Chapter 8 BIOS ROM
Compaq iPAQ Series of Desktop Personal Computers
Review Copy - January 2001
8-10
8.3.9 SECURITY FUNCTIONS
The INT 15 AX=E846h BIOS function is used to control various security features of the system.
This function may be issued by a remote system (over a network). The issuing driver must build a
request buffer for each security feature prior to making the call. This system supports the following
security features:
♦ QuickLock
♦ IDE controller disable
♦
Serial port disable (legacy-light only)
♦ Parallel port disable (legacy-light only)
♦ Change administrator password
♦
QuickLock on suspend
♦ Ownership tag
♦ USB disable (legacy-light only)
The write-protect function that determines diskette write control is extended to cover all drives that
use removable read/write media (i.e., if diskette write protect is invoked, then any diskette drive,
power drive (SCSI and/or ATAPI), and floptical drive installed will be inaccessible for (protected
from) writes). Client management software should check the following bytes of SIT record 07h for
the location and access method for this bit:
System Information Table, Peripheral and Input Device Record (07h) (partial listing)
Byte Bit Function
1Fh 7-0 Removable Read/Write Media Write Protect Enable Byte Offset (0-255)
20h
7..4
3..0
Removable Read/Write Media Write Protect Enable Bit Location:
CMOS Type:
0000 = CMOS
0001 = High CMOS
0010 = NVRAM
0011 = Flat model NVRAM
Bit Location:
0000 = Bit 0 0100 = Bit 4
0001 = Bit 1 0101 = Bit 5
0010 = Bit 2 0110 = Bit 6
0011 = Bit 3 0111 = Bit 7
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