Contributors program archive

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OLPC Developers Program

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.

BTest Systems

We have had the two builds (of three builds) of full OLPC laptops built, for "BTest". The BTest-1 build has been distribution: the BTest-1 Release Notes describes the state of the first build of machines. The BTest-2 build is starting distribution as of February 12. The BTest-2 Release Notes describes the state of the second build of machines.

There is typically one or two builds of systems internally before an external beta test, so our BTest-1 is really beta test for the electronics, while alpha test for the new screen, touch pad, industrial design, and keyboard; this is earlier in the development cycle than systems are usually made available, and is correspondingly rougher.

The BTest-2 hardware is continuing beta test for the electronics, beta test of the new screen (this time with a diffuser improving it futher) and touch pad. The industrial design is only somewhat improved from BTest-1; most of the learning from BTest-1 on mechanical improvements could not be incorporated in time for BTest-2 and so BTest-3 will be significantly more rugged than BTest-1 or BTest-2.

The focus for the developer program BTest-1 machines will be software development on GUI related projects that need to understand the screen, the touch pad, and/or the camera in the system, along with wireless testing, which has been difficult to do sooner due to the cumbersome nature of bare PC boards.

BTest-2's focus will start the process of testing the mesh network, and we're also working on suspend/resume, though as of this writing, suspend/resume is not yet running.

Machine are also being allocated to launch countries and do not come under this program, which is aimed at individual free and open-source developers or research organizations interested in contributing to furthering OLPC's goals.

OLPC's Expectations of BTest-1 Users

Bug Reporting

Note that our process is a fully open one: in a "conventional" beta test program for a product, you would have been asked to sign a non-disclosure agreement, and not disclose any of the problems you might have, or even be aware of problems other beta testers might be having. Usually, such a hardware beta test is done later in the program after more extensive testing has been done than has been done here.

This early beta test hardware means a much higher probability of hardware problems than later beta test or production hardware. The design is just now undergoing stress testing at elevated temperature, cold, vibration, shock, and humidity as well as many other tests.

Components that are fine on paper, may not work well in practice, either by defects in the design of the components or in their use. Beta testing is also used to test different manufacturer's components. Whenever possible in high volume products, components are "multiple-sourced", and the same nominal kind of part from different manufacturers tested for compatibility. This is to ensure steady supply, even if a particular manufacturer later starts having manufacturing problems, alternatives will be available. Examples in our hardware include camera supplier, RAM supplier, PCB supplier, to name just a few. On the ATest boards, for example, we discovered several components that we do not want to use in production, and we can expect similar issues during BTest. A component's design may be new, and have its own design or manufacturing problems to be resolved (e.g. the writing pad problem we note below). Errors can be made in assembly. Errors can be made in design or component selection. A particular lot of components may be defective. The purpose of beta test, particularly for a high volume product, is to discover these problems, long before volume production, analyze the failures completely, and, by understanding the root cause of each failure, be able to eliminate or prevent these problems in the production units. If you have a hardware problem, OLPC may ask you to return the machine quickly for failure analysis; we will do our best to get you a replacement promptly.

We expect that you will quickly enter new hardware and software problems you encounter into our bug tracking system, so that the problems can be tracked and resolved. Please include the firmware version you are using -- displayed at power on time on the second line: e.g. "OpenFirmware CL1 QA62 Q2A"; the QA62 is the firmware version--the operating system build number--which is displayed at the end of the boot process--and the serial number of your machine--found under the battery; this will help us analyze your problem and resolve it.

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, or how often they are encountered; if you find clearly the same problem as some one else, it is still helpful to know how often it is occurring, or any additional details you know. Add such information to the bug reports. Err by too much reporting, rather than too little. A pattern may emerge among the reports or comments on a bug, or we may have a much better idea how severe a problem is and be able to better prioritize its resolution. Bugs are good. Each bug is much easier to fix now than later.

Hardware

User's guide to the hardware

EBook Configuration

Bottom View

You are using a system during test, well before when you would have the opportunity to use 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.

The picture on the right locates most of the features of the machine. To open the machine you must first unlatch the antennae and then lift it open.

To rotate the screen to transform to ebook mode, the screen must be in the 90% upright position. It can only rotate one of two directions to the point where the screen can again be closed down over the keyboard.

The battery pack is located under the screen underneath the keyboard, and is released by two slide latches as seen in the lower thumbnail. You can also see the SD slot clearly. Note: the plastic will be textured in later builds so the surface of the machine will not be shiny.

ATest Board Types

We've had approximately "ATest" 500 developer boards built, to jump start serious development in the free- and open-source software community and the initial deployment countries. Quantities of this generation of boards is limited as we do not have production test fixtures. Note that these are bare printed-circuit boards. At this time, we still have a limited number of boards available, and some more may become available as BTest systems replace many uses of ATest boards.

The hardware specification of these boards is set.

There are a number of ATest board types in the wild:

• 30 Pre A-Test PCB, which have been built and distributed.
• 20 A-Test PCB's, which have been built and distributed.
• 485 A-Test PCB's, which have been built and are being distributed through Brightstar. These can be distinguished from the first 50 boards in that they have serial-number barcodes on them.

These boards lack DCON chips and instead come with the standard VGA connector you'd find on the back of a desktop or laptop computer. We expect that production boards may ship with pads for VGA connectors, but not the connector itself. Additionally, the Pre-A-Test boards have populated mini-pci connectors; on the A-Test boards, these mini-pci connectors have been left off; the pads are included and will probably be included on production boards.

The A-Test boards include a socketed ROM chip for BIOS development; this socket will not be on production boards. The sockets are empty; the BIOS is stored in the serial flash chip that is interfaced via the embedded controller. The process for updating the serial flash under Linux is not yet available and at the moment involves booting DOS and updating the flash chip using a utility from Quanta. Unless you are directly involved in BIOS development, you should stear clear of BIOS updates unless and until instructed by responsible people working on behalf of OLPC.

At this time, the hardware is all believed to work (having been tested), but not all drivers are working properly under Linux. The wireless driver is being completely revamped at the moment.

See: Notes on using the OLPC developer boards.

Setting Expectations

Do not expect:

1. Monitor or flat panel
2. disk, DVD, CD or USB drives
3. keyboard or mice
4. powered USB hubs that may be needed for use with some peripherals
5. USB ethernet adaptors
6. other input devices

We expect you have or can acquire these locally.

Setting Expectations for BTest Machines

Please carefully read the BTest-1 Release Notes or BTest-2 Release Notes and the BTest-1 Demo Notes.

If you get a BTest machine(s), expect to get (a) box(s) with:

1. one or more BTest systems, with localized keyboards if available
2. one AC power adapter for each machine (to the extent possible by our logistics and crystal ball gazing) which will have the right plug type for your country if available
3. one battery pack for each machine
4. factory or OLPC pre-load of some version of the software: you should plan to immediately update the software to a current version upon arrival. This has been made extremely easy with the Autoreinstallation image.

Setting Expectations for ATest Boards

Expect to receive (a) box(s) with:

1. one bare OLPC A-Test board, in a static protective bag, with static warning, with serial number both on the box and on the board.
2. one power supply brick (U.S. plugs), 15-Watt capacity. Note that Sony power bricks should also work fine, and that if you can find the connector (the Sony appears compatible) you can use many different DC voltages.
3. RS-232 cable adapter to DE-9 male connector for serial console use and debugging
4. a small plastic bag with standoffs for the board, along with a diagram showing where they should be inserted
5. one pair of 802.11 antennae, which will need to be connected to the board before use.

Project Hosting

If your interest is primarily on doing some systems level or on applications level coding, then join one of the projects on our Hosting Wiki. We have much more flexibility, bandwidth and CPU available than alternatives like SourceForge, and your project won't be as lost among thousands of other projects unrelated to OLPC. If your project has aspects related to OLPC, but is primarily part of some other project (e.g. GTK+, X11), we're also happy to provide more limited OLPC related facilities, such as bug tracking and our wiki.

Hardware Schedule

In this first generation of boards, which we call A-Test boards, the hardware is fully functional except that video is VGA out, rather than using a flat panel with the DCON chip which appears in the BTest systems.

Packaged BTest-1 machines were built in late November. The BTest-1 systems are fully functional, but use an Altera FPGA in place of the CaFE ASIC which is present in later builds, for NAND flash, camera, and SD interfaces. This FPGA has lower performance and consumes much more power than the CaFE ASIC does. Another build (BTest-2) occurred in late January using the completed CaFE ASIC. The third BTest-3 build, in larger quantities, will sometime in the spring. This final BTest build is the first point where working with children starts to make sense, as the software matures.

Goals

Our goals will vary as the hardware matures. For the BTest systems we need the most help on:

• power management in the device drivers: for us, every joule matters, and a simplistic "oh, we mostly have most of a chip turned off, maybe" isn't good enough. We want to know that every possible power savings has been realized, and that suspend/resume is rock solid and blindingly fast.
• fast suspend/resume: We must go beyond the current state of the art as discussed at the power management summit.
• modal operation: if certain applications are full screen, the system should automatically suspend and resume whenver idle for more than a short period.
• variable speed display driving: (aka: mode change on the fly), again, to save power.
• wireless: we will be deploying mesh networking. Serious experimentation in this area is in order, to shake down the drivers and to gain experience in its behavior in differing conditions (e.g. rural areas with low noise characteristics; busy metropolitan areas). We understand that to do serious tests, more than a single board will be needed. Please be realistic in your expectations: two boards is not interesting; two hundred boards can't be provided.
• compiler optimization: if you are a compiler wizard, we understand that the Geode lacks a specific back end code scheduler, which limits performance, particularly FP performance. We'd love to see work go on in this area which would help everyone.
• tickless operation: there are patches out of tree about to be integrated into Linux that allows Linux to function without periodic tics; we've been experimenting, and while our tick rate is probably the lowest yet observed on a Linux system, it can and should go further. Nothing in the system should poll!
• power management desktop interaction: applications need to be better aware of their power usage and requirements, and communicate this better to the system.
• The OOM (out of memory) killer is naive, to say the least.
• Sugar optimization: While the Sugar environment will get substantially faster as soon as we deploy a rebuilt Python 2.5, further work, particularly on python startup, is in order.
• Sugarizing applications: There are many applications that with minimal work can be made to work well in the Sugar environment for young children. We encourage you to pick one and help out.
• Remote display: we have begun work on a low cost projector. Making it easy to remote applications is well worthwhile. There are a number of ways (and difficulties) of doing this, so there are immediate techniques available, along with much more sophisticated ways of advancing the "state of the X Window System art", depending on your inclinations and abilities.
• Educational applications of all sorts.
• Server based tools for schools and support of the laptops.

We're sure you are brighter than we are and have seen what we're missing in the above list.

You can contribute in many areas which do not require hardware. For example:

• memory usage: many applications and toolkits waste and/or leak memory. Fixing these will help everyone and most easily done on conventional systems.
• performance optimization: fixing memory usage will usually result in faster code.
• toolkit adaptation: the display's effective resolution will change from grayscale to color mode and back. Toolkits and applications need to be able to adapt, and themes that work well in both modes verified.
• UI: most of the user interface work can be done today on conventional Linux desktops. But our system will also have an e-book mode, with dual 4-direction keys and enter. Key applications will need updating to work well in this environment (e.g. evince, web browser). Testing application's behavior under grayscale conditions and making whatever changes are needed would be helpful.
• Applications: goes without saying. The "Sugar" environment under development can be run on conventional desktops.
• IPv6 support, and service discovery, which are very important to us.
• Security: SELinux or other techniques may be a way to protect against Day 0 attacks; as a large ecosystem of similar machines, it is something worth seriously worrying about.

We will give preference for hardware to proposals that require access to the OLPC hardware to make progress; BTest requests should either require mobile use of the systems and focused on GUI and applications where access to our new screen is needed.

Qualifications

We're looking for people able and interested in helping in development. The qualifications needed depend strongly upon where you are interested in working: for example, people working on BIOS/boot paths should be seriously "friends of the electrons", and not scared of JTAG and similar kinds of debugging.

Most driver work takes normal driver debugging skills, though getting power management right can be more challenging than most driver development.

Window system development requires X experience, and so on.

Idle machines

If you no longer have time to contribute to the OLPC effort, please be so kind as to return your board for redistribution.

How to apply

Please send mail to the developer at laptop dot org email alias with the following information:

1. Name
2. Email address
3. Employer (if any), University/College
4. Shipping address and instructions
   1. name,
   2. address, (cannot be a post office box)
   3. city,
   4. postal code,
   5. country,
   6. telephone number, (yes, we really need this for the shipping companies)
   7. any special instructions
5. Description of your plans for the machine(s)
6. Quantity of machines desired
7. Description of your experience, both with hardware and software

Presuming your request is approved, a mail message will be sent to you with shipping information, or a regret. Note that some requests may be more feasible and applicable later in the project, when we more machines available.