I'm not sure there is a one-stop shop for understanding the Device Tree anywhere.
There are at least 4 file types involved: 1. dts- This is the source code (text file) which is a data structure to describe hardware. 2. dtsi- A sub-chunk or "include" file which is used inside dts files. It's somewhat similar to an "include" or "import" in programming languages. 3. dtb- Device tree blob. This is the compiled version of the dts. This is what gets loaded at boot time. It's the foundation of the system used by the kernel. 4. dtbo- Device tree overlay. This can be loaded after boot time. This is how the Beaglebone adjusts itself when different "capes" are plugged in. It does this by reading information stored in the EEPROM in the cape. These "overlays" can also be loaded at the command line using the "slots" in the sysfs virtual file system. Look for a substantial collection of already done overlays in the directory /lib/firmware. If you want to make your own overlay, /lib/firmware is where you want to place it. This topic is really confusing, and no doubt my notes above are full of flaws. You can work through and understand all of the above. However, depending on the complexity of what you are trying to do, this may be sufficient: https://github.com/cdsteinkuehler/beaglebone-universal-io Using the config-pin -f option and a simple text file you can use your .profile or similar start-up configuration file to set the pins to your requirements. This is a relatively straight-forward solution to tacking the problem. In my opinion the device tree is a major hurdle to making progress with the Beaglebones. If you google you will get a bunch of out-dated information, so be careful what you read on the net. Perhaps someone will suggest single source of accurate information on this topic. Regards, Greg -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/2a565144-1715-4bc2-ae74-b6415a30dea1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
