2.11BSD#431 - /usr/man/cat8/autoconfig.0

AUTOCONFIG(8)	    UNIX Programmer's Manual	    AUTOCONFIG(8)


NAME
     autoconfig - configure the running system to the hardware

SYNOPSIS
     autoconfig [-i ifile] [-n nfile] [-k kfile] [-v] [-d] [-c]

DESCRIPTION
     Autoconfig is called by init(8) to configure the currently
     running system.  Init checks the exit status of autoconfig
     to determine if the configuration was successful.	Autocon-
     fig reads the device table /etc/dtab for a list of devices
     which may be on the system.  It first verifies that the ker-
     nel has an attach routine for each device (and therefore has
     a device handler) and that the kernel has a probe routine.
     It then checks each of these devices to see if it is
     present, and if it is, attempts to make it interrupt (if
     possible) to verify that the interrupt vector is correct.
     The interrupt vector is checked to see that it has not pre-
     viously been used.  An interrupt through any of the device's
     consecutive vectors is sufficient.

     Devices which use programmable vectors (MSCP and TMSCP) are
     permitted to have a value of 0 in the dtab vector field.
     This special value tells autoconfig to call the kernel's get
     next available vector routine and assign that to the device.
     For programmable vector devices if the dtab vector field is
     non 0 then the value specified in the dtab file is used.  In
     both cases the driver is called at its xxVec() routine with
     the vector being assigned to the device.

     If the address and vector are correct, it then attaches the
     device by passing the address and unit number to the
     kernel's attach routine and setting up the interrupt vector
     according to the interrupt handlers and priority listed in
     the device table.	If the unit number is given as a '?' in
     the device table, it will be assigned the next available
     unit number if the device exists.	If the device is not
     present or the vector is incorrect, and if the unit number
     was specified (not a '?'), then the kernel is notified that
     that unit is not present, preventing accesses to a nonex-
     istent device address.

     There are only a few flags which are mostly useful for
     debugging but for completeness, here they are.

     -i ifile  Use ifile instead of /etc/dtab as the device
	       table.

     -n nfile  Use nfile instead of /unix for finding the namel-
	       ist of the currently running kernel.

     -k kfile  The file kfile should be used instead of /dev/kmem


Printed 11/26/99	December 30, 1992			1


AUTOCONFIG(8)	    UNIX Programmer's Manual	    AUTOCONFIG(8)


	       to alter and read kernel memory.

     -v        Verbose output, indicates reason for rejecting any
	       device in the device table.  Normally only
	       attached devices are reported.

     -c        Report error messages for devices skipped because
	       of problems with their interrupt vectors.

     -d        Turn on debugging mode.	Shows many gory details
	       of autoconfig's internal processing.

BUGS
     Devices of the same type must be listed with ascending unit
     numbers or with wildcards.

     Disks that could be root devices must have their addresses
     and vectors initialized in the kernel; the kernel uses a
     root attach entry in the block device switch to allow disk
     drivers to do any probes necessary before autoconfiguration.

     Must be run only by init(8).  There is a flag set in the
     kernel that autoconfig has already run, running autoconfig a
     second time results in the error:

     "namelist doesn't match running kernel."
	  Autoconfig attempts to open /dev/kmem for write.  If
	  the kernel is in securelevel 1 or higher the open of
	  /dev/kmem will fail.

FILES
     /etc/dtab		 device table
     /unix
     /dev/kmem

SEE ALSO
     ucall(2), nlist(3), dtab(5)


Printed 11/26/99	December 30, 1992			2