Device Tree: Supporting Similar Boards – The BeagleBone Example

Most of the BeagleBone boards from BeagleBoard.org share the same form factor, have the same headers and therefore can accept the same extension boards, also known as capes in the BeagleBoard world. Of course, a careful PCB design was necessary to make this possible. This must have been relatively easy with the early models (BeagleBone Black, Black Wireless, Green, Green Wireless, Black Industrial and Enhanced) which are based on the same Sitara AM3358 System on Chip (SoC) from Texas Instruments. However, the more recent creation (2019) of the BeagleBone AI board and keeping compatibility with existing capes must have been … Continue reading Device Tree: Supporting Similar Boards – The BeagleBone Example

Using Device Tree Overlays, example on BeagleBone Cape add-on boards

The concept of Device Tree overlays The Device Tree language is a way to describe hardware that is present in a system and cannot be automatically detected. That’s the case of devices directly implemented on a System on a Chip, such as serial ports, Ethernet or Nand flash controllers. That’s also the case of devices connected to a number of buses, such as I2C and SPI, that do not provide mechanisms for dynamic enumeration and identification of devices. For a given CPU architecture (ARM, PowerPC, etc), such a description allows to have a unique kernel supporting many different systems with … Continue reading Using Device Tree Overlays, example on BeagleBone Cape add-on boards