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Table 32—SCSI device path examples
Byte
offset
20.1.8.2
Byte
length
Data
Description
0x00
0x01
0x02
Generic Device Path Header – Type ACPI Device Path
0x01
0x01
0x01
Sub type – ACPI Device Path
0x02
0x02
0x0C
Length – 0x0C bytes
0x04
0x04
0x41D0,
0x0A03
_HID PNP0A03 – 0x41D0 represents a compressed string
‘PNP’ and is in the low-order bytes.
0x08
0x04
0x0000
_UID
0x0C
0x01
0x01
Generic Device Path Header – Type Hardware Device
Path
0x0D
0x01
0x01
Sub type – PCI
0x0E
0x02
0x06
Length – 0x06 bytes
0x10
0x01
0x07
PCI Function
0x11
0x01
0x00
PCI Device
0x12
0x01
0xFF
Generic Device Path Header – Type End of Hardware
Device Path
0x13
0x01
0xFF
Sub type – End of Entire Device Path
0x14
0x02
0x04
Length – 0x04 bytes
Multiple SCSI channels on a multifunction PCI controller
A SCSI host controller with multiple SCSI channels on a multi-function PCI controller
only changes the PCI portion of the device path for each SCII channel. In this example,
SCSI channel 0 is accessed through PCI function #0, and SCSI channel 1 is accessed
through PCI function #1. The following are the device paths for these SCSI channels:
20.1.8.3
•
ACPI(PNP0A03,1)/PCI(7|0)
Access to channel 0
•
ACPI(PNP0A03,1)/PCI(7|1)
Access to channel 1
Multiple SCSI channels on a single function PCI controller
If there is a SCSI PCI controller with multiple SCSI channels connected to a single
function PCI device the device paths must differentiate the SCSI channels. In this
example, SCSI channel 0 is accessed through Controller #0 below PCI function #0, and
SCSI channel 1 is accessed through Controller #1 below PCI function #1. The following
are the device paths for these SCSI channels:
20.1.9
•
ACPI(PNP0A03,1)/PCI(7|0)/Controller(0)
Access to channel 0
•
ACPI(PNP0A03,1)/PCI(7|0)/Controller(1)
Access to channel 1
Using Extended SCSI Pass Thru Protocol
If a SCSI driver supports both blocking and non-blocking I/O modes, any client of the
SCSI driver can use them to perform SCSI I/O.
408
3/8/2012
Version 1.01