missing sys/devices/ at lib/firmware/

epi_kao · June 21, 2016, 3:56pm

Hello all,

I have try to understand export/unexport overlay with following link:
https://learn.adafruit.com/introduction-to-the-beaglebone-black-device-tree/exporting-and-unexporting-an-overlay

But then i don’t found the folder “sys/devices/”

So i have try to remove the # at the line #cape_disable=bone_capemgr.disable_partno= , on the uEnv.txt file.

But after reset, the hdmi-output has switched off.
So I have change the uEnv.txt file back to orginal, but unfortunately the hdmi is not working anymore??

Please find below my current uEnv.txt file, so whats wrong now? - and how can i access/enable overlays like the LCDcap?:

uname_r=4.1.15-ti-rt-r43
#uuid=
#dtb=

##BeagleBone Black/Green dtb’s for v4.1.x (BeagleBone White just works…)

##BeagleBone Black: HDMI (Audio/Video) disabled:
#dtb=am335x-boneblack-emmc-overlay.dtb

##BeagleBone Black: eMMC disabled:
#dtb=am335x-boneblack-hdmi-overlay.dtb

##BeagleBone Black: HDMI Audio/eMMC disabled:
#dtb=am335x-boneblack-nhdmi-overlay.dtb

##BeagleBone Black: HDMI (Audio/Video)/eMMC disabled:
#dtb=am335x-boneblack-overlay.dtb

##BeagleBone Black: wl1835
#dtb=am335x-boneblack-wl1835mod.dtb

##BeagleBone Green: eMMC disabled
#dtb=am335x-bonegreen-overlay.dtb

cmdline=coherent_pool=1M quiet cape_universal=enable

#In the event of edid real failures, uncomment this next line:
cmdline=coherent_pool=1M quiet cape_universal=enable video=HDMI-A-1:x800@400e

##Example v3.8.x
#cape_disable=capemgr.disable_partno=
#cape_enable=capemgr.enable_partno=

##Example v4.1.x
#cape_disable=bone_capemgr.disable_partno=
#cape_enable=bone_capemgr.enable_partno=

##Disable HDMI/eMMC (v3.8.x)
#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN,BB-BONE-EMMC-2G

##Disable HDMI (v3.8.x)
#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

##Disable eMMC (v3.8.x)
#cape_disable=capemgr.disable_partno=BB-BONE-EMMC-2G

##Audio Cape (needs HDMI Audio disabled) (v3.8.x)
#cape_disable=capemgr.disable_partno=BB-BONELT-HDMI
#cape_enable=capemgr.enable_partno=BB-BONE-AUDI-02

##enable Generic eMMC Flasher:
##make sure, these tools are installed: dosfstools rsync
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh

thanks

William_Hermans · June 21, 2016, 4:30pm

If you’re using kernel 4.x you should stop reading anything on adafruit’s web pages unless you know how to parse old outdated information. Which obviously you do not.

So . . . sys/devices won’t always exist. but /sys/devices should. You need the forward slash unless your current working directory is / ( or root ). When used without the precceding forward slash, Linux will only look as far as your current working directory for sys/devices/

As to your specific problem. It’s because you’re not paying close attention to what you’re doing, and what Robert explained to you yesterday.

cmdline=coherent_pool=1M quiet cape_universal=enable

#In the event of edid real failures, uncomment this next line:
cmdline=coherent_pool=1M quiet cape_universal=enable video=HDMI-A-1:x800@400e

You need to comment out the cmdline= line that you’re not using. As you can only have one cmdline= statement.

ramona.pierre · June 21, 2016, 9:04pm

>You need to comment out the cmdline= line that you’re not using. As you can only have one cmdline= statement.

Yes but the problem is, that this two cmdline was already entry in the orginal. So thats because i have try with two. But anyway my hdmi output is already off also with only one cmdline

And concerning /sys/devices, i have verified this not only with the terminal, i could really not found this folder! After lib/firmware/ i could not see any other folder with sys or devices??

epi_kao · June 22, 2016, 6:44am

i don’t know why, but now i can find the folder /sys/devices but not "bone_capemgr.*

root@beaglebone:/lib/firmware# cd /sys/devices/bone_capemgr.*
-bash: cd: /sys/devices/bone_capemgr.*: No such file or directory
root@beaglebone:/lib/firmware# cd /sys/devices/
root@beaglebone:/sys/devices#

and by the way uEnv.txt seems already wrong - hdmi is off (only one cmdline is activated)

#Docs: http://elinux.org/Beagleboard:U-boot_partitioning_layout_2.0