I have an Intel NUC, and I've compiled a kernel extension to control the LED. It has created a .ko file at /lib/modules/4.15.0-38-generic/updates/dkms/nuc_led.ko (which matches uname -r). Manually loading the extension works great:

sudo modprobe wmi
sudo insmod /lib/modules/4.15.0-38-generic/updates/dkms/nuc_led.ko
echo 'ring,80,blink_medium,green' | sudo tee /proc/acpi/nuc_led > /dev/null

This works.

However the extension is not currently loaded at boot. I would like to put commands to turn the LED on and off in rc.local and rc6.d/ but these are not working, I have to run the modprobe commands manually, and even then my file in rc6.d/ (shown below) is not working - the LED remains on.

What am I doing wrong?

$ cat /etc/rc6.d/zz_led_off.sh
#! /bin/bash

echo 'ring,0,none,off' | sudo tee /proc/acpi/nuc_led > /dev/null

$ ls -la /etc/rc6.d/zz_led_off.sh | grep zz
-rwxr-xr-x   1 root root   79 Nov  9 10:07 zz_led_off.sh
  • why not compile directly into the kernel, instead of being a module? – Doug Smythies Nov 9 '18 at 16:18
  • @DougSmythies I'm not sure what that means, how would I compile it directly into the kernel? – user31415629 Nov 12 '18 at 15:32
  • Sorry, I think I was wrong. If I understand correctly, because it isn't part of the kernel code, but rather an extension to it, I don't think direct compile into the kernel is an option. – Doug Smythies Nov 12 '18 at 15:51

Add the module to /etc/modules, in this case, add the following two lines:


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