Upgrading to Raspberry Pi OS Trixie

I just finished the second editions of two of my books: Raspberry Pi Assembly Language Programming and RP2040 Assembly Language Programming, where one of the goals was to update the screenshots and descriptions of the operating system including the name change from Raspbian to Raspberry Pi OS. Of course as soon as the books went to production, Raspberry released a new major version namely Trixie. I was able to sneak one Trixie change into the RP2040 book, namely that the /dev name of the serial port changed yet again from /dev/ttyAMA0 to /dev/ttyACM0.

The Raspberry Pi OS is based on Debian Linux, as are many of the other Linux distributions such as Ubuntu and Mint, so when Debian released their Trixie release, Raspberry wouldn’t be too far behind. This article gives my perspectives and impressions of this release.

The Raspberry Pi foundation recommends doing a clean install with the Raspberry Pi Imager and not to try upgrading from a previous release such as Bookworm. This used to be easy when running from SD cards which I have lots of and it is easy to switch them around. I now run using an SSD drive, which I only have one of, so I thought I would try upgrading against recommendations using this post from the Raspberry Pi forum.

This didn’t work. It got errors in a later stage of the process and the result was an SSD drive that wouldn’t boot. I don’t think my previous install was non-standard, so I don’t know what caused it, but I guess my recommendation is to not bother trying to upgrade, just go straight to the clean install. I had everything needed backed up, so no data lost, just time messing around.

Anyway, I took out the SSD, put it in a USB caddy, connected it to a laptop and ran the Raspberry Pi imager performing a clean install. This then worked quite well.

In this article, I mention enabling PCIE gen 3 by editing /boot/firmware/config.txt to get better performance out of a typical SSD drive. I thought maybe with Trixie, this would be the default, but sadly it isn’t. You still need to manually edit the file to get PCI gen 3 performance.

This new version includes changes from Debian as well as changes added by the Raspberry Pi foundation. These are:

• The most noticeable change is that Raspberry Pi has updated the fonts and screen backgrounds. This makes Trixie visually different from Bookworm and will be the main change people notice.
• Raspberry has provided a new control center application to configure your Pi. With each upgrade, hopefully less editing text files.
• Raspberry upgraded the Bookshelf application, mostly to support features in their official Raspberry PI magazine.
• The Linux kernel is still the 6.12 long term supported version. If you want a newer version, it is best to use a different Linux distribution for the Pi, perhaps the new Ubuntu.

Most Linux distributions have been making the transition from the X11 display server to the newer Wayland display server. The previous Bookworm release configured Wayland by default, but you could switch to X11 using raspi-config. When writing my books, I need screen grabs of various windows. With Bookworm and Wayland, you seemed to only be able to screen grab the whole screen using the Print Screen button, capturing a single window didn’t work and I tried several utilities to do this. Cropping a single window from the whole screen is a pain. I found that configuring back to using X11 allowed all the screen capture utilities to work and made screen grabs of a single window easy.

Sadly, under Trixie this is still the case. To get good screen shots you need to switch from Wayland to X11 using raspi-config in the advanced menu. The only improvement is that the useful screen capture utility Shutter now has a message displayed telling you that Wayland support is limited and greys out all the options that won’t work. Previously, it would crash when you pressed any of these other buttons.

If the Linux world is truly going to stop including X11 then they have to finish fixing all these holes where X11 is required and Wayland doesn’t work.

Trixie is a good upgrade over Bookworm. Everything runs a bit smoother, with a number of improvements. Its too bad screenshots don’t work properly on Wayland and the default PCIE configuration is still gen 2 rather than gen 3, but these were problems in Bookworm as well. A reliable upgrade path would also be nice and with more and more people running SSD drives rather that SD cards, I think the Raspberry Pi Org needs to give some priority to providing an easy upgrade path, since switching SSD drives is a pain and people are running a lot of things on their Pis to move from one drive to another.