Embedded Open Modular Architecture/EOMA68

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A Wikipedia page covering the EOMA68 Standard was created recently and is being edited by people who have clearly not read the standard nor are familiar with the standard's background. In a little under two weeks at the time of writing there have been no less than SIX separate individuals providing false and misleading statements. The page on the site known as "Wikipedia" is NOT AUTHORITATIVE: considerable effort is being expended to ensure that factually inaccurate statements are not made, however at any one time there may be another editor who has, once again, not read the standard, edited the page without thinking of the consequences, and thus brought both EOMA68 and Wikipedia into disrepute as a direct result. If you intend to edit the page on Wikipedia and are unsure of any facts CONSULT THE AUTHOR OF THIS STANDARD. Update 26sep2016: the false and misleading page has been moved to a user page and is currently being developed in a safe environment that clearly carries no implicit "authority" - not that the Wikipedia page will ever be granted "authority"

Table of contents

Glossary of Terms

  • EOMA68: name of the standard (not EOMA-68). stands for "an Embedded Open Modular Architecture Standard (68 pin connector variant)".
  • EOMA68-<designation>: recommended unique naming convention for Cards that implement the EOMA68 standard. Examples: EOMA68-A20 (contains an Allwinner A20 SoC). EOMA68-jz4775 (contains an Ingenic jz4775).
  • Housings: a "base board" into which (one or more) EOMA68 Cards can be plugged. similar to a "motherboard" but "motherboard" is subtly misleading (motherboards typically allow CPU and RAM to be replaced: EOMA68 Cards are where the entire computer is typically housed). previous names used during the development of EOMA68 include "Dock" and "Chassis" - both now deprecated.
  • Card: short-hand for "EOMA68 Card". It slots into "Housings". may contain a fully-functioning computer (Single-Board Computer), but legitimate implementations of the EOMA68 Standard include FPGA Cards and something known as a "Pass-through" Card.
  • MIC: stands for "Manufacturer Identification Code", similar to USB and PCI Manufacturer Identification codes. Currently defined as 4 bytes in length, and present in the EOMA68 I2C EEPROM.

EOMA68 Introduction

The primary purpose of the EOMA68 specification is to bring end-users the right to upgrade their own mass-produced Computing Appliances. To make end-users lives easier, purchasing decision-making should be made not on technical interface capabilities, neither should they be expected to have significant technological expertise. This is the primary reason why EOMA specifications have no optional interfaces of any kind. The tag-line is "Just Plug It In: It Will Work". To achieve this level of simplicity for the lifetime of the specification (anticipated to be at least a decade) all Cards compliant with the EOMA68 specification have to be compatible with all compliant "Housings".

The trade-off between choosing a single-board design or even another modular form-factor is as follows:

  • EOMA68 products will not use all of the integrated functions of single-board designs, automatically resulting in minor cost increases for products, however this cost is negligeable compared to the long-term end-user cost savings.
  • EOMA68 products are user-upgradeable. The Housings can be kept out of landfill - kept in useful service - for the lifetime of its components. Only the Cards need be upgraded at a much lower cost than a single-board design in order to continuously give the product a new lease of life.
  • EOMA68 Cards can be shared by the same end-user across multiple products, automatically resulting in a cost saving that far outweighs the minor overhead of a single EOMA68 system when compared to a single hermetically-sealed throw-away product.
  • However, single-board designs are typically throw-away products where the lifetime of the product is critically dependent on an extremely fast-changing market.
  • Single-board designs are typically throw-away hermetically-sealed products with neither user-serviceable nor user-replaceable parts.
  • Old Housings and Cards can be re-purposed instead of discarded as e-waste.
  • Q-Seven and other similar standards are not realistically user-upgradeable (not for the average person) because products require tools, technical knowledge in the selection of technically-compatible replacement parts, and expert knowledge in the handling of electronics for ESD-precautions before even opening the case.
  • EOMA68 products are upgraded by pushing a button and popping out the module: it literally takes seconds to install a new Card.

So the benefits for end-users are very clear: EOMA68 is easily understandable as a long-term investment for its end-users with significant long-term cost savings and reductions in e-waste. The benefits for factories are very clear: Cards aggregated across multiple products means much better bulk purchasing power, and Housings can also continue to be produced without requiring redesigns pretty much until the components go end-of-life.

No other modular computing standard available today has been designed with these aims in mind. An analysis of the standard is covered in-depth in a whitepaper on Ecocomputing at http://rhombus-tech.net/whitepapers/ecocomputing_07sep2015/


EOMA68 products are completely unlike throw-away single-purpose SBCs (Single-Board Computers) and throw-away hermetically-sealed monolithic devices: re-use, re-purposing and upgrading is encouraged, resulting in a greatly-extended lifetime for both Cards and Housings than would normally be expected. It is perfectly reasonable to expect any Card to change hands five or more times during its useful operational lifetime. As such, the Requirements are correspondingly but simply a natural reflection of the full lifecycle, and may therefore come as a bit of a shock to those used to the usual "fire-and-forget" epidemic and endemic processes currently being deployed for standard mass-volume manufactured products.

EOMA68 is therefore not just a hardware standard: it is more of a collaborative commitment to certain procedures and processes, with each party having different roles and responsibilities to play. The main roles (where an individual or organisation may have more than one role) are:

  • CERTIFIER: an authorised agent who is exclusively permitted to issue Compliance Certification for EOMA68.
  • MANUFACTURER: covers organisations that create both hardware (PCBs and casework) and software, or their authorised agents, or intermediaries (such as OEMs and ODMs).
  • LIBRE_ENGINEER: a form of MANUFACTURER that is given a little bit more leeway if one or more aspects of their work (PCBs, casework, software, ASIC designs) are both libre-licensed and publicly available (as opposed to being kept private on the promise of availability, only being made available after release).
  • RETAILER: anyone selling EOMA68 Cards or Housings.
  • RETAIL_ENDUSER: anyone who buys EOMA68 Cards and Housings sold as new (and receives a warranty). usually will have zero technical knowledge. litmus test: "if they can run a command-prompt and can follow step-by-step instructions on their own initiative", they're not a RETAIL_ENDUSER.
  • TECHNICAL_ENDUSER: anyone who is capable of doing out-of-the-box legal and legitimate things with and to their hardware
  • REPURPOSER: a special form of TECHNICAL_ENDUSER who take it on themselves to buy or collect EOMA68 Cards and Housings, checks them, repairs them, re-flashes them, and either deploys them personally or sells or otherwise passes them on.
  • RECYCLER: an organisation or individual responsible for the safe, legal, legitimate and environmentally-responsible disposal of EOMA68 Cards, Housings and parts associated with the same. a RECYCLER (ideally) represents the sole exclusive sink for all EOMA68-compliant Cards and Housings at end-of-life. not to be confused with REPURPOSER, who would be responsible for ensuring that the Cards or Housings go back into circulation.

This document therefore defines the responsibilities for each role, as well as the relationships between each role, so that together they are able to collaborate and ensure that the lifecycle of EOMA68-compliant devices is extended to the maximum extent possible.

External Considerations

External Factors and Considerations is now on its own page.

EOMA68 Hardware-related Requirements

Hardware-related Requirements is now on its own page.

EOMA68 Software / OS Requirements

Software / OS Requirements is now on its own page.

Example Housings

Here is a list of example designs which conform to the EOMA68 Standard:

  • Mini Engineering Board - suitable for Free Software Developers, ODM Development, SoC "Board Support Packages", Experimentation, Prototyping, Electrical Engineers, Training and R&D purposes.
  • Monster Engineering Board - suitable for ODM Development "Demonstration" Purposes: designed to be "cut down to size", requiring the minimum amount of CAD/CAM Development effort and maximising return on investment.
  • The Obligatory Tablet - a simple tablet motherboard which could potentially be developed as a very low cost single-sided 2-layer PCB. Components are chosen to reduce development cost and risk, as well as reduce manufacturing cost.
  • Laptop - a laptop motherboard which could potentially be developed as a very low cost single-sided 2-layer PCB, through the use of modular and optional components for WIFI and 3G.
  • LCD (TV) - an LCD Monitor (or Picture Frame) which can be upgraded into a TV or an All-in-One Computer or an Internet TV or Personal Video Recorder or Media Centre. very versatile yet simple to do.
  • Passthrough or "Blank" Card - a special type of card which simply passes through the connectors, with little or no signal conversion.

Contact and Discussion

For questions, comments and general discussion, please use arm-netbook mailing list


Introduction of EOMA


The FAQ is now on its own page.