Hi, For beagle bone black or beagleboard you can follow this link to build the kernel and the device tree.
to modify the device tree for beagleboneblack you have to edit KERNEL/arch/arm/boot/dts/am335x-boneblack.dts and run the tools/rebuild.sh , this will not only compiles the kernel but also the modules and the dtbs. in order to change the default gpio you cab do this like this : mycustom-gpio = <&gpio1 17 GPIO_ACTIVE_HIGH>; or mycustom-gpio = <&gpio1 17 0>; 0 = GPIO_ACTIVE_HIGH while 1 = GPIO_ACTIVE_LOW above code will set the 17 pin of gpio bank 1 as active low , this is basically 32*1+17 = 49th Gpio that is 23rd pin on the P9 header. you can google begaleboneblack P9 header or P8 header : http://www.siue.edu/~gengel/bbbWebStuff/BeagleboneBlackP9HeaderTable.pdf Hope it helps ! Thanks and Regards, Saurabh On Tuesday, August 30, 2016 at 11:15:57 PM UTC+5:30, El Smiedro wrote: > > And do you know how to adapt it to the boot time? > > Am Dienstag, 30. August 2016 16:45:47 UTC+2 schrieb Wulf Man: >> >> to test what you want use a device overlay first. >> then you can adapt the overlay to be loaded at boot time >> >> On 8/30/2016 7:24 AM, 'El Smiedro' via BeagleBoard wrote: >> >> >> Hello everyone, >> >> currently I am using a BBB with debian 3.8.13 and I would like to change >> the dtb file to get some GPIO-pins with pulldown by default. I searched >> many sites, but I think many information are not up to date (read something >> about the device tree is not used anymore?!). Is somewhere a good and >> current documentation/tutorial for this topic? Thank you very much for your >> help. >> >> Best regards >> eric >> -- >> 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]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/2f1505e9-2308-46e2-b00d-d46e58345ecd%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/2f1505e9-2308-46e2-b00d-d46e58345ecd%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/e8d58af2-d90e-45cc-9037-fc78453f0bc1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
