How to read a device path and determine the location of a PCI 
card mounted on a PCI I/O board in an Ultra Enterprise 
(UE) 3x00 - 6x00 server.

Example device path from a UE server with a PCI I/O board installed:

/pci@x,4000/scsi@2

First, divide x by 2.  The whole number quotient indicates the 
slot location of the PCI board in the UE server.  If there is a 
remainder of 0, the PCI card is located in the PCI 0 slot of the 
I/O board.  If the remainder is 1, it is located in the PCI 1 
slot of the I/O board.   

/pci@x,4000/SUNW,isptwo@3  is the device path (or physical name) for 
the onboard UltraSCSI port on a PCI I/O board.  This port is controlled 
by the PCI 1 Psycho chip on the board.

/pci@x,4000/SUNW,hme@1,1 is the device path (or physical name) for the 
onboard fast ethernet port on a PCI I/O board.  This port is controlled 
by the PCI 0 Psycho chip on the board.

Example device path:

/pci@6,4000/scsi@2

  From this example, it is determined that the PCI I/O board is in slot 3 
of the UE server (6 divided by 2 = 3).  There is no remainder, so the scsi 
card is in the PCI 0 slot of the PCI I/O board.

These are the most common driver names that may appear in a device path.  This
is to help identify different cards that may be installed.

fas - driver for fast/wide SCSI controllers
hme - driver for Fast Ethernet
isp - driver for differential SCSI controllers and the SunSwift card
glm - driver for UltraSCSI controllers
scsi - driver for Small Computer Serial Interface (SCSI) devices
sf - driver for soc+ or socal Fiber Channel Arbitrated Loop (FCAL)
soc - driver for SPARC(R) Storage Array (SSA) controllers
socal - driver for serial optical controllers for FCAL (soc+)

NOTE: This information is correct as of OBP version 3.2.30 and above.