Why is the pwm setting volatile on Debian 4.4.68-ti-r111 ?

I have cape-universal set up:

0: PF---- -1
1: PF---- -1
2: PF---- -1
3: PF---- -1
4: P-O-L- 0 Override Board Name,00A0,Override Manuf,univ-emmc

root@beaglebone:~# config-pin -q p8.13
P8_13 Mode: pwm

So I configure pwm for pwmchip4 :

sh -c "echo 0 > /sys/class/pwm/pwmchip4/export"

and now I have duty_cycle, period, etc in: /sys/devices/platform/ocp/48304000.epwmss/48304200.pwm/pwm/pwmchip4/pwm0

When the machine reboots all that is gone. Why?

Setup a script to setup your settings on bootup:

https://github.com/adafruit/adafruit-beaglebone-io-python/blob/master/doc/run_config-pin_during_startup.md

Regards,