---
title: Mothership
subtitle: A computing platform that embraces the language
bibliography: bibliography.bib
reference-section-title: Bibliography
link-citations: true
link-bibliography: true
csl: acm-sig-proceedings-long-author-list.csl

abstract: |
  Computing, as any other field, evolved from the previous work on the matter.
  During its development huge advancements have been done in many areas but only
  some are in use today, due to the inertia industry already had, which forced
  some sort of retrocompatibility. In this document a new computing platform is
  presented, one that makes use of some of the ideas that didn't reach the
  mainstream and uses our current computing capabilities in order to achieve a
  personal computing device that embraces the programming language.

# How to cite:
# https://pandoc.org/chunkedhtml-demo/8.20-citation-syntax.html
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# A computing platform that embraces the language



## UNIX's influence

> Applicants must also have extensive knowledge of Unix, although they should
> have sufficiently good programming taste to not consider this an achievement.
>
> -- Hal Abelson

### Von Neumann's heritage

Leaks permission issues

### FileSystem

- folder-based
- Everything is a file

Other options: mobile OS's approach (they hide the filesystem under an index),
RelFS...

#### UGO?

### Text as a universal interface

Text has no structure, forces you to parse things all the time. 1 parser per
program...

### Processes & threads

They don't exist. It's a person that decided they should.

One(or multiple?)-thread-asynchronous system à la JavaScript can be good.

### Virtual Memory

Needed for the binaries to be run directly in CPU but with some protection.
It's a broken model but it was born for the right reasons:

- (virtual) infinite memory => we can use garbage collection for that instead
- Correct permissions => Capability based security?

### System Calls (kernel is king)

Interrupt based. Monolithic vs Microkernel.
Thinking about the kernel as a resource manager.

System calls are passed via registers and a very-low-level ABI (everything as
integers).

Why not embrace the language and its structures and make them be "Just" a
function call.

### Interpreters

Each language has its own interpreter. The interpreter is a resource manager
for the language (allocates memory, uses sockets, files...) but using kernel's
resources: Two layers of the same stuff.

    Language -> interpreter -> kernel -> cpu

Do we need all?

#### We add layers, but all is an Integer in the end

We have tons of layers but in the end we have a Kernel that is an
integer-interpreter. This leaks too many details to the user/developer.


### Shell (fork+exec)

We can do better. Fork+exec embraces the Unix model [@fork:Baumann], not the
language.

### Users (now used for permissions)

Users as people using the computer, not as programs. I'm the only user of this
machine.

### Permissions

They are a concern, so bad, it appears everywhere in different ways:

- Memory
- Processes and threads
- Filesystem (ugo)
- Users

Why not a unified permission system?


## A different world

### Capability Based Security

seL4 => uses identifiers as keys for the capabilities

3L project[@3L:Hintz] => many ideas are the same that we have but it doesn't
embrace the language in the sense it affects how the processor is built (to
help the interpreter). It's written in pre-scheme instead.

Use an interpreted language and give capabilities as functions in an
environment: they can be mocked! Or manipulated! Or executed remotely in a
distributed fashion!

## No interpreter-kernel-CPU distinction

Everything is a function/value

## No fixed ISA

We can extend the language as the base of everything and be able to rebuild the
CPU live, using the same language we use to manipulate it.

## No processes/threads

Event loop maybe?

## Am I taking the ideas of a browser??? Hehe

## Scheme as the heart (R7RS Small)

Lambda calculus approach: everything is a function

It's not text, but Lists.

It's dynamic.

Garbage collection for infinite memory (maybe in hardware). Hardware-assisted
interpreter.



## Developers

Developers understand what a function call is. We are NOT adding more
constructs, but removing some that have nothing but historical sense.

No need to think in Integers anymore. Functions are king now.
The Kernel is a lambda calculus interpreter.

## Possible usages

Small computing / field device.

> Remember, it's not a personal computer if you can't just paint a line in the
> screen

It could delegate some complex functionality to a server (remote interpreter)
installed in a conventional machine.

## Personal computing

Oberon, TempleOS... Computing for one person. That one person can totally
manipulate, alone.