This is an automated email from Gerrit.
"Tomas Vanek <van...@fbl.cz>" just uploaded a new patch set to Gerrit, which
you can find at https://review.openocd.org/c/openocd/+/7350
-- gerrit
commit 3b4c81c6c3f9f7ab41d1bada998884a49d988c2d
Author: Tomas Vanek <van...@fbl.cz>
Date: Tue Nov 15 09:47:43 2022 +0100
jtag/drivers/bcm2835gpio: deprecate /dev/mem access to GPIO control
Deprecate /dev/mem in favour of /dev/gpiomem.
/dev/gpiomem is available in Raspberry linux kernel since ~2016
and unlike /dev/mem doesn't require root access. Also it doesn't need
a peripheral base address.
However the pads configuration (slew rate, drive strength) requires
/dev/mem access, no way to set the pads with mapped /dev/gpiomem.
Without this change the driver code preferred /dev/gpiomem and if not
available falled back /dev/mem.
The pads were configured at a wrong memory address if gpiomem was mapped.
For the limited time until /dev/mem access is completely dropped
use 'bcm2835gpio peripheral_base' parameter to choose the memory
access device.
Without peripheral_base (or peripheral_base 0) use /dev/gpiomem
If a non-zero peripheral_base is configured, use /dev/mem
and issue a warning.
Disable the pads setting if the driver doesn't open /dev/mem.
While on it extend peripheral_base to uint64_t
Raspberry Pi 4 with 64-bit kernel and arm_peri_high=1 config.txt
parameter has peripheral_base 0x47e000000
Signed-off-by: Tomas Vanek <van...@fbl.cz>
Change-Id: I60e427bda795d7a13d55d61443590dd31d694832
diff --git a/doc/openocd.texi b/doc/openocd.texi
index e9f93614c9..ace4459074 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3301,10 +3301,17 @@ speed_coeff defaults to 113714, and speed_offset
defaults to 28.
@end deffn
@deffn {Config Command} {bcm2835gpio peripheral_base} @var{base}
-Set the peripheral base register address to access GPIOs. For the RPi1, use
-0x20000000. For RPi2 and RPi3, use 0x3F000000. For RPi4, use 0xFE000000. A full
-list can be found in the
+Deprecated.
+The peripheral base is no more necessary if GPIO registers are accessed
+through '/dev/gpiomem'.
+If you insist on '/dev/mem' access and don't mind the security risk,
+configure the peripheral base address and run openocd as root.
+For the RPi1, use 0x20000000. For RPi2 and RPi3, use 0x3F000000.
+For RPi4, use 0xFE000000 or 0x47E000000 if arm_peri_high=1.
+A full list can be found in the
@uref{https://www.raspberrypi.org/documentation/hardware/raspberrypi/peripheral_addresses.md,
official guide}.
+If the peripheral base is configured, GPIO 0-27 pads are set to the limited
+slew rate and drive strength is reduced to 4 mA (2 mA on RPi 4).
@end deffn
@end deffn
diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c
index 635d9a5ffc..54a54467f7 100644
--- a/src/jtag/drivers/bcm2835gpio.c
+++ b/src/jtag/drivers/bcm2835gpio.c
@@ -19,7 +19,7 @@
#include <sys/mman.h>
-uint32_t bcm2835_peri_base = 0x20000000;
+uint64_t bcm2835_peri_base;
#define BCM2835_GPIO_BASE (bcm2835_peri_base + 0x200000) /* GPIO
controller */
#define BCM2835_PADS_GPIO_0_27 (bcm2835_peri_base + 0x100000)
@@ -303,9 +303,9 @@ COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
{
if (CMD_ARGC == 1)
- COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
+ COMMAND_PARSE_NUMBER(u64, CMD_ARGV[0], bcm2835_peri_base);
- command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
+ command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08" PRIu64,
bcm2835_peri_base);
return ERROR_OK;
}
@@ -409,13 +409,19 @@ static int bcm2835gpio_init(void)
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");
+ if (bcm2835_peri_base) {
+ LOG_WARNING("Using /dev/mem is DEPRECATED!");
+ LOG_INFO("Remove 'bcm2835gpio peripheral_base' from your config
to use /dev/gpiomem");
+ LOG_INFO("/dev/gpiomem works without root access rights.");
+
dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
+ } else {
+ dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
}
if (dev_mem_fd < 0) {
LOG_ERROR("open: %s", strerror(errno));
+ if (!bcm2835_peri_base && errno == ENOENT)
+ LOG_INFO("If your kernel lacks '/dev/gpiomem' device,
please update OS.");
return ERROR_JTAG_INIT_FAILED;
}
@@ -428,21 +434,30 @@ static int bcm2835gpio_init(void)
return ERROR_JTAG_INIT_FAILED;
}
- pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
+ /* TODO: move pads config to a separate utility */
+ if (bcm2835_peri_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) {
- LOG_ERROR("mmap: %s", strerror(errno));
- bcm2835gpio_munmap();
- close(dev_mem_fd);
- return ERROR_JTAG_INIT_FAILED;
+ if (pads_base == MAP_FAILED) {
+ LOG_ERROR("mmap: %s", strerror(errno));
+ bcm2835gpio_munmap();
+ close(dev_mem_fd);
+ return ERROR_JTAG_INIT_FAILED;
+ }
+ } else {
+ pads_base = MAP_FAILED;
}
close(dev_mem_fd);
- /* set 4mA drive strength, slew rate limited, hysteresis on */
- initial_drive_strength_etc = pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] &
0x1f;
- pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
+ if (pads_base != MAP_FAILED) {
+ /* set 4mA drive strength, slew rate limited, hysteresis on */
+ initial_drive_strength_etc =
pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] & 0x1f;
+LOG_INFO("initial pads conf %08x", pads_base[BCM2835_PADS_GPIO_0_27_OFFSET]);
+ pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
+LOG_INFO("pads conf set to %08x", pads_base[BCM2835_PADS_GPIO_0_27_OFFSET]);
+ }
/* Configure JTAG/SWD signals. Default directions and initial states
are handled
* by adapter.c and "adapter gpio" command.
@@ -513,8 +528,10 @@ static int bcm2835gpio_quit(void)
restore_gpio(ADAPTER_GPIO_IDX_SRST);
restore_gpio(ADAPTER_GPIO_IDX_LED);
- /* Restore drive strength. MSB is password ("5A") */
- pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 |
initial_drive_strength_etc;
+ if (pads_base != MAP_FAILED) {
+ /* Restore drive strength. MSB is password ("5A") */
+ pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5A000000 |
initial_drive_strength_etc;
+ }
bcm2835gpio_munmap();
return ERROR_OK;
--
