Nerves-Project

Getting Started

These instructions assume that you have a BeagleBone. If not, see Buy a BeagleBone. After that, follow the instructions below:

  1. Install drivers on your host PC to be able to access the BeagleBone through USB. See the BeagleBone driver setup instructions.
  2. Download the latest MicroSD image from the project’s github download page.
  3. Unzip the image and copy it to the MicroSD card. The instructions vary depending on OS. On Linux, run sudo dd if=bbone-erlang-x.y.img of=/dev/sdX bs=128k where sdX is the MicroSD device. Some help can be found for Windows on the BeagleBone wiki.
  4. Insert the MicroSD card into the BeagleBone and boot.
  5. Log into the board via the console. Log in as root with password root.

Board Notes

Working on an embedded Linux board is different from working on a PC. The Erlang image for the BeagleBone is no exception. Below are some differences:

  1. The root filesystem is mounted read-only. This means that you can’t just update a file in /etc by just editing it. However, mounting the root filesystem read-only improves the robustness of the device through ungraceful shutdowns. For minor modifications, run mount -o remount,rw /, but be sure to modify the Buildroot configuration when making a change. This way, no changes are forgotten. If you need to write data to storage, write to the /mnt/user directory.
  2. Almost everything is done as root. While this isn’t necessary, many embedded Linux devices operate this way. When so much processing requires root privileges anyway in an embedded Linux system, it is just easier to log in as root. The default user exists in the image for clients who ssh into the BeagleBone.
  3. There is no package manager. This is true for Buildroot embedded Linux systems. Buildroot manages package selection through make menuconfig. While this may seem time consuming at first, the simplicity and repeatability of Buildroot are nice to have in a system. Plus the images are small since they contain very little unused code.