Xobs' Blog

betrusted

Xous Process Creation

A fundamental feature of modern computing is the ability to run programs. In many embedded systems, the list of processes is fixed at startup. In other systems, including mobile phones and desktop computers, new processes can be spawned on a running system. Until now, Xous has been unable to create

betrusted

EC: Phone Home

The main Betrusted SoC CPU gets a lot of interest, but it's the EC CPU that's responsible for networking. This discusses the software and stack of the Betrusted EC, how it's wired up, and why it was designed that way.

xous

Adding Rust Stable libstd Support for Xous

It is possible to add support for a new OS to the Rust compiler's stable channel without rebuilding everything, enablinglibstd support for entirely new operating systems.

Introducing Qomu

Three years ago I announced crowdfunding for Tomu [https://www.crowdsupply.com/sutajio-kosagi/tomu] – a microcontroller in your USB port. This project brought to mass-market a tiny Arm Cortex-M0 CPU in a package that fits directly into a USB port. Now you could take a standalone USB project anywhere. One

renode

Precursor + Renode

Precursor [https://precursor.dev/] is an FPGA-based dev platform for secured applications. The reference design runs a VexRiscv CPU core plus a wide range of peripherals. Developing software for an embedded target can be a challenge in the best of circumstances, and when you're starting out there is no display,

simmel

Trace Together Token: Teardown and Design Overview

On 19 June, GovTech Singapore invited four members of the community to come and inspect their new TraceTogether Token. This token removes the need to carry a phone at all times, and is designed to help both those who do not have a smart device capable of running TraceTogether well,

Xous: Support Tooling

As part of the Betrusted Project [betrusted.io/], I am working on an operating system to power the hardware.  I've talked about [https://p.xobs.io/lca20-bt/#/3] the need for a new operating system for the project, which boils down to the need for software to be secure and

xous

Announcing Xous: the Betrusted Operating System

Today we're pleased to announce the Betrusted project. The goals of this project are to create a secure platform that is auditable by the end user, and is capable of performing secure communications.

Cobbled-together Profiler

I recently got Circuitpython working on Fomu [https://github.com/xobs/circuitpython/releases]! But there's an issue with the speed of Fomu's SPI flash: It's currently incredibly slow, and that makes for a poor experience. Worse still, the program runs so slowly that the tinyusb stack can't keep up with

Clocks and Timing are Hard

Computers are binary things, right?  A bit is either "1" or "0". Except when it isn't. Computers are built from logic gates, which are built up from silicon, which is based in physics.  In physics, things very rarely are clear cut, and silicon gates are no exception.  Signals take time

Fomu EVT: Prototype or Business Card?

When starting a project from scratch, it's important to create prototypes. For programming, you usually create small snippets that demonstrate what you want. Fortunately, software is quick to compile, so you're free to create hyper-specialized programs that exist only to test out particular theories. With hardware, the build cycle is

Fomu: An FPGA in your USB Port

We've just started crowdfunding Fomu [https://www.crowdsupply.com/sutajio-kosagi/fomu], and FPGA that fits in your USB port! The original project -- Tomu -- was a really interesting little device. It was a simple ARM Cortex M0 MCU that fit entirely inside a Type A USB port. It was

Tomu Plastic Case Part 2: PCB Modifications

When designing a plastic case, it is important to work within the limitations of the medium. The design process begins with the PCB, which must fit within the final design space and still be manufacturable. You must take into account manufacturing tolerances and design specifications, while still providing plenty of

Making Tomu: Plastic Case Overview

This series of blogposts details the steps I took to create a plastic case for Tomu. Tomu [https://tomu.im/] is a project I helped to crowdfund. Initially created by Tim "mithro" Ansell, Tomu is a tiny computer that fits entirely inside a Type-A USB port -- the sort usually

palawan

Palawan project #1: button box

June saw lots of progress on Palawan. Many bugs were fixed in the Grainuum stack, the bootloader was fleshed out, and stability was improved. The system is usable now, and just about feature-complete. Enough to think about shipping. An image is worth many words, so let's start with a box

Grainuum 1.3: Now with fewer bugs

In the process of bringing up Palawan DVT1, I've run across a number of bugs in Grainuum. Most notably, several subtle timing errors where the loop was one cycle too short or too long. Or in the case of the end-of-packet signal, four cycles too short. There was also an

Love-to-Code Debug Shoe

Looking to debug your Chibitronics Love-to-Code board, but don't want to solder on headers? If you have access to a 3D printer, grab the LtC Debug Shoe [http://www.thingiverse.com/thing:2211948], print it out, and crimp on some tinned wires. Read on to learn more about the project.

novena

Clustering Novena

Server clustering is a topic I've been cirous about for a rather long time, from back in the Slashdot days where one would constantly "imagine a beowulf cluster of" any given low-powered device. With modern clustering software, such thoughts become practical reality. And with some cardboard, everything goes together nicely.

palawan

Palawan DVT1 Build

I've just finished taping out Palawan DVT1. This is the first build in a long time, and is a rather heavy redesign. The three biggest changes are: * New CPU/Radio pair * 433 MHz operation * Redesigned in KiCad KL02 and RFM69HW Previously, Palawan was based on a Freescale KW01 [http://www.

usb

Palawan's USB Stack is Now Known as Grainuum

The USB stack from project Palawan has grown beyond its original scope. The bootloader contains a completely separate copy, and it has been ported to at least one other platform. It is confusing to refer to both the hardware platform and the USB stack as "Palawan". To help alleviate confusion

Seafile: Filesharing that's pretty great

Seafile is a piece of software that I use every day that I find exceedingly handy. The elevator pitch is something along the lines of "Like Dropbox, but self-hosted, with versioning." I use it on all of my stuff, and it is fantastic. I run it on Linux, Windows, and

xobs.io

Promising URLs for the future

A statement floating around on Twitter is that "A URL is a promise" [https://twitter.com/kzwa/status/787022500244885505]. A fine sentiment, and I hope that link continues to work in the future. The Internet is not a static thing, but being able to send someone a link and have

novena

Novena-as-a-Keyboard

There's just something magical about watching text flow along a screen. It's the basis for Defcon boards made popular by the movie Wargames, and is popular in the background of most movies. It's rare that such a display happens in the real world, but I actually had the occasion to

Palawan: Part Selection and Schematics

When starting a project, the first step is obviously to decide what it should do. Do you want to do a light blinker or a laptop? Maybe you have something prototyped already on something like an Arduino, and you'd like to move to Mass Production (MP). Either way, entire industries

palawan

Introducing: Project Palawan

I want to learn more about hardware design, and the best way to learn something is to do it. I've started work on a new project to create an easy-to-use hardware input platform. The project, codenamed Palawan, allows you to make contraptions that show up wirelessly as a keyboard, joystick,