'The Xen Project has ported its hypervisor to the 64-bit Raspberry Pi 4. The Register reports: The idea to do an official port bubbled up from the Xen community and then reached the desk of George Dunlap, chairman of the Xen Project's Advisory Board. Dunlap mentioned the idea to an acquaintance who works at the Raspberry Pi Foundation, and was told that around 40 percent of Pis are sold to business users rather than hobbyists. With more than 30 million Arm-based Pis sold as of December 2019, and sales running at a brisk 600,000-plus a month in April 2020, according to Pi guy Eben Upton, Dunlap saw an opportunity to continue Xen's drive towards embedded and industrial applications. Stefano Stabellini, who by day works at FPGA outfit Xilinx, and past Apache Foundation director Roman Shaposhnik took on the task of the port. The pair clocked that the RPi 4's system-on-chip used a regular GIC-400 interrupt controller, which Xen supports out of the box, and thought this was a sign this would, overall, be an easy enough job. That, the duo admitted, was dangerous optimism. Forget the IRQs, there was a whole world of physical and virtual memory addresses to navigate. The pair were "utterly oblivious that we were about to embark on an adventure deep in the belly of the Xen memory allocator and Linux address translation layers," we're told. [The article goes on to explain the hurdles that were ahead of them.] "Once Linux 5.9 is out, we will have Xen working on RPi4 out of the box," the pair said. [...] Stefano Stabellini told The Register that an official Xen-on-RPi port will make a difference in the Internet-of-Things community, because other Arm development boards are more costly than the Pi, and programmers will gravitate towards a cheaper alternative for prototyping. He also outlined scenarios, such as a single edge device running both a real-time operating system alongside another OS, each dedicated to different tasks but inhabiting the same hardware and enjoying the splendid isolation of a virtual machine rather than sharing an OS as containers. George Dunlap also thinks that an official Xen-on-RPi port could also be of use to home lab builders, or perhaps just give developers a more suitable environment for their side projects than a virtual machine or container on their main machines. Stay tuned to Project EVE's Github page for more details about how to build your own Xen-for-RPi. Hacks to get it up and running should also appear on the Xen project blog.' -- source: https://hardware.slashdot.org/story/20/09/29/2025213 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/