcm2835gpio_swd_write;
- bitbang_switch_to_swd();
- }
-
return ERROR_OK;
}
static int bcm2835gpio_quit(void)
{
- SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
- SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
- SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
- SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
- SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
- SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
- if (trst_gpio != -1)
- SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
- if (srst_gpio != -1)
+ if (transport_is_jtag()) {
+ SET_MODE_GPIO(tdo_gpio, tdo_gpio_mode);
+ SET_MODE_GPIO(tdi_gpio, tdi_gpio_mode);
+ SET_MODE_GPIO(tck_gpio, tck_gpio_mode);
+ SET_MODE_GPIO(tms_gpio, tms_gpio_mode);
+ if (is_gpio_valid(trst_gpio))
+ SET_MODE_GPIO(trst_gpio, trst_gpio_mode);
+ }
+
+ if (transport_is_swd()) {
+ SET_MODE_GPIO(swclk_gpio, swclk_gpio_mode);
+ SET_MODE_GPIO(swdio_gpio, swdio_gpio_mode);
+ }
+
+ if (is_gpio_valid(srst_gpio))
SET_MODE_GPIO(srst_gpio, srst_gpio_mode);
+ if (is_gpio_valid(swdio_dir_gpio))
+ SET_MODE_GPIO(swdio_dir_gpio, swdio_dir_gpio_mode);
+
+ bcm2835gpio_munmap();
+
return ERROR_OK;
}
projects / fw / openocd / blobdiff