Firmware

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Introduction

The firmware of the XO laptop is the software that runs before and during the operating system.

Updating

Updating the XO to a new operating system release updates the firmware, if required. Normally, users should update to the latest stable operating system release in order to update the firmware.

However, users can also upgrade just the firmware to the latest official (signed) release, see Upgrading firmware

Technical Background

The firmware is in two parts:

  • EC Firmware, which runs on the embedded controller as soon as the battery is installed or external power is plugged in, and is responsible for managing the battery, charging, power switching, and indicator LEDs,
  • Open Firmware, which runs on the main processor when the power button is pressed, and is responsible for preparing that hardware and loading the operating system.

These two parts are bundled together as one .rom file.

This firmware goes in the little 1 MB SPI flash that's used for booting, not the 1GB NAND flash (or 512MB in earlier prototypes) used for the OS image and user data.

The SPI flash contains the Embedded controller ("EC") firmware, Open Firmware, and 2k Manufacturing Data.

See Firmware SPI FLASH Map or its dia source file.

Updating - For Developers

Developers who have an unsecured laptop or a developer key have more options.

Note: Once you upgrade to the Q2Cxx series of firmware do not downgrade to Q2Bxx! Doing so will destroy the manufacturing data. Downgrading from Q2F01 to Q2C01 will "Brick" your XO-1 :-(

Firmware Releases

The latest release is the first in the list:

XO-1.75

WARNING! XO-1.75 Firmware will NOT work on an XO-1 or an XO-1.5.

XO-1.5

WARNING! XO-1.5 Firmware will NOT work on a XO-1.

XO-1

Do not downgrade from C series to B series
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