DEV and IOMMU: a story of two DMA protection mechanisms
Published at July 3, 2020 · Krystian Hebel · 12 min read
Both DEV and IOMMU can help with protection against malicious DMA. This post roughly describes the difference between those two, as well as the impact they have on each other in the context of TrenchBoot...
Easy way to stay secure - XEN on the PC Engines apu2
Published at February 5, 2020 · Norbert Kamiński · 3 min read
Xen Project creates a software system that allows the execution of multiple virtual guest operating systems simultaneously on a single physical machine. In this case, it is a PC Engines apu2 platform....
Categories: manufacturing os-dev security
Meltdown and Spectre on PC Engines apu2
Published at May 29, 2019 · Michał Żygowski · 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....
Published at May 22, 2019 · Krystian Hebel · 3 min read
Recently we made sure that every build of PC Engines' firmware is built in a reproducible manner. This short post shows what exactly does it mean and why this should be important to firmware developers....
Categories: firmware
How to enable Core Performance Boost on AMD platforms?
Published at February 14, 2019 · Michał Żygowski · 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
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
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
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....
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
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:...
PC Engines APU2 netboot Debian installation
Published at March 26, 2016 · Piotr Król · 3 min read
In previous post I described how to setup PXE server and boot Debian installer using it. I mentioned that provided setup is limited and some extensive configuration is needed to make it useful for real world example. Since that time I learned that there is chain command in iPXE, which give ability to use arbitrary TFTP server as boot file source. Using RPi PXE server For example by changing my test network topology from previous post to something like that:...
Categories: os-dev
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