The following startup options are available only when an MBA UNDI is used. If an
UNDI developed by another vendor is used with the MBA base code, these options
are not available.
T
ABLE
5: S
TARTUP
O
PTIONS
Option
Name
Possible
Values
Description
Default
Boot
Control
Auto
Detection
Interrupt 19
Interrupt 18
BBS Boot
Order
Choose the method that MBA UNDI participates in
the PC's booting process. All PCs have two system
interrupts involved when the PC starts—Interrupt
18 (ROM BASIC/Boot Failure) and Interrupt 19
(Bootstrap Loader). Before the BBS specification
was created, boot firmware such as MBA would take
control of one or both of these interrupts so it would
be executed during the PC boot process. With the
BBS specification, this is no longer required and the
PC's BIOS executes the boot device, such as MBA,
as specified in the boot order.
Choose Auto Detection to enable MBA UNDI to
detect whether the PC has a BBS-compliant BIOS. If
so, BIOS executes MBA UNDI as its position in the
boot order dictates. If not, MBA UNDI takes over
interrupt 18 and 19 and forces its execution when
the PC boots.
Choose Interrupt 18 or Interrupt 19 to have MBA
take control of these settings. This may be
necessary if MBA UNDI incorrectly detects that the
PC has a BBS BIOS when in fact it does not. If
either of these interrupts is selected on a PC that
has a BBS BIOS, the BBS boot order is ignored and
the PC is always booted using MBA UNDI. MBA
behavior and options are present as though the PC
does not have a BBS BIOS.
Choose the BBS Boot Order setting to enable the
MBA UNDI to execute as specified in the boot order
of a BBS BIOS. This may be necessary if MBA UNDI
incorrectly detects that the PC does not have a BBS
BIOS when in fact it does. If this setting is selected
on a PC that does not have a BBS BIOS, MBA UNDI
will never be executed.
You should be familiar with the technical aspects of
the PC boot process before modifying these
settings.
Auto
Detection
ROM MBA
Base Code
Enabled
Disabled
If your MBA is integrated in a ROM on a NIC and
not integrated into the BIOS, you can disable the
MBA base code. When the MBA base code is
disabled and the MBA UNDI is executed (either by a
BBS BIOS or by taking control of Interrupt 18
and/or 19), the MBA UNDI tries to locate another
PXE-compatible base code (which could reside in
the PC's BIOS). This allows the MBA UNDI on a
specific NIC to use a base code that is different than
the base code contained in the ROM.
Enabled
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