What is an OEM-Enhanced BIOS?
by
Michele Lukowski, VersaLogic Corp.

An OEM-enhanced BIOS comes with every VersaLogic embedded computer. But what exactly is an “OEM-enhanced” BIOS, how is it different from a standard BIOS, and why is it better? Because we purchase the BIOS source code and modify it to custom fit each of our boards, we can build in enhancements that allow OEM developers more control over the hardware-level functions of our boards, and add in control features that are specifically of interest to developers of embedded systems.

The BIOS firmware usually allows some configuration settings for users to change how the hardware behaves. Devices often have specific requirements for port settings and IRQs that are automatically configured for the user. But embedded computers may need to interface with unusual or proprietary devices, for which manually-controlled BIOS settings are preferred. In addition, hardware-level control and monitoring functions are typically not necessary on a desktop PC, but are common in embedded systems, and these require special BIOS-level controls for operation.

VersaLogic adapts the BIOS for each of its embedded computers using the source code for Embedded BIOS from General Software. Personality modules for the chipsets used on the board are integrated with the General Software core, followed by additional modifications made to enhance the functionality of the BIOS. Many OEM-desirable features are included in the design of the BIOS at this stage, such as enabling manual IRQ and port settings, selecting device behavior, or disabling devices to free up resources, the ability to save custom CMOS defaults, and control over boot devices and boot order. Also common are on/off controls for many hardware functions, such as the PC/104-plus connector (Cobra only) and on-board I/O. The BIOS also allows for routing of the digital I/O to IRQ lines for transition monitoring. In the recently-designed Cobra, a special CMOS setting has been integrated to allow user control over the CPU speed and power consumption so that the performance can be custom tailored to the needs of the application.

Because OEMs are often using an embedded computer to control or interface with other devices, designers commonly face the necessity of a customized BIOS. Through the ability to save custom CMOS defaults in Flash memory, many VersaLogic customers have been able to eliminate the need for development of a custom BIOS. The BIOS storage area includes additional space to store a secondary BIOS with these custom default settings.The primary BIOS is safely kept unaltered, providing a failsafe boot mechanism for developers, and changing between the two is an easy jumper switch. There is also space in the Flash memory for customized splash screens and BIOS extensions such as network boot agents.

Recent changes in firmware integration have also played a role in BIOS storage and usage. Many hardware manufacturers, including VersaLogic, are moving the BIOS from a 512 KB ISA-based flash chip to a firmware hub, which allows double the storage memory and can provide additional space for advanced BIOS extensions and firmware applications. The benefit of increased capacity is multiplied by the way in which data is organized in the flash. Stored resources can be compressed and concatenated without regard to 64 KB sector boundaries, so that no bytes are wasted. These advantages, among others, make the move from a conventional BIOS very advantageous. However, going to a firmware hub raises certain challenges in providing a failsafe boot mechanism. VersaLogic has implemented proprietary BIOS functionality to preserve this failsafe boot feature in its Cobra EBX single board computer, which is the first to use the firmware hub BIOS. This ensures that embedded developers will still have the capability of customizing the BIOS for the specialized functionality of their design without compromising the integrity of the protected BIOS for booting should the customized version fail.

In addition to the many BIOS options and functionality improvements VersaLogic has introduced to the BIOS for its products, the BIOS on all VersaLogic embedded computers is also field-upgradeable. Using a small upgrade utility and a new binary file, the BIOS can be upgraded to the latest version without any hardware changes. The BIOS upgrade utility is also used to program a splash screen, BIOS extension, custom video BIOS, and custom CMOS defaults. VersaLogic keeps customers informed of available upgrades, which can be downloaded from the private product support pages on the VersaLogic website. (To access these pages, simply enter the URL listed in the front of the user manual into the address line of the browser program you are using. The page is immediately accessible – no login or password is required.)

VersaLogic’s emphasis on manual control, flexible configuration and customization, predictability, and reliability has driven the development of the BIOS for VersaLogic boards and results in what we provide as an “OEM-enhanced” BIOS. Because of the many manually-selectable options, hardware functionality control and storage capability for customized BIOS versions, OEMs have found that the BIOS supplied with Versalogic embedded computers allows enough user-level control to eliminate the need for costly custom BIOS development. This can significantly shorten the overall design time required to get a product to market, and ultimately results in one less item a manufacturer has to worry about in their design.