Jakub Jermář

Panel discussion and an extended Q&A session on the state of microkernel-based operating systems in 2021 and related topics. The panelists (in order of acceptance):

• Martin Decky (HelenOS, Huawei)
• Jakub Jermar (Kernkonzept, HelenOS)
• Norman Feske (Genode Labs)
• Julian Stecklina (Cyberus)
• Udo Steinberg (BedRock Systems)
• Matthias Lange (Kernkonzept)
• Gernot Heiser (seL4)

The discussion will smoothly evolve into the traditional and less formal "microkernel dinner". Please bring your own food and beverages.

Other people: Martin Děcký Norman Feske Julian Stecklina Udo Steinberg Matthias Lange Gernot Heiser

This is going to be an all-encompassing update talk for HelenOS developments that happened in the Year of the Pig (since the last FOSDEM).

Due to a cancellation, the Microkernel devroom will offer a lightning talk session in the field of Microkernels, Unikernels, and component based systems on Sunday from 15:25-15:55. Feel free to offer proposals.

Current proposals:

15:25 - 15:45 Norman Feske - Genode's Sculpt OS - A general purpose microkernel based OS in daily use

15:45 - 16:00 Jakub Jermar - What is new in HelenOS

Please note this session replaces Jiří Svoboda's talk "Evolution of file system and disk management in HelenOS" due to illness. We wish him a speedy recovery.

Other people: Norman Feske

L4Re is an operating system framework for building systems with real-time, security, safety and virtualization requirements. It consists of the L4Re hypervisor/kernel and a user-level infrastructure that includes basic services such as program loading and memory management. L4Re also provides the environment for applications, including libraries and process-local functionality. L4Re has been released in the form of open source snapshots and also an increasing number of L4Re components has been published on GitHub. This talk will show how some of them can be composed together to create a functional microkernel-based system.

Capabilities can be found in most modern microkernel-based systems. Sometimes the capability pattern is masqueraded under a different name though. In this talk I will tell the story of how HelenOS unwittingly started with a primitive capability system embedded in its IPC, how it evolved into the present state in which capabilities are used as task-local names for an increasing amount of user-visible kernel objects and where this might lead in the future.

HelenOS could not have been developed without certain tools such as compilers, interpreters and emulators. In many cases, these tools have been evolving or leaving their age of infancy at the same time as HelenOS. The long exposure to these tools gave us invaluable experience regarding their strengths and weaknesses. In this talk, I would like to share some of it.

The devroom is not supposed to schedule a lunch break. Let's do something different then.

Let's do some microkernel-related networking while eating in the devroom!

A few warm words...

...to open the devroom.

A detailed walk through the analysis of a deadlock in the HelenOS filesystem layer involving IPC communication and spread across four server processes. The talk will focus on demonstrating how a problem like this can be root caused from within the same running HelenOS instance that was affected by it, relying solely on its own observability features.

In this presentation, I will briefly talk about the developments that have taken place within the HelenOS project since the last FOSDEM. Codewise, I will mention both the new interesting features already merged into the HelenOS mainline repository and a selection of not yet merged ones. This includes features from a variety of areas such as networking, file systems, platforms, audio, testing, and others. In addition, I would like to utter a word or two about our participation in the Summer of Code in Space program during 2013.

During the development of HelenOS, we have made a couple of wrong technical decisions that required a major fix later on. In this talk, I will mention several instances of these mistakes and describe how we fixed them. I will also attempt to generalize the cause of each problem and give some bold recommendations for avoiding it. The idea is to share this part of our experience with the other projects so that we can learn from each other.

Panel discussion on various topics with authors of several microkernel / multiserver operating systems.

Other people: Ben Gras Christian Helmuth Julian Stecklina

HelenOS is a general-purpose multiserver operating system written from scratch. It is based on a custom microkernel, SPARTAN, which currently runs on seven different CPU architectures (ARM, IA-32, x86-64, Itanium, MIPS, PowerPC and SPARC V9) . Most system services (e.g. device drivers, file systems, networking) are implemented in regular user-space processes which communicate via asynchronous messaging. First, the talk will briefly introduce the HelenOS project history and community structure. Second, we will briefly talk about the major technical areas and specifics of the system (boot and kernel, IPC mechanisms and naming services, devices and filesystems). This part will be supported by demos of the running system as well as by showing the structure of the source code. Last, we will look at what functionality is already there, what is currently being actively worked on and what are the future plans, which aim toward making the system self-hosting.

This short talk is intended as the opening talk of the entire devroom. After a welcome greeting, I will briefly ponder about the motivation for meeting together and attempt a basic quantitative comparison of participating projects based on available project-metric data. The goal of this quick comparison is to illustrate some apparent similarities and differences between our projects, and to further support our common cause.