An effort to port the Plan 9 from Bell Labs operating system to the Raspberry Pi family of low-cost single-board computers has received initial support for the new Raspberry Pi 4 – though there’s still work to do on the project.
First released in 1992 for academic users and 1995 for the general public, Plan 9 from Bell Labs – named for infamous Ed Wood sci-fi effort Plan 9 from Outer Space – replaced Unix as the telecommunications company’s primary research platform. Despite being defocused by the company in 1996 and having never reached the popularity of Linux or BSD, Plan 9 from Bell Labs lives on: 2000 saw a free third edition released and 2002 the fourth edition, which continues to be updated – including new support for the Raspberry Pi 4 single-board computer.
“I’m not suggesting anyone should rush out to buy a [Raspberry Pi 4] just yet,” writes Richard Miller in a post to the 9fans mailing list. “Unlike previous releases of the board, this incarnation has some very big changes, so a lot of new driver writing will be needed before it’s at all useful under Plan 9. It’s quite daunting actually.
“[It] boots as far as the root prompt, but there are too many new peripherals without driver support (or documentation so far) to do anything useful: USB host sockets are all connected to new USB 3 controller; SD card is connected to new eMMC controller (can’t use sdhost); Ethernet is connected to new native GBE controller. Wifi is unchanged from 3B+, but currently fails intermittently with emmc IO_RW_EXTENDED data corruption.”
Those already running Plan 9 from Bell Labs can get access to Miller’s kernel source with the command “srv -nq tcp!9p.io sources /n/sources”; anyone else can find it via web browser.