nuc8-led

Linux kernel module for controlling the front indicator LED on Intel NUC 8th Generation Mini PCs (Bean Canyon).

Background

Legacy tools like the 2017 intel_nuc_led driver depend on the ACPI WMI SLED method. On Intel NUC 8 boards, the BIOS hardcodes SLED to return 0xE1 (NOSUPPORT), completely disabling userspace control through standard WMI.

This module talks directly to the Embedded Controller (EC) via memory-mapped I/O (MMIO at 0xFE410500), enabling software-controlled LED management across modern Linux kernels (5.x, 6.x, and 7.x+).

Tested Hardware

• Intel NUC8i3BEK / NUC8i3BEH
• Intel NUC8i5BEK / NUC8i5BEH
• Intel NUC8i7BEH
• OS: Debian 11/12/13, Ubuntu, Proxmox VE, OpenMediaVault

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BIOS Configuration

Before using this driver, you must hand control of the LED over to software in the BIOS:

1. Power on or reboot your NUC and repeatedly press F2 to enter BIOS setup.
2. Navigate to: Advanced -> Power -> Secondary Power Settings
3. Look for the LED configuration section.
4. Set HDD LED to Software Control (SW Control).
5. Press F10 to save changes and reboot into Linux.

(Note: If left on "HDD Activity", the Embedded Controller hardware will keep overriding the LED).

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Installation

Prerequisites (Debian / Ubuntu / Proxmox / OMV)

Install build tools, DKMS, and the kernel headers:

sudo apt update
sudo apt install -y build-essential linux-headers-amd64 linux-headers-$(uname -r) dkms git

(Note: linux-headers-amd64 ensures that future kernel upgrades automatically pull matching headers so DKMS can rebuild the driver).

Option 1: DKMS (Recommended)

Installs the driver and automatically rebuilds it across kernel upgrades:

git clone https://github.com/CraftingTH/nuc8-led.git
cd nuc8-led
sudo cp -r . /usr/src/nuc8-led-1.1.0
sudo dkms add -m nuc8-led -v 1.1.0
sudo dkms build -m nuc8-led -v 1.1.0
sudo dkms install -m nuc8-led -v 1.1.0
echo "nuc_led" | sudo tee /etc/modules-load.d/nuc_led.conf
sudo modprobe nuc_led

Option 2: Manual Build

If you prefer to compile and test manually without DKMS:

git clone https://github.com/CraftingTH/nuc8-led.git
cd nuc8-led
make
sudo insmod nuc_led.ko

Verify the driver is active:

cat /proc/nuc_led

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Usage

Control the LED by writing parameters directly to /proc/nuc_led.

Command Syntax

# Quick syntax (solid color)
echo '<brightness>,<color>' > /proc/nuc_led

# Full syntax
echo 'hdd,<brightness>,<mode>,<color>' > /proc/nuc_led
echo 'hdd,<brightness>,blink,<frequency>,<color>' > /proc/nuc_led
echo 'hdd,<brightness>,breathe,<frequency>,<color>' > /proc/nuc_led

# Restore hardware disk activity
echo 'hdd,auto' > /proc/nuc_led

Parameters

• Brightness: 0 (off) to 100 (full brightness)
• Colors: green, red, blue, yellow, amber, purple, white
• Modes:
  • solid - Continuous light
  • blink - Symmetrical 50/50 square-wave flash (kernel timer)
  • breathe - Sinusoidal breathing (hardware PWM)
  • fade - Sawtooth ramp-down (hardware pulse)
  • auto - Restores hardware disk activity
• Frequencies (for blink and breathe):
  • fast / 2.0hz
  • normal / 1.0hz (default)
  • slow / 0.5hz

Examples

# Solid green at 100%
echo '100,green' > /proc/nuc_led

# Solid red dimmed to 10%
echo '10,red' > /proc/nuc_led

# Blinking green at 1 Hz
echo 'hdd,100,blink,1.0hz,green' > /proc/nuc_led

# Fast flashing red alert (2 Hz)
echo 'hdd,100,blink,fast,red' > /proc/nuc_led

# Slow breathing blue
echo 'hdd,100,breathe,slow,blue' > /proc/nuc_led

# Turn LED off
echo '0,green' > /proc/nuc_led

# Restore hardware disk activity
echo 'hdd,auto' > /proc/nuc_led

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Uninstallation

To completely remove the DKMS module from your system:

sudo dkms remove -m nuc8-led -v 1.1.0 --all
sudo rm -rf /usr/src/nuc8-led-1.1.0
sudo rm -f /etc/modules-load.d/nuc_led.conf
sudo rmmod nuc_led

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License

GPL-2.0