3.2.6.1.1 CS Disable
The on-board push button SW2 controls the selection (CS#) of the bootable memory components (QSPI) using a non-inverting 3-state buffer.
The rule of operation is:
SW2 (DISABLE_BOOT) pressed = booting from QSPI is disabled when a reset occurs
Refer to the SAMA5D2 Series data sheet for more information on standard boot strategies and sequencing.