Macintosh Firmware: Extensible Firmware Interface (Paperback)

Purchase includes free access to book updates online and a free trial membership in the publisher's book club where you can select from more than a million books without charge. Excerpt: The Extensible Firmware Interface (EFI) is a specification that defines a software interface between an operating system and platform firmware. EFI is a much larger, more complex, replacement for the older BIOS firmware interface present in all IBM PC-compatible personal computers. The EFI specification was originally developed by Intel, and is now managed by the Unified EFI Forum. The original motivation for EFI came during early development of the first Intel-HP Itanium systems in the mid-1990s. PC BIOS limitations (16-bit processor mode, 1 MB addressable space, PC AT hardware dependencies, etc.) were seen as clearly unacceptable for the larger server platforms Itanium was targeting. The effort to address these concerns was initially called Intel Boot Initiative and was later renamed to EFI. In 2005, the UEFI Forum was created, and is now responsible for EFI development and promotion. Version 2.1 of the UEFI (Unified Extensible Firmware Interface) specification was released on January 7, 2007. As of March 2007, it added cryptography, network authentication, and the User Interface Architecture (Human Interface Infrastructure in UEFI). Interaction between the EFI boot manager and EFI driversThe interface defined by the EFI specification includes data tables that contain platform information, and boot and runtime services that are available to the OS loader and OS. UEFI firmware provides several technical advantages: Some existing enhancements to PC BIOS, such as the Advanced Configuration and Power Interface (ACPI) and System Management BIOS (SMBIOS), are also present in EFI, as they do not rely on a 16-bit runtime interface. EFI defines two types of services: boot services and runtime services. Boot services include text and graphical consol... More: http://booksllc.net/?id=866065