ejaaskel.bsky.social
@ejaaskel.bsky.social
Embedded Software developer, blogger and maybe a few other things as well.

Blog at https://ejaaskel.dev
I’ll be presenting at Yocto Project Summit this year. It’ll be a quick lighting talk about creating generic Yocto distributions

pretalx.com/yocto-projec...
Writing a Distro for No-one (or Anyone) Yocto Project Summit 2025.12
In Yocto-based projects, the distribution is commonly a means to an end - sandwiched between the BSP and business logic, it often simply "exists". But what if the distro itself is the focus of the pro...
pretalx.com
November 12, 2025 at 8:25 AM
New blog post on how to harden access to the U-Boot command line interface

ejaaskel.dev/protecting-u...
Protecting U-Boot Command Line - ejaaskel
This text should help you harden U-Boot by fixing the lowest-hanging fruit: unfettered access to the bootloader control interface.
ejaaskel.dev
November 5, 2025 at 10:53 AM
Release 0.2.0 of the secure Yocto distro Sulka is out now. You can get started here, and feel free to ask if you’ve got questions

codeberg.org/AltidSec/kas...
kas-sulka
kas configuration for building Sulka
codeberg.org
October 14, 2025 at 5:35 PM
I’ll be presenting at Hack After Dark in Oulu, Finland on October 18th. The topic is a familiar one, humans and cybersecurity. More info from the link below

tarlab.fi/HackAfterDark
Hack After Dark
Hack After Dark on Oulussa 18.10.2025 järjestettävä hakkerihenkinen tapahtuma. Tapahtuma on vapaamuotoinen, sisältää puheenvuoroja, verkostoitumista, keskusteluita ja mahtavan hakkerivisan. Hack After...
tarlab.fi
October 3, 2025 at 9:26 AM
I wrote a bit more about the kernel module signing to my blog

ejaaskel.dev/module-signi...
Module Signing Keys (Without Building Kernel) - ejaaskel
In this blog post we will talk about module signing keys in a situation where the entity developing and signing kernel modules cannot build in their keys.
ejaaskel.dev
October 1, 2025 at 6:57 AM
New blog post about Yocto hardening is now out. This time we’ll discuss about signing kernel modules

ejaaskel.dev/yocto-harden...
Yocto Hardening: Kernel Module Signing - ejaaskel
This time we have a relatively simple and effective hardening measure that may prevent big headaches: kernel module signing.
ejaaskel.dev
September 22, 2025 at 9:56 AM
I spent a day studying and trying to understand EU CRA. Surprisingly, it wasn’t the dullest day ever
September 17, 2025 at 7:06 PM
The slides for my #OSSummit Europe presentation are pretty much done, and the “beta test” presentation today went well. Looking forward to doing the actual presentation the next Monday!

osseu2025.sched.com/event/25VnI/...
Open Source Summit Europe 2025: Thinking Outside the (Linux) Box: Securi...
View more about this event at Open Source Summit Europe 2025
https://osseu2025.sched.com/event/25VnI/thinking-outside-the-linux-box-security-considerations-from-human-actors-esa-jaaskela-buutti-oy?iframe=yes&w=100%&sidebar=yes&bg=no
August 21, 2025 at 8:05 AM
Making a presentation feels a bit like making music. After certain point all the “improvements” end up making the final result worse
August 18, 2025 at 10:12 AM
For someone who’s scared of flying, the constant “your flight is in X days” reminder mails are quite stressing
August 13, 2025 at 7:08 AM
Some recent updates to Sulka distro, too many to list out in a single post so you’ll have to settle for LinkedIn screenshot
July 22, 2025 at 3:04 PM
It's frustrating when you accidentally copy-paste your secret password into a chat and get your account hacked. Fortunately, multi-factor authentication can prevent that. This applies to the embedded Linux devices as well. I wrote a blog on how to enable MFA on Yocto: ejaaskel.dev/yocto-harden...
Yocto Hardening: Multi-Factor Authentication - ejaaskel
In this blog post, I'll show how to integrate Google Authenticator into a Yocto system to enhance the security of remote login flows.
ejaaskel.dev
July 2, 2025 at 8:43 AM
Balatro is going to destroy my productivity
June 27, 2025 at 8:16 PM
Some additions to Sulka, secure Yocto distro, from the past few weeks:
- Added kas configuration
- Added rudimentary tests
- Added password expiration option
- Hardened /proc and tmpfs moutns
- Changed password encryption to yescrypt
- Few more smaller changes

Link here
codeberg.org/altidsec/met...
meta-sulka-distro
Meta-layer for Sulka, hardened Yocto Linux distribution
codeberg.org
June 26, 2025 at 5:41 AM
In my excitement I forgot to share here that I’ll speaking in the Embedded Linux conference (part of Open Source Summit Europe) about how humans affect the security of embedded systems osseu2025.sched.com/event/25VnI/...
Open Source Summit Europe 2025: Thinking Outside the (Linux) Box: Securi...
View more about this event at Open Source Summit Europe 2025
https://osseu2025.sched.com/event/25VnI/thinking-outside-the-linux-box-security-considerations-from-human-actors-esa-jaaskela-buutti-oy?iframe=yes&w=100%&sidebar=yes&bg=no
June 24, 2025 at 5:40 AM
I started to write a secure Yocto distro to put the lessons learned from my Yocto Hardening blog series into use. It’s still quite early in the development, but it’s in a stage where it can be tested ejaaskel.dev/introducing-...
Introducing Sulka, the Hardened Yocto Distro - ejaaskel
For years I have been telling myself that it's a bit too much for a single person to try and manage a distro, but now I think it's time to give it a go.
ejaaskel.dev
June 13, 2025 at 7:19 AM
Continuing with the FPGA stuff in the new blog post, getting a bit deeper into the block design.

ejaaskel.dev/adding-spi-a...
Adding SPI & AXI to NEORV32 Design - ejaaskel
In the previous part we created an FPGA design that runs NEORV32 and is capable of booting Zephyr. Let's improve it by adding an SPI block and external memory.
ejaaskel.dev
May 21, 2025 at 6:17 AM
Stydying FPGA continues, this time we’re throwing an RTOS into the mix ejaaskel.dev/running-zeph...
Running Zephyr RTOS on NEORV32 Soft Processor - ejaaskel
The last time I was playing with an FPGA I connected Basys 3 and Raspberry Pi. It's time to increase the difficulty a bit and create our SoC using FPGA.
ejaaskel.dev
May 15, 2025 at 6:36 AM
New blog post about package configuration in Yocto is out now:

ejaaskel.dev/configuratio...
Configuration with PACKAGECONFIG in Yocto - ejaaskel
The OpenEmbedded build system used by the Yocto Project has a powerful feature that is slightly hidden in the documentation: package configuration.
ejaaskel.dev
May 7, 2025 at 6:54 AM
I wrote a blog post about how to connect two boards with three jumper wires, and that’s approximately a 14 minute read. I may need to learn more concise writing. But yes, a new text about connecting a RasPi and an FPGA board to each other and using UART to communicate:

ejaaskel.dev/linux-fpga-t...
Linux & FPGA, The Perfect Match? - ejaaskel
FPGA, one of life's big mysteries. Let's combine Raspberry Pi 5 and Basys 3 boards and see how we can demonstrate communication between these two devices.
ejaaskel.dev
April 24, 2025 at 9:36 AM
Reposted
From an internal conference
April 2, 2025 at 8:27 PM
You might wonder why the new encryption blog post has a picture of a deer in it. It's because it is a key deer, and encryption uses keys, and that is hilarious.

ejaaskel.dev/encrypting-i...
Encrypting In Yocto With fscryptctl - ejaaskel
In this blog text I'll briefly cover how to use fscryptctl to encrypt and decrypt directories in an embedded Linux system.
ejaaskel.dev
April 2, 2025 at 4:47 PM
I'd like to switch back to Mastodon, but I already spent an hour trying to make a Bluesky feed plug-in look correct in WordPress. I feel like I'm too invested in this to quit.
April 2, 2025 at 12:27 PM
Vibe coding basically sounds like an upgrade to low-code/no-code tools. Or a downgrade, not 100% sure yet.
March 19, 2025 at 1:32 PM
The second blog post about encryption in Yocto is out now. This time we’re getting into file system encryption.

ejaaskel.dev/yocto-harden...
Yocto Hardening: File System Encryption with fscrypt - ejaaskel
Let's continue encryption with the second part and move on to file system encryption.
ejaaskel.dev
March 19, 2025 at 7:51 AM