Hardware Reference
In-Depth Information
boot from a GPT drive. The solution to the GPT boot problem is UEFI, which replaces the BIOS boot
loader with a UEFI loader that supports both MBR and GPT-formatted drives, thus breaking the
2.2TB limitation.
UEFI does not completely replace the BIOS, at least not yet. At a minimum, it runs on top of the BIOS
as a replacement for the boot loader and runtime services (see
Figure 5.8
)
. UEFI does not
specifically define POST or BIOS Setup functionality, but it does allow enhanced versions of those
preboot functions to be created along with additional preboot applications. Because of this, a
motherboard with UEFI firmware may look exactly like a standard BIOS Setup from the user's
perspective, with the only difference being a UEFI Boot option somewhere in the BIOS Setup.
Enabling this option allows the UEFI boot loader to replace the BIOS boot loader, thus enabling the
ability to boot from a drive 2.2TB or greater in capacity.
Figure 5.8. MSI ClickBIOS II UEFI BIOS Main Screen.
Although some UEFI firmware implementations will look like a standard BIOS, most will be notable
by their enhanced mouse-driven graphical interfaces combined with additional features not found in
older PC BIOS (see
Figure 5.8
)
. You may find the following features in the UEFI firmware of
motherboards:
•
Diagnostics
—Tests that are much more comprehensive than the standard POST, including tests
for memory and hard disks.
•
Live Update
—A tool that can check the motherboard manufacturer website to see if a
firmware/BIOS update is available and then automatically download and install the proper
update.
•
HDD Backup
—A tool that backs up or clones a hard disk drive (HDD) from outside the OS.
This allows for complete backups and easy HDD upgrades.
•
Overclocking
—Enhanced intelligent overclocking utilities that virtually automate the process
and can easily undo the settings if they fail.
•
Boot Logo
—The ability to easily update or change the graphical boot logo seen when you turn
the system on.
UEFI firmware may also include applications for web browsing, email, and other useful capabilities
