Bitfields for Intel 82371MX BIOS enable register:
Bit(s)	Description	)
 7	Extended BIOS Enable
 6	Lower BIOS Enable 1
 5	Lower BIOS Enable 0
 4	Lower BIOS CS# Enable 0
 3	F Segment BIOS Enable
 2	BIOSCS# Write Protect
 1-0	reserved
SeeAlso: #01168,PORT xxxxh"Intel 82371"