The project is still mostly stalled, unfortunately. But a couple of things were achieved :
- Simon Venken reported a bug on semaphores, which were reworked.
- Simon Venken also reported a bug concerning the chaining of wake-ups in sleep queues, which was fixed.
- the kern/mbuf module, providing message ring buffers, was added.
- the kern/log module was reworked to use a message ring buffer, and a bug on the log buffer being full was fixed.
How does a developer come up with code ? How does he know what to write, and if it’s a correct thing to do ? Spoiler alert: it’s much more art than science.
As a result of personal events, the project has been mostly stalled these last six months. However a few changes were made, the most important being :
- Interrupt handling rework on x86, with the merging of the trap module into the cpu module.
- Red zone support on x86 (amd64), which is required for full ABI compliance.
- Suspend/resume thread operations, similar to SIGSTOP/SIGCONT on Unix.
Since I got myself an ARM Chromebook, I made it a goal to be able to work on X15 directly on that small device. This implies cross compiling from ARM (actually aarch64) to x86, and running it in an emulator. More »
The major change of this quarter is the addition of a generic low level performance monitoring system, developed in large part by Rémy Noël.
It’s been a while since I’ve written about the progress on X15. As an open source project I work on in my free time, its development pace is unsurprisingly not constant, but despite that, a lot of progress was made since it was seriously restarted in 2017.
As my interest in the ARM architecture is growing, I decided to buy myself a toy to play with, based on one of those big.LITTLE asymmetric multicore 64-bit ARM processors, and see how they perform. I settled on the ASUS C101PA Chromebook after a friend successfully installed a Linux distribution on it.
I used to be an OVH DSL user. The service was very good. The only thing that could have been improved was the Technicolor router, which is clearly sub-par compared to the quality normally associated with OVH services, but as long as you stick to the default configuration, it would run fine. More »
Among the goals of the X15 operating system is real time. This expression is undoubtedly one of the vaguest buzzwords out there in the computer industry, which means I can’t really say anything about it without first attempting to provide a decent definition. More »
This could be the title of a novel, but no, the subject is really about computers and systems. More »