enable pru in beaglebone black wireless

I am new to beaglebone.
I had followed the link https://github.com/MarkAYoder/PRUCookbook their . I came around the guide for the setup of pru from this https://www.element14.com/community/community/designcenter/single-board-computers/next-gen_beaglebone//blog/2013/05/22/bbb–working-with-the-pru-icssprussv2
the problem that i faced is that it was build on the older kernel version.
so when following the
step1 : modprobe uio_pruss was loaded with sucess
step2 : but when following the next step:The device tree needs updating to enable the PRUs. Once you have got a text version of am335x-boneblack.dtb (using the method described earlier under “What is the device tree?”)
it is not being possible for me to make this text version(or dtc version as stated on the site ) of the file it is saying permission denied regardless of applying sudo with the commands .
the command failed on this step: dtc -I dtb -O dts am335x-boneblack-wireless.dtb > am335x-boneblack-wireless.dts_orig

by saying :permission denied

After finding the solutions for hours now lastly i checked my kernel version it was running at 4.9 version. so,Then i decided to update my system to the latest version.and downloaded and boot fresh iso file from the beaglebone site. But the problem still remain as it is.
Is their any other way to edit the device tree.

If some one know a better resource on how to enable pru please suggest.

Hello,

I tried the PRUCookbook too. I was unsuccessful at some parts. Anyway: http://processors.wiki.ti.com/index.php/PRU_Training:_Hands-on_Labs.

That should be a good starter point where you can learn more about the PRUSS. Oh and do not forget about TI b/c they have the PRUSS on the am335x TRM listed.

Seth

P.S. It is not easy. I remember trying and trying again and again. Failure is success. Go to your am335x reference manual for other ideas on the PRUSS for your chip on the BBB. It will prove useful.