Single-board computers with fatal flaws
The Raspberry Pi requires nonfree software to start up. It can't reach
the point of executing free software unless this nonfree program is part of
the installed system software.
The startup program is, in fact, the same program that runs the GPU and
the video decoding hardware. Thus, the GPU and the video decoding hardware
are unusable in the free world, but these jobs can be done with free software
on the CPU.
That program appears to implement intentional restrictions, such as
blocking the video decoding hardware for MPEG-2 and VC-1 in the absence of a
key that is specific to the machine in hand.
-- https://www.fsf.org/resources/hw/single-board-computers
Unless this has changed I don't think we'll see Trisquel on raspberry.
On ARM maybe however.
