Linux Kernel 5.5 brings changes to ARM, RISC-V and MIPS

At the end of last week, Linus Torvalds brought a complete list of Linux 5.5 changes for ARM, MIPS and RISC-V architectures. Io_uring asynchronous I/O has been improved, adding the ability to modify the set of files being operated on without starting over, user-specifiable completion-ring sizes, absolute timeouts, and support for accept() calls among others.

Also the Airtime Queue Limits (AQL) for WiFi that make CoDel work more effectively with wireless drivers that utilized firmware/hardware offloading. KUnit unit testing framework for the Linux kernel with tests can now be run locally on a developer’s workstation without any VM or special hardware. Another change is SMB rootfs and multichannel support using SMB as root file systems, and support for using multiple network connections for the same SMB session.

For more information about changes to different architectures, check out the article exploring the subject:

Linux 5.5 changes announcement

So this last week was pretty quiet, and while we had a late network update with some (mainly iwl wireless) network driver and netfilter module loading fixes, David didn’t think that warranted another -rc. And outside of that, it’s really been very quiet indeed – there’s a panfrost driver update too, but again it didn’t really seem to make sense to delay the final release by another week.

Outside of those, it’s all really tiny, even if some of those tiny changes touched some core files.

So despite the slight worry that the holidays might have affected the schedule, 5.5 ended up with the regular rc cadence and is out now.

That means that the merge window for 5.6 will open tomorrow, and I already have a couple of pull requests pending. The timing for this next merge window isn’t optimal for me – I have some travel and other things going on during the same two weeks, but hopefully it won’t be all that noticeable. But there might be random timezones, odd hours, and random delays because of that. I try to avoid scheduling things during the merge window, but hey, it doesn’t always work out, and I’d have to delay things by two weeks to avoid the conflicts, which just doesn’t seem worth it.

Particularly since it’s not necessarily going to be a problem to begin with. We’ll see.

Anyway. Go out and test 5.5, and start sending me those pull requests for all the new development that is ready,


Ubuntu 19.10 for latest Raspberry Pi applications

With 19.10 release of Ubuntu Server, Canonical announced official support for the Raspberry Pi 4. The latest board from the Raspberry Pi Foundation sports a faster system-on-a-chip with a processor that uses the Cortex-A72 architecture (quad-core 64-bit ARMv8 at 1.5GHz). Additionally, it offers up to 4GB of RAM. We are supporting the Raspberry Pi 4 to give developers access to a low-cost board, powerful enough to consolidate compute workloads at the edge. 

The Raspberry Pi has established itself as a most accessible platform for innovators in the embedded space. Canonical is dedicated to empowering innovators with open-source software. Consequently, Canonical endeavors to offer full official support for all the boards in the Raspberry Pi family. Canonical will therefore enable both Ubuntu Server and Ubuntu Core for existing and upcoming Pi boards.

Ubuntu Roadmap. Source:

Industrial use of Raspberry Pi 4

A year ago, TECHBASE released an updated version of the ModBerry M500 industrial IoT computer, replacing the aging Raspberry Pi 3 with a 3B+, giving it better performance. With the recent launch of the Raspberry Pi 4, TECHBASE has yet again, announced another upgrade to the M500, which now packs the latest single-board computer.

Raspberry Pi 4

Over 10 million Raspberry Pi’s have been sold and the Raspberry Pi is likely to stay as a new standard in the industry. Official Raspbian OS is free operating system based on Linux Debian optimized for the Raspberry Pi comes with over 35,000 packages, pre-compiled software bundled in a nice format for easy installation. ModBerry devices are compatible with Raspberry Pi accessories, supported by Raspberry Pi Foundation. ModBerry M500 now with Raspberry Pi 3 Model B+ / Raspberry Pi 4 Model B support.