SW_RPi_armboost

RaspBerry Pi boot failure

If your Raspberry PI under a newer Linux image does not boot through e.g. on an SEU-M card, but does so when connected to the original power supply:

Error:

Raspi detects undervoltage (journalctl -f results in ‘undervoltage...’ every few moments) and aborts booting without additional power. With additional power supply it boots up.

Solution:

Edit /boot/firmware/config.txt (sudo nano /boot/firmware/config.txt), search for arm_boost=1 and change this to arm_boost=0

 [pi4]
 # Run as fast as firmware / board allows
 arm_boost=1

Cause:

arm_boost=1 instructs the system to run as fast as it can. This leads to higher power consumption and to an undervoltage being detected during booting, for example. This is particularly the case if the input voltage is below 5.2 volts. 5 volts are provided on the SEU-M.
By setting arm_boost=0, the RPi is not forced to run at maximum speed. This reduces the power consumption significantly, so that an undervoltage error is less likely.

Important

This workaround applies only to RPi4 oder higher (e.g. RPi400)! See https://www.raspberrypi.com/documentation/computers/config_txt.html#arm_boost

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Contributed by Wolfram Henkel in telexforum.de