Maintaining Your Stock BeagleBone Angstrom Images and Demos

In a previous news article, we described building and deploying the latest U-boot and Linux kernels on several armv7 machines, including a BeagleBoneBlack.

In this "HOWTO" we’ll talk about restoring/upgrading/maintaining your stock Angstrom install on both BeagleBone White and Black. Why would we do this? Several reasons, but typically to restore the default install or upgrade to the latest build. The nice thing about BeagleBoneBlack is that Angstrom lives on the eMMC and you can always boot whatever you need off the SDCard. Since BeagleBoneWhite only has an SDCard, you simply swap your default 4 GB card with Angstrom for another (possibly larger) card running your OS/Distro of choice. The two models have slightly different bleeding-edge patch sets and hardware interfaces, but otherwise are very similar:

Out of the Box

Depending on when it was produced/packaged, your BeagleBone will most likely come with one of the Angstrom builds for SDCard and/or eMMC install. There are some builds which are supposed to support both White and Black, as well as an SDCard image for "flashing" the eMMC on the Black. There are changes in both the Bone101/Cloud9 IDE and Gnome desktop config in the various builds so it’s probably worth it to try a couple of them (some seem to have a less optimal Cloud9 bonescript environment than others).

The recommended builds are given below, "latest" for Black, and a slightly older one for White (recommended for a good new user experience). Simply download the desired image, either from the archive or the latest link, and use the standard tools (dd or WinDiskImager) to uncomnpress and write the image to your SDCard device (be sure and select the .img file unless you want to manually create your card and deploy the rootfs, etc). Use the links above for the manual method, otherwise download one or more of the following images:

Note

The BeagleBoneWhite Rev A6 I received came with the above 2012.11.22 image on a 4 GB SDCard. The Bone101 slideshow is highly recommended for new users.

Although these kernels are fairly recent, they are several versions behind the latest kernel source (typically 3.10.x rather than 3.16.x) and do not yet support HDMI out. A future HOWTO will discuss building your own OS images with custom kernels, etc.

BeagleBoneWhite Cloud9 IDE and Bone101 Web Tutorial

One of the hardware differences on the White is a built-in USB serial converter on the mini-USB port, so as long as your desktop kernel (or other OS drivers) is configured properly, you should have a serial console as soon as you plug in the USB cable (use minicom or putty to connect at 115200,8N1, no flow control). However, even more interesting is the web server and Cloud9 IDE running on the network interface, which should configure itself if you have DHCP (if not you’ll need to configure it manually via the serial console (login as root with no password).

Download one of the Cloud9-IDE build images and write it to a card:

$ wget http://downloads.angstrom-distribution.org/demo/beaglebone/archive/Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.11.22.img.xz
$ xz -d Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.11.22.img.xz
$ sudo dd if=Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.11.22.img of=/dev/sdX bs=4M

(where sdX is your SDCard device)

Once your BeagleBoneWhite is on the network, use Avahi/Zeroconf or the serial console to discover the IP address, then point your browser at the IP address of your White (anything modern except IE should work). You should see the Bone101 introduction, which will introduce you to, and allow you to interact with, your new BBW. There are bonescript demos and hardware diagrams, including details on the board itself and all the pinouts. Click on the Cloud9 IDE link and try some of the demo scripts (note the BlinkLED demo calls out an external LED, but should also trigger the onboard USR3 LED).

BeagleBoneBlack eMMC Flashing Tool w/ Latest Cloud9 IDE and Documentation

In addition to the bootable micro-SDCard slot, the Black also has onboard eMMC flash (not technically true flash, but consider it like a faster and built-in SDCard). The Black should come out of the box with one of the recent builds listed above; if yours is older or corrupted and you’d like to update to the latest "official" build (including the latest Cloud9 IDE and documentation) then perform the following steps.

Download the latest Cloud9-IDE build image and write it to a card:

$ wget http://downloads.angstrom-distribution.org/demo/beaglebone/archive/BBB-eMMC-flasher-2013.09.07.img.xz
$ xz -d BBB-eMMC-flasher-2013.09.07.img.xz
$ sudo dd if=BBB-eMMC-flasher-2013.09.07.img.xz of=/dev/sdX bs=4M

(where sdX is your SDCard device)

Note

If your BeagleBoneBlack is a Rev C, it should have a 4 GB eMMC, and you can use one of the larger flash images.

Boot the Black with the new card and wait (you can connect a network cable if you like; this will allow you to login and check the status). Once the kernel loads, the LEDs will blink in their default config:

  • USR0 - blink in a heartbeat pattern
  • USR1 - light during microSD card accesses
  • USR2 - light during CPU activity
  • USR3 - light during eMMC accesses

The USR3 LED will (for the most part) stay lit while the flashing script does the formatting, unpacking, and configuration of the rootfs. When this process is finished, all 4 USR LEDs will light up solid. You can then power down and remove the card, then boot your new Angstrom install.

BeagleBone USB/Ethernet Network Configuration and Automation

Both Black and White BeagleBones default to DHCP for the ethernet interface, so the IP address will depend on your own local network setup. While the White has the serial console on the mini USB interface, the Black has the same port configured as a USB gadget interface. IF your kernel is properly configured, it should appear as 3 devices: an ethernet interface (either usb0 or ethX), an ACM tty device (/dev/ttyACM0), and a USB storage device. Check dmesg or the kernel log for something similar to this:

kernel: usb 2-6: new high-speed USB device number 5 using ehci-pci
kernel: usb 2-6: New USB device found, idVendor=1d6b, idProduct=0104
kernel: usb 2-6: New USB device strings: Mfr=2, Product=3, SerialNumber=4
kernel: usb 2-6: Product: BeagleBoneBlack
kernel: usb 2-6: Manufacturer: Circuitco
kernel: usb 2-6: SerialNumber: 6A-0314BBBK4860
kernel: usb-storage 2-6:1.4: USB Mass Storage device detected
kernel: scsi12 : usb-storage 2-6:1.4
mtp-probe: checking bus 2, device 5: "/sys/devices/pci0000:00/0000:00:13.2/usb2/2-6"
mtp-probe: bus: 2, device: 5 was not an MTP device
kernel: cfg80211: Calling CRDA to update world regulatory domain
kernel: usbcore: registered new interface driver cdc_ether
kernel: rndis_host 2-6:1.0 eth1: register 'rndis_host' at usb-0000:00:13.2-6, RNDIS device, 90:59:af:68:74:cf
kernel: usbcore: registered new interface driver rndis_host
kernel: usbcore: registered new interface driver rndis_wlan
kernel: cdc_acm 2-6:1.2: This device cannot do calls on its own. It is not a modem.
kernel: cdc_acm 2-6:1.2: ttyACM0: USB ACM device
kernel: usbcore: registered new interface driver cdc_acm
kernel: cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
kernel: cfg80211: World regulatory domain updated:
kernel: cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
kernel: cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm)
kernel: cfg80211:   (2457000 KHz - 2482000 KHz @ 40000 KHz), (N/A, 2000 mBm)
kernel: cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm)
kernel: cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz), (N/A, 2000 mBm)
kernel: cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm)
kernel: cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm)
kernel: ip_tables: (C) 2000-2006 Netfilter Core Team
kernel: nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
kernel: scsi 12:0:0:0: Direct-Access     Linux    File-CD Gadget   0308 PQ: 0 ANSI: 2
kernel: sd 12:0:0:0: [sdb] 144522 512-byte logical blocks: (73.9 MB/70.5 MiB)
kernel: sd 12:0:0:0: [sdb] Write Protect is off
kernel: sd 12:0:0:0: [sdb] Mode Sense: 0f 00 00 00
kernel: sd 12:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

The gadget ethernet device can be configured just like any other, whether manually, with a script, or your distro’s config tools. The latter is recommended; for example on Gentoo you can add a new config file in /etc/conf.d for the ethernet interface (eth1 in this example). You must also allow network hotplugging in rc.conf (or /etc/conf.d/rc if your system is old). The default IP address on the Black side of gadget ethernet is 192.168.7.2, and will assign 192.168.7.1 to the desktop side if left to DHCP (here we hard-code a static address since this is a local subnet).

From /etc/rc.conf:

# This allows all services to be hotplugged
rc_hotplug="*"

And /etc/conf.d/net.eth1:

config_eth1="192.168.7.1 netmask 255.255.255.0 brd 192.168.7.255"
routes_eth1="default via 192.168.7.1"

preup() {
iptables -A POSTROUTING -t nat -j MASQUERADE -s 192.168.7.0/24
echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -P FORWARD ACCEPT
return 0
}

postdown() {
echo 0 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -F
return 0
}

It’s also possible to use a udev rule or manual script instead, but I prefer the network-config approach best. The above configuration should configure everything automatically on the host side when the Black USB cable is plugged in. Now you can browse the web interface over the BeagleBone gadget ethernet (just point your browser to 192.168.7.2).

Default BeagleBone USBNet Config Missing DNS Servers and Default Route

If you’re logged in remotely to your BeagleBone over the USB ethernet connection, you might notice there’s only a host route and the default DNS server is the loopback address. If you want your BeagleBone to see outside the local subnet, then you’ll need to add a default route:

# route add default gw 192.168.7.1

You can do this permanently by editing the default dhcp udev rule. You’ll need to edit /etc/udev/rules.d/udhcpd.rules and change this:

SUBSYSTEM=="net",ACTION=="add",KERNEL=="usb0",RUN+="/sbin/ifconfig usb0 192.168.7.2 netmask 255.255.255.252",RUN+="/bin/systemctl start udhcpd.service"

to this:

SUBSYSTEM=="net",ACTION=="add",KERNEL=="usb0",RUN+="/sbin/ifconfig usb0 192.168.7.2 netmask 255.255.255.252",RUN+="/sbin/route add default gw 192.168.7.1",RUN+="/bin/systemctl start udhcpd.service"

and then add your preferred DNS servers to /etc/resolv.conf.