Since the early days of the PC, BIOS (Basic Input/Output System) was the firmware platform for booting a computer out of reset and for providing basic run-time services to an operating system. Of course, PCs have evolved over the years with new system architectures, processor technologies, option ROMs, security safeguards, addressing enhancements and many other innovations which meant that BIOS needed to expand as well. Over time, managing the assembly-level code of BIOS had become more and more problematic for the industry.
Born out of the Intel-HP Itanium collaboration, EFI (Extensible Firmware Interface) was further developed by Intel® as a new platform for computer firmware that was targeted at the needs of enterprise computing. EFI eventually evolved into an industry-wide SIG called the Unified Extensible Firmware Interface (UEFI) Forum. UEFI provides many advantages over BIOS, including a structured, well documented platform, scalable and reusable code, and industry support.
UEFI became a standard for Intel x86 processors and replaced most of the legacy BIOS. The UEFI Forum is very involved, building the value of the code base and providing continued support for rapid change in the computer industry. One of those changes has been the emergence and widespread adoption of the ARM® architecture. In response to this, a UEFI port to ARM was initiated by Andrew Sloss. The port has been well received and at the tenth anniversary of the UEFI Forum the Board of Directors recently presented Mr. Sloss with a Top Contributor Award for his contribution.
While a limited number of 32-bit ARM devices have been deployed in enterprise systems, the biggest shift in ARM adoption in enterprise computing has come about with the introduction of ARM 64-bit processor cores. Applied Micro (APM) introduced the first commercially available system-on-a-chip based on 64-bit ARM IP and targeted at the enterprise. And now, APM’s X-Gene has been adopted by various OEMs as an alternative to x86-based devices. APM, in conjunction with software partners, provided an ARM-based UEFI on its platform.
Currently, some of the hot ARM UEFI topics include the adoption of ACPI (Advanced Configuration and Power Interface) in the enterprise and UEFI in mobile computing.
For more information on software debug on Intel and ARM platforms, as well as UEFI, check out our eResources page.
Here’s a link to a useful eBook on UEFI debugging.