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Thoughts dereferenced from the scratchpad noise.

Latest posts


Enabling ECC on PC Engines platforms

Published at October 16, 2018 · Krystian Hebel ·  14 min read

In this post I want to share some findings about ECC on PC Engines apu platforms. I’ll try to shortly describe what ECC is, why is it so desired, what problems with enabling this feature were encountered and how to test whether ECC works or not using MemTest86. Introduction Sometimes a bit in RAM changes its value spontaneously due to electrical or magnetic interference. It can be caused by background radiation, cosmic rays or recently attacks using row hammering....

Categories: firmware

debos image for HummingBoard Edge

Published at October 10, 2018 · Maciej Pijanowski ·  8 min read

Intro In my previous posts I have shared my first experience with debos and how to run debos in a container. In today’s post, I’d like to present how can we use all of that to generate base Debian image for an ARM board. My board of choice for this particular example will be the HummingBoard Edge. The post is inspired by the feedback from the new users (such as this one) that there are no end-to-end examples how to quickly start using this tool....

Categories: os-dev

RTE for automated kernel deployment and everyday use

Published at October 3, 2018 · Piotr Król ·  9 min read

We continue our effort to enable IOMMU and as side effect I have to play with various technologies to exercise reliable development environment which base on RTE. In this blog post I would like to present semi-automated technique to debug firmware, Xen and Linux kernel. The goal is to have set of tools that help in enabling various features in Debian-based dom0. We would like: update Linux kernel which is exposed over HTTP server update rootfs provided through NFS I will use following components:...

Categories: firmware os-dev

Optimize performance in Docker containers used by Embedded Systems Consulting business

Published at September 27, 2018 · Piotr Król ·  11 min read

In 3mdeb we use Docker heavily. Main tasks that we perform using it are: firmware and embedded software building - each software in Embedded System requires little bit different building environment, configuring those development environments on your host may quickly make a mess in your system for daily use, because of that we created various containers which I enumerate below trainings/workshops - when we perform trainings we don’t want to waste time for users to reconfigure the environment....

Categories: firmware miscellaneous

PC Engines APU2 platform validation with RTE

Published at September 13, 2018 · Artur Raglis ·  6 min read

Introduction Remote work is trending nowadays. The best example is the IT industry - purely software tasks with handheld devices allow you to work practically from anywhere. This approach saves a big amount of time and makes a job easier. Unfortunately, as an embedded / firmware developer, there are often situations when interaction with hardware such as a power cycle is required. This leads to a barrier for successful remote work....

Categories: firmware

debos in docker - the second attempt

Published at August 23, 2018 · Maciej Pijanowski ·  5 min read

Intro In the previous post, I have shared my first experience with the Debian images builder - debos. I have posted my current results on the issue but since there was no response, I’ve decided to try to move forward by myself. Just to remind - I was stuck at the following error (when building for arm64): 1 2 3 4 5 6 7 8 9 10 11 12 2018/07/26 18:36:39 Debootstrap (stage 2) | chroot: failed to run command '/debootstrap/debootstrap': Exec format error 2018/07/26 18:36:39 debootstrap....

Categories: os-dev

Xen HVM guests on PC Engines apu2

Published at August 16, 2018 · Piotr Król ·  15 min read

Continuing blog post series around Xen and IOMMU enabling in coreboot we are reaching a point in which some features seem to work correctly on top of recent patch series in firmware. What we can do at this point is PCI passthrough to guest VMs. Previously trying that on Xen caused problems: random hangs firmware cause Linux kernel booting issues (hang during boot) IOMMU disabled - unable to use PCI passthrough Now we can see something like that in dom0:...

Categories: firmware os-dev

Our first look at debos - new Debian images generator

Published at July 27, 2018 · Maciej Pijanowski ·  7 min read

What is debos debos is quite a new tool allowing easier Debian images generation. It seems to be following current trends - it is written in Go, using YAML as an input format. The idea of taking away debootstrap shell scripts and replacing it with a single, simple YAML file looks tempting enough to give it a try. Full feature description can be found in this introductory post on Collabora’s blog....

Categories: os-dev

How to boot Xen over PXE and NFS on PC Engines apu2

Published at July 18, 2018 · Piotr Król ·  9 min read

From time to time we face requests to correctly enable support for various Xen features on PC Engines apu2 platform. Doing that requires firmware modification, which 3mdeb is responsible for. Xen have very interesting requirements from firmware development perspective. Modern x86 have a bunch of features that support virtualization in hardware. Those features were described in Xen FAQ. It happens that most requesting were IOMMU and SR-IOV. First, give the ability to dedicate PCI device to given VM and second enables so-called Virtual Functions, what means on a physical device (e....

Categories: firmware os-dev

Basics of x86 assembly (AT&T syntax)

Published at May 17, 2018 · Bartek Pastudzki ·  12 min read

Nowadays, application of programming in assembly language is very small. Writing production code in assembly may be found in the most demanding tasks in embedded. Even in modern firmware (coreboot, EDK2) most of the code is written in C. Honesly, that’s quite undestandable, assembly code isn’t easy to read nor write and some state that it’s no longer needed to be known. In my opinion, that’s far from the truth....

Categories: programming




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