selfie in 13 minutes: a system that compiles, executes and hosts itself

Selfie is a self-contained 12KLOC C implementation of a self-compiling
compiler, a self-executing emulator, and a self-hosting hypervisor -- an
educational platform for teaching the design and implementation of compilers,
libraries, operating systems and virtual machine monitors, built around the
one thing those subjects have in common and textbooks tend to step over:
self-reference in systems code.

This is a cut of the full talk. It walks the three selves -- compiling,
executing and hosting yourself -- and then spends its middle on the
distinction that makes operating systems hard to understand: an operating
system built by emulation is semantically equivalent to one built by
virtualization. The same guest executes the same 86,380 instructions either
way. Virtualization is needed only for performance -- and it buys that
performance by introducing self-reference, which is the bootstrapping problem,
the trusted computing base, and the whole microkernel programme.

Every number quoted is measured, and the commands that produce them are in the
repository.

The full 29-slide talk, in your browser: https://selfie.cs.uni-salzburg.at/talk
Code, book, slides and autograder: https://github.com/cksystemsteaching/selfie

Narrated with a voice cloned from the author's Compiler Construction lectures.

00:00 One file
00:37 Three commands
01:17 The system
02:05 What a compiler really is
02:49 Self-compilation
03:43 Self-execution
04:34 Self-hosting
05:21 Two ways to build one operating system
06:12 They are the same operating system
07:35 So why virtualize?
08:29 The price is self-reference
09:30 What you can decide about a program
10:57 Why learn this now
12:05 Take a selfie