Linux + APC Smart UPS 750 notes (apcupsd and other stuff)

Introduction These are my somewhat messy jots while setting up an APC Smart UPS 750 (SMT750I) with a Linux Mint 19 machine, for a clean shutdown on power failure. Failures and mistakes shown as well. Even though I had issues with receiving a broken UPS at first, and waiting two months for a replacement (ridiculous [...]

Controlling GPIO on the Z-Turn Lite board with Xillinux

Introduction This post shows how to access some GPIO functionalities from Xillinux running on a Z-Turn Lite board (with an Z-turn Lite IO Cape board attached), directly from the command line. Watchdog When the “WD” jumper at J26 on the board is placed, it’s possible to utilize the board’s watchdog chip, which resets the processor [...]

Linux: When Vivado’s GUI doesn’t start with an error on locale

Trying to running Vivado 2017.3 with GUI and all on a remote host with X forwarding, i.e. $ ssh -X mycomputer setting the environment with $ . /path/to/Vivado/2017.3/ it failed with $ vivado & terminate called after throwing an instance of ‘std::runtime_error’ what(): locale::facet::_S_create_c_locale name not valid Now here’s the odd thing: The error message [...]

Nvidia graphics cards on Linux: PCIe link speed and width

Why is it at 2.5 GT/s??? With all said about Nvidia’s refusal to release their drivers as open source, their Linux support is great. I don’t think I’ve ever had such a flawless graphics card experience with Linux. After replacing the nouveau driver with Nvidia’s, of course. Ideology is nice, but a computer that works [...]

Quartus / Linux: Programming the FPGA with command-line

Command-line? Yes, it much more convenient than the GUI programmer. Programming an FPGA is a repeated task, always the same file to the same FPGA on the same board connected to the computer. And somehow the GUI programming tools turn it into a daunting ceremony (and sometimes even a quiz, when it can’t tell exactly [...]

Solved: netcat (nc) doesn’t terminate at end of transmission

Introduction I often use netcat to transmit chunks of data between two Linux machines. I usually go something like $ pv backup-image.iso | nc -l 1234 on one machine, and then maybe # nc 1234 > /dev/sdb1 This is an example for using another machine to write data into a USB disk-on-key, because writing [...]

Synplify Pro on Linux Mint 18.1: The cheat sheet

Introduction I needed to run Synplify Pro for a short trial period on my Fedora 12 machine (yup, it’s 2018, and still). And I have a full Mint 18.1 as a chroot jail on that machine for installing contemporary software. So these are my notes on the go. Consider everything below as run om Mint [...]

fetchmail, openssl and a sudden failure to authenticate certificates

Since around the beginning of December 2017, fetchmail stopped retrieving mails form Gmail servers silently, without issuing any kind of error message. Only when starting fetchmail in the foreground, I got fetchmail: Server certificate verification error: unable to get local issuer certificate fetchmail: This means that the root signing certificate (issued for /C=US/O=Google Trust Services/CN=Google [...]

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 [...]