Boot modes for a Mac with Apple silicon
A Mac with Apple silicon has the boot modes described below.
From a shutdown state, press and release the power button.
From a shutdown state, press and hold the power button.
Note: Security downgrades aren’t allowed on the recoveryOS LocalPolicy.
From a shutdown state, double-press and hold the power button.
The same process as recoveryOS boot, except that it boots to a second copy of recoveryOS that is kept for resiliency. However, LLB doesn’t lock an indication into the Boot Progress Register saying it is going into recoveryOS, and therefore the fallback recoveryOS doesn’t have the capability to change the system security state.
Boot into recoveryOS per the above, then hold Shift while selecting the startup volume.