Odroid c2

ODROID-C2.md

@@ -6,3 +6,32 @@
     * Note: Reboot after installation for udev rules to take effect.
 * Framebuffer Mali EGL and GLES drivers: odroid-c2-libgl-fb
 * wiringPi modified for the ODROID-C2: wiringc1
+
+## Headless Mode
+For servers (ie, no need for a display), uncomment the following in
+`/boot/boot.ini` to free up approx 300M of memory at the cost of disabling the
+video subsystem:
+
+    setenv nographics "1"
+
+## LEDs
+ODROIDs have dual LEDs: a red power LED which is always on if power is
+supplied, and a blue LED which can be configured.
+
+By default, the blue LED is a heartbeat LED, which flashes when the kernel is
+running. This can be configured in `/sys/class/leds/blue:heartbeat/trigger`.
+
+To list available triggers:
+
+    # cat /sys/class/leds/blue:heartbeat/trigger
+
+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
+
+To create a persistent configuration, edit or create
+`/etc/tmpfiles.d/leds.conf`:
+
+    w /sys/class/leds/blue:heartbeat/trigger - - - - TRIGGER
+