how does one recognize a USER/BOOT button press?

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1

i'm sure the answer is simple, but on a running BBB, how does one
recognize when the USER/BOOT button has been pressed? is it tied to an
interrupt somewhere?

rday

2

It is tied to a pin (SYSBOOT) that upon the booting of the system is read by the ROM to determine the boot order. There is no interrupt or system message generated by this even as it runs before the kernel is even loaded.

Gerald

3

ah, gotcha. i am apparently misremembering something from before.

rday

4

It shares the LCD pin. Back in the BeagleBoard and -xM, you could use the button as an interrupt if you chose to. With it being shared with the LCD pins, that is harder to do on the BeagleBone Black.

Gerald

5

Hi,

How do I configure gpio_keys to call my custom handler on pressing user button? I want to write a custom handler for user button and then glow the on board LED on button press. I am new to driver dev can someone help me this?

Thanks
Sanket