Levinux, a Small Linux Distro without GUI for Education

by Mike Levin

Sunday, May 29, 2022

In this post, I answer the following questions:

…and then go off on a complete tangent, fixing an obscure little issue in my distribution of Linux called Levinux.

I have a Linux of my own.
My name is Mike Levinux.
It’s not a distro I have grown
So much as a respinux!

—Mike Levin, 2022

  1. Can I teach myself Linux? Yes!
  2. How long will it take to learn Linux? About 5 minutes.
  3. Is Linux hard for beginners? No, not with an open mind.
  4. Can you learn Linux for free? Yes.

But Not in This Article. This Is Not Even a Levinux Lesson.

This article is me rambling on forever about all the profoundly cool stuff that went into this still applicable today timeless fossil of a learning-piece for those taking up Unix and Linux (collectively known as *nix) operating systems. For a lighter overview, may I suggest:

But by all means, continue.

Face your FEAR OF HEADLESS SERVERS with this ~20MB Virtual Linux w/ Python, vim & git. Stick your hand in the *nix gom jabbar with a double-click from the desktop of your Mac, Windows or Linux PC.

Now Onto Some Truly Geeky *nix Talk

Genuinely new Linux distros are actually few in number, or at least mainstream popularity (plenty of tire-kickers) because it’s not easy building Linux from source and actually adding value in a way that’s of interest and use to the public. There are a few and the two king-of-the-hills are (as of the time I last cared to research):

A Few From-Scratch Linux Distros

You know, this list really probably goes on a bit. Maybe genuine Linux distros are few in number versus the nearly infinite second-order derivatives like Ubuntu. But I’ve hit some of my favorite high-points. There’s others mixed in and some are even surprisingly popular Unix versions, one you’re running right now and don’t even know it.

The Invisible Hands Reaching Into Your Intel-PC Right Now

Minix in particular is of interest to me. I looked at basing Levinux on that back in the day. Intel had been baking it into your processors since around 2008. I didn’t start looking for the beating heart of Levinux until around 2012 or so, when my kid was 2 years old and I realized I needed a sort of “Noah’s Arc” for my work. Looking around, I found and fell in love with Tiny Core Linux, which comes form this guy Robert Shingledecker who is the first person to bring Linux to municipal government in the United States. He’s got a great story and is another one of those decisive be and divisive individuals.

I guess I ought to shout out to QNX Unix. It’s a proprietary version of Minix, basically baked into everything from Blackberries to coin-op laundry machines. If it’s got a computer inside, nobody’s has the time for truly proprietary shit anymore, so it’s going to be some tiny form of Unix or Linux… always. Did I mention drones?

Curses! Foiled Again.

I tried building my own Linux from scratch (Refer to LFS above) along with compiling QEMU from source. I could have gotten the 20MB zipped distro down to probably 2MB to 5MB and not had the QEMU disappearing pointer problem. The key to this appeared to be MinGW (today MinGW-64), a subset of Cygwin (a way of turning Windows PCs into POSIX-compliant *nix machines) plus a wonderful library (I still want to use it) called Curses. Curses lets you do a lot of neat tricks with text-terminals that you think are reserved for Graphics. The popular Python pip install rich makes wonderful use of it today, validating my suspicions 10-years ago when I was researching this stuff.

A Very Deep Rabbit Hole

Roomba can only crash into a wall, turn a bit and retry so many times. Channeling the spirit of The Incredible Hulk with only a touch of Bruce Banner to manage the turns (how I work) wasn’t good enough. This task was going to take a whole lot more Bruce and a whole lot less Hulk.

Ugh! Did I mention Rabbit Hole evaluations. This rabbit hole was too deep for me. Controlling the linking of libraries in C to bake-in static libraries that resisted for a thousand-tiny reasons… plus learning Curses and about a zillion QEMU compile-options.

Uncle! Uncle! I cry uncle.

80/20-Rule To The Rescue!

Oh wait, wasn’t everything just working perfectly a moment ago but for the pointer disappearing. And you know, maybe someone out there wants the options for graphics in the Levinux console. And a 20MB download isn’t really so bad. And many other sour grapes I could conjure.

Just focus on a good Alice in Wonderland-style experience. People will appreciate it in any case. Did I mention the 80/20-rule? And those QEMU-binaries… there’s that one from Japan everyone uses. And there’s that one for the Mac that was mainstream there for awhile. Okay, okay, mix them together in this magical cocktail based around Mac’s packaging system that copies my & Howard Harrison’s WBScript for the Amiga back in the 90s (I later found out Sun Microsystems also used this directory-as-an-app trick), shake well, then bash a few times… voila!

Bob’s your uncle! (he really is.. I’ve got an Uncle Bob)

The Basic Ingredients for a Tiny Linux Server

So, what I chose for Levinux and some of the ingredients and components that went into it are:

Pshwew! Honestly, it was a miracle this whole thing worked in the first place. It’s a miracle it still works as well as it does today and still serves its purpose for education so quintessentially. A paragon of perfection, as I said in the YouTube description. Every time I see the Dropbear SSH server doing its thing and the busybox-httpd webserver doing its thing, and using the default vi program built into BusyBox Linux, I get the chills. It is a true example of how Unix/Linux skills are generic in nature and when you go this route, you’re not learning one particular thing, but really technology in general.

That’s because Unix/Linux simply has ascended to unchallenged already-won dominance. Even Microsoft has come around in the most “I meant to do that” way.

And a final note before we get onto the nitty gritty of what I’m fixing here, QEMU is actually in fact using the much maligned lately technique of PC EMULATION (vs. virtualisation or containerization). It’s much maligned because emulation is very slow compared to virtualisation, and practically not moving at all compared to the so-popular containerization (docker, LXC/LXD) of today.

Stick Your Hand In The Pain-Box. Go Ahead-less!

In other words, don’t expect Levinux to do anything for you other than to kick off your schooling in old’s kool text-based Unix/Linux. I view it as the Gom Jabbar pain-box of Dune that is used by the Bene Gesserit sisterhood (kind of like Minix) to determine whether you’re fit to be a leader of human race. Levinux is a similar little black pain-box testing whether you’re fit to learn *nix.

Dune Gom Jabbar Pain Box Levinux Linux

Don’t Get All Diffie w/Me. You Can Go To Hellman.

Go ahead. Download Levinux, unzip it and double-click the icon for your OS. You’ll get the server-build phase and be invited to SSH. I bet you can’t. Not with the instructions I give. That’s because since I released Levinux, SHA-1, the encryption/checksum system for secure communication has been hacked. Something in the system changed, probably the ssh programs run from Powershell, PuTTY, default on the Mac and such changed to give warnings. It couldn’t be Levinux because nothing big has really much changed there… for 7 years!

QEMU Virtual LAN & Network Address Translation

So I researched it and figured it out. SSH programs can be told to go ahead and work with SHA-1 anyway. The nattering naybobs who will yell at you for this don’t know what they’re talking about. It’s about the same as the ninny’s who think you shouldn’t pickle data in Python even if it’s not a program to be used by the public. That’s like saying you shouldn’t shoot a gun in a shooting range. Levinux runs in QEMU’s virtual LAN (local area network) context. It’s got its own subnet and DHCP server. No traffic is getting in unless you create a NAT-rule (network address translation). It’s safe.

To understand more about the technology being used here:

OpenSSH Legacy Option

Whoah, whoah there Hulk! Slow down there a minute. No amount of smashing is going to make it work. You need to let Bruce Banner take the wheel for a minute. Just for a minute, Hulk. Then you can smash Linux with

sudo su
rm -rf /*

…all you want. But to actually log into Levinux using a modern ssh client, you’re going to have to type:

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 tc@localhost -p 2222

Hulk SMASH!

Okay, got it? No? Well, the password is “foo”. Stop and read man, will you?!?! Oh yeah… The Hulk. Anyway, type in:

foo

…as the password for user “tc” when challenged. You won’t see it… no, Hulk! No smash. It’s okay… not seeing passwords is intentional. It’s a security precaution. Think about it… oh yeah, The Hulk.

You okay, boy? You in? Okay now. Follow the instructions. Maybe install Python. Maybe check out vim. You don’t really have to do either if you’ve got some vi-skills or are willing to develop some.

Bruce Banner Controllig The Hulk

When I advocate vim, I do so in part because it’s little sibling, vi, is built into everything including 500KB busybox Linux, I shit you not.

Is that good, Hulk? Hulk vi?

No? Not of interest? Still want to smash… sigh, okay. Type:

sudo su
rm -rf /

Now you can go into the Reset folder, double-click whichever reset script appears to be the right one for your OS. If Windows, override all the resistance. If Linux, the execute-bits may not be set right or the double-click action not registered or any one of a thousand other little details.

Eash, Hulk! The Gom Jabbar test will tell you if you’re human.

Still with me?

Congratulations, You’re Human

You may even be qualified to lead humanity into the future. Just learn yourself the Bene Gesserit ways of Linux, Python, vim & git.

Mom! He’s using the voice again!

Candace Flynn Phineas Turned Into A Badass

Next Step After Levinux

I’ve really given up tiny versions of Linux. I wanted them as a sort of Noah’s Arc so that my (mostly) Python code was not tied to one particular server, Raspberry Pi, Cloud service, or whatever. I wanted my code to live on my keychain in an always-ready-to-run with a double-click sort of Kung Fu way.

I was so hurt so many times by technology going obsolete on me that my desire to future-proof myself led to a sort of paranoia that led to the concept of tiny virtual Linux (or maybe Unix) servers. I don’t feel this way anymore. And I still totally think tiny linux servers are as cool as talking frogs, I’ll still kiss the frog. Otherwise, this frog is cooked.

But A Talking Frog Is Cooler Than A Princess Engineer Joke

Play with tiny linux servers from time to time, but don’t rely on them as your main development machine or anything. Maybe if you work on embedded systems like those in drones, they become your main thing. But 99 times out of 100, just use a mainstream OS that supports a good Unix or Linux. Macs ARE Unix with fully operational bash-like Terminal Shells and Windows has recently become good enough, thanks to Windows Subsystem for Linux (WSL). And ChromeOS has a good Debian-based bash Terminal.

The Promise of Unix / Linux has Borne Out

In other words, the promise of Unix / Linux has borne out and you don’t have to carry an extra one around with you as a Noah’s Arc backup. Just keep your code in Github. Clone it onto any machine. Run it.

So long as you use forward-slashes instead of back-slashes and beware of the Mac’s slightly non-standard directory structures, your code will pretty much run anywhere. No Noah’s Arc required.

Python, vim & git play into this delivered promise too. Python 3.x code will pretty much run on anything with Python 3.x. For an added bonus, resist direct reference to file-systems and instead go through Python’s pathlib. But even that’s not really necessary. The world has yielded to forward-slashes and the Unix/Linux directory structure.

Death by broken Windows paths is over.

This will now be true for every hardware platform past, present and future, which will always include some version of vi or git (if those platforms want to pretend to exist). Developers won’t allow otherwise.

And with standardization, comes the great unwashed hordes of developers, with which comes the great groundswell of a new literate class of global citizens who would laugh at a proprietary Windows without putting WSL Linux capabilities first.

The new lingua franca of tech has settled down, and it’s known as LPvg:

Final Shout-Out to Jupyter

Getting started ain’t easy. The universal code-runner that I sought in Levinux is now replaced in my heart with JupyterLab Desktop. Download it. Install it. Forget all this Linux, vim & git stuff for a few hours. Just let the Pythonic pythoniness of Python wash over you for a little.

In JupyterLab Desktop, the “Hello World” program is:

"Hello World"

Category: Linux Playgrounds (WSL & LXD)