I’ll quote my current boss’s boss’s boss when he asked a question of me:
@inetknght, can you please not write a book? I need a quick answer
I’ll quote my current boss’s boss’s boss when he asked a question of me:
@inetknght, can you please not write a book? I need a quick answer
https://en.wikipedia.org/wiki/Serial_console
tl;dr:
Serial ports are (for example) commonly RS-232, although other types of ports exist. Imagine it to be a very slow Ethernet device. Because it’s so slow (and the technology predates Ethernet and also has different requirements), it’s usually attached directly to a device instead of to a network. But you could connect a modem to it and it becomes connected to a network device.
It could also be connected to a system console device. These are commonly called terminals. Such devices are often monochrome (especially older ones) because a serial connection is often bandwidth limited (eg, measured in kilobits per second instead of megabits or gigabits). Since it’s so slow, it’s not practical for video, so it’s generally just text-only.
Note that your GPU might also output a system console but rendered on your display at very high resolution and with graphics-drawing capabilities. So a system console would be any console that connects to the system.
What is a console? Well, Wikipedia presents several valid articles and the common theme as far as computers go is that a “console” is typically something that a human and a computer use to interact with each other.
For serial consoles, you might find device files for them at /dev/tty*
. But for general serial devices, it could be any of several different types of device files.
Wikipedia’s article on /dev
devices has a pretty decent listing of what kinds of devices you might find and several of them might be classified as a serial port. Any serial port might be connected to a serial console.
So in my case, a serial console is:
That’s pretty much it in a nutshell. Then
grub
configuration to enable a serial console on the attached USB-to-serial device file and saves changes, then unmounts failing system partitionscreen
(oh wow those were some old days)To be fair, a lot of that complexity could have been done by either reinstalling, or removing the hard drive and attaching it to another computer. But doing it this way allowed me to poke around and try different ways of solving the issue, rebooting, etc. It was a learning experience worth exploring.
It was years ago though and I think there was some complication with trying to understand what device file (or device number or something) needed to be to work on the correct serial device (there are often multiple)
have an nvidia GPU
have Fedora
download RPM package of drivers for Red Hat (after all, Fedora and Red Hat are… compatible, right?)
Everything goes fine
Six months later, upgrade to a new version of Fedora
oops, kernel panic at boot after the upgrade, and no video to troubleshoot after UEFI boot
figure out how to boot into a recovery partition from UEFI
figure out how to enable a serial console over a USB device
figure out how to connect to the serial console from another computer using another USB device
figure out what the kernel panic is from (not the upgrade, but the driver which wasn’t upgraded)
figure out how to uninstall the incorrectly installed driver
figure out how to install the correct driver
That was a fun three week OS upgrade.
I’m honestly on Torvalds’ side here.
Tabs are a necessary part of the tooling and configuration files. Any tool which doesn’t properly handle files that are correctly formatted for other tools is… a broken tool.
grep -oP ' *'
oops no tabs
cut -d ' ' -f 3
oops no tabs
I have had to un-teach dumb things that people learn from Windows.
A menu item to run a GUI program as root it is indeed a rather absurd scenario. It suggests that you want to violate the admin/user barrier which is intended to be difficult to surpass except in certain circumstances.
There can be a lot of things under the hood that are necessary to run a GUI program as root depending on whether you’re using X11 or Wayland or something more esoteric. It’s doable though.
But instead of doing that, why not just learn how to use the command line? Every administrative task can be done via the command line, but not every administrative task has a GUI counterpart. So you’re going to need to learn to use the command line sooner or later.
and would not include it in the main repo
Tests that verify behavior at run time belong elsewhere
The test blobs belong in whatever repository they’re used.
It’s comically dumb to think that a repository won’t include tests. So binary blobs like this absolutely do belong in the repository.
Disabling a systemd service won’t prevent it from starting. For example, if another service depends on it then it will start anyway.
You have to mask the service which redirects the service files to /dev/null
so that the service effectively has zero directives.
systemctl mask --now snapd
It also means that anything which depends on snapd will likely fail. That is absolutely an improvement since we obviously don’t want anything that depends on snaps.
As someone who’s written pipelines who do exactly that on Windows, macOS, Linux across x86_64, aarch64, and MIPS, with optimized, unoptimized, instrumented for ASAN, instrumented for TSAN, and instrumented for coverage, and does it all in a distributed containerized workflow… It’s not as easy as it sounds. Honestly macOS is way more of a hassle to deal with than Linux.
Unless you need ROS. ROS is utter garbage. ROS is popular in robots. ROS is, unlike its name, not actually an operating system but rather a system of tools and utilities which do not follow any standards and certainly not the OS standards. I literally hate ROS. I would burn that shit to the ground and rebuild-the-world if I had the time to.