# ODROID

Related articles

- Installation guide

There are several supported ODROID ARM boards available to consumers. This wiki page offers general configuration that should be applicable to them all. At this point, the content has been verified to work on the ODROID-C2 and ODROID-U3.

Note: Support for the ARM architecture is provided on http://archlinuxarm.org not through posts to the official Arch Linux Forum. Any posts related to ARM specific issues will be promptly closed per the Code of conduct#Arch Linux distribution support *only* policy.

## Installation

See the installation instructions at the Arch ARM project page.

- ODROID-U2 (armv8)
- ODROID-C1 (armv7)
- ODROID-U2 (armv7)
- ODROID-U3 (armv7)

- ODROID-U3 (armv7)
- ODROID-X2 (armv7)
- ODROID-XU (armv7)
- ODROID-XU3 (armv7)
- ODROID-XU4 (armv7)

## Kernel updates

It should be noted that unlike the Raspberry Pi kernels that boot without an initramfs, the AArch64 kernels (kirkwood and linux-odroid-c2 for example) do require an initramfs which is generated by mkinitcpio just like Arch x86_64 or i686. Upon updates, it is known that mkinitcpio does not detect ARM kernel modules and as such, will display following warnings which are harmless:

    -> Running build hook: [base]
    -> Running build hook: [udev]
    -> Running build hook: [autodetect]
    find: ‘/sys/devices/platform/’: No such file or directory
    -> Running build hook: [modconf]
    ...
    -> Running build hook: [fsck]
    ==> WARNING: No modules were added to the image. This is probably not what you want.

## CPU scaling and temperature management

### Headless mode for the C2

For servers (ie no need for a display), one can uncomment the following in `/boot/boot.ini` to free up approx 300 M of memory at the cost of disabling the video subsystem:

    setenv nographics "1"

### CPU frequency scaling

The cpupower package can be used to select alternative CPU governors for power savings. Edit `/etc/default/cpupower` and set the governor= line followed by start cpupower.service.

#### Show online/offline cores

If using the hotplug governor, idle cores are switched off to reduce power consumption and heat generation.

    lscpu |grep line

## Onboard hardware sensors

### CPU temperature

    awk '{printf "%3.1f°C\n", $1/1000}' /sys/class/thermal/thermal_zone0/temp

### CPU frequency

    awk '{printf "%3.1f MHz\n", $1/1000}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

### CPU governor

    cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

### Lightweight monitoring suite

monitorixAUR has specific support for the the ODROID since v3.8.2 through the `gensens = y` setting in `/etc/monitorix/monitorix.conf`. Core temperature and CPU frequency are logged; screenshots available here.

## Hardware tweaks

### LEDs

Several ODROID models have dual LEDs: a red power LED which is always on if power is supplied, and a blue LED which can be configured.

#### Blue LED

By default, the blue LED is a heartbeat LED, which flashes when the kernel is running. Depending on the model, this can be changed through the following..

- ODROID-C2: `/sys/class/leds/blue:heartbeat/trigger`
- ODROID-U3: `/sys/class/leds/led1/trigger`

##### List available triggers

    # cat /sys/class/leds/blue:heartbeat/trigger

    none rc-feedback nand-disk timer oneshot [heartbeat] backlight gpio cpu0 cpu1 cpu2 cpu3 default-on transient flash torch sd emmc battery-charging-or-full battery-charging battery-full battery-charging-blink-full-solid ac-online

##### Temporary configuration

Replace `TRIGGER` with one of the available triggers. This setting will apply instantly, but be lost upon reboot.

    # echo TRIGGER > /sys/class/leds/blue:heartbeat/trigger

##### Permanent configuration

Replace `TRIGGER` with one of the available triggers. This setting will apply upon reboot.

    /etc/tmpfiles.d/leds.conf

    w /sys/class/leds/blue:heartbeat/trigger - - - - TRIGGER

### CPU Fan

The optional CPU fan can be controlled via the `/sys/devices/platform/odroidu2-fan` interface.

#### Fan Mode

    # echo auto > /sys/devices/platform/odroidu2-fan/fan_mode

    # echo manual > /sys/devices/platform/odroidu2-fan/fan_mode

#### Fan Speed (Manual Only)

Values range from 0 (0%) to 255 (100%)

    # echo 0 > /sys/devices/platform/odroidu2-fan/pwm_duty

    # echo 255 > /sys/devices/platform/odroidu2-fan/pwm_duty

## See also

- Hardkernel product page
- Support forums

Category:

- ARM architecture