Using a picoLCD 256×64 on OpenBSD 4.7

Bit of hacking to get the picoLCD working on OpenBSD

Posted on Thu, 12 Jan 2012 12:00:00 MST by Aaron Bieber

Tags: OpenBSD

The first thing you will notice if you connect your fancy picoLCD 256×64 to your OpenBSD box, is that it shows up as a Human Interface Device.

Unfortunately libusb doesn’t know what to do with devices on bsd systems that are NOT using the ugen driver:

 464     if (strncmp(di.udi_devnames[0], "ugen", 4) != 0)
 465       /* best not to play with things we don't understand */
 466       continue;

Fine libusb! We will have to come up with another way to use this screen! OR! We could tell OpenBSD to use ugen when ever it sees the lcd! :D

To do that – you need the the OpenBSD source, knowledge of how to build Open’s kernel, and my patch! Getting the source is beyond the scope of this little post.. so you will have to rtfm that action.

cd to the usb source directory: cd /usr/src/sys/dev/usb
Download the patch ( md5: 85e7498826635c612ede672f5e295e7a ): picoLCD256x64.patch
Apply said patch: patch -p1 < picoLCD256x64.patch
pkg_add libusb
Compile your kernel, install and reboot!
Once you are running your freshly compiled kernel, download the lcd4linux-256×64 source from http://picolcd.com/drivers/ . Apply this patch ( md5: 3852103e3e5a13a3cd6b0c49389688f6 ): lcd4linux-256×64.patch, compile ( You will have to play around with the plugins as some of them use linux’s proc fs and are not compatible with OpenBSD ).

Now check out the sample config files and have fun!

Notes

Using a picoLCD 256×64 on OpenBSD 4.7