I tend to suspect it's unrelated, but if you add "nomodeset nofb" to
your boot command line it will turn off the graphics drivers.
Yes, I guess it is indeed unrelated. With buster I can see the same messages during boot:
- *ERROR* Failed to load firmware! on drm
- pcc_cpufreq_init: Too many CPUs, dynamic performance scaling disabled
But no crash happens, Buster boots correctly (every time) and I can use the system.
I currently suspect a Kernel bug in 5.10. I might be dead wrong, but that's my current guess.