Return to 2.t CVS log

Up to [CSRG BSD Unix] / 43BSDReno / share / doc / smm / 02.config

Annotation of 43BSDReno/share/doc/smm/02.config/2.t, revision 1.1

1.1     ! root        1: .\" Copyright (c) 1983 Regents of the University of California.
        !             2: .\" All rights reserved.  The Berkeley software License Agreement
        !             3: .\" specifies the terms and conditions for redistribution.
        !             4: .\"
        !             5: .\"    @(#)2.t 6.2 (Berkeley) 6/3/86
        !             6: .\"
        !             7: .\".ds RH "Configuration File Contents
        !             8: .ne 2i
        !             9: .NH
        !            10: CONFIGURATION FILE CONTENTS
        !            11: .PP
        !            12: A system configuration must include at least the following
        !            13: pieces of information:
        !            14: .IP \(bu 3
        !            15: machine type
        !            16: .IP \(bu 3
        !            17: cpu type
        !            18: .IP \(bu 3
        !            19: system identification
        !            20: .IP \(bu 3
        !            21: timezone
        !            22: .IP \(bu 3
        !            23: maximum number of users
        !            24: .IP \(bu 3
        !            25: location of the root file system
        !            26: .IP \(bu 3
        !            27: available hardware
        !            28: .PP
        !            29: .I Config
        !            30: allows multiple system images to be generated from a single
        !            31: configuration description.  Each system image is configured
        !            32: for identical hardware, but may have different locations for the root
        !            33: file system and, possibly, other system devices.
        !            34: .NH 2
        !            35: Machine type
        !            36: .PP
        !            37: The 
        !            38: .I "machine type"
        !            39: indicates if the system is going to operate on a DEC VAX-11\(dg computer,
        !            40: .FS
        !            41: \(dg DEC, VAX, UNIBUS, MASSBUS and MicroVAX are trademarks of Digital
        !            42: Equipment Corporation.
        !            43: .FE
        !            44: or some other machine on which 4.3BSD operates.  The machine type
        !            45: is used to locate certain data files which are machine specific, and
        !            46: also to select rules used in constructing the resultant
        !            47: configuration files.
        !            48: .NH 2
        !            49: Cpu type
        !            50: .PP
        !            51: The
        !            52: .I "cpu type"
        !            53: indicates which, of possibly many, cpu's the system is to operate on.
        !            54: For example, if the system is being configured for a VAX-11, it could
        !            55: be running on a VAX 8600, VAX-11/780, VAX-11/750, VAX-11/730 or MicroVAX II.
        !            56: (Other VAX cpu types, including the 8650, 785 and 725, are configured using
        !            57: the cpu designation for compatible machines introduced earlier.)
        !            58: Specifying
        !            59: more than one cpu type implies that the system should be configured to run
        !            60: on any of the cpu's specified.  For some types of machines this is not
        !            61: possible and 
        !            62: .I config
        !            63: will print a diagnostic indicating such.
        !            64: .NH 2
        !            65: System identification
        !            66: .PP
        !            67: The
        !            68: .I "system identification"
        !            69: is a moniker attached to the system, and often the machine on which the
        !            70: system is to run.  For example, at Berkeley we have machines named Ernie
        !            71: (Co-VAX), Kim (No-VAX), and so on.  The system identifier selected is used to
        !            72: create a global C ``#define'' which may be used to isolate system dependent
        !            73: pieces of code in the kernel.  For example, Ernie's Varian driver used
        !            74: to be special cased because its interrupt vectors were wired together.  The
        !            75: code in the driver which understood how to handle this non-standard hardware
        !            76: configuration was conditionally compiled in only if the system
        !            77: was for Ernie.  
        !            78: .PP
        !            79: The system identifier ``GENERIC'' is given to a system which
        !            80: will run on any cpu of a particular machine type; it should not
        !            81: otherwise be used for a system identifier.
        !            82: .NH 2
        !            83: Timezone
        !            84: .PP
        !            85: The timezone in which the system is to run is used to define the
        !            86: information returned by the \fIgettimeofday\fP\|(2)
        !            87: system call.  This value is specified as the number of hours east
        !            88: or west of GMT.  Negative numbers indicate a value east of GMT.
        !            89: The timezone specification may also indicate the
        !            90: type of daylight savings time rules to be applied.
        !            91: .NH 2
        !            92: Maximum number of users
        !            93: .PP
        !            94: The system allocates many system data structures at boot time
        !            95: based on the maximum number of users the system will support.
        !            96: This number is normally between 8 and 40, depending
        !            97: on the hardware and expected job mix.  The rules
        !            98: used to calculate system data structures are discussed in
        !            99: Appendix D.
        !           100: .NH 2
        !           101: Root file system location
        !           102: .PP
        !           103: When the system boots it must know the location of
        !           104: the root of the file system
        !           105: tree.  This location and the part(s) of the disk(s) to be used
        !           106: for paging and swapping must be specified in order to create
        !           107: a complete configuration description.  
        !           108: .I Config
        !           109: uses many rules to calculate default locations for these items;
        !           110: these are described in Appendix B.
        !           111: .PP
        !           112: When a generic system is configured, the root file system is left
        !           113: undefined until the system is booted.  In this case, the root file
        !           114: system need not be specified, only that the system is a generic system.
        !           115: .NH 2
        !           116: Hardware devices
        !           117: .PP
        !           118: When the system boots it goes through an
        !           119: .I autoconfiguration
        !           120: phase.  During this period, the system searches for all
        !           121: those hardware devices
        !           122: which the system builder has indicated might be present.  This probing
        !           123: sequence requires certain pieces of information such as register
        !           124: addresses, bus interconnects, etc.  A system's hardware may be configured
        !           125: in a very flexible manner or be specified without any flexibility
        !           126: whatsoever.  Most people do not configure hardware devices into the
        !           127: system unless they are currently present on the machine, expect
        !           128: them to be present in the near future, or are simply guarding
        !           129: against a hardware
        !           130: failure somewhere else at the site (it is often wise to configure in
        !           131: extra disks in case an emergency requires moving one off a machine which
        !           132: has hardware problems).
        !           133: .PP
        !           134: The specification of hardware devices usually occupies the majority of
        !           135: the configuration file.  As such, a large portion of this document will
        !           136: be spent understanding it.  Section 6.3 contains a description of
        !           137: the autoconfiguration process, as it applies to those planning to
        !           138: write, or modify existing, device drivers.
        !           139: .NH 2
        !           140: Pseudo devices
        !           141: .PP
        !           142: Several system facilities are configured in a manner like that used
        !           143: for hardware devices although they are not associated with specific hardware.
        !           144: These system options are configured as
        !           145: .IR pseudo-devices .
        !           146: Some pseudo devices allow an optional parameter that sets the limit
        !           147: on the number of instances of the device that are active simultaneously.
        !           148: .NH 2
        !           149: System options
        !           150: .PP
        !           151: Other than the mandatory pieces of information described above, it
        !           152: is also possible to include various optional system facilities
        !           153: or to modify system behavior and/or limits.
        !           154: For example, 4.3BSD can be configured to support binary compatibility for
        !           155: programs built under 4.1BSD.  Also, optional support is provided
        !           156: for disk quotas and tracing the performance of the virtual memory
        !           157: subsystem.  Any optional facilities to be configured into
        !           158: the system are specified in the configuration file.  The resultant
        !           159: files generated by
        !           160: .I config
        !           161: will automatically include the necessary pieces of the system.

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.