Inconsistent behavior for Pi 5 rev 1.0 vs 1.1 when only libgpiod.so.3[.x.x] is installed

[voinokin]

Firmware code 0xD04171 (Pi 5 rev 1.1) is not mapped in RaspberryBoardInfo.GetBoardModel() and thus the argument-less GpioController constructor which invokes GetBestDriverForBoardOnLinux() falls back to UnixDriver.Create()

iot/src/System.Device.Gpio/System/Device/Gpio/GpioController.cs

Line 481 in 9c867ff

return UnixDriver.Create();

which tries to relatively safely auto-detect libgpiod version or to fall back to sysfs driver. So on Pi 5 rev 1.1 we have no crash when only libgpiod.so.3 is installed which is the case with some recent Pi OS images.

On the other hand, firmware code 0xD04170 (Pi 5 rev 1.0) is mapped so GetBestDriverForBoardOnLinux() tries to invoke

iot/src/System.Device.Gpio/System/Device/Gpio/GpioController.cs

Line 469 in 9c867ff

var chips = LibGpiodDriver.GetAvailableChips();

which leads to crash in absense of libgpiod.so.2.

Thus the same binary or image deployed on different Pi 5 revisions eventually behaves different ways.

Steps to reproduce
Invoke

_ = new GpioController();

on Pi 5 rev 1.0 and 1.1 separately on the same image.

We've used Raspberry Lite OS 64-bit image dated March 2026 which only contains these versions of libgpiod:

$ sudo find /usr/lib -name "*libgpiod*"
/usr/lib/aarch64-linux-gnu/libgpiodcxx.so.2.1.0
/usr/lib/aarch64-linux-gnu/libgpiod.so.3
/usr/lib/aarch64-linux-gnu/libgpiod.so.3.1.1
/usr/lib/aarch64-linux-gnu/libgpiodcxx.so.2

Expected behavior
The behavior should be consistent across Pi 5 revisions.

Actual behavior
Works on Pi 5 rev 1.1.
Crashes on Pi 5 rev 1.0 with the stack trace below:

kiosk[3790]: /home/user/app/libgpiod.so.2: cannot open shared object file: No such file or directory
kiosk[3790]: /home/user/app/liblibgpiod.so.2: cannot open shared object file: No such file or directory
kiosk[3790]: /home/user/app/libgpiod.so.2.so: cannot open shared object file: No such file or directory
kiosk[3790]: /home/user/app/liblibgpiod.so.2.so: cannot open shared object file: No such file or directory
kiosk[3790]:    at Interop.LibgpiodV1.gpiod_chip_iter_new()
kiosk[3790]:    at Interop.LibgpiodV1.gpiod_chip_iter_new()
kiosk[3790]:    at System.Device.Gpio.Drivers.LibGpiodDriver.GetAvailableChips()
kiosk[3790]:    at System.Device.Gpio.GpioController.GetBestDriverForBoardOnLinux()
kiosk[3790]:    at System.Device.Gpio.GpioController.GetBestDriverForBoard()
kiosk[3790]:    at System.Device.Gpio.GpioController..ctor()

Versions used
Checked with Iot.Device.Bindings and System.Device.Gpio versions 4.0.1 and 4.2.0.

dotnet --info on our WSL build machine:

.NET SDK:
 Version:           9.0.312
 Commit:            c45411d3fd
 Workload version:  9.0.300-manifests.d333777a
 MSBuild version:   17.14.43+2a0eb78b3

Runtime Environment:
 OS Name:     ubuntu
 OS Version:  22.04
 OS Platform: Linux
 RID:         linux-x64
 Base Path:   /home/.../.dotnet/sdk/9.0.312/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.14
  Architecture: x64
  Commit:       19c07820cb

.NET SDKs installed:
  9.0.312 [/home/.../.dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.14 [/home/.../.dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.14 [/home/.../.dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

dotnet --info on the machine where app is being run (not applicable for self-contained apps):
Not applicable

Version of System.Device.Gpio package: present in 4.0.1 and 4.2.0

[voinokin]

This workaround on Pi 5 works:

        var driver = UnixDriver.Create();
        var gpioController = new GpioController(driver);