system(4)                      DG/UX 5.4R3.00                      system(4)


NAME
       system - format of a kernel description file

DESCRIPTION
       The system file contains information about the hardware and system-
       dependent parameters found on your system.  This information is used
       in conjunction with one or more master files as input into the
       config(1M) program.  The config(1M) program is used to generate a
       conf.c file, which is then compiled and linked with kernel libraries
       to form a kernel image.  A more complete description of the system
       file is found in Managing the DG/UX System.

       Each line in a the system file is a separate entry.  An entry
       contains one or more fields, separated by one or more space and/or
       tab characters.  Any line with a number sign (#) in column 1 is
       treated as a comment and is ignored.  Blank lines are also ignored.
       Each non-comment entry represents a device, STREAMS module, protocol,
       or tunable system parameter.  Entries of any type may appear in any
       order.

   Device Entries
       An entry of the form:

              devname(parameters)
       or
              devname@devcode(parameters)

       specifies a device or pseudo-device to be configured into the kernel.

       The device name devname must be listed in a $device section of one of
       the master files.

       The devcode notation, if present, specifies that a non-default
       hardware device code will be used for that device.  The device code
       must appear as a two-digit hexadecimal number.

       The parameters string represents a specific unit or instantiation of
       the device; its interpretation is left to the specific device driver.
       If parameters is the null string, the driver's default parameter
       values will be used.  Note that the parameters string may itself be a
       device specification, such as:

              sd(insc(),*)

   Protocol Entries
       Each single-word entry that matches an entry in a master file's
       $protocol section specifies a socket protocol to be configured into
       the kernel.

   STREAMS Module Entries
       Each single-word entry that matches an entry in a master file's
       $stream section specifies a STREAMS module to be configured into the
       kernel.




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system(4)                      DG/UX 5.4R3.00                      system(4)


   Tunable Parameter Entries
       Each one or two-word entry whose first word matches an entry in a
       master file's $keyword section specifies a tunable system parameter
       for which a non-default value should be configured into the kernel.
       The first word of the entry names the parameter that is to be tuned;
       the second word specifies its value.  The value field may be omitted
       if an implied value is specified in the master file.  Note that the
       implied value may be different from the default value.

       The default value is configured in /usr/etc/master.d/dgux.  While the
       default value may be stated as an equation to help the user
       understand how to arrive at a new value, the tunable alias will not
       recognise an equation in the kernel configuration file.  All
       parameters should be configured as numeric values rather than
       equations.

       For example, If you would like to tune SHMMAX, the alias for
       cfpsmaxsegmentsize, you would add the following to the tunable
       parameter section:
                   SHMMAX             4194304

       rather than:

                   SHMMAX             (4*1024*1024)

       (4*1024*1024) is the default value in /usr/etc/master.d/dgux
       for cfpsmaxsegm

SEE ALSO
       config(1M), sysdef(1M), master(4).
       Installing the DG/UX System, Customizing the DG/UX System, Managing
       the DG/UX System.

























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