Chapter 4. OpenHPI 10,000 foot view
This chapter attempts to give an overview of the current OpenHPI implementation. It will always lag behind the actually source code base, so interested parties are best served by retrieving OpenHPI from our CVS repository, and joining the OpenHPI mailing lists.
4.1. Theory
4.1.1. Guiding Principles
The goal of OpenHPI is to become the reference implemention for HPI. HPI is an emerging specification, of great importance to those wishing to have a standardized mechanism for Platform Management. By producing a reliable Open Source implementation of HPI, the OpenHPI team will help to turn HPI from an emerging specification to an industry standard.
There are a few guiding principals behind the design and implementation of the OpenHPI project. To succeed, the project must be:
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Simple - the easier the code is to follow, the easier it is to find and fix bugs.
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Reliable - OpenHPI will be used in very dynamic environments, and will need to be as robust as possible. To this end, the reliance on well known, well debugged external libraries is perfered to writing our own implementations of the same functions.
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Efficient - this is both in terms of performance as well as code re-use. For performance, the reasons are obvious; you don't want your management layers to bring down the performance of your system. In regard to code re-use--the more that pieces of code can be re-used the faster that others can develop hardware specific components to sit within the OpenHPI domain.
4.1.2. Requirements / Expectations
4.1.2.1. Compliance
OpenHPI will be a fully compliant implementation of the HPI specification. The OpenHPI team is committed to providing a 100% compliant implementation HPI, and to that end has produced a compliance test suite as part of the OpenHPI project. It is expected that many vendors may wish to reuse or contribute to the compliance test suite separate from the OpenHPI library itself.
As of the writing of this document, there has only be one official release of HPI (1.0, released October 2002). Due to the nature of HPI specification design, the OpenHPI team can only have access to officially released material. The OpenHPI team is committed to supporting future versions of HPI after they are released. However, given OpenHPI is an Open Source project, and the requirements that any HPI branded product be fully compliant to and major release verion of the HPI spec, no formal commitment to the timing of future specification support can be made.
4.1.2.2. Commercialization
It is expected that many vendors may wish to offer a version of HPI for their users, but do not wish to incur the cost of developing an HPI solution from scratch. OpenHPI wishes to be a reference implementation for these vendors. For this reason OpenHPI is licensed under a BSD style license, that allows this commercialization. Contributions by these entities back to the OpenHPI base are always welcomed and encouraged, but not required.
To a similar end, it is expected the plugin interface will be standardized so that vendors may produce object code only enablement for their hardware when appropriate. OpenHPI still encourages those vendors to contribute their sources back to OpenHPI whenever possible, but understands that this will not always be the case.
4.1.2.3. External Requirements
HPI is a new specification. As of the writing of this document the OpenHPI team is unaware of any externally available HPI based applications or implementations. Given that fact, the OpenHPI team is getting most of its requirements from the OpenHPI participants directly. As available HPI applications become prevelant, OpenHPI expects to work with those application vendors to gather further external requirements which