Unable to Access and Export GPIOs on BeagleBone Black with Yocto Kirkstone

General Discussion
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With the Yocto Kirkstone release and recent kernel updates, GPIO control on BeagleBoard devices like the BeagleBone Black has officially transitioned from the older sysfs interface to the gpiod (General Purpose Input/Output Daemon) interface. This change aligns with the deprecation of sysfs for GPIO, which is now largely unsupported and no longer maintained in new Linux kernels.

Why the Change? The sysfs interface for GPIO has been marked as deprecated for some time due to limitations in efficiency and scalability, especially as GPIO demands have evolved. The gpiod library, introduced as a modern alternative, provides several advantages:

  • Improved Performance: gpiod operations are generally faster, as they avoid the indirect file-system interaction used in sysfs.
  • Better Support for Complex GPIO Management: With tools like gpiodset and gpioget, gpiod supports multi-pin handling, debounce settings, and edge detection.
  • Standardized Interface: gpiod offers a more uniform interface for GPIO across various boards, making code more portable.

How to Use gpiod for GPIO on BeagleBoard Using gpiod is straightforward with commands that map closely to common GPIO tasks:

  • Read a GPIO Pin: gpioget gpiochip0 <pin_number>
  • Set a GPIO Pin: gpiodset gpiochip0 <pin_number> 1 (for HIGH) or 0 (for LOW)

For developers who previously relied on sysfs commands, the transition can involve only minor code adjustments to start using gpiod. There’s also the libgpiod C library if you’re integrating GPIO control directly in your applications.

Getting Started If you’re setting up your BeagleBoard with Yocto, adding gpiod is as simple as including it in your recipe with IMAGE_INSTALL_append = " libgpiod". You can then access GPIO functionality through the command line or integrate it directly into your applications using libgpiod.

For Developers and Contributors This transition represents a big step toward future-proofing GPIO management on Linux. While sysfs may still work on legacy systems, gpiod is now the preferred and supported path forward. Feel free to share your experiences and tips on the BeagleBoard forums to help other developers make a smooth transition.