Overview of BIOS Features
61
3.3
Resource Configuration
3.3.1
PCI Express Autoconfiguration
The BIOS can automatically configure PCI Express devices. PCI Express devices may
be onboard or add-in cards. Autoconfiguration lets a user insert or remove PCI
Express cards without having to configure the system. When a user turns on the
system after adding a PCI Express card, the BIOS automatically configures interrupts,
the I/O space, and other system resources. Any interrupts set to Available in Setup
are considered to be available for use by the add-in card.
3.4
System Management BIOS (SMBIOS)
SMBIOS is a Desktop Management Interface (DMI) compliant method for managing
computers in a managed network.
The main component of SMBIOS is the Management Information Format (MIF)
database, which contains information about the computing system and its
components. Using SMBIOS, a system administrator can obtain the system types,
capabilities, operational status, and installation dates for system components. The
MIF database defines the data and provides the method for accessing this information.
The BIOS enables applications such as third-party management software to use
SMBIOS. The BIOS stores and reports the following SMBIOS information:
•
BIOS data, such as the BIOS revision level
•
Fixed-system data, such as peripherals, serial numbers, and asset tags
•
Resource data, such as memory size, cache size, and processor speed
•
Dynamic data, such as event detection and error logging
Non-Plug and Play operating systems require an additional interface for obtaining the
SMBIOS information. The BIOS supports an SMBIOS table interface for such operating
systems. Using this support, an SMBIOS service-level application running on a
non-Plug and Play operating system can obtain the SMBIOS information. Additional
board information can be found in the BIOS under the Additional Information header
under the Main BIOS page.
3.5
Legacy USB Support
Legacy USB support enables USB devices to be used even when the operating
system’s USB drivers are not yet available. Legacy USB support is used to access the
BIOS Setup program, and to install an operating system that supports USB. By
default, Legacy USB support is set to Enabled.
Legacy USB support operates as follows:
1.
When you apply power to the computer, legacy support is disabled.
2.
POST begins.
3.
Legacy USB support is enabled by the BIOS allowing you to use a USB keyboard to
enter and configure the BIOS Setup program and the maintenance menu.
4.
POST completes.