70 IBM ^ xSeries 450 Planning and Installation Guide
When you select one of the network controllers (marked PXE boot), you initiate
the PXE remote boot process. When no PXE boot server is discovered on the
network during this process, a failure message appears as well.
Beyond the options mentioned, in this section we cover the following:
򐂰 The EFI shell
򐂰 Flash update
򐂰 Configuration and Setup utility
򐂰 Diagnostic utility
򐂰 Boot maintenance menu
4.1.1 The EFI shell
The EFI shell allows the loading of EFI applications (including booting installed
operating systems) from any EFI-defined file system. The EFI environment
replaces DOS to perform maintenance operations, such as upgrading firmware
or running system diagnostics.
To start the EFI shell,
select EFI Shell [Built-in] from the Boot Manager menu. As
the shell starts, a device mapping table is displayed, as shown in Figure 4-2.
Figure 4-2 Entering EFI shell
This mapping table lists both block devices (blk) and file systems (fs). All fixed
disks, CD-ROM drives, and USB storage devices will appear as block devices. If
the server contains additional controllers and disks, they will appear as additional
block devices. The EFI automatically maps known file systems on the block
devices to their FSx mappings (FSx is referred to as the
file system identifier).
Loading.: EFI Shell [Built-in]
EFI Boot Manager ver 1.10 [14.60]
Device Mapping Table
fs0 : MemMap(0:FF000000-FFFFFFFF)
fs1 : MemMap(0:FF800200-FFBFFFFF)
fs2 : Acpi(PNP0A03,0)/Pci(5|1)/Ata(Primary,Master)/CDROM(Entry0)
fs3 : Acpi(PNP0A03,1)/Pci(3|0)/Scsi(Pun0,Lun0)/HD(Part1,Sig4879D0ED-F
blk0 : MemMap(0:FF000000-FFFFFFFF)
blk1 : MemMap(0:FF800200-FFBFFFFF)
blk2 : Acpi(PNP0A03,0)/Pci(5|1)/Ata(Primary,Master)
blk3 : Acpi(PNP0A03,0)/Pci(5|1)/Ata(Primary,Master)/CDROM(Entry0)
blk4 : Acpi(PNP0A03,1)/Pci(3|0)/Scsi(Pun0,Lun0)
blk5 : Acpi(PNP0A03,1)/Pci(3|0)/Scsi(Pun0,Lun0)/HD(Part1,Sig4879D0ED-F
Chapter 4. Installation 71
Here are some tips for easier identification of devices in the list:
򐂰 Even with no storage devices, the server has at least two default mappings —
the MemMap entries listed as
fs0: and fs1: in Example 4-2 on page 70.
These are read-only RAM disks created during POST so they will always be
available. The first MemMap file system is the content of the 4 MB of NVRAM
assigned to the EFI, and contains a number of drivers. The second MemMap
file system is the content of the NVRAM assigned to the server diagnostics.
򐂰 The internal disks contain Scsi and HD strings. In Figure 4-2 on page 70:
where Lun0 is disk’s SCSI ID, Part1 stands for Partition1, and Sig is the disk’s
GUID (discussed in 1.3.1, “GUID Partition Table disk” on page 7).
򐂰 The disk partitions are numbered from 1 onwards: the first partition is Part1,
the second Part2, and so on.
򐂰 EFI System Partition is easily identifiable in Figure 4-2 on page 70 if we
realize that EFI is always the first partition on the disk (that is, it is identified by
HD Part1 in the string). In this case it is fs3.
򐂰 In Figure 4-2 on page 70, the CD-ROM is represented as fs2.
򐂰 The USB memory devices include the string USB.
File operations in the EFI shell
From the EFI shell you may access FAT/FAT32 file systems on existing disk
partitions, run EFI executables, and manipulate with disk contents on various
media. The EFI executables are text mode utilities similar to DOS or UNIX
commands. In general, EFI commands are not case-sensitive.
Access to the file system on a device is done through the
FSn: command (where
n is the file system number shown in the device mapping table). This is similar in
concept to changing drive letters in DOS. You can use the
map command at any
time to remind yourself of the available file systems.
Note: Unless CD-ROM media is inserted, there is no FSx mapping created
for the CD-ROM.
Tip: All the EFI executable files have an extension of .EFI. The executables
may be run only from within EFI, not from within any operating system.

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