The Raspberry pi is classified as fatally flawed in the article on single board computers at the FSF. According to the article "The Raspberry Pi requires nonfree software to start up". The article reviewed the first two Raspberry PI.
Nowadays a free software implementation of the boot software is available but at the time of writing, it's not stable enough to make the Raspberry PI usable. See the Raspberry bootloader section in the list of tasks in the ReverseEngineering page
Having an usable free software implementation of the boot software would make Raspberry Pi usable in freedom. This is interesting as many of such devices were sold.
While many other Single Board computers exist, some of which are less flawed, being compatible with devies sold in such large quantity brings a lot of advantages:
- Many cases and add-on electronic circuits were made specially for the Raspberry PI formfactor.
- Many projects and documentation uses Raspberry PI.
Fortunately, several other single board computers (some of which are probably not fatally flawed) have compatible formfactor and electronical interfaces.
Such boards can enable people to leverage the advantages mentioned above while preserving users freedom.
This is a preliminary list:
- Many devices with "PI" inside their name in this list: https://linux-sunxi.org/Table_of_Allwinner_based_boards
- The "HummingBoard Base" and "HummingBoard Pro" from https://www.solid-run.com/nxp-family/hummingboard/
It was not yet checked for fitness, electrical/electronical compatibility or freedom.