/sys/device/bone_capemgr* doesn't exist on fresh image

Sorry for the super newbie question. What do I need to install in order to have the /sys/devices/bone_capemgr* directory show up on a fresh Ubuntu image? My software uses this to configure the device tree for PWM slots.

Background: I was operating fine using the default Debian image that came on the BBB Rev C, but for various reasons I decided to switch to Ubuntu (Trusty). I used the image located here and all seemed to go well. I can list the GPIOs at /sys/class/gpio, but there is no bone* under /sys/devices like there used to be with the Debian (Wheezy) image.

Any pointers would be appreciated.


Down grade to v3.8.x:

sudo apt-get update
sudo apt-get install linux-image-3.8.13-bone68
sudo reboot


That did it, thanks Robert!

Install device tree compiler using sudo apt-get install device-tree-compiler

When I installed Ubuntu 14.04, it didn’t have dtbo files for pwm, had to compile them manually. Faced errors with -@ option in while compiling device tree overlay, overcame with commands as given below

wget -c https://raw.github.com/RobertCNelson/tools/master/pkgs/dtc.sh
chmod +x dtc.sh

source: http://hipstercircuits.com/problems-with-beaglebone-black-and-their-solution/


got the missing dts files from


now at https://github.com/venkaty89/devicetree-source/tree/master/arch/arm/boot/dts



compiled required files using build file


echo “Compiling the overlay from .dts to .dtbo”

dtc -O dtb -o am33xx_pwm-00A0.dtbo -b 0 -@ am33xx_pwm-00A0.dts

dtc -O dtb -o bone_eqep0-00A0.dtbo -b 0 -@ bone_eqep0-00A0.dts

dtc -O dtb -o bone_eqep1-00A0.dtbo -b 0 -@ bone_eqep1-00A0.dts

dtc -O dtb -o bone_eqep2-00A0.dtbo -b 0 -@ bone_eqep2-00A0.dts

dtc -O dtb -o bone_pwm_P8_13-00A0.dtbo -b 0 -@ bone_pwm_P8_13-00A0.dts

dtc -O dtb -o bone_pwm_P8_19-00A0.dtbo -b 0 -@ bone_pwm_P8_19-00A0.dts

dtc -O dtb -o bone_pwm_P8_34-00A0.dtbo -b 0 -@ bone_pwm_P8_34-00A0.dts

dtc -O dtb -o bone_pwm_P8_36-00A0.dtbo -b 0 -@ bone_pwm_P8_36-00A0.dts

dtc -O dtb -o bone_pwm_P8_45-00A0.dtbo -b 0 -@ bone_pwm_P8_45-00A0.dts

dtc -O dtb -o bone_pwm_P8_46-00A0.dtbo -b 0 -@ bone_pwm_P8_46-00A0.dts

dtc -O dtb -o bone_pwm_P9_14-00A0.dtbo -b 0 -@ bone_pwm_P9_14-00A0.dts

dtc -O dtb -o bone_pwm_P9_16-00A0.dtbo -b 0 -@ bone_pwm_P9_16-00A0.dts

dtc -O dtb -o bone_pwm_P9_21-00A0.dtbo -b 0 -@ bone_pwm_P9_21-00A0.dts

dtc -O dtb -o bone_pwm_P9_22-00A0.dtbo -b 0 -@ bone_pwm_P9_22-00A0.dts

dtc -O dtb -o bone_pwm_P9_28-00A0.dtbo -b 0 -@ bone_pwm_P9_28-00A0.dts

dtc -O dtb -o bone_pwm_P9_29-00A0.dtbo -b 0 -@ bone_pwm_P9_29-00A0.dts

dtc -O dtb -o bone_pwm_P9_31-00A0.dtbo -b 0 -@ bone_pwm_P9_31-00A0.dts

dtc -O dtb -o bone_pwm_P9_42-00A0.dtbo -b 0 -@ bone_pwm_P9_42-00A0.dts

copied compiled dtbo files to /lib/firmware using

cp -f *.dtbo /lib/firmware

Dear Robert

my kernel is v4.0, i have the same problem. can not find the bone_capemgr* file. i used your way, but when i reboot bbb, it stoped at “Stopping System V runlevel compatibility [ok]” .

what can i do ?

Dear Robert

                    my kernel is v4.0, i have the same problem. can not find
the bone_capemgr* file.

Really!!! it's not in v4.0??? Oh my what are we going to do!

Down grade to v3.8.x:

sudo apt-get update
sudo apt-get install linux-image-3.8.13-bone71
sudo reboot

i used your way, but when i reboot bbb, it stoped
at "Stopping System V runlevel compatibility [ok]" .
what can i do ?

sudo apt-get install bb-customizations

will fix that..


Talk about your FAQ...

Sadly, I think this will persist so long as 99% of all guides online for how to interface the BBB to anything talk about capemgr. Is there active work on a replacement?


The main infrastructure is now in mainline... But the 'knobs n dials'
for control are still being discussed..

When something gets usable, things will be announced here. :wink:


When I downgrade to this image all four of my LEDs are illuminated upon reboot and stay this way for a long time. Is this normal?


Considering this specific thread went back a year ago...

What image did you start with? Before you down-graded?


I just used Debian 8.2 from the website.

Well, bone68 was over a year ago.. so yeah, probally broken..

Today, 3.8.13-bone79 is the latest:


So you should have done:

sudo apt-get update ; sudo apt-get install linux-image-3.8.13-bone79 ;
sudo reboot

Or you could have used the script listed here:


or here:


Lesson, don't follow directions more then a year old..


Ah, thank you for the help! I’ll give that a try.

Yeah, doing a quick google search I found this thread and was running into an issue with trying to use the PRU so I figured I’d give this a try.

For the pru, compatible with 3.8 you can use:



or the real time version:


With the magic script:

cd /opt/scripts/tools/
git pull

sudo ./update_kernel.sh --bone-kernel --lts


sudo ./update_kernel.sh --bone-rt-kernel --lts


Oh, cool. Should I install the 8.2 image from the website, install linux-image-4.1.14-bone-rt-r17 using apt-get and then update the kernel?

Hey, quick question. Trying to

Either or.. they both do the same thing.. the "update_kernel.sh"
always get's the latest.. So in a month's time, when this email
exchange is old, "bone17" will be long replaced. :wink:


^^ don’t mind that second line, didn’t realize I started typing in the box… was meant for a different window :slight_smile:

Awesome, thanks for the help!

Hey, since I’ve got you here. Do you have anything good to read on using the PRU with the GPIOs on the board?


This one is different from the “stock” repo as he’s added 3 examples all related to blinking LEDs. LEDs which are tied to GPIO pins . . .After that, google has lots to read.