2017-01-04

Got a chance to play with the Beagle Board. Installed the latest Debian Jessie IoT image[1]. Supposed to be an alternative distribution that removes all of the GUI stuff which sounds perfect for this project since all that this BBB is going to do is sit in a closet and pretend it’s a PLC. It’s certainly much more svelte than the default distribution with X11 and what not, but it’s still bloated in my opinion. Do we really need ‘systemd’, ‘dnsmasq’, ‘connman’, and etc. on an embedded platform. Seems like unnecessary cruft to me. So I deleted them all.

Took a bit of button pushing, but I managed to get rid of most of systemd and migrate to a system V init system. This [2] guide was very helpful in the process. Some things are still a bit lumpy; the power button doesn’t work and I can’t get /opt/scripts/boot/am335x_evm.sh to run on startup to save my life. But, it boots up, sucks down an IP address via DHCP and you can get in via ssh.

After deleting all of the javascript nonsense and other bloat here’s the final storage usage:

Filesystem	Size	Used	Avail	Use%	Mounted on
udev		10M	0	10M	0%	/dev
tmpfs		49M	124K	49M	1%	/run
/dev/mmcblk1p1	3.5G	1.3G	2.0G	39%	/
tmpfs		5.0M	4.0K	5.0M	1%	/run/lock
tmpfs		98M	0	98M	0%	/run/shm

And here is before:

Filesystem Size Used Avail Use% Mounted on
udev 10M 0 10M 0% /dev
tmpfs 49M 124K 49M 1% /run
/dev/mmcblk1p1 3.5G 1.5G 1.8G 45% /
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 98M 0 98M 0% /run/shm

Freed up 200MB of space. Not terrible.

Next step will be to setup some blinking lights to represent relay outputs and to build a 4-20 ma simulator so that I can simulate my sensor inputs without laying out the cash.

1 — https://debian.beagleboard.org/images/bone-debian-8.6-iot-armhf-2016-12-09-4gb.img.xz

2 — http://without-systemd.org/wiki/index.php/How_to_remove_systemd_from_a_Debian_jessie/sid_installation

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