path_to_inst(4)

NAME

     path_to_inst - device instance number file

SYNOPSIS

     /etc/path_to_inst

DESCRIPTION

     /etc/path_to_inst records mappings of physical device  names
     to instance numbers.

     The instance number of a device  is  encoded  in  its  minor
     number, and is the way that a device driver determines which
     of the possible devices that it may drive is referred to  by
     a given special file.

     In order to keep instance numbers persistent across reboots,
     the system records them in /etc/path_to_inst.

     This file is read only at  boot  time,  and  is  updated  by
     add_drv(1M) and drvconfig(1M).

     Note that it is  generally  not  necessary  for  the  system
     administrator  to change this file, as the system will main-
     tain it.

     The  system  administrator  can  change  the  assignment  of
     instance  numbers  by editing this file and doing a reconfi-
     guration reboot. However, any changes made in this file will
     be  lost  if  add_drv(1M) or drvconfig(1M) is run before the
     system is rebooted.

     Each instance entry is a single line of the form:

     "physical name"  instance number "driver binding name"

     where

      physical name
           is the absolute physical pathname of  a  device.  This
           pathname must be enclosed in double quotes.

     instance number
           is a decimal or hexadecimal number.

     driver binding name
           is the name used to determine the driver for the  dev-
           ice.
            This name may be a driver alias  or  a  driver  name.
           The  driver  binding  name  must be enclosed in double
           quotes.

EXAMPLES

     Example 1: Sample path_to_inst Entries

     Here are some sample path_to_inst entries:

     "/iommu@f,e0000000" 0 "iommu"
     "/iommu@f,e0000000/sbus@f,e0001000" 0 "sbus"
     "/iommu@f,e0000000/sbus@f,e0001000/sbusmem@e,0" 14 "sbusmem"
     "/iommu@f,e0000000/sbus@f,e0001000/sbusmem@f,0" 15 "sbusmem"
     "/iommu@f,e0000000/sbus@f,e0001000/ledma@f,400010" 0 "ledma"
     "/obio/serial@0,100000" 0 "zs"
     "/SUNW,sx@f,80000000" 0 "SUNW,sx"

FILES

     /etc/path_to_inst

SEE ALSO

     add_drv(1M), boot(1M), drvconfig(1M), mknod(1M)

WARNINGS

     If the file is removed the system may not be bootable (as it
     may rely on information found in this file to find the root,
     usr or swap device).  If it does successfully boot, it  will
     regenerate the file, but  after rebooting devices may end up
     having different minor numbers than  they  did  before,  and
     special  files  created via mknod(1M) may refer to different
     devices than expected.

     For the same reasons, changes should not  be  made  to  this
     file without careful consideration.

NOTES

     This document does not constitute an API.  path_to_inst  may
     not  exist or may have a different content or interpretation
     in a future release. The existence of this notice  does  not
     imply  that  any  other documentation that lacks this notice
     constitutes an API.