Lubuntu 16.04 on ARM: Turning off the “Suspend” etc. options

In short On an embedded ARM-based Lubuntu 16.04, I had LXDE’s logoff dialog window offering suspend as an option, and when that was chosen, the system got itself into some nasty state with network and keyboard off. The serial console was still active, and yet, I was better off without it. It turned out that [...]

systemd random jots

As systemd seems to be here to stay (or at least I hope so), this is a post of random notes to self that I jot down as I explore it. It will probably grow with time, and become a mixture of basic issues and rather advanced stuff. Useful references man systemd.service and man systemd.unit [...]

A watchdog script for restarting Cinnamon hogging memory at startup

Introduction Having installed Linux Mint 18.1 (kernel 4.4.0-53) with overlayroot on a Gigabyte Brix BACE-3160 (see other notes on this here and here) for my living room media center, I had an issue with bringing up the computer every now and then. Namely, I had a blank screen with mouse pointer only, 100% CPU on [...]

systemd user services and Pulseaudio on Lubuntu 16.04

Introduction These are my notes as I made Pulseaudio work on an ARM v7-based Embedded Lubuntu 16.04, which doesn’t support Pulseaudio otherwise. The goal: On a mini-distribution based upon Lubuntu, for use of others, make Pulseaudio work even though the Lubuntu desktop won’t start it. In fact, it’s supposed to run even without any X [...]

The updated DVB-T channels in Israel

Background On November 1, 2017, the Israeli broadcast authorities split Channel 2 into two channels, 12 and 13. To avoid unfair competition with the other channels, as channel 2 might lose viewers due to the confusion, channel 10 was moved to 14 as well. This requires a rescan of DVB receivers. The changes are rather [...]

Gtkwave notes

General Gtkwave is a simple and convenient viewer of electronic waveforms. It’s a free software tool at its best: A bit rough to start working with, but after a while it becomes clear that the decisions have been made by someone who uses the tool himself. Really recommended. So here are my jumpstart notes for [...]

Fedora 12: Bringing keyboard autorepeat back

For some weird reason (actually, running an old Atari 800 emulator), my autorepeat was suddenly not working. On any window. That’s the moment one becomes aware of how often it’s used. Quick solution: $ xset r on and it was all fine again. Or $ xset q to see all settings.

Quartus/Linux: Setting PATH and environment for command-line

The classic way: $ export QUARTUS_ROOTDIR=/path/to/altera/15.1/quartus $ . $QUARTUS_ROOTDIR/adm/qenv.sh Or open a shell (will set path, but not a full environment): $ /path/to/altera/15.1/nios2eds/nios2_command_shell.sh This is good for compiling for NIOS etc.

Linux: Where the USB related kernel files are

A few notes on where to find USB related kernel files on a Linux system (kernel 3.12.20 in my case) $ lsusb [ ... ] Bus 001 Device 059: ID 046d:c52b Logitech, Inc. Now find the position in the tree. It should be device 59 under bus number 1: $ lsusb -t [ ... ] [...]

gcc: Solving “undefined reference” even when the required library is listed with -l

It worked all so nicely on my Fedora 12 machine, and then on Ubuntu 14.04.1 it failed colossally: $ make gcc -Wall  -O3 -g -lusb-1.0 -c  -o bulkread.o bulkread.c gcc -Wall  -O3 -g -lusb-1.0 -c  -o usberrors.o usberrors.c gcc -Wall  -O3 -g -lusb-1.0 bulkread.o usberrors.o -o bulkread bulkread.o: In function `main’: bulkread.c:39: undefined reference to [...]