CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Mon, 20 Jul 2026 17:10:42 -0000

wird nicht mit kopiert - sorry:
PermittedPath.0=/dev/i2c
PermittedPath.1=/dev/spidev
PermittedPath.2=/sys/class/gpio/
PermittedPath.3=/dev/gpiochip

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Mon, 20 Jul 2026 17:09:11 -0000

Problem gefunden und erledigt => in CODESYSControl_User.cfg ergänzt:
[CmpCharDevice]
PermittedPath.0=/dev/i2c
PermittedPath.1=/dev/spidev
PermittedPath.2=/sys/class/gpio/
PermittedPath.3=/dev/gpiochip

Dann funktioniert es wieder
Gruß
Karl Schuler

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Mon, 20 Jul 2026 12:58:05 -0000

Noch eine Info dazu:
als Version der Pi MC SL wird mir 4.21.0.0 angezeigt.
In der log steht jedoch für IoDrvGPIO: 4.17.0.0
was ist das Problem?

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Mon, 20 Jul 2026 11:16:20 -0000

Hallo Herr Schwellinger - Danke für die Info. Der Fehler besteht weiterhin:
Follow-up: Rootless mode is not the cause here — verified with ps aux, the runtime binary runs as root:

root 1974 48.9 0.7 854852 62140 ? SLl 13:00 0:04 /opt/codesys/bin/codesyscontrol.bin /etc/codesyscontrol/CODESYSControl.cfg

gpioinfo gpiochip0 as root also works flawlessly (all 54 lines listed correctly, no permission errors at the kernel level). So the block is happening purely inside CmpCharDevice's own sandboxing, not at the Linux/kernel permission level and not due to a dedicated unprivileged user. The correct config key to whitelist /dev/gpiochip0 for CmpCharDevice is still what I'm looking for.

Im Voraus herzlichen Dank für Ihre Hilfe
Karl Schuler

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Mon, 20 Jul 2026 11:16:15 -0000

Hallo Herr Schwellinger - Danke für die Info. Der Fehler besteht weiterhin:
Follow-up: Rootless mode is not the cause here — verified with ps aux, the runtime binary runs as root:

root 1974 48.9 0.7 854852 62140 ? SLl 13:00 0:04 /opt/codesys/bin/codesyscontrol.bin /etc/codesyscontrol/CODESYSControl.cfg

Im Voraus herzlichen Dank für Ihre Hilfe
Karl Schuler

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

eschwellinger — Sun, 19 Jul 2026 11:20:52 -0000

this is probably:
https://content.helpme-codesys.com/en/CODESYS%20Control/_rtsl_linux_dedicated_user.html
..switch back from rootless mode due GPIO will not work.

CmpCharDevice blocks gpiochip access on Raspberry Pi 5 since update from SP18 to SP21

charly29160 — Sun, 19 Jul 2026 09:55:12 -0000

Hi,
after updating CODESYS Control for Raspberry Pi SL from patch level 18 to 21 (currently 4.21.0.0), the IoDrvGPIO driver ("GPIOs B+/Pi2") can no longer open any GPIO chip on a Raspberry Pi 5. Log output on login:

Could not open GPIOChip0.
Access to path /dev/gpiochip0 not allowed. Add /dev/gpiochip0 to permitted paths in configuration file if required
Could not open GPIOChip4. Trying to open GPIOChip0
Access to path /dev/gpiochip4 not allowed. Add /dev/gpiochip4 to permitted paths in configuration file if required
Could not open any GPIOChip.

System details:
Raspberry Pi 5, 32-bit Raspberry Pi OS (armv7l), kernel 6.12.47+rpt-rpi
gpiodetect correctly shows gpiochip0 [pinctrl-rp1] (54 lines) as the RP1 GPIO controller
Runtime: CODESYS Control for Raspberry Pi SL 4.21.0.0, Runtime Toolkit SP21+

This worked without issues before the update to SP21. I've tried adding the following to CODESYSControl_User.cfg without success:
ini[CmpCharDevice]
Linux.DevicePath.1=/dev/gpiochip0
Linux.DevicePath.2=/dev/gpiochip4
Could you tell me the correct section/key to whitelist /dev/gpiochip0 (and /dev/gpiochip4) for CmpCharDevice? I suspect this is part of the general security hardening introduced around SP21 (similar to ForceIecFilePath for SysFile, or the new Gateway "accept local clients only" default), but I couldn't find it documented anywhere.
Thanks in advance!

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