On the BCM2711, the base VCore was greatly lowered from previous processors, though the
over_voltage setting still uses 0.025V increments. On my Pi 4,
vcgencmd measure_volts returns 0.8563V when not overvolted and 1.0063V at
over_voltage=6, the highest allowed without tripping the warranty bit.
However, it seems the Raspberry Pi 400, which uses a newer stepping of the BCM2711, ships with
over_voltage=0x11170 by default. I have not seen hexadecimal values for this setting documented anywhere, but as far as I can tell, this corresponds to an offset of 70,000 microvolts (0.07V), just shy of
over_voltage=6 corresponds to a 0.15V offset, can I safely use an arbitrary value between
0x249F0 for precise voltage offsets?