BeagleBone Black Power Button Pin P9_09, issue with DTS 5.x

[lists at cyclaero.com]

I finished a project with the BeagleBone Black running FreeBSD 13.0-CURRENT #0 r350899M: Mon Aug 12 11:40:06 -03 2019. Once I mounted it into the closure and connected the external power button to P9_09 and ground (P9_01), the BBB freezes instantly and completely when the power button is pressed. From this I could only recover by pulling the 5 V plug. 

I build the very same kernel after only replacing the DTS 5.1 with the DTS 4.2, using the following command sequence:

   cd src/sys/gnu/dts
   mv arm arm-5.1
   svn checkout -r 346091 https://svn.freebsd.org/base/head/sys/gnu/dts/arm arm-4.2
   ln -s arm-4.2 arm
   cd ../../..
   
   make -j4 buildkernel TARGET_ARCH=armv7 KERNCONF=CyControl
   mount -o noatime /dev/ufs/SYSTEM /back
   sudo -E make installkernel TARGET_ARCH=armv7 KERNCONF=CyControl DESTDIR=/back
   mount_msdosfs -o noatime /dev/da0s1 /mnt
   rm -r /mnt/dtb
   cp -r /back/boot/dtb/ /mnt/dtb
   umount /mnt
   umount /back

Afterwards, the power button works as expected.

My projects with the BBB are finished, and I don’t ask for fixing this. I only wanted to report the issue. In case you need an external power button with the BBB then you want to avoid DTS 5.x.

Best regards

Rolf