Michał Żygowski

Firmware engineer and core developer of coreboot. Maintainer of Braswell SoC, PC Engines, Protectli and Libretrend platforms. Interested in advanced hardware features, security and coreboot. Open source firmware enthusiast and conference speaker.


Articles (24)


Meltdown and Spectre on PC Engines apu2

Published at May 29, 2019 ·  9 min read

As a continuation the Meltdown and Spectre blog post, this post present the vulnerability status and mitigation with microcode update on PC Engines apu2. Read the post and get to know the open source tools for vulnerability and mitigation checks, as well as exploiting proof of concepts....

Categories: firmware security

Meltdown and spectre. What are they and what they are not?

Published at March 20, 2019 ·  6 min read

Meltdown and Spectre At the turn of the year 2017 and 2018, the world of security and computing has shaken. It was the time when we first heard about vulnerabilities that affect almost every modern processor (mainly x86 architecture) manufactured during the last 20 years. They have been named as Meltdown and Spectre and belong to one family of flaws caused by speculative execution. In this post, I will describe what they are and how they are threatening the users of modern machines....

Categories: security

How to enable Core Performance Boost on AMD platforms?

Published at February 14, 2019 ·  13 min read

Pushing hardware to its limits In the epoch of efficient and fast processors, performance becomes one of the most crucial aspects when choosing and working with hardware. We want our computers to execute their tasks with possibly highest speeds. But what really influences the performance of our platforms? It’s the processor’s manufacturer design one may say. In this post, I will show You how firmware may boost Your silicon to higher performance level....

Categories: firmware

How to handle a DHT22 sensor using ARM mbed OS?

Published at August 1, 2017 ·  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