XO 1.75 A1
XO-1.75 Laptop Alpha test model, also known as A-test or A1.
Contents
Description
The A1 are the first prototypes of the XO-1.75 built. The A1 bring up is happening in late Oct., 2010.
The number of boards obtained will be small, and distribution will be limited to hardware testing and OFW and Linux kernel driver development.
Identification
- Bare circuit board, no case or display
Photographs:
Software Support
XO-1.75 use Q4xxx firmware releases. These will not work on an XO-1 or XO-1.5. For the first time, Open Firmware is provided as part of the Linux image, and the EC firmware is separate. The current firmware release is Q4A04.
It is strongly recommended that you have two sources of power (a charged battery and an external power source) when you upgrade your EC or Open Firmware. Failure to do so may require the use of an SPI programmer to recover your laptop.
Upgrading OFW
Place a recent release of the Q4XYY firmware onto an SD device, and place it in the external SD slot.
Interrupt the OFW boot process by pressing the ESC key.
Type (assuming a q4a04 release):
flash ext:\q4a04.rom
Reboot by holding down the power button once this is completed.
Upgrading the EC code
Place a recent release of the EC firmware onto an SD device, and place it in the external SD slot.
Interrupt the OFW boot process by pressing the ESC key.
Type some magic incantation (to be provided):
Reboot by holding down the power button once this is completed.
Upgrading Linux
A Linux image for the A1 is available at ?.
Installing from Linux
To install on an XO-1.5, you can run:
zcat os175.img.gz > /dev/hda
Installing from OFW
You will need the .zd version of the OS image. Download it, then:
- Place the image on a USB stick, and insert it into the XO-1.5 laptop's USB port.
- Boot the laptop, pressing the escape key ('X' in upper left hand corner of keyboard) within a few seconds after boot to enter Open Firmware.
- To install onto the internal SD card, type:
fs-update u:\os34.zd
To install an image onto the external SD card, you need to type:
devalias fsdisk /sd/disk@2:0 fs-update u:\os34.zd
Restrictions
There is a list of recommended modifications.
Despite the lack of any heat sink at this time, we haven't seen any overheating even in closed units.
Audio Inputs
The audio inputs are messed up. The internal microphone is wired to one channel, and one channel of the external microphone is wired to the other. Despite this, if the microphone is rewired the audio sounds pretty good (using Q4A05 or greater, type "test /audio")
Video Display
The video display is wired incorrectly, giving a pink hue to the video. It grows on you after a while...
SD Flakiness
Versions of OFW up to Q4A05 operate the SD interfaces at 25 MHz unless it is told otherwise:
dev /sd false to avoid-high-speed? dend
Starting with Q4A05A (private release), operation of SD interfaces at 50 MHz is supported.
There are still some problems (#10457) on some motherboards.
USB
Still doesn't work (reliably/at all)
Documentation
Supporting documentation for these boards (all in PDF):
Please note that production boards will likely have different pin mappings and connector locations.
