Figure 83 EFI Boot Sequence
The EFI boot manager loads EFI applications (including the OS first stage loader) and EFI drivers
from an EFI-defined file system or image loading service. Non-volatile RAM (NVRAM) variables
point to the file to be loaded. These variables contain application-specific data that is passed
directly to the EFI application. EFI variables provides system firmware a boot menu that points to
all the operating systems, even multiple versions of the same operating systems.
The EFI boot manager allows you to control the server’s booting environment. Depending on how
you have configured the boot options, after the server is powered up the boot manager presents
you with different ways to bring up the server. For example, you can boot to the EFI Shell, to an
operating system located on the network or residing on media in the server, or the Boot Maintenance
menu. See “Using the Boot Option Maintenance Menu” (page 174) for more information.
• Boot from a File— Automatically adds EFI applications as boot options or allows you to boot
from a specific file. When you choose this option, the server searches for an EFI directory. If
the EFI directory is found, then it looks in each of the subdirectories below EFI. In each of those
subdirectories, it looks for the first file that is an executable EFI application. Each of the EFI
applications that meet this criterion can be automatically added as a boot option. In addition,
legacy boot options for A: and C: are also added if those devices are present. You can also
launch a specific application without adding it as a boot option. In this case the EFI boot
manager searches the root directories and the \EFI\TOOLS directories of all of the EFI system
partitions present in the server for the specified EFI application.
• Add a Boot Option— Adds a boot option to the EFI boot manager. You specify the option by
providing the name of the EFI application. Along with the name you can also provide either
ASCII or UNICODE arguments the file might use. Given the EFI application name and any
options, the EFI boot manager searches for the executable file in the same directories as
described in the Boot from a File option. When the file is found, it is issued.
• Delete Boot Options – Deletes a specific boot option or all boot options.
• Change Boot Order – Controls the relative order in which the EFI boot manager attempts boot
options. For help on the control key sequences you need for this option, see the help menu.
• Manage BootNext Setting – Selects a boot option to use one time (the next boot operation).
• Set Automatic Boot Timeout – Defines the value in seconds that pass before the server
automatically boots without user intervention. Setting this value to zero disables the timeout
feature.
• Exit – Returns control to the EFI boot manager main menu. This displays the active boot devices,
including a possible integrated shell (if the implementation is so constructed).
EFI Commands
Table 31 lists EFI commands for the server blade, and the equivalent BCH commands for reference.
152 Utilities
To Next Page
Loading...
Need help?
General