NXDART: Distributed Automated Build and Runtime Test Environment for Apache NuttX RTOS

Here goes  my latest technical publication from the world of embedded systems and electronics, authored by Tomasz Cedro (1,2,5,6), Gregory Nutt (1), Lup Yuen Lee (1), Grzegorz Południewski (2,6), Szymon Wilk (2,4), and Wojciech Glinkowski (2,3), from the (1) Apache NuttX RTOS; (2) Polish Telemedicine and e-Health Society; (3) Warsaw Medical University, Poland; (4) Poznan University of Technology, Poland; (5) CeDeROM, Poland, (6) IQCREDO, Poland.

Paper was published in the International Journal of Electronics and Telecommunications Vol. 72 No. 3 (2026) and is available online in open-access at IJET [1] and NuttX [2] websites.

Abstract

This paper presents the concept and initial implementation of a distributed automated build and runtime test environment for NuttX, called NXDART. NuttX is Apache 2.0 licensed Free and Open-Source (FOSS) Real-Time Operating System (RTOS), created by Gregory Nutt and released to the public in 2007, with strong focus on portability, small footprint, scalability, and compatibility with POSIX, ANSI, and other stan dards commonly used by Unix and other RTOSes (e.g. VxWorks).

NuttX community consists of volunteering hobbyists, academia, and small/medium/large enterprise professionals from around the world. NuttX supports over 15 different 8..64-bit CPU architectures (RISC-V, ARM, ARM64, AVR, CEVA, HC, MIPS, Misoc, OpenRISC, Renesas, SPARC, TriCore, x86, AMD64, Xtensa, Z16, Z80, FPGA) on over 340 unique hardware boards with over 1600 example target firmware configurations. Project development intensity is measured in thousands of files changed every month with hundreds thousands of code lines modifications.

In order to assure self-compatibility and long term maintenance for supported platform all new source code contributions are always processed manually by independent reviewers and automated Continuous Integration (CI) software tools. Unfortunately, not all breaking changes can be detected that way. Code may build for various architectures and even run correctly on emulators but it may still not work as expected on real world hardware. Therefore, comprehensive runtime tests are required.

Hardware testing of hundreds of different devices in one place turned out impossible for our free and community driven project. To address this problem we have invented distributed hardware-in-the-loop (HIL) test environment that is easy to set up and maintain as it reuses hardware components already owned by hundreds of users around the world. This approach assures maximum coverage of possible boards and build environments, independence and uninterrupted redundant availability of build and runtime test automation, with feedback logs reporting directly to the project upstream, at virtually zero cost.

[1] https://ijet.pl/index.php/ijet/article/view/10.24425-ijet.2026.157953
[2] https://nuttx.apache.org/articles

Sony Xperia Unlocked Mobile Firmware Restore

Sony Xperia phones are my favorite. Very good and durable electronics, amazing photo camera, nice utilities on top of standard Google Android OS. I have also always respected Xperia for allowing users to unlock their phones for Open-Source Firmware Customization on this amazing hardware..

xperiacompanionfail

Unfortunately, Sony seems to have this habit to make a bad decisions, so amazing hardware is not always followed with a good software. This is why Open-Source Customization is so important. I have already found several nice devices with a really bad firmware. What is more, this corruption seems to spread, and Sony blocks factory firmware restore for an unlocked devices with their official Xperia Companion utility. This means unlocking a device does not only Voids a Warranty, but also silently makes it Impossible to Go Back to a Stock Firmware! This is really bad idea.

emma

Luckily smart people tends to predict and help each other out. Developer team of Sony Mobile released EMMA utility (nice name by the way) that allows you to re-flash mobile that is unlocked in case something goes wrong or you simply want to get back to a stock firmware.

Open-Source Firmware Customization will become a standard, even for large enterprises, with mutual benefit to their customers, because looking at the big picture we are part of the same eco(no)system..

Google Android Nexus Device Un-Brick

GoogleNexus

If you happen to brick your Google Nexus device you can always use stock ROM images [1] to revert it to a default and operational state. Package contains not only OS but also bootloader and radio firmware images!

I have bricked my device by installing custom firmware that messed partitions layout inside a Flash Memory. I have seen lots of people having similar problem of endless bootloader-loop. There is no need to send a device to a service when bootloader is operational. All you need is a stock firmware image from Google [1], USB cable, and fastboot utility from Android SDK. If you happen to damage a bootloader, then hardware manipulation at low-level is necessary over JTAG, I can help to recover your device in that case.. no worries :-)

[1] https://developers.google.com/android/nexus/images