I’m in the process of designing a custom version of the BeagleBone Black. In my application, I don’t want a power button. I’d like the board to boot as soon as the AC or USB signal is energized on the PMIC. I know that, by default, the BeagleBone Black looks for the PB INT bit in the PMIC INT register before asserting the PMIC_PWR_EN. In my application, I assume I’d need to modify boot code to look for the AC or USB INT bits in the PMIC INT register. My question is whether or not this requires a modification of the SPL or if the processor handles this in the primary boot code in ROM.
Any advice is much appreciated.