Firmware

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Introduction

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

Updating - For Users

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 may upgrade just the firmware to the latest signed release.

Updating - For Developers

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

  • install any of the firmware releases below; click the firmware version for instructions.
  • alter the secure upgrade to use one of the firmware files below.

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 :-(

Brick Recovery

Updating using the methods above requires working firmware. If the firmware is not working, and the laptop is bricked, the options are:

Both these require electronics lab bench skills and service tooling.

Firmware Releases

The latest release is the first in the list. There is a list for each laptop model. Do not mix firmware between models; it should not install, and it would be harmful if it does install.

XO-1.75

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

WARNING! XO-1.75 Firmware versions >= q4a10 will NOT work on A1 version boards.

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

EC 1.75

EC 1.75 firmware and change log EC 1.75 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.

For XO-1 and XO-1.5, 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.

For XO-1.75, the .rom file contains Open Firmware and 2k Manufacturing Data and is stored in one SPI FLASH chip attached to the SoC. The Embedded controller ("EC") firmware is stored in another SPI FLASH chip attached to the EC. Therefore EC firmware is not bundled with OpenFirmware.

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