Newsletter in May 2025

                  - Understanding the internals of the application and RTOS
                                     - From mandate to mindset
                               - Percepio Detect 2025.1 released 
                              - Segger emFile for large databases
                                       - emFile in use worldwide                                   

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If you are developing applications that run on an RTOS, you will most likely have to deal with threads of different priorities and determine which tasks should be executed within an interrupt service routine. If you do not yet know your RTOS well, you should familiarize yourself with the handling of threads and interrupts before you start development.

Understanding the internals of the application and RTOS This is the situation Rick Jen, Azure Technical Specialist at Microsoft, found himself in when he started developing for Zephyr RTOS. He used Tracealyzer from Percepio and used the tool to explore and understand the internals of his application and the RTOS, and then he wrote a blog post about what he learned: What I learned about Zephyr threads We know that Tracealyzer is mainly used for debugging, but Rick's article shows how it can also be used for exploration and learning. A month later, he wrote another blog post, this time to describe the inner workings of zbus, a software messaging bus used in Zephyr for inter-process messaging: What I Learned About Zbus Seriously, read these two posts and you'll probably learn some new ways to use Tracealyzer.

I am happy to adopt the observations of Andreas Lifvendahl, CEO of Percepio:   From mandate to mindset   Regulations such as the EU's Cyber Resilience Act (CRA) are a major concern for many in the embedded software world right now, and understandably so. The pressure to comply is great, especially for teams already struggling with tight schedules and complex development environments. But as disruptive as these regulations may feel, they are also an opportunity and perhaps a necessary nudge to adopt better habits that can strengthen the software we develop far beyond compliance. Think back to the early days of the COVID-19 pandemic. Remember how we were suddenly all asked to wash our hands much more often? It was a reactive measure taken out of necessity. But in hindsight, many of us realized that better hygiene isn't just good in times of crisis - it's always good. In the same way, the practices promoted by the CRA - such as real-time monitoring, trace analysis and observational development - are not just about complying with regulations. It's about building stronger, more resilient systems. Percepio calls this mindset Continuous Observability. It's about extending the visibility you have during development and testing to the field so you can continuously detect, fix and improve. That's not just good hygiene, that's long-term product health. Yes, stress levels are high at the moment. But if we use this moment to strengthen our processes and integrate observability into CI/CT pipelines and field operations, we don't just survive the wave of regulation. We build better products. Curious to see what that looks like in practice?  Read more in this new article: The growing importance of continuous observability in the age of cyber resilience

Percepio Detect 2025.1 released Percepio releases Detect 2025.1 with improved Linux support Percepio Detect brings Continuous Observability to targets crashes and stability risks in RTOS-based embedded software. Designed for seamless integration into your internal testing, CI/CT pipelines and field testing, Detect helps your development team detect and resolve issues early - long before they reach production. Detect 2025.1 currently targets ARM Cortex-M devices running either FreeRTOS or bare-metal code. An evaluation package with a pre-built demo project for the STM32 development board B-L475E-IoT01A is available on request. Read more about Percepio Detect here. Get a quote here.

Segger emFile for large data bases SEGGER emFile is a fail-safe file system library that enables embedded applications to store data reliably and securely on a wide variety of storage media. SEGGER extends emFile to support large databases by integrating SQLite in combination with SEGGER's BigFAT technology and Microsoft's exFAT. BigFAT is a specification developed by SEGGER for storing large files (> 4 GB). With the BigFAT add-on, emFile can process files of almost any size on any FAT-formatted drive. With conventional FAT systems, these large files appear as several individual files that can be read, written and copied. exFAT for emFile is an implementation of the exFAT file system that has been specially optimized for the requirements of embedded systems. For all those who want to work with exFAT, SEGGER can also offer the Microsoft license directly. SQLite is a library written in C that implements a small, fast, self-contained, highly reliable and fully featured SQL database engine. With a view to data security, read and write accesses via emFile are atomic. This ensures that even in the event of a sudden power failure or system crash, neither the file system nor stored data is damaged or put into an inconsistent state. With emFile Journaling, SEGGER offers an additional component that sits on top of the file system and makes the data fail-safe. This add-on ensures that all changes are first logged in a journal and only then transferred to the main file system. This ensures that consistency is maintained. For additional security in the storage layer, RAID modes 1 and 5 can also be supported, while journaling secures the file system level. emFile is optimized for minimum RAM and ROM usage, high speed and maximum flexibility.

emFile in use worldwide   The SEGGER emFile library is the result of over 28 years of continuous development. It is used in billions of devices worldwide and is considered one of the most proven file systems in the embedded industry. Written in portable C, emFile is hardware-independent and can be used on 8-bit controllers as well as on 16/32/64-bit systems. SEGGER offers ready-to-use device drivers for SD/SDHC/SDXC/MMC- cards, e.MMC memory and USB sticks. High-performance drivers for NAND and NOR flash with wear-leveling technology are also available. Read more about emFile here. For price information drop me a line.

I will be writing to you again on July 1. The newsletter on June 1st will not be published, as personal circumstances prevent me from doing so. Sincerely Yours, Marian A. Wosnitza   „A great defeat is a means of self-knowledge and thus of regeneration like no others.“ (Carl Hilty, Swiss constitutional lawyer, politician & ethicist)