BTest-1 Release Notes

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Introductions and Expectations Setting

There is a major difference between the OLPC system and a conventional laptop of approximately five years ago; that is, our base system software is much more capable than it was then. The Linux environment now supports internationalization capability for scripts that were out of our reach then, and much higher quality rendering and, best of all, a much wider range of applications.

This has come somewhat at a cost, however: Moore's "Law" has allowed us to become sloppy, both in memory usage and CPU usage; this tends to force us to make some tough choices to keep the "footprint" of the software acceptable. The OLPC laptop have only 512 MB of storage (Flash), and probably the most serious limitation, 128 MB of RAM, and a single-core processor. Over the last year or so, the community has become much more sensitive to these issues, and work is well underway toward reigning in this "bloat" and performance work in general. Small is beautiful (and usually faster!).

Our base technology choices have been predicated on the ability of the software to achieve the best overall worldwide "user experience". This drove our choice of GTK+ and Pango (with Cairo as the graphical underpinnings), since Pango's abilities in complex scripts are currently most advanced of free software technologies. Other toolkits can be used: but they come at a cost in memory and flash footprint, and today, in the ability of software based on them to be localized to many of the scripts we face immediately, which include both Thai and Arabic. Including other toolkits as a standard part of our base system is therefore problematic, and experience on embedded systems show that including multiple toolkits would almost certainly cause the overall experience to suffer.

The Meaning of BTest-1

This is the beta test of fully functional hardware. The camera, SD slot and NAND flash are currently interfaced by an FPGA version of CaFE; the ASIC version will be available by BTest-2.

However, the software is alpha test.

Most of our effort to date has been consumed by basic device support as well as putting together the basic user interface framework for children, which has known performance problems. Major components are as yet not complete: power management and the wiki editing system to name two large components. Enough is now present to begin to sketch the outline of where we believe the children's software should go: enabling the construction of software in which children and teachers can easily collaborate is central to our vision. Children should not be passive receivers of "content" but creators as well.

We do not expect that the software is yet ready for trials with children: BTest-1 is aimed primarily at developers to become familiar with the hardware and to enable testing of both the hardware and software.

OLPC's Expectations of BTest-1 Users

We expect that you should enter new hardware and software problems you encounter into our bug tracking system, so that the problems can be tracked and resolved. While duplicate bug entries are inevitable, searching to see if the problem has already been reported will be very helpful to us. Problems cannot be fixed if we don't know what you encounter.

Hardware

User's guide to the hardware

Note you are seeing a system during test, well before when you would see a "normal" commercial product. This is to allow both hardware and software testing to start, since our system is significantly different than conventional laptops (e.g. the screen, power management, ruggedness), and will be used in very different environments. You will see "behind the curtain" (and be part of) the process that computer system manufacturers hide from you: the good, the bad, and the ugly process of hardware and software debug.

Hardware Specification

The BTest-1 systems were built with an extra 128meg of RAM, to partially make up for well known memory problems in key applications, in particular the web browser, based on Firefox's Gecko technology. Work is well underway to reduce the browser's footprint; some of this work is visible in Firefox 2.0. BTest-2 will be built with 128 meg of RAM total.

Note that the BTest-1 systems use an Altera FPGA to implement that CaFE ASIC (which interfaces the camera, NAND flash and SD slot), which will not be available until the BTest-2 build. This has allowed us to test the design of CaFE and to build early systems more than 6 weeks sooner. Using an FPGA has several consequences: the FPGA consumes considerable power, and it is relatively slow. CaFE's NAND flash controller, while several times faster than on the Geode's controller on ATest boards, is still very slow relative to what it will be when implemented as an ASIC; similarly the SD controller is also slow relative to its eventual performance, both due the limitations on the speed of the FPGA, and since high speed mode for SD is just now being implemented in the device driver.

The hardware specification is elsewhere in the wiki.

Hardware Release Notes

Our master list of hardware and mechanical issues and status can be found in the trac system we use. Please check this list before entering new issues: but please do enter issues you discover. The items below are the most significant from the list.

ESD problem with the embedded controller

One of the most irritating and noticeable problems is a static discharge problem that can lockup pins or entirely crash the embedded controller, causing some or all of the keyboard keys or touchpad to stop functioning. Power the machine off and on again to reset it (Note: you may need to remove and re-insert the battery to reset the EC completely).

The resistive sensor does not work

(for use with a stylus for writing), due to a design flaw: The stylus pad area was disabled and should be fixed in BTest-2 machines

The arrow keys ("game keys") cannot be distinguished from the arrow keys on the keyboard

This will be fixed on BTest-2 system.

Manufacturing data values are in the wrong order

This will be fixed the first time we update the BIOS SPI ROM.

Power management is as yet unimplemented

Therefore you cannot suspend and resume the machine (yet).

The battery charging algorithms have problems

These will be fixed as part of BIOS updates, which include the code for the ENE embedded controller used to control battery charging.

The screen is covered by a plastic film by mistake

With care, it can be removed.

Design Release Notes

The BTest-1 systems do not have textured plastic: this is intended for future builds.

Other design issues are also under investigation

Note that design is always an over constrained problem: it is often not possible to get every thing you would like in a design, though you can usually get most or all of what you value most.

Software

These are very early days for the OLPC software (alpha test).

Installation

How to upgrade BIOS firmware

Warning! Warning!

The current BTest units should NOT have their firmware upgraded by the previous methods. The Linux 'olpcflash' tool and the OpenFirmware 'flash' command will erase the manufacturing data that was written by the factory. The tools are currently in progress of being updated so that they will preserve the manufacturing data across a firmware upgrade.

                       How to install/upgrade OLPC Fedora
                       How to upgrade Marvell firmware

Device Driver Notes

The sensor input mode of the audio hardware is not supported in the audio driver of build 185

The code for this awaits merging shortly.

SD high speed mode is not yet supported in the driver in Build 185

High speed cards themselves work fine, but will not get above 8MB/second transfer rate.

Suspend/Resume not yet implemented

This is up next on our agenda.

Functional Wireless Driver

The driver is functional, though still somewhet buggy, and it is still undergoing major work, and the Marvell's boot2 code has yet to be deployed.

LED illumination driver needs writing

We'd like this for BTest-2, if we can.

Want interrupt on power/battery status change

We have the embedded controller code for this, along with the lid-switch, and the ebook mode, but it isn't yet hooked up to the Linux framework, nor integrated into the UI.

X Window System

The X Window System does not yet support the RandR extension, (rotation of the screen).

If a console application manages to somehow modify the colormap, the system won't recover without rebooting the machine.

We are not happy with the behavior of the touchpad: how much of this is hardware and how much software remains to be determined. The writing (stylus) mode of the touchpad has been disabled in the BTest-1 units, as the hardware does not work properly and is being redesigned.

Much performance optimization work is possible, and awaits our time or volunteers to work on.

The X Window System Xvideo extension is supported in the X server; note that a slightly different colormap is loaded while video is playing to improve video quality; other colors in use may become slightly strange during this period.

The keymaps for our initial set of keyboards are only installed when Build 185 is installed

There are known issues with the keyboard descriptions.

User Interface

Sugar

The "Sugar" user interface environment for children is in place. The OLPC Human Interface Guidelines should be observed when building or repackaging applications. Conventional human interface guidelines have been designed for first world office workers, and are totally unsuitable for children who are just learning to read in any part of the world. As young children are the many/most of the intended audience of our system, their needs are being met first.

Conversion of applications to function under Sugar is very straightforward and most applications can work with little change.

intent and goals

The core ideas: Activities, Not Applications; Presence is Always Present; Tools of Expression; and Journaling are detailed here.

Navigation

Navigation, including the Zoom Metaphor and The Frame, is detailed here.

Release Notes

The Sugar activity launch has performance problems we are actively investigating. There are many user interface issues we intend to fix. Among the most notable issues are:

Sugar seems to lock up with the frame out

Pressing F5 allows the Sugar to unhang, and you can then launch applications again.

Sugar needs a UI for controlling audio

This needs to be written.

Sugar presumes applications exit

Usually, you can find some other way to cause an application to exit.

Launching activities are slow

This is under investigation.

The timing of many of the user interactions, such as hover and the coming and going of the Frame are in need of fine-tuning.

Programming Sugar

Sugar Activity Bundles are explained in detail here.

                               Sugar interfaces
                               goocanvas
                               GTK+
                               Cairo
                               Pango/ATK

Activities

EToys

The EToys learning environment has been integrated into the Sugar environment, and you are encouraged both to visit the Squeakland site. Sugar EToys has information specific to EToys in our Sugar environment.

TamTam

The current TamTam is the first echo of a much more open-ended, collaborative, multiuser, music activity.

TamTam doesn't seem to load all instruments initially

Restarting TamTam solves the problem.

The microphone ought to be controlled by TamTam itself

You can use alsamixer in the meanwhile.

AbiWord

As a place-holder, a simplified version of AbiWord is provided, and efficient, light weight text editor. Some version of AbiWord will be included long term, at a minimum as a viewer, as AbiWord has the ability to read Microsoft .doc content well and there is a significant amount of web content in this form.

Temporary placeholders and Missing Pieces

There is no user interface for controlling the audio input/output. The workaround right now is to use "alsamixer" in a terminal window.

Our plans include a web server and wiki system and journal, with a simple what you see is what you get editor. These did not make BTest-1.

Video/Camera Player

The controls (brightness, hue, saturation) are not hooked up in the device driver or video player applcation in BTest-1 (build 185). The driver adding these controls to Alsa (the Advanced Linux Sound Architecture) will be merged in a build soon.

The camera is exhibiting more noise than expected in assembled units; whether this is hardware or software is to be determined.

We have used mplayer on the machine, but as it pulls in many dependencies, we put together a simple gstreamer based application for demonstration of the camera and video playing. Others have reported successful playback of videos and DVD's on the system.

The BTest-1 system does not have a LED to indicate if the camera or microphone is enabled. Such a LED will be present on a later system.

A camera application is under development.

Base system

OLPC Platform

Inventory of "permanent" packages Inventory of "debug" packages Inventory of "optional" packages (?)

Development environment

                               Languages - Logo, javascript, python
                               Libraries
                       Where to find source            
                       Internationalization/Localization

Other Multimedia Software

Other software that has been tested on the OLPC systems includes Adobe Flash, and Real's RealPlayer® and Helix player.

How to Contribute

dev.laptop.org

                               git
                                       general hosting offer
                                       olpc-2.6 repository
                                       fedora kernel image
                               trac
                               wiki
                               mailing lists
                               who is who

Pointers to Key Technology Organizations

OLPC depends on key technologies and projects, including:

• Gnome
• GTK+ toolkit, Pango Text Layout Library
• Cairo Graphics Library
• X Window System
• Linux Kernel
• Gecko Rendering Engine of the Mozilla Foundation
• AbiWord word processor

content

                               public
                               contacts at OLPC

Contacts

Mail

The OLPC mailing lists cover a variety of topics.

General questions can go to info at laptop dot org

Snail mail please sent to: One Laptop per Child P.O. Box 425087 Cambridge, MA 02142 USA

IRC Chat

We primarily use IRC instant messaging, and can be found on irc.freenode.net, #OLPC and #sugar channels.