NVM Information Guide—ICH8
20
Table 19.
Boot Agent Configuration Customization Options (Word 31h)
Bit
Name
Description
15:14
SIG
Signature. These bits must be set to 01b to indicate that this word has
been programmed by the agent or other configuration software.
13:11
Reserved
Reserved for future use. All bits must be set to 0b.
10:8
MODE
Selects the agent's boot order setup mode. This field changes the
agent's default behavior in order to make it compatible with systems
that do not completely support the BBS and PnP Expansion ROM
standards. Valid values and their meanings are:
000b = Normal behavior. The agent attempts to detect BBS and PnP
Expansion ROM support as it normally does.
001b = Force Legacy mode. The agent does not attempt to detect BBS
or PnP Expansion ROM supports in the BIOS and assumes the BIOS is
not compliant. The BIOS boot order can be changed in the Setup Menu.
010b = Force BBS mode. The agent assumes the BIOS is BBS-
compliant, even though it may not be detected as such by the agent's
detection code. The BIOS boot order CANNOT be changed in the Setup
Menu.
011b = Force PnP Int18 mode. The agent assumes the BIOS allows
boot order setup for PnP Expansion ROMs and hooks interrupt 18h (to
inform the BIOS that the agent is a bootable device) in addition to
registering as a BBS IPL device. The BIOS boot order CANNOT be
changed in the Setup Menu.
100b = Force PnP Int19 mode. The agent assumes the BIOS allows
boot order setup for PnP Expansion ROMs and hooks interrupt 19h (to
inform the BIOS that the agent is a bootable device) in addition to
registering as a BBS IPL device. The BIOS boot order CANNOT be
changed in the Setup Menu.
101b = Reserved for future use. If specified, treated as value 000b.
110b = Reserved for future use. If specified, treated as value 000b.
111b = Reserved for future use. If specified, treated as value 000b.
7:6
Reserved
Reserved for future use. These bits must be set to 0b.
5
DFU
Disable Flash Update.
If set to 1b, no updates to the Flash image using PROSet is allowed.
The default for this bit is 0b; allow Flash image updates using PROSet.
4
DLWS
Disable Legacy Wakeup Support.
If set to 1b, no changes to the Legacy OS Wakeup Support menu
option is allowed.
The default for this bit is 0b; allow Legacy OS Wakeup Support menu
option changes.
3
DBS
Disable Boot Selection.
If set to 1b, no changes to the boot order menu option is allowed.
The default for this bit is 0b; allow boot order menu option changes.
