>>3
Raspberry Pi 1, 2 and 3 require loading binary blobs to boot. Raspberry Pi 4's Cortex-A72 is vulnerable to Spectre. I'll probably start hardening the RPi by using another cheap board like the Olimex A20-OLinuXino-LIME2.
See:
http://textboard.org/prog/130
http://textboard.org/prog/96