Arch Linux ARM currently includes an unpatched version of dtc (device tree compiler) which lacks the “@” option. If you want to enable additional UARTs, SPI, I2C, or just use GPIO without recompiling the bootloader, you need a patched version of dtc. You can download the source code and manually patch/compile, but to make this process easier I created a PKGBUILD which builds a patched version of dtc from git. Grab the raw PKGBUILD after the break, or just run packer to install from the AUR:

packer -S dtc-git-patched

Make sure you don’t have the vanilla version of dtc installed, pacman will throw “file exists on filesystem” errors if it’s already installed from the standard repository.

After installing dtc you can easily mux pins with the flattened device tree. For more information on muxing pins and enabling UARTs, check out the hipstercircuits guide.

Read more »