FreeBSD/Linux Kernel Cross Reference
sys/i386/conf/LINT

     #
     # LINT -- config file for checking all the sources, tries to pull in
     #       as much of the source tree as it can.
     #
     # $FreeBSD: src/sys/i386/conf/LINT,v 1.286.2.68 1999/09/05 08:10:50 peter Exp $
     #
     # NB: You probably don't want to try running a kernel built from this
     # file.  Instead, you should start from GENERIC, and add options from
     # this file as required.
    #
    
    #
    # This directive is mandatory; it defines the architecture to be
    # configured for; in this case, the 386 family based IBM-PC and
    # compatibles.
    #
    machine         "i386"
    
    # 
    # This is the ``identification'' of the kernel.  Usually this should
    # be the same as the name of your kernel.
    #
    ident           LINT
    
    #
    # The `maxusers' parameter controls the static sizing of a number of
    # internal system tables by a complicated formula defined in param.c.
    #
    maxusers        10
    
    #
    # Under some circumstances it is convenient to increase the defaults
    # for the maximum number of processes per user and the maximum number
    # of open files files per user.  E.g., (1) in a large news server, user
    # `news' may need more than 100 concurrent processes.  (2) a user may
    # need lots of windows under X.  In both cases, it may be inconvenient
    # to start all the processes from a parent whose soft rlimit on the
    # number of processes is large enough.  The following options work by
    # changing the soft rlimits for init.
    #
    options         CHILD_MAX=128
    options         OPEN_MAX=128
    
    #
    # Certain applications can grow to be larger than the 128M limit
    # that FreeBSD initially imposes.  Below are some options to
    # allow that limit to grow to 256MB, and can be increased further
    # with changing the parameters.  MAXDSIZ is the maximum that the
    # limit can be set to, and the DFLDSIZ is the default value for
    # the limit.  You might want to set the default lower than the
    # max, and explicitly set the maximum with a shell command for processes
    # that regularly exceed the limit like INND.
    #
    options         "MAXDSIZ=(256*1024*1024)"
    options         "DFLDSIZ=(256*1024*1024)"
    
    # When this is set, be extra conservative in various parts of the kernel
    # and choose functionality over speed (on the widest variety of systems).
    #
    # (Note that one of the effects of removing this option is to enable
    # tagged commands in the `ncr' driver.  See the comments to
    # AHC_TAGENABLE for a note of warning.)
    options         FAILSAFE
    
    # This allows you to actually store this configuration file into
    # the kernel binary itself, where it may be later read by saying:
    #    strings /kernel | grep ^___ | sed -e 's/^___//' > MYKERNEL
    #
    options         INCLUDE_CONFIG_FILE     # Include this file in kernel
    
    #
    # This directive defines a number of things:
    #  - The compiled kernel is to be called `kernel'
    #  - The root filesystem might be on partition wd0a
    #  - Crash dumps will be written to wd0b, if possible.  Specifying the
    #    dump device here is not recommended.  Use dumpon(8).
    #
    config          kernel  root on wd0 dumps on wd0
    
    
    #####################################################################
    # CPU OPTIONS
    
    #
    # You must specify at least one CPU (the one you intend to run on);
    # deleting the specification for CPUs you don't need to use may make
    # parts of the system run faster.  This is especially true removing
    # I386_CPU.
    #
    cpu             "I386_CPU"
    cpu             "I486_CPU"
    cpu             "I586_CPU"              # aka Pentium(tm)
    cpu             "I686_CPU"              # aka Pentium Pro(tm)
    
    #
    # Options for CPU features.
    #
    # CPU_BLUELIGHTNING_FPU_OP_CACHE enables FPU operand cache on IBM
    # BlueLightning CPU.  It works only with Cyrix FPU, and this option
   # should not be used with Intel FPU.
   #
   # CPU_BLUELIGHTNING_3X enables triple-clock mode on IBM Blue Lightning 
   # CPU if CPU supports it. The default is double-clock mode on
   # BlueLightning CPU box.  
   #
   # CPU_BTB_EN enables branch target buffer on Cyrix 5x86 (NOTE 1).
   #
   # CPU_DIRECT_MAPPED_CACHE set L1 cache of Cyrix 486DLC CPU in direct
   # mapped mode.  Default is 2-way set associative mode.
   #
   # CPU_CYRIX_NO_LOCK enables weak locking for the entire address space
   # of Cyrix 6x86 and 6x86MX CPUs.  If this option is not set and
   # FAILESAFE is defined, NO_LOCK bit of CCR1 is cleared.  (NOTE 3)
   #
   # CPU_DISABLE_5X86_LSSER disables load store serialize (i.e. enables
   # reorder).  This option should not be used if you use memory mapped
   # I/O device(s). 
   #
   # CPU_FASTER_5X86_FPU enables faster FPU exception handler.
   #
   # CPU_I486_ON_386 enables CPU cache on i486 based CPU upgrade products
   # for i386 machines. 
   #
   # CPU_IORT defines I/O clock delay time (NOTE 1).  Default vaules of
   # I/O clock delay time on Cyrix 5x86 and 6x86 are 0 and 7,respectively
   # (no clock delay).
   #
   # CPU_LOOP_EN prevents flushing the prefetch buffer if the destination
   # of a jump is already present in the prefetch buffer on Cyrix 5x86(NOTE
   # 1). 
   #
   # CPU_RSTK_EN enables return stack on Cyrix 5x86 (NOTE 1).
   #
   # CPU_SUSP_HLT enables suspend on HALT.  If this option is set, CPU
   # enters suspend mode following execution of HALT instruction.
   #
   # CPU_WT_ALLOC enables write-through allocation.
   #
   # CYRIX_CACHE_WORKS enables CPU cache on Cyrix 486 CPUs with cache
   # flush at hold state.
   #
   # CYRIX_CACHE_REALLY_WORKS enables (1) CPU cache on Cyrix 486 CPUs
   # without cache flush at hold state, and (2) write-back CPU cache on
   # Cyrix 6x86 whose revision < 2.7 (NOTE 2).
   #
   # NO_F00F_HACK disables the hack that prevents Pentiums (and ONLY
   # Pentiums) from locking up when a LOCK CMPXCHG8B instruction is
   # executed.  This should be included for ALL kernels that won't run
   # on a Pentium.
   #
   # NOTE 1: The options, CPU_BTB_EN, CPU_LOOP_EN, CPU_IORT,
   # CPU_LOOP_ENand CPU_RSTK_EN should no be used becasue of CPU bugs.
   # These options may crash your system. 
   #
   # NOTE 2: If CYRIX_CACHE_REALLY_WORKS is not set, CPU cache is enabled
   # in write-through mode when revision < 2.7.  If revision of Cyrix
   # 6x86 >= 2.7, CPU cache is always enabled in write-back mode.
   #
   # NOTE 3: This option may cause failures for software that requires
   # locked cycles in order to operate correctly.
   #
   options         "CPU_BLUELIGHTNING_FPU_OP_CACHE"
   options         "CPU_BLUELIGHTNING_3X"
   options         "CPU_BTB_EN"
   options         "CPU_DIRECT_MAPPED_CACHE"
   options         "CPU_DISABLE_5X86_LSSER"
   options         "CPU_FASTER_5X86_FPU"
   options         "CPU_I486_ON_386"
   options         "CPU_IORT"
   options         "CPU_LOOP_EN"
   options         "CPU_RSTK_EN"
   options         "CPU_SUSP_HLT"
   options         "CYRIX_CACHE_WORKS"
   options         "CYRIX_CACHE_REALLY_WORKS"
   #options        "NO_F00F_HACK"
   
   #
   # A math emulator is mandatory if you wish to run on hardware which
   # does not have a floating-point processor.  Pick either the original,
   # bogus (but freely-distributable) math emulator, or a much more
   # fully-featured but GPL-licensed emulator taken from Linux.
   #
   options         MATH_EMULATE            #Support for x87 emulation
   # Don't enable both of these in a real config.
   options         GPL_MATH_EMULATE        #Support for x87 emulation via
                                           #new math emulator 
   
   
   #####################################################################
   # COMPATIBILITY OPTIONS                                             
   
   #
   # Implement system calls compatible with 4.3BSD and older versions of
   # FreeBSD.  You probably do NOT want to remove this as much current code
   # still relies on the 4.3 emulation.
   #
   options         "COMPAT_43"
   
   #
   # Allow user-mode programs to manipulate their local descriptor tables.
   # This option is required for the WINE Windows(tm) emulator, and is
   # not used by anything else (that we know of).
   #
   options         USER_LDT                #allow user-level control of i386 ldt
   
   #
   # These three options provide support for System V Interface
   # Definition-style interprocess communication, in the form of shared
   # memory, semaphores, and message queues, respectively.
   #
   options         SYSVSHM
   options         SYSVSEM
   options         SYSVMSG
   
   #
   # This option includes a MD5 routine in the kernel, this is used for
   # various authentication and privacy uses.
   #
   options         "MD5"
   
   
   #####################################################################
   # DEBUGGING OPTIONS
   
   #
   # Enable the kernel debugger.
   #
   options         DDB
   
   #
   # Don't drop into DDB for a panic. Intended for unattended operation
   # where you may want to drop to DDB from the console, but still want
   # the machine to recover from a panic
   #
   options         DDB_UNATTENDED
   
   # 
   # KTRACE enables the system-call tracing facility ktrace(2).
   #
   options         KTRACE                  #kernel tracing
   
   #
   # The DIAGNOSTIC option is used in a number of source files to enable
   # extra sanity checking of internal structures.  This support is not
   # enabled by default because of the extra time it would take to check
   # for these conditions, which can only occur as a result of
   # programming errors.
   #
   options         DIAGNOSTIC
   
   #
   # PERFMON causes the driver for Pentium/Pentium Pro performance counters
   # to be compiled.  See perfmon(4) for more information.
   #
   options         PERFMON
   
   # XXX - this doesn't belong here.
   # Allow ordinary users to take the console - this is useful for X.
   options         UCONSOLE
   
   # XXX - this doesn't belong here either
   options         USERCONFIG              #boot -c editor
   options         USERCONFIG_BOOT         #imply -c and parse info area
   options         VISUAL_USERCONFIG       #visual boot -c editor
   
   #####################################################################
   # NETWORKING OPTIONS
   
   #
   # Protocol families:
   #  Only the INET (Internet) family is officially supported in FreeBSD.
   #  Source code for the NS (Xerox Network Service) is provided for amusement
   #  value.
   #
   options         INET                    #Internet communications protocols
   
   options         IPX                     #IPX/SPX communications protocols
   options         IPXIP                   #IPX in IP encapsulation (not available)
   options         IPTUNNEL                #IP in IPX encapsulation (not available)
   
   options         NETATALK                #Appletalk communications protocols
   
   # These are currently broken but are shipped due to interest.
   #options                NS                      #Xerox NS protocols
   
   # These are currently broken and are no longer shipped due to lack
   # of interest.
   #options                CCITT                   #X.25 network layer
   #options                ISO
   #options                TPIP                    #ISO TP class 4 over IP
   #options                TPCONS                  #ISO TP class 0 over X.25
   #options                LLC                     #X.25 link layer for Ethernets
   #options                HDLC                    #X.25 link layer for serial lines
   #options                EON                     #ISO CLNP over IP
   #options                NSIP                    #XNS over IP
   
   #
   # Network interfaces:
   #  The `loop' pseudo-device is MANDATORY when networking is enabled.
   #  The `ether' pseudo-device provides generic code to handle
   #  Ethernets; it is MANDATORY when a Ethernet device driver is
   #  configured.
   #  The 'fddi' pseudo-device provides generic code to support FDDI.
   #  The `sppp' pseudo-device serves a similar role for certain types
   #  of synchronous PPP links (like `cx', `ar').
   #  The `sl' pseudo-device implements the Serial Line IP (SLIP) service.
   #  The `ppp' pseudo-device implements the Point-to-Point Protocol.
   #  The `bpfilter' pseudo-device enables the Berkeley Packet Filter.  Be
   #  aware of the legal and administrative consequences of enabling this
   #  option.  The number of devices determines the maximum number of
   #  simultaneous BPF clients programs runnable.
   #  The `disc' pseudo-device implements a minimal network interface,
   #  which throws away all packets sent and never receives any.  It is
   #  included for testing purposes.
   #  The `tun' pseudo-device implements the User Process PPP (iijppp)
   #
   # The PPP_BSDCOMP option enables support for compress(1) style entire
   # packet compression, the PPP_DEFLATE is for zlib/gzip style compression.
   # PPP_FILTER enables code for filtering the ppp data stream and selecting
   # events for resetting the demand dial activity timer - requires bpfilter.
   # See pppd(8) for more details.
   #
   pseudo-device   ether                   #Generic Ethernet
   pseudo-device   fddi                    #Generic FDDI
   pseudo-device   sppp                    #Generic Synchronous PPP
   pseudo-device   loop                    #Network loopback device
   pseudo-device   sl      2               #Serial Line IP
   pseudo-device   ppp     2               #Point-to-point protocol
   pseudo-device   bpfilter        4       #Berkeley packet filter
   pseudo-device   disc                    #Discard device
   pseudo-device   tun     1               #Tunnel driver(user process ppp)
   options PPP_BSDCOMP                     #PPP BSD-compress support
   options PPP_DEFLATE                     #PPP zlib/deflate/gzip support
   options PPP_FILTER                      #enable bpf filtering (needs bpfilter)
   
   #
   # Internet family options:
   #
   # TCP_COMPAT_42 causes the TCP code to emulate certain bugs present in
   # 4.2BSD.  This option should not be used unless you have a 4.2BSD
   # machine and TCP connections fail.
   #
   # MROUTING enables the kernel multicast packet forwarder, which works
   # with mrouted(8).
   #
   # IPFIREWALL enables support for IP firewall construction, in
   # conjunction with the `ipfw' program.  IPFIREWALL_VERBOSE sends
   # logged packets to the system logger.  IPFIREWALL_VERBOSE_LIMIT
   # limits the number of times a matching entry can be logged.
   #
   # WARNING:  IPFIREWALL defaults to a policy of "deny ip from any to any"
   # and if you do not add other rules during startup to allow access,
   # YOU WILL LOCK YOURSELF OUT.  It is suggested that you set firewall=open
   # in /etc/rc.conf when first enabling this feature, then refining the
   # firewall rules in /etc/rc.firewall after you've tested that the new kernel
   # feature works properly.
   #
   # IPFIREWALL_DEFAULT_TO_ACCEPT causes the default rule (at boot) to
   # allow everything.  Use with care, if a cracker can crash your
   # firewall machine, they can get to your protected machines.  However,
   # if you are using it as an as-needed filter for specific problems as
   # they arise, then this may be for you.  Changing the default to 'allow'
   # means that you won't get stuck if the kernel and /sbin/ipfw binary get
   # out of sync.
   #
   # IPDIVERT enables the divert IP sockets, used by ``ipfw divert.''
   # See ipfw(8) and divert(4) man pages for details.
   #
   # IPFW_DIVERT_RESTART alters the interpretation of the "sin_port" field
   # when writing a packet to a divert socket. Without this option, "sin_port"
   # indicates that "divert port" ipfw rules should be ignored, where
   # "port" is the (host-order) value of "sin_port". With this option, this
   # field is the ipfw rule number at which to (re)start when checking
   # the packet, minus one. Note that 3.X kernels do not have this option,
   # and always behave as if IPFW_DIVERT_RESTART were defined.
   #
   # TCPDEBUG is undocumented.
   #
   options         "TCP_COMPAT_42"         #emulate 4.2BSD TCP bugs
   options         MROUTING                # Multicast routing
   options         IPFIREWALL              #firewall
   options         IPFIREWALL_VERBOSE      #print information about
                                           # dropped packets
   options         "IPFIREWALL_VERBOSE_LIMIT=100" #limit verbosity
   options         IPFIREWALL_DEFAULT_TO_ACCEPT #allow everything by default
   options         IPDIVERT                #divert sockets
   options         IPFW_DIVERT_RESTART     #divert writeback specifies ipfw rule
   options         TCPDEBUG
   
   #
   # options BRIDGE can be used to enable bridging -- see bridge(4)
   # options DUMMYNET enables the "Dummynet" bandwidth manager and
   # delay emulator -- see dummynet(4) . It requires IPFIREWALL.
   #
   # options DUMMYNET
   # options BRIDGE
   
   #####################################################################
   # FILESYSTEM OPTIONS
   
   #
   # Only the root, /usr, and /tmp filesystems need be statically
   # compiled; everything else will be automatically loaded at mount
   # time.  (Exception: the UFS family---FFS, MFS, and LFS---cannot
   # currently be demand-loaded.)  Some people still prefer to statically
   # compile other filesystems as well.
   #
   # NB: The LFS, NULL, PORTAL, UMAP and UNION filesystems are known to be
   # buggy, and WILL panic your system if you attempt to do anything with
   # them.  They are included here as an incentive for some enterprising
   # soul to sit down and fix them.
   #
   # Note: 4.4BSD NQNFS lease checking has relatively high cost for
   # _local_ I/O as well as remote I/O. Don't use it unless you will
   # using NQNFS.
   #
   
   # One of these is mandatory:
   options         FFS                     #Fast filesystem
   options         NFS                     #Network File System
   
   # The rest are optional:
   options         NQNFS                   #Enable NQNFS lease checking
   # options       NFS_NOSERVER            #Disable the NFS-server code.
   options         "CD9660"                #ISO 9660 filesystem
   options         FDESC                   #File descriptor filesystem
   options         KERNFS                  #Kernel filesystem
   options         LFS                     #Log filesystem
   options         MFS                     #Memory filesystem
   options         MSDOSFS                 #MS DOS filesystem
   options         NULLFS                  #NULL filesystem
   options         PORTAL                  #Portal filesystem
   options         PROCFS                  #Process filesystem
   options         CFS                     #CODA filesystem.
   options         UMAPFS                  #UID map filesystem
   options         UNION                   #Union filesystem
   # This DEVFS is experimental but seems to work
   options         DEVFS                   #devices filesystem
   
   # Make space in the kernel for a MFS root filesystem.  Define to the number
   # of kilobytes to reserve for the filesystem.
   options         MFS_ROOT=10
   # Allow the MFS_ROOT code to load the MFS image from floppy if it is missing.
   options         MFS_AUTOLOAD
   
   # Allow this many swap-devices.
   options         NSWAPDEV=20
   
   # Disk quotas are supported when this option is enabled.  If you
   # change the value of this option, you must do a `make clean' in your
   # kernel compile directory in order to get a working kernel.
   #
   options         QUOTA                   #enable disk quotas
   
   # Add more checking code to various filesystems
   #options                NULLFS_DIAGNOSTIC
   #options                KERNFS_DIAGNOSTIC
   #options                UMAPFS_DIAGNOSTIC
   #options                UNION_DIAGNOSTIC
   
   # In particular multi-session CD-Rs might require a huge amount of
   # time in order to "settle".  If we are about mounting them as the
   # root f/s, we gotta wait a little.
   #
   # The number is supposed to be in seconds.
   options                 "CD9660_ROOTDELAY=20"
   
   # Add some error checking code to the null_bypass routine
   # in the NULL filesystem
   #options                SAFETY
   
   
   #####################################################################
   # SCSI DEVICES
   
   # SCSI DEVICE CONFIGURATION
   
   # The SCSI subsystem consists of the `base' SCSI code, a number of
   # high-level SCSI device `type' drivers, and the low-level host-adapter
   # device drivers.  The host adapters are listed in the ISA and PCI
   # device configuration sections below.
   #
   # Beginning with FreeBSD 2.0.5 you can wire down your SCSI devices so
   # that a given bus, target, and LUN always come on line as the same
   # device unit.  In earlier versions the unit numbers were assigned
   # in the order that the devices were probed on the SCSI bus.  This
   # means that if you removed a disk drive, you may have had to rewrite
   # your /etc/fstab file, and also that you had to be careful when adding
   # a new disk as it may have been probed earlier and moved your device
   # configuration around.
   
   # This old behavior is maintained as the default behavior.  The unit
   # assignment begins with the first non-wired down unit for a device
   # type.  For example, if you wire a disk as "sd3" then the first
   # non-wired disk will be assigned sd4.
   
   # The syntax for wiring down devices is:
   
   # controller    scbus0 at ahc0          # Single bus device
   # controller    scbus1 at ahc1 bus 0    # Single bus device
   # controller    scbus3 at ahc2 bus 0    # Twin bus device
   # controller    scbus2 at ahc2 bus 1    # Twin bus device
   # disk          sd0 at scbus0 target 0 unit 0
   # disk          sd1 at scbus3 target 1
   # disk          sd2 at scbus2 target 3
   # tape          st1 at scbus1 target 6
   # device        cd0 at scbus?
   
   # "units" (SCSI logical unit number) that are not specified are
   # treated as if specified as LUN 0.
   
   # All SCSI devices allocate as many units as are required.
   
   # The "unknown" device (uk? in pre-2.0.5) is now part of the base SCSI
   # configuration and doesn't have to be explicitly configured.
   
   controller      scbus0  #base SCSI code
   device          ch0     #SCSI media changers
   device          sd0     #SCSI disks
   device          st0     #SCSI tapes
   device          cd0     #SCSI CD-ROMs
   device          od0     #SCSI optical disk
   
   # The previous devices (ch, sd, st, cd) are recognized by config.
   # config doesn't (and shouldn't) know about these newer ones,
   # so we have to specify that they are on a SCSI bus with the "at scbus?"
   # clause.
   
   device worm0 at scbus?  # SCSI worm
   device pt0 at scbus?    # SCSI processor type
   device sctarg0 at scbus? # SCSI target
   
   # SCSI OPTIONS:
   
   # SCSIDEBUG: When defined enables debugging macros
   # NO_SCSI_SENSE: When defined disables sense descriptions (about 4k)
   # SCSI_REPORT_GEOMETRY: Always report disk geometry at boot up instead
   #                       of only when booting verbosely.
   options         SCSIDEBUG
   #options        NO_SCSI_SENSE
   options         SCSI_REPORT_GEOMETRY
   
   # Options for the `od' optical disk driver:
   #
   # If drive returns sense key as 0x02 with vendor specific additional
   # sense code (ASC) and additional sense code qualifier (ASCQ), or
   # illegal ASC and ASCQ. This cause an error (NOT READY) and retrying.
   # To suppress this, use the following option.
   #
   options         OD_BOGUS_NOT_READY
   #
   # For an automatic spindown, try this.  Again, preferrably as an
   # option in your config file.
   # WARNING!  Use at your own risk.  Joerg's ancient SONY SMO drive
   # groks it fine, while Shunsuke's Fujitsu chokes on it and times
   # out.
   #
   options         OD_AUTO_TURNOFF
   
   
   
   #####################################################################
   # MISCELLANEOUS DEVICES AND OPTIONS
   
   #
   # Of these, only the `log' device is truly mandatory.  The `pty'
   # device usually turns out to be ``effectively mandatory'', as it is
   # required for `telnetd', `rlogind', `screen', `emacs', and `xterm',
   # among others. 
   # If you wish to run certain
   # system utilities which are compressed by default (like /stand/sysinstall)
   # then `gzip' becomes mandatory too.
   #
   pseudo-device   pty     16      #Pseudo ttys - can go as high as 256
   #pseudo-device  vcfs    4       #coda minicache <-> venus comm.
   pseudo-device   speaker         #Play IBM BASIC-style noises out your speaker
   pseudo-device   log             #Kernel syslog interface (/dev/klog)
   pseudo-device   gzip            #Exec gzipped a.out's
   pseudo-device   vn              #Vnode driver (turns a file into a device)
   pseudo-device   snp     3       #Snoop device - to look at pty/vty/etc..
   pseudo-device   ccd     4       #Concatenated disk driver
   
   # These are only for watching for bitrot in old tty code.
   # broken
   #pseudo-device  tb
   
   # These are only for watching for bitrot in old SCSI code.
   pseudo-device   su              #scsi user
   pseudo-device   ssc             #super scsi
   
   # Size of the kernel message buffer.  Should be N * pagesize.
   options         "MSGBUF_SIZE=40960"
   
   
   #####################################################################
   # HARDWARE DEVICE CONFIGURATION
   
   # ISA and EISA devices:
   # EISA support is available for some device, so they can be auto-probed.
   # Micro Channel is not supported at all.
   
   #
   # Mandatory ISA devices: isa, sc or vt, npx
   #
   controller      isa0
   
   #
   # Options for `isa':
   #
   # AUTO_EOI_1 enables the `automatic EOI' feature for the master 8259A
   # interrupt controller.  This saves about 0.7-1.25 usec for each interrupt.
   # This option breaks suspend/resume on some portables.
   #
   # AUTO_EOI_2 enables the `automatic EOI' feature for the slave 8259A
   # interrupt controller.  This saves about 0.7-1.25 usec for each interrupt.
   # Automatic EOI is documented not to work for for the slave with the
   # original i8259A, but it works for some clones and some integrated
   # versions.
   #
   # BOUNCE_BUFFERS provides support for ISA bus-master SCSI adapter"
   # card on machines with more than 16 megabytes of memory."
   # Some broken EISA and VLB hardware may need this, too."
   # If you do not have these devices, make this option commented out."
   #
   # MAXMEM specifies the amount of RAM on the machine; if this is not
   # specified, FreeBSD will first read the amount of memory from the CMOS
   # RAM, so the amount of memory will initially be limited to 64MB or 16MB
   # depending on the BIOS.  If the BIOS reports 64MB, a memory probe will
   # then attempt to detect the installed amount of RAM.  If this probe
   # fails to detect >64MB RAM you will have to use the MAXMEM option.
   # The amount is in kilobytes, so for a machine with 128MB of RAM, it would
   # be 131072 (128 * 1024).
   #
   # TUNE_1542 enables the automatic ISA bus speed selection for the
   # Adaptec 1542 boards. Does not work for all boards, use it with caution.
   #
   # BROKEN_KEYBOARD_RESET disables the use of the keyboard controller to
   # reset the CPU for reboot.  This is needed on some systems with broken
   # keyboard controllers.
   #
   # PAS_JOYSTICK_ENABLE enables the gameport on the ProAudio Spectrum
   
   options         "AUTO_EOI_1"
   #options        "AUTO_EOI_2"
   options         BOUNCE_BUFFERS          #ISA busmaster SCSI + >16MB system only
   options         "MAXMEM=(128*1024)"
   #options        "TUNE_1542"
   #options        BROKEN_KEYBOARD_RESET
   #options        PAS_JOYSTICK_ENABLE
   
   # Enable PnP support in the kernel.  This allows you to automaticly 
   # attach to PnP cards for drivers that support it and allows you to  
   # configure cards from USERCONFIG.  See pnp(4) for more info.
   controller      pnp0
   
   # Enable this and PCVT_FREEBSD for pcvt vt220 compatible console driver
   device          vt0     at isa? port "IO_KBD" tty irq 1 vector pcrint
   options         XSERVER                 # support for running an X server.
   options         FAT_CURSOR              # start with block cursor
   # This PCVT option is for keyboards such as those used on IBM ThinkPad laptops
   options         PCVT_SCANSET=2          # IBM keyboards are non-std
   
   # The syscons console driver (sco color console compatible).
   device          sc0     at isa? port "IO_KBD" tty irq 1 vector scintr
   options         MAXCONS=16              # number of virtual consoles
   options         SLOW_VGA                # do byte-wide i/o's to TS and GDC regs
   options         SC_HISTORY_SIZE=200     # number of history buffer lines
   options         SC_DISABLE_REBOOT       # disable reboot key sequence
   # Try the following option if the mouse pointer is not drawn correctly 
   # or font does not seem to be loaded properly.  May cause flicker on 
   # some systems.
   #options        SC_ALT_SEQACCESS
   
   #
   # `flags' for sc0:
   #       0x01    Use a 'visual' bell
   #       0x02    Use a 'blink' cursor
   #       0x04    Use a 'underline' cursor
   #       0x06    Use a 'blinking underline' (destructive) cursor
   #       0x08    Force detection of keyboard, else we always assume a keyboard
   #       0x10    Old-style (XT) keyboard support, useful for older ThinkPads
   #       0x20    Don't reset keyboard, useful for some newer ThinkPads
   
   #
   # This device is mandatory.
   #
   # The Numeric Processing eXtension is used to either enable the
   # coprocessor or enable math emulation.  If your machine doesn't contain
   # a math co-processor, you must *also* add the option "MATH_EMULATE".
   # THIS IS NOT AN OPTIONAL ENTRY, DO NOT REMOVE IT
   device          npx0    at isa? port "IO_NPX" iosiz 0x0 flags 0x0 irq 13 vector npxintr
   
   #
   # `flags' for npx0:
   #       0x01    don't use the npx registers to optimize bcopy
   #       0x02    don't use the npx registers to optimize bzero
   #       0x04    don't use the npx registers to optimize copyin or copyout.
   # The npx registers are normally used to optimize copying and zeroing when
   # all of the following conditions are satisfied:
   #       "I586_CPU" is an option
   #       the cpu is an i586 (perhaps not a Pentium)
   #       the probe for npx0 succeeds
   #       INT 16 exception handling works.
   # Then copying and zeroing using the npx registers is normally 30-100% faster.
   # The flags can be used to control cases where it doesn't work or is slower.
   # Setting them at boot time using userconfig works right (the optimizations
   # are not used until later in the bootstrap when npx0 is attached).
   #
   
   #
   # `iosiz' for npx0:
   # This can be used instead of the MAXMEM option to set the memory size.  If
   # it is nonzero, then it overrides both the MAXMEM option and the memory
   # size reported by the BIOS.  Setting it at boot time using userconfig takes
   # effect on the next reboot after the change has been recorded in the kernel
   # binary (the size is used early in the boot before userconfig has a chance
   # to change it).
   #
   
   #
   # Optional ISA and EISA devices:
   #
   
   #
   # SCSI host adapters: `aha', `aic', `bt', `nca'
   #
   # aha: Adaptec 154x
   # ahc: Adaptec 274x/284x/294x
   # aic: Adaptec 152x and sound cards using the Adaptec AIC-6360 (slow!)
   # bt: Most Buslogic controllers
   # nca: ProAudioSpectrum cards using the NCR 5380 or Trantor T130
   # uha: UltraStor ULTRA 14F/24F/34F
   # sea: Seagate ST01/02 8 bit controller (slow!)
   # wds: Western Digital WD7000 controller (no scatter/gather!).
   #
   # Note that the order is important in order for Buslogic cards to be
   # probed correctly.
   #
   
   controller      bt0     at isa? port "IO_BT0" bio irq ? vector bt_isa_intr
   controller      aha0    at isa? port "IO_AHA0" bio irq ? drq 5 vector ahaintr
   controller      uha0    at isa? port "IO_UHA0" bio irq ? drq 5 vector uhaintr
   
   controller      aic0    at isa? port 0x340 bio irq 11 vector aicintr
   controller      nca0    at isa? port 0x1f88 bio irq 10 vector ncaintr
   controller      nca1    at isa? port 0x1f84
   controller      nca2    at isa? port 0x1f8c
   controller      nca3    at isa? port 0x1e88
   controller      nca4    at isa? port 0x350 bio irq 5 vector ncaintr
   
   controller      sea0    at isa? bio irq 5 iomem 0xdc000 iosiz 0x2000 vector seaintr
   controller      wds0    at isa? port 0x350 bio irq 15 drq 6 vector wdsintr
   
   #
   # ST-506, ESDI, and IDE hard disks: `wdc' and `wd'
   #
   # NB: ``Enhanced IDE'' is NOT supported at this time.
   #
   # The flags fields are used to enable the multi-sector I/O and
   # the 32BIT I/O modes.  The flags may be used in either the controller
   # definition or in the individual disk definitions.  The controller
   # definition is supported for the boot configuration stuff.
   #
   # Each drive has a 16 bit flags value defined:
   #       The low 8 bits are the maximum value for the multi-sector I/O,
   #       where 0xff defaults to the maximum that the drive can handle.
   #       The high bit of the 16 bit flags (0x8000) allows probing for
   #       32 bit transfers.
   #
   # The flags field for the drives can be specified in the controller
   # specification with the low 16 bits for drive 0, and the high 16 bits
   # for drive 1.
   # e.g.:
   #controller     wdc0    at isa? port "IO_WD1" bio irq 14 flags 0x00ff8004 vector wdintr
   #
   # specifies that drive 0 will be allowed to probe for 32 bit transfers and
   # a maximum multi-sector transfer of 4 sectors, and drive 1 will not be
   # allowed to probe for 32 bit transfers, but will allow multi-sector
   # transfers up to the maximum that the drive supports.
   #
   
   controller      wdc0    at isa? port "IO_WD1" bio irq 14 vector wdintr
   disk            wd0     at wdc0 drive 0
   disk            wd1     at wdc0 drive 1
   controller      wdc1    at isa? port "IO_WD2" bio irq 15 vector wdintr
   disk            wd2     at wdc1 drive 0
   disk            wd3     at wdc1 drive 1
   
   #
   # Options for `wdc':
   #
   # CMD640 enables serializing access to primary and secondary channel
   # of the CMD640B IDE Chip. The serializing will only take place
   # if this option is set *and* the chip is probed by the pci-system.
   #
   options         "CMD640"        #Enable work around for CMD640 h/w bug
   #
   # ATAPI enables the support for ATAPI-compatible IDE devices
   #
   options         ATAPI   #Enable ATAPI support for IDE bus
   options         ATAPI_STATIC    #Don't do it as an LKM
   
   # Use either the acd or the wcd device, not both!
   # IDE CD-ROM & CD-R/RW  driver - requires wdc controller and ATAPI option
   device          acd0 
   
   # IDE CD-ROM driver - requires wdc controller and ATAPI option
   device          wcd0
   
   # IDE floppy driver - requires wdc controller and ATAPI option
   device          wfd0
   
   #
   # Standard floppy disk controllers and floppy tapes: `fdc', `fd', and `ft'
   #
   controller      fdc0    at isa? port "IO_FD1" bio irq 6 drq 2 vector fdintr
   #
   # FDC_DEBUG enables floppy debugging.  Since the debug output is huge, you
   # gotta turn it actually on by setting the variable fd_debug with DDB,
   # however.
   options         FDC_DEBUG
   # This option is undocumented on purpose.
   options         FDC_PRINT_BOGUS_CHIPTYPE
   #
   # Activate this line instead of the fdc0 line above if you happen to
   # have an Insight floppy tape.  Probing them proved to be dangerous
   # for people with floppy disks only, so it's "hidden" behind a flag:
   #controller fdc0 at isa? port "IO_FD1" bio flags 1 irq 6 drq 2 vector fdintr
   
   disk            fd0     at fdc0 drive 0
   disk            fd1     at fdc0 drive 1
   tape            ft0     at fdc0 drive 2
   
   
   #
   # Other standard PC hardware: `lpt', `mse', `psm', `sio', etc.
   #
   # lpt: printer port
   #       lpt specials:
   #               port can be specified as ?, this will cause the driver to scan
   #               the BIOS port list;
   #               the irq and vector clauses may be omitted, this
   #               will force the port into polling mode.
   # mse: Logitech and ATI InPort bus mouse ports
   # psm: PS/2 mouse port [note: conflicts with sc0/vt0, thus "conflicts" keywd]
   # sio: serial ports (see sio(4))
   
   device          lpt0    at isa? port? tty irq 7 vector lptintr
   device          lpt1    at isa? port "IO_LPT3" tty irq 5 vector lptintr
   device          mse0    at isa? port 0x23c tty irq 5 vector mseintr
   device          psm0    at isa? port "IO_KBD" conflicts tty irq 12 vector psmintr
   # Options for psm:
   options         PSM_HOOKAPM             #hook the APM resume event, useful
                                           #for some laptops
   options         PSM_RESETAFTERSUSPEND   #reset the device at the resume event
   
   device          sio0    at isa? port "IO_COM1" tty irq 4 vector siointr
   
   # Options for sio:
   options         COMCONSOLE              #prefer serial console to video console
   options         COM_ESP                 #code for Hayes ESP
   options         COM_MULTIPORT           #code for some cards with shared IRQs
   options         DSI_SOFT_MODEM          #code for DSI Softmodems
   options         BREAK_TO_DEBUGGER       #a BREAK on a comconsole goes to 
                                           #DDB, if available.
   
   #
   # Network interfaces: `cx', `ed', `el', `ep', `ie', `is', `le', `lnc'
   #
   # ar: Arnet SYNC/570i hdlc sync 2/4 port V.35/X.21 serial driver (requires sppp)
   # cx: Cronyx/Sigma multiport sync/async (with Cisco or PPP framing)
   # ed: Western Digital and SMC 80xx; Novell NE1000 and NE2000; 3Com 3C503
   # el: 3Com 3C501 (slow!)
   # ep: 3Com 3C509 (buggy)
   # ex: Intel EtherExpress Pro/10 and other i82595-based adapters
   # fe: Fujitsu MB86960A/MB86965A Ethernet
   # ie: AT&T StarLAN 10 and EN100; 3Com 3C507; unknown NI5210
   # le: Digital Equipment EtherWorks 2 and EtherWorks 3 (DEPCA, DE100,
   #     DE101, DE200, DE201, DE202, DE203, DE204, DE205, DE422)
   # lnc: Lance/PCnet cards (Isolan, Novell NE2100, NE32-VL)
   # sr: RISCom/N2 hdlc sync 1/2 port V.35/X.21 serial driver (requires sppp)
   # wl: Lucent Wavelan (ISA card only).
   # ze: IBM/National Semiconductor PCMCIA ethernet controller.
   # zp: 3Com PCMCIA Etherlink III (It does not require shared memory for
   #     send/receive operation, but it needs 'iomem' to read/write the
   #     attribute memory)
   #
   
   device ar0 at isa? port 0x300 net irq 10 iomem 0xd0000 vector arintr
   device cs0 at isa? port 0x300 net irq ? vector csintr
   device cx0 at isa? port 0x240 net irq 15 drq 7 vector cxintr
   device ed0 at isa? port 0x280 net irq 5 iomem 0xd8000 vector edintr
   device eg0 at isa? port 0x310 net irq 5 vector egintr
   device el0 at isa? port 0x300 net irq 9 vector elintr
   device ep0 at isa? port 0x300 net irq 10 vector epintr
   device ex0 at isa? port 0x300 net irq 10 iomem 0xd0000 vector exintr
   device fe0 at isa? port 0x300 net irq ? vector feintr
   device ie0 at isa? port 0x300 net irq 5 iomem 0xd0000 vector ieintr
   device ie1 at isa? port 0x360 net irq 7 iomem 0xd0000 vector ieintr
   device le0 at isa? port 0x300 net irq 5 iomem 0xd0000 vector le_intr
   device lnc0 at isa? port 0x300 net irq 10 drq 0 vector lncintr
   device sr0 at isa? port 0x300 net irq 5 iomem 0xd0000 vector srintr
   options         WLCACHE         # enables the signal-strength cache
   options         WLDEBUG         # enables verbose debugging output
   device wl0 at isa? port 0x300 net irq ? vector wlintr
   # Needed so that we can (bogusly) include both the dedicated PCCARD
   # drivers and the generic support
   options LINT_PCCARD_HACK
   device ze0 at isa? port 0x300 net irq 5 iomem 0xd8000 vector zeintr
   device zp0 at isa? port 0x300 net irq 10 iomem 0xd8000 vector zpintr
   
   
   #
   # Audio drivers: `snd', `sb', `pas', `gus', `pca'
   #
   # snd: Voxware sound support code
   # sb: SoundBlaster PCM - SoundBlaster, SB Pro, SB16, ProAudioSpectrum
   # sbxvi: SoundBlaster 16
   # sbmidi: SoundBlaster 16 MIDI interface
   # pas: ProAudioSpectrum PCM and MIDI
   # gus: Gravis Ultrasound - Ultrasound, Ultrasound 16, Ultrasound MAX
   # gusxvi: Gravis Ultrasound 16-bit PCM  (do not use)
   # mss: Microsoft Sound System
   # opl: Yamaha OPL-2 and OPL-3 FM - SB, SB Pro, SB 16, ProAudioSpectrum
   # uart: stand-alone 6850 UART for MIDI
   # mpu: Roland MPU-401 stand-alone card
   # 
   # Beware!  The addresses specified below are also hard-coded in
   # i386/isa/sound/sound_config.h.  If you change the values here, you
   # must also change the values in the include file.
   #
   # pca: PCM audio through your PC speaker
   #
   # If you have a GUS-MAX card and want to use the CS4231 codec on the
   # card the drqs for the gus max must be 8 bit (1, 2, or 3).
   # 
   # If you would like to use the full duplex option on the gus, then define
   # flags to be the ``read dma channel''.
   #
   # options BROKEN_BUS_CLOCK      #PAS-16 isn't working and OPTI chipset
   # options SYMPHONY_PAS          #PAS-16 isn't working and SYMPHONY chipset
   # options EXCLUDE_SBPRO         #PAS-16
   # options SBC_IRQ=5             #PAS-16. Must match irq on sb0 line.
   # PAS16: The order of the pas0/sb0/opl0 is important since the
   #       sb emulation is enabled in the pas-16 attach.
   #
   # The i386/isa/sound/sound.doc has more information.
   
   # Controls all "VOXWARE" driver sound devices.  See Luigi's driver
   # below for an alternate which may work better for some cards.
   #
   controller      snd0
   device pas0     at isa? port 0x388 irq 10 drq 6 vector pasintr
   device sb0      at isa? port 0x220 irq 5 drq 1 vector sbintr
   device sbxvi0   at isa? drq 5
   device sbmidi0  at isa? port 0x330
   #device awe0     at isa? port 0x620 
   device gus0 at isa? port 0x220 irq 12 drq 1 vector gusintr
   #device gus0 at isa? port 0x220 irq 12 drq 1 flags 0x3 vector gusintr
   device mss0 at isa? port 0x530 irq 10 drq 1 vector adintr
   # Use this line for PAS avoid port conflict
   device opl0     at isa? port 0x38a
   # For normal case use next line
   # device opl0     at isa? port 0x388
   device mpu0     at isa? port 0x330 irq 6 drq 0
   device uart0 at isa? port 0x330 irq 5 vector "m6850intr"
   
   # More undocumented sound devices with bogus configurations for linting.
   # broken
   #device sscape0  at isa? port 0x330 irq 6 drq 0
   #device trix0    at isa? port 0x330 irq 6 drq 0 vector sscapeintr
   
   # Luigi's snd code (use INSTEAD of snd0 and all VOXWARE drivers!).
   # You may also wish to enable the pnp controller with this, for pnp
   # sound cards.
   #
   #device pcm0 at isa? port ? tty irq 10 drq 1 flags 0x0 vector pcmintr
   
   # Not controlled by `snd'
   device pca0 at isa? port IO_TIMER1 tty
   
   #
   # Miscellaneous hardware:
   #
   # mcd: Mitsumi CD-ROM
   # scd: Sony CD-ROM
   # matcd: Matsushita/Panasonic CD-ROM
   # wt: Wangtek and Archive QIC-02/QIC-36 tape drives
   # ctx: Cortex-I frame grabber
   # apm: Laptop Advanced Power Management (experimental)
   # spigot: The Creative Labs Video Spigot video-acquisition board
   # meteor: Matrox Meteor video capture board
   # bktr: Bt848 capture boards (http://www.freebsd.org/~fsmp/HomeAuto/Bt848.html)
   # cy: Cyclades serial driver
   # dgb: Digiboard PC/Xi and PC/Xe series driver (ALPHA QUALITY!)
   # gp:  National Instruments AT-GPIB and AT-GPIB/TNT board
   # asc: GI1904-based hand scanners, e.g. the Trust Amiscan Grey
   # gsc: Genius GS-4500 hand scanner.
   # joy: joystick
  # labpc: National Instrument's Lab-PC and Lab-PC+
  # rc: RISCom/8 multiport card
  # tw: TW-523 power line interface for use with X-10 home control products
  # si: Specialix SI/XIO 4-32 port terminal multiplexor
  # stl: Stallion EasyIO and EasyConnection 8/32 (cd1400 based)
  # stli: Stallion EasyConnection 8/64, ONboard, Brumby (intelligent)
  
  #
  # Notes on APM
  #  Some APM implementations will not work with the `statistics clock'
  #  enabled, so it's disabled by default if the APM driver is enabled.
  #  However, this is not true for all laptops.  Try removing the option
  #  APM_BROKEN_STATCLOCK and see if suspend/resume work
  #
  
  options APM_IDLE_CPU    # Tell APM to idle rather than halt'ing the cpu
  
  #
  # Notes on the spigot:
  #  The video spigot is at 0xad6.  This port address can not be changed.
  #  The irq values may only be 10, 11, or 15
  #  I/O memory is an 8kb region.  Possible values are:
  #    0a0000, 0a2000, ..., 0fffff, f00000, f02000, ..., ffffff
  #    The start address must be on an even boundary.
  #  Add the following option if you want to allow non-root users to be able
  #  to access the spigot.  This option is not secure because it allows users
  #  direct access to the I/O page. 
  #       options SPIGOT_UNSECURE
  #
  
  # Notes on the Digiboard driver:
  #
  # The following flag values have special meanings:
  #       0x01 - alternate layout of pins
  #       0x02 - use the windowed PC/Xe in 64K mode
  
  # Notes on the Specialix SI/XIO driver:
  #  **This is NOT a Specialix supported Driver!**
  #  The host card is memory, not IO mapped.
  #  The Rev 1 host cards use a 64K chunk, on a 32K boundary.
  #  The Rev 2 host cards use a 32K chunk, on a 32K boundary.
  #  The cards can use an IRQ of 11, 12 or 15.
  
  # Notes on the Stallion stl and stli drivers:
  #  See src/i386/isa/README.stl for complete instructions.
  #  This is version 0.0.5alpha, unsupported by Stallion.
  #  The stl driver has a secondary IO port hard coded at 0x280.  You need
  #     to change src/i386/isa/stallion.c if you reconfigure this on the boards.
  #  The "flags" and "iosiz" settings on the stli driver depend on the board:
  #       EasyConnection 8/64 ISA:     flags 23         iosiz 0x1000
  #       EasyConnection 8/64 EISA:    flags 24         iosiz 0x10000
  #       EasyConnection 8/64 MCA:     flags 25         iosiz 0x1000
  #       ONboard ISA:                 flags 4          iosiz 0x10000
  #       ONboard EISA:                flags 7          iosiz 0x10000
  #       ONboard MCA:                 flags 3          iosiz 0x10000
  #       Brumby:                      flags 2          iosiz 0x4000
  #       Stallion:                    flags 1          iosiz 0x10000
  
  device          mcd0    at isa? port 0x300 bio irq 10 vector mcdintr
  # for the Sony CDU31/33A CDROM
  device          scd0    at isa? port 0x230 bio
  # for the SoundBlaster 16 multicd - up to 4 devices
  controller      matcd0  at isa? port 0x230 bio
  device          wt0     at isa? port 0x300 bio irq 5 drq 1 vector wtintr
  device          ctx0    at isa? port 0x230 iomem 0xd0000
  device          spigot0 at isa? port 0xad6 irq 15 iomem 0xee000 vector spigintr
  device          qcam0   at isa? port "IO_LPT3" tty
  device          apm0    at isa?
  options         APM_BROKEN_STATCLOCK
  device          gp0     at isa? port 0x2c0 tty
  device          gsc0    at isa? port "IO_GSC1" tty drq 3
  device          joy0    at isa? port "IO_GAME"
  device          cy0     at isa? tty irq 10 iomem 0xd4000 iosiz 0x2000 vector cyintr
  device          dgb0    at isa? port 0x220 iomem 0xfc0000 iosiz ? tty
  device          labpc0  at isa? port 0x260 tty irq 5 vector labpcintr
  device          rc0     at isa? port 0x220 tty irq 12 vector rcintr
  # the port and irq for tw0 are fictitious
  device          tw0     at isa? port 0x380 tty irq 11 vector twintr
  device          si0     at isa? iomem 0xd0000 tty irq 12
  device          asc0    at isa? port IO_ASC1 tty drq 3 irq 10 vector ascintr
  device          bqu0    at isa? port 0x150
  device          stl0    at isa? port 0x2a0 tty irq 10 vector stlintr
  device          stli0   at isa? port 0x2a0 tty iomem 0xcc000 flags 23 iosiz 0x1000
  
  #
  # EISA devices:
  #
  # The EISA bus device is eisa0.  It provides auto-detection and
  # configuration support for all devices on the EISA bus.
  #
  # The `ahb' device provides support for the Adaptec 174X adapter.
  #
  # The `ahc' device provides support for the Adaptec 274X and 284X
  # adapters.  The 284X, although a VLB card responds to EISA probes.
  #
  # fea: DEC DEFEA EISA FDDI adapter
  #
  controller      eisa0
  controller      ahb0
  controller      ahc0
  device          fea0
  
  # enable tagged command queueing, which is a major performance win on
  # devices that support it (and controllers with enough SCB's)
  #
  # Note that some drives claim to grok tagged commands, but actually
  # don't.  The HP C3725S is a known offender.
  options AHC_TAGENABLE
  
  # enable SCB paging - See the ahc.4 man page for usage warnings.
  # (IOW: better don't use it by now.)
  options AHC_SCBPAGING_ENABLE
  
  # The aic7xxx driver will attempt to use memory mapped I/O for all PCI
  # controllers that have it configured only if this option is set. Unfortunately,
  # this doesn't work on some motherboards, which prevents it from being the
  # default.
  options AHC_ALLOW_MEMIO
  
  # By default, only 10 EISA slots are probed, since the slot numbers
  # above clash with the configuration address space of the PCI subsystem,
  # and the EISA probe is not very smart about this.  This is sufficient
  # for most machines, but in particular the HP NetServer LC series comes
  # with an onboard AIC7770 dual-channel SCSI controller on EISA slot #11,
  # thus you need to bump this figure to 12 for them.
  options "EISA_SLOTS=12"
  
  #
  # PCI devices:
  #
  # The main PCI bus device is `pci'.  It provides auto-detection and
  # configuration support for all devices on the PCI bus, using either
  # configuration mode defined in the PCI specification.
  #
  # The `ahc' device provides support for the Adaptec 29/3940(U)(W)
  # and motherboard based AIC7870/AIC7880 adapters.
  #
  # The `ncr' device provides support for the NCR 53C810 and 53C825
  # self-contained SCSI host adapters.
  #
  # The `amd' device provides support for the Tekram DC-390 and 390T
  # SCSI host adapters, but is expected to work with any AMD 53c974
  # PCI SCSI chip and the AMD Ethernet+SCSI Combo chip, after some
  # local patches were applied to the sources (that had originally
  # been written by Tekram and limited to work with their SCSI cards).
  #
  # The `de' device provides support for the Digital Equipment DC21040
  # self-contained Ethernet adapter.
  #
  # The `fxp' device provides support for the Intel EtherExpress Pro/100B
  # PCI Fast Ethernet adapters.
  #
  # The 'tl' device provides support for the Texas Instruments TNETE100
  # series 'ThunderLAN' cards and integrated ethernet controllers. This
  # includes several Compaq Netelligent 10/100 cards and the built-in
  # ethernet controllers in several Compaq Prosignia, Proliant and
  # Deskpro systems. It also supports several Olicom 10Mbps and 10/100
  # boards.
  #
  # The `tx' device provides support for the SMC 9432TX cards.
  #
  # The `vx' device provides support for the 3Com 3C590 and 3C595
  # early support
  #
  # The `xl' driver provides support for the 3Com 3c900, 3c905 and
  # 3c905B (Fast) Etherlink XL cards and integrated controllers. This
  # includes the integrated 3c905B-TX chips in certain Dell Optiplex and
  # Dell Precision desktop machines and the integrated 3c905-TX chips
  # in Dell Latitude laptop docking stations.
  #
  # The `fpa' device provides support for the Digital DEFPA PCI FDDI
  # adapter. pseudo-device fddi is also needed.
  #
  # The `meteor' device is a PCI video capture board. It can also have the
  # following options:
  #   options METEOR_ALLOC_PAGES=xxx      preallocate kernel pages for data entry
  #       figure (ROWS*COLUMN*BYTES_PER_PIXEL*FRAME+PAGE_SIZE-1)/PAGE_SIZE
  #   options METEOR_DEALLOC_PAGES        remove all allocated pages on close(2)
  #   options METEOR_DEALLOC_ABOVE=xxx    remove all allocated pages above the
  #       specified amount. If this value is below the allocated amount no action
  #       taken
  #   option METEOR_SYSTEM_DEFAULT={METEOR_PAL|METEOR_NTSC|METEOR_SECAM}, used
  #       for initialization of fps routine when a signal is not present.
  #
  # The 'bktr' device is a PCI video capture board. It also has a TV tuner
  # on board.
  # The 'dpt' driver provides hardware RAID-{0,1,5} support, multi-initiator I/O
  # and is part of the DIO (Distributed I/O) option.  Only the PCI controllers
  # are supported.  the following options are controlled from here.
  # See sys/dev/dpt for debugging and other subtle options.
  #
  #   DPT_VERIFY_HINTR        Performs some strict hardware interrupts testing.
  #                           Increases interrupt latency so leave it off under
  #                           normal conditions.
  #   DPT_RESTRICTED_FREELIST Normally, the freelisat used by the DPT for queue
  #                           management grows dynamically.  On heavily loaded
  #                           systems this can consume 1-8MB of kernel memory.
  #                           Enabling this option resticts the number of queue 
  #                           slots to DPT_FREE_LIST_INCREMENT (64).
  #   DPT_TRACK_CCB_STATES    Enabling thos option will try to enforce sanity in
  #                           state transitions in the conntroller Command
  #                           Blocks.  It is a debugging/development option.
  #   DPT_MEASURE_PERFORMANCE Enables a set of (semi)invasive metrics. Various
  #                           phases of the CCB's, as well as all SCSI commands 
  #                           are timed and tallied.  Costs about 1us/command.
  #   DPT_FREELIST_IS_STACK   For optimat L{1,2} CPU cache utilization, enable 
  #                           this option.  It may invoke race conditions on some
  #                           motherboards.
  #   DPT_HANDLE_TIMEOUTS     Normally device timeouts are handled by the DPT 
  #                           firmware.  With this option enabled, an independant
  #                           mechanism is run in the FreeBSD kernel.  Leave this
  #                           option enabled for now, as some hardware fails 
  #                           without it.
  #   DPT_TIMEOUT_FACTOR      Used to compute the excessive amount of time to
  #                           wait in case of a command that is too late.  It is
  #                           a multiplication factor.
  #  DPT_DEBUG_xxxx           These are controllable from sys/dev/dpt/dpt.h
  #
  
  options DPT_MEASURE_PERFORMANCE
  
  # The 'isp' driver provides support for the Qlogic ISP 1020, 1040, 1080
  # and 1240 SCSI controllers and ISP 2100 and 2200 Fibre Channel SCSI
  # controllers
  #
  #
  #       SCSI_ISP_NO_FWLOAD_MASK - mask of isp unit numbers (obviously
  #                                 a max of 32) that you wish to disable
  #                                 to disable the loading of firmware on.
  #       SCSI_ISP_NO_NVRAM_MASK  - mask of isp unit numbers (obviously
  #                                 a max of 32) that you wish to disable
  #                                 them picking up information from NVRAM
  #                                 (for broken cards you can't fix the NVRAM
  #                                 on- very rare, or for systems you can't
  #                                 change NVRAM on (e.g. alpha) and you don't
  #                                 like what's in there)
  #       SCSI_ISP_PREFER_MEM_MAP - control preference for using memory mappings
  #                                 instead of I/O space mappings. It defaults
  #                                 to 1 for i386, 0 for alpha. Set to 1 to
  #                                 unconditionally prefer mapping memory,
  #                                 else it will use I/O space mappings. Of
  #                                 course, this can fail if the PCI implement-
  #                                 ation doesn't support what you want.
  #
  #       SCSI_ISP_FCDUPLEX       - mask of isp unit numbers (obviously
  #                                 a max of 32) that you wish to set fibre
  #                                 channel full duplex mode on.
  #                                 to disable the loading of firmware on.
  #       SCSI_ISP_FABRIC           enable loading of Fabric f/w flavor (2100).
  #       SCSI_ISP_SCCLUN           enable loading of expanded lun f/w (2100).
  #
  #       ISP_DISABLE_1020_SUPPORT        Disable support for 1020/1040 cards
  #       ISP_DISABLE_1080_SUPPORT        Disable support for 1080/1240 cards
  #       ISP_DISABLE_2100_SUPPORT        Disable support for 2100 cards
  #       (these really just to save code space)
  #       (use of all three will cause the driver to not compile)
  options SCSI_ISP_NO_FWLOAD_MASK=0x12    # disable FW load for isp1 and isp4
  options SCSI_ISP_NO_NVRAM_MASK=0x1      # disable NVRAM for isp0
  options SCSI_ISP_PREFER_MEM_MAP=0       # prefer I/O mapping
  options SCSI_ISP_FCDUPLEX=0x4           # isp2 is a Fibre Channel card
                                          # we want in full duplex mode.
  #options ISP_DISABLE_1020_SUPPORT
  #options ISP_DISABLE_1080_SUPPORT
  #options ISP_DISABLE_2100_SUPPORT
  
  controller      pci0
  controller      ahc1
  controller      ncr0
  controller      isp0
  controller      amd0
  controller      dpt0
  device          de0
  device          fxp0
  device          tl0
  device          tx0
  device          vx0
  device          xl0
  device          fpa0
  device          meteor0
  device          bktr0
  
  #
  # PCCARD/PCMCIA
  #
  # card: slot controller
  # pcic: slots
  controller      card0
  controller      pcic0 at card?
  controller      pcic1 at card?
  
  #
  # Laptop/Notebook options:
  #
  # See also:
  #  apm under `Miscellaneous hardware'
  # above.
  
  # For older notebooks that signal a powerfail condition (external
  # power supply dropped, or battery state low) by issuing an NMI:
  
  options         POWERFAIL_NMI   # make it beep instead of panicing
  
  # Kernel BOOTP support 
  
  options         BOOTP           # Use BOOTP to obtain IP address/hostname
  options         BOOTP_NFSROOT   # NFS mount root filesystem using BOOTP info
  options         "BOOTP_NFSV3"   # Use NFS v3 to NFS mount root
  options         BOOTP_COMPAT    # Workaround for broken bootp daemons.
  
  # If you want to disable loadable kernel modules (LKM), you
  # might want to use this option.
  options         NO_LKM
  
  # More undocumented options for linting.
  
  options         CLK_CALIBRATION_LOOP
  options         "CLK_USE_I8254_CALIBRATION"
  options         "CLK_USE_I586_CALIBRATION"
  options         COMPAT_LINUX
  options         DEBUG
  options         DEVFS_ROOT
  options         "EXT2FS"
  options         "I586_CTR_GUPROF"
  options         "I586_PMC_GUPROF=0x70000"
  options         "IBCS2"
  options         KBD_MAXRETRY=4
  options         KBD_MAXWAIT=6
  options         KBD_RESETDELAY=201
  options         KBDIO_DEBUG=2
  options         MSGMNB=2049
  options         MSGMNI=41
  options         MSGSEG=2049
  options         MSGSSZ=16
  options         MSGTQL=41
  options         NBUF=512
  options         NMBCLUSTERS=1024
  options         PSM_DEBUG=1
  options         "SCSI_2_DEF"
  options         SCSI_DELAY=8    # Be pessimistic about Joe SCSI device
  options         SCSI_NCR_DEBUG
  options         SCSI_NCR_DFLT_TAGS=4
  options         SCSI_NCR_MAX_SYNC=10000
  options         SCSI_NCR_MAX_WIDE=1
  options         SCSI_NCR_MYADDR=7
  options         SEMMAP=31
  options         SEMMNI=11
  options         SEMMNS=61
  options         SEMMNU=31
  options         SEMMSL=61
  options         SEMOPM=101
  options         SEMUME=11
  options         SHOW_BUSYBUFS   # List buffers that prevent root unmount
  options         SHMALL=1025
  options         "SHMMAX=(SHMMAXPGS*PAGE_SIZE+1)"
  options         SHMMAXPGS=1025
  options         SHMMIN=2
  options         SHMMNI=33
  options         SHMSEG=9
  options         SI_DEBUG
  options         SPX_HACK

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