Storage Indicator

A storage indicator is built into the XO-1.5 and XO-1.75. It is the second LED on the left.

The indicator is managed by the main processsor. It is controlled by firmware or software.

Software

By default the indicator lights when the internal storage is accessed. A user may learn how to predict the responsiveness of the laptop by watching the indicator.

Turning on the LED and leaving it on

cd /sys/devices/platform/leds-gpio/leds/storage
echo 1 > brightness

(unfortunately this requires root)

Assigning the LED to another trigger

For example, this makes the LED act as an AC online indicator:

cd /sys/devices/platform/leds-gpio/leds/storage
cat trigger
[list of possible triggers]
echo olpc-ac-online > trigger

Firmware

OpenFirmware uses the storage indicator when rewriting the SPI FLASH (XO-1.5 and XO-1.75) or the EC (on XO-1.75). The laptop must be left to complete the process, and the indicator is used to show this. Interrupting the process may break the laptop.

OpenFirmware words (functions):

* hdd-led-on turns on the indicator,
* hdd-led-off turns off the indicator,
* hdd-led-toggle changes the state of the indicator.

Restrictions

XO-1.75 C1 has the light sensor next to the storage indicator. The storage indicator is turned off briefly during each sample capture. XO-1.75 B1 and A3 do not do this.