Recently I dug up an old BeagleBone Black and a 4DCAPE-70T LCD cape from 4d Systems. Apparently, I bought both back in 2014. So I figured it would be a great side project to get this decade old, fully open-hardware, single-board computer running again.
Who knows, maybe later I'll put it all into some sort of enclosure or case and have myself a portable electronics development computer. BeagleBone Black comes with a ton of pins, both digital and analog, which makes it much more versatile than Raspberry Pi.
Upon further research, it turned out that latest official OS images for that board are Debian 11.7 in IoT and Xfce spins. While it is still maintained, and will keep receiving security updates until 2026, I figured I wanted something newer. Specifically, current stable Debian version 12 (Bookworm). A minimal image is also desirable, as the board comes with only 4GB eMMC on-board storage, a whopping 500MB of RAM and ARM Cortex-A8 single core processor with max 1GHz clock rate. I don't really need a DE/WM, IDEs and other stuff the stock BeableBone Black images usually come with. Luckily there's a minimal image of Debian 12 for the board here.
Unfortunately, the LCD cape does not work with Debian 12 image out of the box, since it requires the bb-cape-overlays package. Which isn't available in Debian 12 anymore. In this first part of the BeableBone Black post series I'll be focusing on getting that to work. The steps to do so are:
If you don't have (or care) about the LCD cape, some stuff below might still be useful to you.
bone refers to commands that have to be entered on the BeagleBone.
host refers to commands that have to be entered on the computer you're connecting the BeagleBone to.
$ is for commands that can be run as a normal user.
# is for commands that have to be run as root (or sudo).
It's possible to just boot from the micro SD card every time. In which case there's nothing special you have to do. Just insert the SD card and start the board. However, I prefer to have the OS on built-in eMMC and then use the SD card slot for swappable extra storage for whatever I want.
Download the Debain 12.4 minimal eMMC flasher image either through the browser or the terminal. Don't forget the sha256sum file in order to make sure the file isn't corrupt.
host$ cd ~/Downloads
host$ curl -O https://rcn-ee.com/rootfs/release/2024-01-06/bookworm-minimal-armhf/am335x-eMMC-flasher-debian-12.4-minimal-armhf-2024-01-06-2gb.img.xz
host$ curl -O https://rcn-ee.com/rootfs/release/2024-01-06/bookworm-minimal-armhf/am335x-eMMC-flasher-debian-12.4-minimal-armhf-2024-01-06-2gb.img.xz.sha256sum
host$ cat am335x-eMMC-flasher-debian-12.4-minimal-armhf-2024-01-06-2gb.img.xz.sha256sum | sha256sum -cFormat the micro SD card, if necessary. Write image to micro SD card. Double-clicking on .img.xz file will open Gnome Disks (safest). Alternatively, find the inserted SD card with fdisk, extract with unxz and write to the card with dd.
host$ fdisk -lWill be something like /dev/sdc1 or /dev/mmcblk0. Likely at the very bottom. Let's say it's /dev/sdc.
host$ unxz am335x-eMMC-flasher-debian-12.4-minimal-armhf-2024-01-06-2gb.img.xz
host# dd if=am335x-eMMC-flasher-debian-12.4-minimal-armhf-2024-01-06-2gb.img.xz of=/dev/sdc1 bs=1MInsert SD card into the slot on the board, hold USR button (next to the USB-A port), power on the BeableBone. The system light will start bouncing back and forth. Wait for flashing lights to stop, then remove the micro SD card. Now reboot the board by re-plugging it in or pushing the POWER button.
Connect the board to your computer using the mini USB port. Assuming you already booted up the board, you can look through the system journal to see when the board was connected.
host$ journalctl | grep -A 5 BeagleBoardYou'll see something along the lines of kernel: cdc_acm 1-10:1.2: ttyACM0: USB ACM device. This means your board is on /tty/ttyACM0.
Connect to the card with picocom or screen. You might have to wait a few minutes for the board to boot up and become available.
host$ picocom -b 115200 -f h /dev/ttyACM0OR
host$ screen -U /dev/ttyACM0 115200You will be presented with a login prompt. Default username: debian, default password: temppwd.
You might want to change the default username and hostname, but expecially consider changing the default password. To do so, on the BeagleBoard run passwd
Ethernet is pretty much plug and play. But you'll have to access your router interface and find which IP is given to the BeagleBone by DHCP. Only then can you ssh into it.
Wi-Fi requires a USB dongle as well as some setup and configuration with wpa_supplicant. Just like Ethernet it will require access to the router to be able to use ssh.
Another option is passing your internet connection through USB. This too requires some configuration but since you should already have access to the BeagleBone using serial through USB (described in the previous section). This option makes the most sense. At least initially. You can switch to Ethernet or Wi-Fi after this.
Access the BeagleBone. Once you're logged in, double check the usb interface.
bone$ ip addrYou should see a usb0 section with something like this in it:
inet 192.168.7.2 netmask 255.255.255.252
This is the USB network interface you have to use.
Ping the host to make sure that it works.
bone$ ping -c 3 192.168.7.1You should get no packet loss. If you do, there's something seriously wrong.
Set up DNS. You can use either Google's (8.8.8.8 and 8.8.4.4), CloudFlare's (1.1.1.1) or any other service you want.
bone# vi /etc/resolv.confAdd:
nameserver 8.8.8.8
nameserver 8.8.4.4Save and quit.
Setup up static networking for the usb0 interface.
bone# vi /etc/network/interfaces.d/usb0Add:
iface usb0 inet static
address 192.168.7.2
netmask 255.255.255.252
network 192.168.7.0
gateway 192.168.7.1
dns-nameservers 8.8.8.8
dns-nameservers 8.8.4.4Save and quit.
Add the host computer as default gateway in the routing table. You'll have to do this after every boot.
bone# route add default gw 192.168.7.1Now you have to set up the firewall rules on host machine. You'll have to do this after every reboot of the host computer. You could apply these iptables rules, or write a script to do this automatically. But honestly, if you're setting up the LCD cape, you won't need to connect to the host through USB to interact with the BeagleBone, all you need is a keyboard. Alternatively, you can either plug in an Ethernet cable or connect to WiFi (more on that later) and just ssh into the board.
Another reason to avoid internet through USB is that for some reason NTP doesn't work when passing the connection to BeagleBone through the USB. More on that in the next section.
Anyway, figure out which interface you use to connect to the internet.
host$ ip addrThere should be a section that looks something like enp3s0 (Ethernet) or wlp4s0 (Wi-Fi). Lets say it's enp3s0.
host# iptables --table nat --append POSTROUTING --out-interface enp3s0 -j MASQUERADE
host# iptables --append FORWARD --in-interface enp3s0 -j ACCEPTMake sure ip forwarding is turned on:
host$ cat /proc/sys/net/ipv4/ip_forwardIf it returns 1, then it's on, if not then:
host# echo 1 > /proc/sys/net/ipv4/ip_forwardBack to the board, ping something to make sure networking works.
bone$ ping www.google.comThe image is old and the hardware clock will probably be wildly wrong if the board has been off for a log time (years in my case). This will prevent you from updating. As I mentioned before, NTP (using systemd-timesyncd) will not work for some reason when connecting to the internet through USB. I have no idea why and I couldn't figure it out. So, I used a different method.
Check the time just to see how bad it is:
bone$ dateTemporarily set the timezone to GMT, since we'll get accurate time from an external server and it will almost always be in GMT.
bone# timedatectl set-timezone GMTGet accurate time from the response headers of an external server. Most external servers will work, I'm using Google as an example.
bone# date -s "$(curl -s --head http://google.com | grep ^Date: | tr -d '\r\n' | sed 's/Date: //g')"Check the time again with date, if it's correct, you can switch to your actual timezone, if you want.
bone$ timedatectl list-timezones
bone# timedatectl set-timezone US/EasternCheck hardware clock, it's probably completely wrong too. Sync it to the system clock.
bone# hwclock -r
bone# hwclock --systohcNow you can update as normal.
bone# apt update && apt upgradeYour kernel was very likely updated, so you might want to reboot too.
bone# rebootThen reconnect and log back into the BeableBone.
The 4DCAPE-70T LCD cape I have was supported out of the box on older Debian releases with bb-cape-overlays package, but for some reason that package isn't in Debian 12 repos anymore.
Make sure it's actually absent both from the system and repos.
bone# beagle-version | grep bb-cape-overlays
WARNING:pkg:[bb-cape-overlays]:[NOT_INSTALLED]
bone$ apt search bb-cape-overlaysOnly choice now is to install from source. Luckily it's available on github
bone$ cd /opt/source
bone$ git clone https://github.com/beagleboard/bb.org-overlays
bone$ cd bb.org-overlays/
bone$ ./dtc-overlay.sh
bone$ ./install.sh
bone# rebootThe LCD should come to life. Now you don't have to use the serial connection through USB to interact with the board. All you have to do is connect a keyboard to the USB port and you're good to go.