I'm a n00b, but I have a requirement to make a few of my GPIO pins not 
output any voltage during boot.

I've got a new beaglebone black.

I can disable them through the /sys/class/gpio/export just fine but doing 
so in a bash script on boot leaves current through the pin for about 4-5 
seconds before it runs my script.

So next, I looked into modifying the boot loader. I tried commenting out 
the bottom section of beagle.c:


        /* Set GPIO states before they are made outputs
        writel(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1,
                &gpio6_base->setdataout);
        writel(GPIO31 | GPIO29 | GPIO28 | GPIO22 | GPIO21 |
                GPIO15 | GPIO14 | GPIO13 | GPIO12, 
&gpio5_base->setdataout); */

        /* Configure GPIOs to output
        writel(~(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1), &gpio6_base->oe);
        writel(~(GPIO31 | GPIO29 | GPIO28 | GPIO22 | GPIO21 |
                GPIO15 | GPIO14 | GPIO13 | GPIO12), &gpio5_base->oe); */

        dieid_num_r();

and recompiled and tested and there is still voltage coming from pin 11 
during boot.

Would someone that has experience doing this at least point me in the right 
direction? It would be so much appreciated!

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to