Thoughts dereferenced from the scratchpad noise.

Latest posts


ssh reverse tunnel for PXE, NFS and DHCP setup on Qubes OS

Published at December 5, 2017 · Piotr Król ·  6 min read

At some point I stuck in the forest with WiFi connection and no physical access to router to create nice networking for my coreboot development needs. Recently I switched my laptop to Qubes OS what give interesting flexibility, but also additional problems. My key requirement is to boot system over PXE, so I can easily do kernel development and play with Xen. Because only available connection for my apu2 platform was directly to my laptop I had to provide configured DHCP server and PXE server on it....

Categories: os-dev

Flashing MinnowBoard Turbot with Raspberry Pi Zero W

Published at November 20, 2017 · Piotr Król ·  10 min read

Recently we started preparation of coreboot training for one of our customers. Our platform of choice for that training is MinnowBoard Turbot. There are couple reasons for that: During training we can show recent firmware trends - despite we don’t like blobs (FSP, AGESA, PSP, ME etc.) and bloated designs (UEFI) we cannot escape reality and have to show customers how to deal with those components. MinnowBoard Turbot use couple of them, but also supports coreboot....

Categories: firmware

UEFI/EDK II CorebootPayloadPkg on PC Engines apu2

Published at November 3, 2017 · Piotr Król ·  9 min read

Recently we were reached by person interested in running CoreOS on apu2. CoreOS is a very interesting system from security point of view. It was created to support containers and scalability out of the box. Unfortunately it requires firmware supporting GPT. At that point I was not sure if I can utilize GRUB GPT support on apu2, but this led to other questions: Is it possible to boot UEFI-aware OS on PC Engines apux boards?...

Categories: firmware

PC Engines apu2 python Robot Framework validation automation

Published at November 2, 2017 · Piotr Król ·  8 min read

Recently we attended ECC2017 conference. One of topics that we considered was a system for development and validation automation. Unfortunately this talk was not accepted, but we present some research below and plan to provide more soon. As maintainers of PC Engines platforms in coreboot we debug and fix quite a lot of bugs, but to take full responsibility for our code everything should be validated each time we do release....

Categories: firmware

How to handle a DHT22 sensor using ARM mbed OS?

Published at August 1, 2017 · Michał Żygowski ·  8 min read

Recently I have encountered with temperature and humidity measurements using DHT22 sensor. I was developing a driver source code in ARM mbed OS SDK on particular STM32 NUCLEO L432KC platform. Thorough analysis of DHT22 documentation led me to the following questions: Is it possible to accurately measure voltage-level durations during read process? What duration time values should be considered as timeout or/and error? Should I weaken the time restrictions in order to avoid random delays in voltage level transitions be considered as failure?...

Categories: firmware iot

How to use Ansible via Python

Published at June 14, 2017 · Maciej Ruciński ·  5 min read

Ansible is designed around the way people work and the way people work together What is Ansible Ansible is simple IT engine for automation, it is designed for manage many systems, rather than just one at a time. Ansible automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT operations. It is easy to deploy due to using no agents and no additional custom security infrastructure. We can define own configuration management in simple YAML language, which is named ansible-playbook....

Categories: app-dev

SWUpdate for feature-rich IoT applications

Published at May 21, 2017 · Maciej Pijanowski ·  11 min read

When you work with embedded systems long enough, sooner or later you realize that some sort of update mechanism is required. This is especially true when more complex systems, running with an operating system, are taken into account. Nowadays Linux is being picked increasingly as operating system for embedded IoT devices. In following post we will focus on those in particular. In fact, from my experience update mechanism is vital part of many embedded applications....

Categories: app-dev

Installing OpenWRT on APU3 platform

Published at May 12, 2017 · Kamil Wcisło ·  13 min read

This guide should be considered as a simple walk-through for using APU3 platform in some generic use-cases. I’m trying to explain how to work with the device and use it in a generic manner. There is a part about the coreboot firmware, which could be used as a reference of how to start customizing it for own purposes. Configuring the hardware At first, let’s figure out some basic requirements for our new device:...

Categories: firmware os-dev

OpenOCD and development environment for Zephyr on NXP FRDM-K64F

Published at March 18, 2017 · Piotr Król ·  12 min read

In this post I would like to describe process of setting up NXP FRDM-K64F development environment under Linux and start Zephyr development using it. Why NXP FRDM-K64F ? I choose this platform mostly because of ready to use guide about using 802.15.4 communication by attaching TI CC2520, which was presented here. Typical wireless stack starts with 802.15.4, then 6LoWPAN adaptation and then IPv6, which carries application protocols. 6LoWPAN compress IPv6 so it can fit BLE and 802....

Categories: firmware iot

Nerves project triage on BeagleBone Black Black

Published at March 10, 2017 · Piotr Król ·  6 min read

Recently one of my customers brought to my attention Nerves. It aims to simplify use of Elixir (functional language leveraging Erlang VM) in embedded systems. This system has couple interesting features that are worth of research and blog post. First is booting directly to application which is running in BEAM (Erlang VM). Nerves project replace systemd process with programming language virtual machine running application code. Concept is very interesting and I wonder if someone tried to use that with other VMs ie....

Categories: firmware os-dev