Dell PowerEdge 7250 - Manual (Page 85)

Terminal Mode Commands 83
Boot flags
(semi-volatile)
(continued)
5 Data 4
[7:4] - Reserved.
[3] - BIOS Shared Mode Override.
Can be used to request BIOS to temporarily place the channel into
shared access mode.
Per the recommendations in the IPMI specification, "Shared"
access would cause the baseboard serial controller to both remain
enabled after POST/start of OS boot, while also allowing the BMC
to be accessible. This can be useful when booting to an alternative
device such as a Diagnostic Partition since it means the partition
can use the serial port but that communication with the BMC can
remain available if the partition software fails.
1b = Request BIOS to temporarily set the access mode for the
channel specified in parameter #6 to "Shared." This is typically
accomplished by sending a Set Channel Access command to set
the volatile access mode setting in the BMC.
0b = No request to BIOS to change present access mode setting
[2:0] - BIOS Mux Control Override.
Can be used to request BIOS to force a particular setting of the
serial/modem mux at the conclusion of POST / start of operating
system boot. This override takes precedence over the mux settings
for the access mode even if the BIOS Shared Mode Override is set.
000b = BIOS uses recommended setting of the mux at the end of
POST.
001b = Requests BIOS to force mux to BMC at conclusion of
POST/start of operating system-boot. If honored, this overrides the
recommended setting of the mux at the end of POST.
010b = Requests BIOS to force mux to system at conclusion of
POST/start of operating system-boot. If honored, this overrides the
recommended setting of the mux at the end of POST.
Data 5 - Reserved.
Table C-5. Boot Option Parameters (continued)
Parameter Number Parameter Data (non-volatile unless otherwise noted)