1.\" $NetBSD: options.4,v 1.136 2001/04/21 20:51:18 fvdl Exp $ 2.\" 3.\" Copyright (c) 1996 4.\" Perry E. Metzger. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgment: 16.\" This product includes software developed for the NetBSD Project 17.\" by Perry E. Metzger. 18.\" 4. The name of the author may not be used to endorse or promote products 19.\" derived from this software without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31.\" 32.\" 33.Dd August 29, 2000 34.Os 35.Dt OPTIONS 4 36.Sh NAME 37.Nm options 38.Nd Miscellaneous kernel configuration options 39.Sh SYNOPSIS 40.Cd options ... 41.Sh DESCRIPTION 42This manual page describes a number of miscellaneous kernel 43configuration options that may be specified in a kernel config 44file. 45See 46.Xr config 8 47for information on how to configure and build kernels. 48.Em Note : 49Options are passed to the compile process as -D flags to the C 50compiler. 51.Ss Compatibility Options 52.Bl -ohang 53.It Cd options COMPAT_09 54Enable binary compatibility with 55.Nx 0.9 . 56This enables support for 5716-bit user, group, and process ids (following revisions support 5832-bit identifiers), 59It also allows the use of the deprecated 60.Xr getdomainname 3 , 61.Xr setdomainname 3 , 62and 63.Xr uname 3 64syscalls. 65This option also allows using numeric filesystem identifiers rather 66than strings. 67Post 68.Nx 0.9 69versions use string identifiers. 70.It Cd options COMPAT_10 71Enable binary compatibility with 72.Nx 1.0 . 73This option allows the use of the filesystem name of 74.Dq ufs 75as an alias for 76.Dq ffs . 77The name 78.Dq ffs 79should be used post 1.0 in 80.Pa /etc/fstab 81and other files. 82It also adds old syscalls for the 83.At V 84shared memory interface. 85This was changed post 1.0 to work on 64-bit architectures. 86This option also enables 87.Dq sgtty 88compatibility, without which programs using the old interface produce 89an 90.Dq inappropriate ioctl 91error. 92.It Cd options COMPAT_11 93Enable binary compatibility with 94.Nx 1.1 . 95This allows binaries running on the i386 port to gain direct access to 96the io ports by opening 97.Pa /dev/io 98read/write. 99This functionality was replaced by 100.Xr i386_iopl 2 101post 1.1. 102On the 103.Tn Atari 104port, the location of the disk label was moved after 1.1. 105When the 106.Em COMPAT_11 107option is set, the kernel will read (pre) 1.1 style disk labels as a 108last resort. 109When a disklabel is re-written, the old style label will be replaced 110with a post 1.1 style label. 111.It Cd options COMPAT_12 112Enable binary compatibility with 113.Nx 1.2 . 114This allows the use of old syscalls for 115.Fn reboot 116and 117.Fn swapon . 118The syscall numbers were changed post 1.2 to add functionality to the 119.Xr reboot 2 120syscall, and the new 121.Xr swapctl 2 122interface was introduced. 123.It Cd options COMPAT_13 124Enable binary compatibility with 125.Nx 1.3 . 126This allows the use of old syscalls for 127.Fn sigaltstack , 128and also enables the old 129.Xr swapctl 2 130command 131.Dv SWAP_STATS 132(now called 133.Dv SWAP_OSTATS ) , 134which does not include the 135.Fa se_path 136member of 137.Va struct swapent . 138.It Cd options COMPAT_14 139Enable binary compatibility with 140.Nx 1.4 . 141This allows some old 142.Xr ioctl 2 143on 144.Xr wscons 4 145to be performed, and allows the 146.Dv NFSSVC_BIOD 147mode of the 148.Xr nfssvc 2 149system call to be used for compatibility with the deprecated nfsiod program. 150.It Cd options COMPAT_43 151Enables compatibility with 152.Bx 4.3 . 153This adds an old syscall for 154.Xr lseek 2 . 155It also adds the ioctls for 156.Dv TIOCGETP 157and 158.Dv TIOCSETP . 159The return values for 160.Xr getpid 2 , 161.Xr getgid 2 , 162and 163.Xr getuid 2 164syscalls are modified as well, to return the parent's pid and 165uid as well as the current process's. 166It also enables the deprecated 167.Dv NTTYDISC 168terminal line discipline. 169It also provides backwards compatibility with 170.Dq old 171SIOC[GS]IF{ADDR,DSTADDR,BRDADDR,NETMASK} interface ioctls, including 172binary compatibility with code written before the introduction of the 173sa_len field in sockaddrs. 174It also enables 175support for some older pre 176.Bx 4.4 177socket calls. 178.It Cd options COMPAT_SVR4 179On those architectures that support it, this enables binary 180compatibility with 181.At V.4 182applications built for the same architecture. 183This currently includes the i386, m68k and sparc port. 184.It Cd options COMPAT_LINUX 185On those architectures that support it, this enables binary 186compatibility with Linux ELF and 187.Xr a.out 5 188applications built for the same architecture. 189This currently includes the alpha, i386, powerpc, and m68k 190port. COMPAT_LINUX for powerpc is still experimental. 191.It Cd options COMPAT_SUNOS 192On those architectures that support it, this enables binary 193compatibility with 194.Tn SunOS 4.1 195applications built for the same architecture. 196This currently includes the sparc, sparc64 and most or all m68k ports. 197Note that the sparc64 requires the 198.Em COMPAT_NETBSD32 199option for 64-bit kernels, in addition to this option. 200.It Cd options COMPAT_ULTRIX 201On those architectures that support it, this enables binary 202compatibility with 203.Tn Ultrix 204applications built for the same architecture. 205This currently is limited to the pmax. 206The functionality of this option is unknown. 207.It Cd options COMPAT_FREEBSD 208On those architectures that support it, this enables binary 209compatibility with 210.Fx 211applications built for the same architecture. 212At the moment this is limited to the i386 port. 213.It Cd options COMPAT_HPUX 214On those architectures that support it, this enables binary 215compatibility with 216.Tn HP/UX 217applications built for the same architecture. 218This is limited to the hp300 port, and has some known bugs. 219A limited set of programs do work. 220.It Cd options COMPAT_IBCS2 221On those architectures that support it, this enables binary 222compatibility with iBCS2 or SVR3 applications built for the same architecture. 223This is currently limited to the i386 and vax ports. 224.It Cd options COMPAT_OSF1 225On those architectures that support it, this enables binary 226compatibility with 227.Tn Digital 228.Ux 229.Po 230formerly 231.Tn OSF/1 232.Pc 233applications built for the same architecture. 234This is currently limited to the alpha port. 235.It Cd options COMPAT_NOMID 236Enable compatibility with 237.Xr a.out 5 238executables that lack a machine ID. 239This includes 240.Nx 0.8 Ns 's 241ZMAGIC format, and 386BSD and BSDI's 242QMAGIC, NMAGIC, and OMAGIC 243.Xr a.out 5 244formats. 245.It Cd options COMPAT_NETBSD32 246On those architectures that support it, this enables binary 247compatibility with 32-bit applications built for the same architecture. 248This is currently limited to the sparc64 port, and only applicable for 24964-bit kernels. 250.It Cd options COMPAT_SVR4_32 251On those architectures that support it, this enables binary 252compatibility with 32-bit SVR4 applications built for the same architecture. 253This is currently limited to the sparc64 port, and only applicable for 25464-bit kernels. 255.It Cd options COMPAT_AOUT_M68K 256On m68k architectures which have switched to ELF, 257this enable binary compatibility with 258.Nx Ns Tn /m68k 259.Xr a.out 5 260executables on 261.Nx Ns Tn /m68k 262ELF kernel. 263This handles alignment incompatibility of m68k ABI between 264a.out and ELF which causes the structure padding differences. 265Currently only some system calls which use 266.Va struct stat 267are adjusted and some binaries which use 268.Xr sysctl 3 269to retrieve network details would not work properly. 270.El 271.Ss Debugging Options 272.Bl -ohang 273.It Cd options DDB 274Compiles in a kernel debugger for diagnosing kernel problems. 275See 276.Xr ddb 4 277for details. 278.Em NOTE : 279not available on all architectures. 280.It Cd options DDB_FROMCONSOLE=integer 281If set to non-zero, DDB may be entered by sending a break on a serial 282console or by a special key sequence on a graphics console. 283A value of "0" ignores console breaks or key sequences, 284It not explicitly specified, the default value is "1". 285Note that this sets the value of the 286.Em ddb.fromconsole 287.Xr sysctl 3 288variable which may be changed at run time -- see 289.Xr sysctl 8 290for details. 291.It Cd options DDB_HISTORY_SIZE=integer 292If this is non-zero, enable history editing in the kernel debugger 293and set the size of the history to this value. 294.It Cd options DDB_ONPANIC 295If set to non-zero, the DDB will be entered upon kernel panic. 296The default if not specified is "1". 297Note that this sets the value of the 298.Em ddb.onpanic 299.Xr sysctl 3 300variable which may be changed at run time -- see 301.Xr sysctl 8 302for details. 303.It Cd options DDB_BREAK_CHAR=integer 304This option overrides the using break to enter the kernel debugger 305on the serial console. 306The value given will is the ascii value to be used instead. 307This is currently only supported by the com driver. 308.It Cd options KGDB 309Compiles in a remote kernel debugger stub for diagnosing kernel problems 310using the 311.Dq remote target 312feature of gdb. 313See 314.Xr gdb 1 315for details. 316.Em NOTE : 317not available on all architectures. 318.It Cd makeoptions DEBUG="-g" 319The -g flag causes 320.Pa netbsd.gdb 321to be built in addition to 322.Pa netbsd . 323.Pa netbsd.gdb 324is useful for debugging kernel crash dumps with gdb. 325The command 326.Dl gdb -k 327invokes gdb in kernel debugger mode. 328See 329.Xr gdb 1 330for details. 331This also turns on 332.Em options DEBUG 333(which see). 334.It Cd options DEBUG 335Turns on miscellaneous kernel debugging. 336Since options are turned into preprocessor defines (see above), 337.Em options DEBUG 338is equivalent to doing a 339.Em #define DEBUG 340throughout the kernel. 341Much of the kernel has 342.Em #ifdef DEBUG 343conditionalized debugging code. 344Note that many parts of the kernel (typically device drivers) include their own 345.Em #ifdef XXX_DEBUG 346conditionals instead. 347This option also turns on certain other options, 348which may decrease system performance. 349.It Cd options DIAGNOSTIC 350Adds code to the kernel that does internal consistency checks. 351This code will cause the kernel to panic if corruption of internal data 352structures is detected. These checks can decrease performance up to 15%. 353.It Cd options KTRACE 354Add hooks for the system call tracing facility, which allows users to 355watch the system call invocation behavior of processes. 356See 357.Xr ktrace 1 358for details. 359.It Cd options MSGBUFSIZE=integer 360This option sets the size of the kernel message buffer. 361This buffer holds the kernel output of 362.Fn printf 363when not (yet) read by 364.Xr syslogd 8 . 365This is particularly useful when the system has crashed and you wish to lookup 366the kernel output from just before the crash. 367Also, since the autoconfig output becomes more and more verbose, 368it sometimes happens that the message buffer overflows before 369.Xr syslogd 8 370was able to read it. 371Note that not all systems are capable of obtaining a variable sized message 372buffer. 373There are also some systems on which memory contents are not preserved 374across reboots. 375.It Cd options MALLOCLOG 376Enables an event log for 377.Xr malloc 9 . 378Useful for tracking down 379.Dq Data modified on freelist 380and 381.Dq multiple free 382problems. 383.It Cd options MALLOCLOGSIZE=integer 384Defines the number of entries in the malloc log. 385Default is 100000 entries. 386.El 387.Ss File Systems 388.Bl -ohang 389.It Cd file-system FFS 390Includes code implementing the Berkeley Fast File System 391.Em ( FFS ) . 392Most machines need this if they are not running diskless. 393.It Cd file-system EXT2FS 394Includes code implementing the Second Extended File System 395.Em ( EXT2FS ) 396, revision 0 and revision 1 with the 397.Em filetype 398and 399.Em sparse_super 400options. This is the most commonly used file system on the Linux operating 401system, and is provided here for compatibility. 402Some of the specific features of 403.Em EXT2FS 404like the "behavior on errors" are not implemented. 405This file system can't be used with UID or GID greater than 65535. 406See 407.Xr mount_ext2fs 8 408for details. 409.It Cd file-system LFS 410.Em [EXPERIMENTAL] 411Include the Log-structured File System 412.Em ( LFS ) . 413See 414.Xr mount_lfs 8 415and 416.Xr newfs_lfs 8 417for details. 418.It Cd file-system MFS 419Include the Memory File System 420.Em ( MFS ) . 421This file system stores files in swappable memory, and produces 422notable performance improvements when it is used as the file store 423for 424.Pa /tmp 425and similar file systems. 426See 427.Xr mount_mfs 8 428for details. 429.It Cd file-system NFS 430Include the client side of the Network File System 431.Pq Tn NFS 432remote file sharing protocol. 433Although the bulk of the code implementing 434.Tn NFS 435is kernel based, several user level daemons are needed for it to work. 436See 437.Xr mount_nfs 8 438for details. 439.It Cd file-system CD9660 440Includes code for the 441.Tn ISO 4429660 + Rock Ridge file system, which is the standard file system on many 443.Tn CD-ROM 444discs. 445Useful primarily if you have a 446.Tn CD-ROM 447drive. 448See 449.Xr mount_cd9660 8 450for details. 451.It Cd file-system MSDOSFS 452Includes the 453.Tn MS-DOS 454FAT file system, which is reportedly still used 455by unfortunate people who have not heard about 456.Nx . 457Also implements the 458.Tn Windows 95 459extensions to the same, which permit the use of longer, mixed case 460file names. 461See 462.Xr mount_msdos 8 463and 464.Xr fsck_msdos 8 465for details. 466.It Cd file-system NTFS 467[EXPERIMENTAL] Includes code for the 468.Tn Microsoft Windows NT 469file system. 470See 471.Xr mount_ntfs 8 472for details. 473.It Cd file-system FDESC 474Includes code for a file system, conventionally mounted on 475.Pa /dev/fd , 476which permits access to the per-process file descriptor space via 477special files in the file system. 478See 479.Xr mount_fdesc 8 480for details. 481Note that this facility is redundant, and thus unneeded on most 482.Nx 483systems, since the 484.Xr fd 4 485pseudodevice driver already provides identical functionality. 486On most 487.Nx 488systems, instances of 489.Xr fd 4 490are mknoded under 491.Pa /dev/fd/ 492and on 493.Pa /dev/stdin , 494.Pa /dev/stdout , 495and 496.Pa /dev/stderr . 497.It Cd file-system KERNFS 498Includes code which permits the mounting of a special file system 499(normally mounted on 500.Pa /kern ) 501in which files representing various kernel variables and parameters 502may be found. 503See 504.Xr mount_kernfs 8 505for details. 506.It Cd file-system NULLFS 507Includes code for a loopback file system. 508This permits portions of the file hierarchy to be re-mounted in other places. 509The code really exists to provide an example of a stackable file system layer. 510See 511.Xr mount_null 8 512for details. 513.It Cd file-system OVERLAY 514Includes code for a file system filter. 515This permits the overlay file system to intercept all access to an underlying 516file system. This file system is intended to serve as an example of 517a stacking file system which has a need to interpose itself between an 518underlying file system and all other access. 519See 520.Xr mount_overlay 8 521for details. 522.It Cd file-system PORTAL 523.Em [EXPERIMENTAL] 524Includes the portal filesystem. 525This permits interesting tricks like opening 526.Tn TCP 527sockets by opening files in the file system. 528The portal file system is conventionally mounted on 529.Pa /p 530and is partially implemented by a special daemon. 531See 532.Xr mount_portal 8 533for details. 534.It Cd file-system PROCFS 535Includes code for a special file system (conventionally mounted on 536.Pa /proc ) 537in which the process space becomes visible in the file system. 538Among 539other things, the memory spaces of processes running on the system are 540visible as files, and signals may be sent to processes by writing to 541.Pa ctl 542files in the procfs namespace. 543See 544.Xr mount_procfs 8 545for details. 546.It Cd file-system UMAPFS 547Includes a loopback file system in which user and group ids may be 548remapped -- this can be useful when mounting alien file systems with 549different uids and gids than the local system. 550See 551.Xr mount_umap 8 552for details. 553.It Cd file-system UNION 554.Em [EXPERIMENTAL] 555Includes code for the union file system, which permits directories to 556be mounted on top of each other in such a way that both file systems 557remain visible -- this permits tricks like allowing writing (and the 558deleting of files) on a read-only file system like a 559.Tn CD-ROM 560by mounting a local writable file system on top of the read-only file system. 561See 562.Xr mount_union 8 563for details. 564.It Cd file-system CODA 565.Em [EXPERIMENTAL] 566Includes code for the Coda file system. 567Coda is a distributed file system like NFS and AFS. It is 568freely available, like NFS, but it functions much like AFS in being a 569"stateful" file system. Both Coda and AFS cache files on your local 570machine to improve performance. Then Coda goes a step further than AFS 571by letting you access the cached files when there is no available 572network, viz. disconnected laptops and network outages. In Coda, both 573the client and server are outside the kernel which makes them easier 574to experiment with. Coda is available for several UNIX and non-UNIX 575platforms. 576See http://www.coda.cs.cmu.edu for more details. 577NOTE: You also need to enable the pseudo-device, vcoda, for the Coda 578filesystem to work. 579.El 580.Ss File System Options 581.Bl -ohang 582.It Cd options NFSSERVER 583Include the server side of the 584.Em NFS 585(Network File System) remote file sharing protocol. 586Although the bulk of the code implementing 587.Em NFS 588is kernel based, several user level daemons are needed for it to 589work. 590See 591.Xr mountd 8 592and 593.Xr nfsd 8 594for details. 595.It Cd options QUOTA 596Enables kernel support for file system quotas. 597See 598.Xr quotaon 8 , 599.Xr edquota 8 , 600and 601.Xr quota 1 602for details. 603Note that quotas only work on 604.Dq ffs 605file systems, although 606.Xr rpc.rquotad 8 607permits them to be accessed over 608.Em NFS . 609.It Cd options FFS_EI 610Enable ``Endian-Independent'' FFS support. 611This allows a system to mount an FFS filesystem created for another 612architecture, at a small performance cost for all FFS filesytems. 613See also 614.Xr newfs 8 , 615.Xr fsck_ffs 8 , 616.Xr dumpfs 8 617for filesystem byte order status and manipulation. 618.It Cd options NVNODE=integer 619This option sets the size of the cache used by the name-to-inode translation 620routines, (a.k.a. the 621.Fn namei 622cache, though called by many other names in the kernel source). 623By default, this cache has 624.Dv NPROC 625(set as 20 + 16 * MAXUSERS) * (80 + NPROC / 8) entries. 626A reasonable way to derive a value of 627.Dv NVNODE , 628should you notice a large number of namei cache misses with a tool such as 629.Xr systat 1 , 630is to examine your system's current computed value with 631.Xr sysctl 8 , 632(which calls this parameter "kern.maxvnodes") and to increase this value 633until either the namei cache hit rate improves or it is determined that 634your system does not benefit substantially from an increase in the size of 635the namei cache. 636.It Cd options NAMECACHE_ENTER_REVERSE 637Causes the namei cache to always enter a reverse mapping (vnode -> name) 638as well as a normal one. Normally, this is already done for directory 639vnodes, to speed up the getcwd operation. This option will cause 640longer hash chains in the reverse cache, and thus slow down 641getcwd somewhat. However, it does make vnode -> path translations 642possible in some cases. For now, only useful if strict /proc/#/maps 643emulation for Linux binaries is required. 644.It Cd options EXT2FS_SYSTEM_FLAGS 645This option changes the behavior of the APPEND and IMMUTABLE flags 646for a file on an 647.Em EXT2FS 648filesystem. 649Without this option, the superuser or owner of the file can 650set and clear them. 651With this option, only the superuser can set them, and 652they can't be cleared if the securelevel is greater than 0. 653See also 654.Xr chflags 1 . 655.It Cd options NFS_BOOT_BOOTP 656Enable use of the BOOTP protocol (RFC 951, 1048) to get configuration 657information if NFS is used to mount the root file system. 658See 659.Xr diskless 8 660for details. 661.It Cd options NFS_BOOT_DHCP 662Same as 663.Dq NFS_BOOT_BOOTP 664, but use the DHCP extensions to the 665BOOTP protocol (RFC 1541). 666.It Cd options NFS_BOOT_BOOTP_REQFILE 667Specifies the string sent in the bp_file field of the BOOTP / DHCP 668request packet. 669.It Cd options NFS_BOOT_BOOTPARAM 670Enable use of the BOOTPARAM protocol, consisting of RARP and 671BOOTPARAM RPC, to get configuration information if NFS 672is used to mount the root file system. 673See 674.Xr diskless 8 675for details. 676.It Cd options NFS_BOOT_RWSIZE=value 677Set the initial NFS read and write sizes for diskless-boot requests. 678The normal default is 8Kbytes. This option provides a way to lower 679the value (e.g., to 1024 bytes) as a workaround for buggy network 680interface cards or boot proms. Once booted, the read and write request 681sizes can be increased by remounting the filesystem. See 682.Xr mount_nfs 8 683for details. 684.It Cd options NFS_V2_ONLY 685Reduce the size of the NFS client code by omitting code that's only required 686for NFSv3 and NQNFS support, leaving only that code required to use NFSv2 687servers. 688.El 689.Ss Miscellaneous Options 690.Bl -ohang 691.It Cd options LKM 692Enable loadable kernel modules. 693See 694.Xr lkm 4 695for details. 696.Em NOTE : 697not available on all architectures. 698.It Cd options INSECURE 699Hardwires the kernel security level at -1. 700This means that the system 701always runs in secure level 0 mode, even when running multiuser. 702See the manual page for 703.Xr init 8 704for details on the implications of this. 705The kernel secure level may manipulated by the superuser by altering the 706.Em kern.securelevel 707.Xr sysctl 3 708variable (the secure level may only be lowered by a call from process ID 1, 709i.e. 710.Xr init 8 ) . 711See also 712.Xr sysctl 8 713and 714.Xr sysctl 3 . 715.It Cd options UCONSOLE 716Normally, only the superuser can execute the 717.Dv TIOCCONS 718.Xr ioctl 2 , 719which redirects console output to a non-console tty. 720See 721.Xr tty 4 722for details. 723This option permits any user to execute the 724.Dv TIOCCONS 725.Xr ioctl 2 . 726This is useful on 727machines such as personal workstations which run 728.Xr X 7 729servers, where one would prefer to permit console output to be 730viewed in a window without requiring a suid root program to do it. 731.It Cd options MEMORY_DISK_HOOKS 732This option allows for some machine dependent functions to be called when 733the 734.Tn RAM 735disk driver is configured. 736This can result in automatically loading a 737.Tn RAM 738disk from floppy on open (among other things). 739.It Cd options MEMORY_DISK_IS_ROOT 740Forces the 741.Tn RAM 742disk to be the root device. 743This can only be overridden when 744the kernel is booted in the 'ask-for-root' mode. 745.It Cd options VNODE_OP_NOINLINE 746Do not inline the VOP_*() calls in the kernel. 747On i386 GENERIC, this saves 36k of kernel text. Useful 748for install media kernels, small memory systems and embedded systems. 749.It Cd options NTP 750Turns on in-kernel precision timekeeping support used by software 751implementing 752.Em NTP 753(Network Time Protocol, RFC1305). 754The 755.Em NTP 756option adds an in-kernel Phase-Locked Loop (PLL) for normal 757.Em NTP 758operation, and a Frequency-Locked Loop (FLL) for intermittently-connected 759operation. 760.Xr ntpd 8 761will employ a user-level PLL when kernel support is unavailable, 762but the in-kernel version has lower latency and more precision, and 763so typically keeps much better time. 764The interface to the kernel 765.Em NTP 766support is provided by the 767.Xr ntp_adjtime 2 768and 769.Xr ntp_gettime 2 770system calls, which are intended for use by 771.Xr ntpd 8 772and are enabled by the option. 773On systems with sub-microsecond resolution timers, or where (HZ / 100000) 774is not an integer, the 775.Em NTP 776option also enables extended-precision arithmetic to keep track of 777fractional clock ticks at NTP time-format precision. 778.It Cd options PPS_SYNC 779This option enables a kernel serial line discipline for receiving time 780phase signals from an external reference clock such as a radio clock. 781(The 782.Em NTP 783option (which see) must be on if the 784.Em PPS_SYNC 785option is used.) 786Some reference clocks generate a Pulse Per Second (PPS) signal in 787phase with their time source. 788The 789.Em PPS 790line discipline receives this signal on either the data leads 791or the DCD control lead of a serial port. 792.Em NTP 793uses the PPS signal to discipline the local clock oscillator to a high 794degree of precision (typically less than 50 microseconds in time and 7950.1 ppm in accuracy). 796.Em PPS 797can also generate a serial output pulse when the system receives a PPS 798interrupt. 799This can be used to measure the system interrupt latency and thus calibrate 800.Em NTP 801to account for it. 802Using 803.Em PPS 804usually requires a 805gadget box 806to convert from TTL to RS-232 signal levels. 807The gadget box and PPS are described in more detail in the HTML documentation 808shipped with the ntpd distribution. 809.It Cd options SETUIDSCRIPTS 810Allows scripts with the setuid bit set to execute as the effective 811user rather than the real user, just like binary executables. 812.Pp 813.Em NOTE : 814Using this option will also enable 815.Em options FDSCRIPTS 816.It Cd option FDSCRIPTS 817Allows execution of scripts with the execute bit set, but not the 818read bit, by opening the file and passing the file descriptor to 819the shell, rather than the filename. 820.Pp 821.Em NOTE : 822Execute only (non-readable) scripts will have 823.Va argv[0] 824set to 825.Pa /dev/fd/* . 826What this option allows as far as security is 827concerned, is the ability to safely ensure that the correct script 828is run by the interpreter, as it is passed as an already open file. 829.It Cd options PUCCN 830Enables treating serial ports found on PCI boards 831.Xr puc 4 832as potential console devices. The method for choosing such a console 833device is port dependent. 834.It Cd options RTC_OFFSET=integer 835The kernel (and typically the hardware battery backed-up clock on 836those machines that have one) keeps time in 837.Em UTC 838(Universal Coordinated Time, once known as 839.Em GMT , 840or Greenwich Mean Time) 841and not in the time of the local time zone. 842The 843.Em RTC_OFFSET 844option is used on some ports (such as the i386) to tell the kernel 845that the hardware clock is offset from 846.Em UTC 847by the specified number of minutes. 848This is typically used when a machine boots several operating 849systems and one of them wants the hardware clock to run in the 850local time zone and not in 851.Em UTC , 852e.g. 853.Em RTC_OFFSET=300 854means 855the hardware clock is set to US Eastern Time (300 minutes behind 856.Em UTC ) , 857and not 858.Em UTC . 859(Note: 860.Em RTC_OFFSET 861is used to initialize a kernel variable named 862.Va rtc_offset 863which is the source actually used to determine the clock offset, and 864which may be accessed via the kern.rtc_offset sysctl variable. 865See 866.Xr sysctl 8 867and 868.Xr sysctl 3 869for details. 870Since the kernel clock is initialized from the hardware clock very 871early in the boot process, it is not possible to meaningfully change 872.Va rtc_offset 873in system initialization scripts. 874Changing this value currently may only be done at kernel compile 875time or by patching the kernel and rebooting). 876.Pp 877.Em NOTE : 878Unfortunately, in many cases where the hardware clock 879is kept in local time, it is adjusted for Daylight Savings 880Time; this means that attempting to use 881.Em RTC_OFFSET 882to let NetBSD coexist with such an operating system, like Windows, 883would necessitate changing 884.Em RTC_OFFSET 885twice a year. As such, this solution is imperfect. 886.It Cd options KMEMSTATS 887The kernel memory allocator, 888.Xr malloc 9 , 889will keep statistics on its performance if this option is enabled. 890Unfortunately, this option therefore essentially disables the 891.Fn MALLOC 892and 893.Fn FREE 894forms of the memory allocator, which are used to enhance the performance 895of certain critical sections of code in the kernel. 896This option therefore can lead to a significant decrease in the 897performance of certain code in the kernel if enabled. 898Examples of such code include the 899.Fn namei 900routine, the 901.Xr ccd 4 902driver, 903the 904.Xr ncr 4 905driver, 906and much of the networking code. 907.It Cd options MAXUPRC=integer 908Sets the 909.Em RLIMIT_NPROC 910resource limit, which specifies the maximum number of simultaneous 911processes a user is permitted to run, for process 0; 912this value is inherited by its child processes. 913It defaults to 914.Em CHILD_MAX , 915which is currently defined to be 160. 916Setting 917.Em MAXUPRC 918to a value less than 919.Em CHILD_MAX 920is not permitted, as this would result in a violation of the semantics of 921.St -p1003.1-90 . 922.It Cd options DEFCORENAME=string 923Sets the default value of the 924.Em kern.defcorename 925sysctl variable, otherwise it is set to 926.Nm %n.core . 927See 928.Xr sysctl 8 929and 930.Xr sysctl 3 931for details. 932.It Cd options RASOPS_CLIPPING 933Enables clipping within the 934.Nm rasops 935raster-console output system. 936.Em NOTE : 937only available on architectures that use 938.Nm rasops 939for console output. 940.It Cd options RASOPS_SMALL 941Removes optimized character writing code from the 942.Nm rasops 943raster-console output system. 944.Em NOTE : 945only available on architectures that use 946.Nm rasops 947for console output. 948.El 949.Ss Networking Options 950.Bl -ohang 951.It Cd options GATEWAY 952Enables 953.Em IPFORWARDING 954(which see) 955and (on most ports) increases the size of 956.Em NMBCLUSTERS 957(which see). 958In general, 959.Em GATEWAY 960is used to indicate that a system should act as a router, and 961.Em IPFORWARDING 962is not invoked directly. 963(Note that 964.Em GATEWAY 965has no impact on protocols other than 966.Tn IP , 967such as 968.Tn CLNP 969or 970.Tn XNS ) . 971.It Cd options IPFORWARDING=value 972If 973.Em value 974is 1 this enables IP routing behavior. If 975.Em value 976is 0 (the default), it disables it. The 977.Em GATEWAY 978option sets this to 1 automatically. 979With this option enabled, the machine will forward IP datagrams destined 980for other machines between its interfaces. 981Note that even without this option, the kernel will 982still forward some packets (such as source routed packets) -- removing 983.Em GATEWAY 984and 985.Em IPFORWARDING 986is insufficient to stop all routing through a bastion host on a 987firewall -- source routing is controlled independently. 988To turn off source routing, use 989.Em options IPFORWSRCRT=0 990(which see). 991Note that IP forwarding may be turned on and off independently of the 992setting of the 993.Em IPFORWARDING 994option through the use of the 995.Em net.inet.ip.forwarding 996sysctl variable. 997If 998.Em net.inet.ip.forwarding 999is 1, IP forwarding is on. 1000See 1001.Xr sysctl 8 1002and 1003.Xr sysctl 3 1004for details. 1005.It Cd options IPFORWSRCRT=value 1006If 1007.Em value 1008is set to zero, source routing of IP datagrams is turned off. 1009If 1010.Em value 1011is set to one (the default) or the option is absent, source routed IP 1012datagrams are forwarded by the machine. 1013Note that source routing of IP packets may be turned on and off 1014independently of the setting of the 1015.Em IPFORWSRCRT 1016option through the use of the 1017.Em net.inet.ip.forwsrcrt 1018sysctl variable. 1019If 1020.Em net.inet.ip.forwsrcrt 1021is 1, forwarding of source routed IP datagrams is on. 1022See 1023.Xr sysctl 8 1024and 1025.Xr sysctl 3 1026for details. 1027.It Cd options IFA_STATS 1028Tells the kernel to maintain per-address statistics on bytes sent 1029and received over (currently) internet and appletalk addresses. 1030.\"This can be a fairly expensive operation, so you probably want to 1031.\"keep this disabled. 1032The option is not recommended as itdegrades system stability. 1033.It Cd options MROUTING 1034Includes support for IP multicast routers. 1035You certainly want 1036.Em INET 1037with this. 1038Multicast routing is controlled by the 1039.Xr mrouted 8 1040daemon. 1041.It Cd options INET 1042Includes support for the 1043.Tn TCP/IP 1044protocol stack. 1045You almost certainly want this. 1046See 1047.Xr inet 4 1048for details. 1049This option is currently required. 1050.It Cd options INET6 1051Includes support for the 1052.Tn IPv6 1053protocol stack. 1054See 1055.Xr inet6 4 1056for details. 1057Unlike 1058.Em INET , 1059.Em INET6 1060enables multicast routing code as well. 1061This option requires 1062.Em INET 1063at this moment, but it should not. 1064.It Cd options ND6_DEBUG 1065The option sets the default value of net.inet6.icmp6.nd6_debug to 1, 1066for debugging IPv6 neighbor discovery protocol handling. 1067See 1068.Xr sysctl 3 1069for details. 1070.It Cd options IPSEC 1071Includes support for the 1072.Tn IPsec 1073protocol. 1074See 1075.Xr ipsec 4 1076for details. 1077.Em IPSEC 1078will enable 1079secret key management part, 1080policy management part, 1081.Tn AH 1082and 1083.Tn IPComp . 1084Kernel binary will not be subject to export control in most of countries, 1085even if compiled with 1086.Em IPSEC . 1087For example, it should be okay to export it from within the United States 1088to the outside. 1089.Em INET6 1090and 1091.Em IPSEC 1092are orthogonal so you can get IPv4-only kernel with IPsec support, 1093IPv4/v6 dual support kernel without IPsec, and so forth. 1094This option requires 1095.Em INET 1096at this moment, but it should not. 1097.It Cd options IPSEC_DEBUG 1098Enables debugging code in 1099.Tn IPsec 1100stack. 1101This option assumes 1102.Em IPSEC . 1103.It Cd options IPSEC_ESP 1104Includes support for 1105.Tn IPsec 1106.Tn ESP 1107protocol. 1108See 1109.Xr ipsec 4 1110for details. 1111.Em IPSEC_ESP 1112will enable source code that is subject to export control in some countries 1113.Pq including the United States , 1114and compiled kernel binary will be subject to certain restriction. 1115This option assumes 1116.Em IPSEC . 1117.It Cd options SUBNETSARELOCAL 1118Sets default value for net.inet.ip.subnetsarelocal variable, which 1119controls whether non-directly-connected subnets of connected networks 1120are considered "local" for purposes of choosing the MSS for a TCP 1121connection. This is mostly present for historic reasons and 1122completely irrelevant if you enable Path MTU discovery. 1123.It Cd options HOSTZEROBROADCAST 1124Sets default value for net.inet.ip.hostzerobroadcast variable, which 1125controls whether the zeroth host address of each connected subnet is 1126also considered a broadcast address. Default value is "1", for 1127compatibility with old systems; if this is set to zero on all hosts on 1128a subnet, you should be able to fit an extra host per subnet on the 1129".0" address. 1130.It Cd options MCLSHIFT=value 1131This option is the base-2 logarithm of the size of mbuf clusters. 1132The 1133.Bx 1134networking stack keeps network packets in a linked 1135list, or chain, of kernel buffer objects called mbufs. 1136The system provides larger mbuf clusters as an optimization for 1137large packets, instead of using long chains for large packets. 1138The mbuf cluster size, 1139or 1140.Em MCLBYTES , 1141must be a power of two, and is computed as two raised to the power 1142.Em MCLSHIFT . 1143On systems with Ethernet network adaptors, 1144.Em MCLSHIFT 1145is often set to 11, giving 2048-byte mbuf clusters, large enough to 1146hold a 1500-byte 1147.Tn Ethernet 1148frame in a single cluster. 1149Systems with network interfaces supporting larger frame sizes like 1150.Tn ATM , 1151.Tn FDDI , 1152or 1153.Tn HIPPI 1154may perform better with 1155.Em MCLSHIFT 1156set to 12 or 13, giving mbuf cluster sizes of 4096 and 8192 bytes, 1157respectively. 1158.It Cd options NS 1159Include support for the 1160.Tn Xerox 1161.Tn XNS 1162protocol stack. 1163See 1164.Xr ns 4 1165for details. 1166.It Cd options ISO,TPIP 1167Include support for the ubiquitous 1168.Tn OSI 1169protocol stack. 1170See 1171.Xr iso 4 1172for details. 1173This option assumes 1174.Em INET . 1175.It Cd options EON 1176Include support for tunneling 1177.Tn OSI 1178protocols over 1179.Tn IP . 1180Known to be broken, or at least very fragile, and undocumented. 1181.It Cd options CCITT,LLC,HDLC 1182Include support for the 1183.Tn CCITT 1184(nee 1185.Tn ITU-TSS ) 1186.Tn X.25 1187protocol stack. 1188The state of this code is currently unknown, and probably contains bugs. 1189This option assumes 1190.Em INET . 1191.It Cd options NETATALK 1192Include support for the 1193.Tn AppleTalk 1194protocol stack. 1195The kernel provides provision for the 1196.Em Datagram Delivery Protocol 1197(DDP), providing SOCK_DGRAM support and 1198.Tn AppleTalk 1199routing. 1200This stack is used by the 1201.Em NETATALK 1202package, which adds support for 1203.Tn AppleTalk 1204server services via user libraries and applications. 1205.It Cd options IPNOPRIVPORTS 1206Normally, only root can bind a socket descriptor to a so-called 1207.Dq privileged 1208.Tn TCP 1209port, that is, a port number in the range 0-1023. 1210This option eliminates those checks from the kernel. 1211This can be useful if there is a desire to allow daemons without 1212privileges to bind those ports, e.g. on firewalls. 1213The security tradeoffs in doing this are subtle. 1214This option should only be used by experts. 1215.It Cd options TCP_COMPAT_42 1216.Tn TCP 1217bug compatibility with 1218.Bx 4.2 . 1219In 1220.Bx 4.2 , 1221.Tn TCP 1222sequence numbers were 32-bit signed values. 1223Modern implementations of TCP use unsigned values. 1224This option clamps the initial sequence number to start in 1225the range 2^31 rather than the full unsigned range of 2^32. 1226Also, under 1227.Bx 4.2 , 1228keepalive packets must contain at least one byte or else 1229the remote end would not respond. 1230.It Cd options PFIL_HOOKS 1231This option turns on the packet filter interface hooks. 1232See 1233.Xr pfil 9 1234for details. 1235This option assumes 1236.Em INET . 1237.It Cd options IPFILTER_LOG 1238This option, in conjunction with 1239.Em pseudo-device ipfilter , 1240enables logging of IP packets using ip-filter. 1241.It Cd options IPFILTER_DEFAULT_BLOCK 1242This option sets the default policy of ip-filter. 1243If it is set, ip-filter will block packets by default. 1244.It Cd options PPP_BSDCOMP 1245Enable support for BSD-compress 1246.Pq Sq bsdcomp 1247compression in ppp. 1248.It Cd options PPP_DEFLATE 1249Enable support for deflate 1250compression in ppp. 1251.It Cd options PPP_FILTER 1252This option turns on 1253.Xr pcap 3 1254based filtering for ppp connections. 1255This option is used by 1256.Xr pppd 8 1257which needs to be compiled with 1258.Em PPP_FILTER 1259defined (the current default). 1260.El 1261.Ss System V IPC Options 1262.Bl -ohang 1263.It Cd options SYSVMSG 1264Includes support for 1265.At V 1266style message queues. 1267See 1268.Xr msgctl 2 , 1269.Xr msgget 2 , 1270.Xr msgrcv 2 , 1271.Xr msgsnd 2 . 1272.It Cd options SYSVSEM 1273Includes support for 1274.At V 1275style semaphores. 1276See 1277.Xr semctl 2 , 1278.Xr semget 2 , 1279.Xr semop 2 . 1280.It Cd options SYSVSHM 1281Includes support for 1282.At V 1283style shared memory. 1284See 1285.Xr shmat 2 , 1286.Xr shmctl 2 , 1287.Xr shmdt 2 , 1288.Xr shmget 2 . 1289.It Cd options SHMMAXPGS=value 1290Sets the maximum number of 1291.At V 1292style shared memory pages that are available through the 1293.Xr shmget 2 1294system call. 1295Default value is 1024 on most ports. 1296See 1297.Pa /usr/include/machine/vmparam.h 1298for the default. 1299.El 1300.Ss VM Related Options 1301.Bl -ohang 1302.It Cd options NMBCLUSTERS=value 1303The number of mbuf clusters the kernel supports. Mbuf clusters are 1304MCLBYTES in size (usually 2k). This is used to compute the size of 1305the kernel VM map 1306.Em mb_map , 1307which maps mbuf clusters. 1308Default on most ports is 256 (512 with 1309.Dq options GATEWAY 1310). 1311See 1312.Pa /usr/include/machine/param.h 1313for exact default information. 1314Increase this value if you get 1315.Dq mb_map full 1316messages. 1317.It Cd options NKMEMPAGES=value 1318.It Cd options NKMEMPAGES_MIN=value 1319.It Cd options NKMEMPAGES_MAX=value 1320Size of kernel VM map 1321.Em kmem_map , 1322in PAGE_SIZE-sized chunks (the VM page size; this value may be read 1323from the 1324.Xr sysctl 8 1325variable 1326.Em hw.pagesize 1327). 1328This VM map is used to map the kernel malloc arena. 1329The kernel attempts to auto-size this map based on the amount of 1330physical memory in the system. Platform-specific code may place 1331bounds on this computed size, which may be viewed with the 1332.Xr sysctl 8 1333variable 1334.Em vm.nkmempages . 1335See 1336.Pa /usr/include/machine/param.h 1337for the default upper and lower bounds. 1338The related options 1339.Sq NKMEMPAGES_MIN 1340and 1341.Sq NKMEMPAGES_MAX 1342allow the bounds to be overridden in the kernel configuration file. 1343These options are provided in the event the computed value is 1344insufficient resulting in an 1345.Dq out of space in kmem_map 1346panic. 1347.It Cd options BUFCACHE=value 1348Size of the buffer cache as a percentage of total available 1349.Tn RAM . 1350Ignored if BUFPAGES is also specified. 1351.It Cd options NBUF=value 1352.It Cd options BUFPAGES=value 1353These options set the number of pages available for the buffer cache. 1354Their default value is a machine dependent value, often calculated as 1355between 5% and 10% of total available 1356.Tn RAM . 1357.El 1358.Ss amiga-specific Options 1359.Bl -ohang 1360.It Cd options BB060STUPIDROM 1361When the bootloader (which passes 1362.Tn AmigaOS 1363.Tn ROM 1364information) claims we have a 68060 1365.Tn CPU 1366without 1367.Tn FPU , 1368go look into the Processor Configuration Register (PCR) to find out. 1369You need this with 1370.Tn Amiga 1371.Tn ROM Ns s 1372up to (at least) V40.xxx (OS3.1), 1373when you boot via the bootblocks and don't have a DraCo. 1374.It Cd options IOBZCLOCK=frequency 1375The IOBlix boards come with two different serial master clocks: older ones 1376use 24 MHz, newer ones use 22.1184 MHz. The driver normally assumes the latter. 1377If your board uses 24 MHz, you can recompile your kernel with 1378options IOBZCLOCK=24000000 1379or patch the kernel variable 1380.Tn iobzclock 1381to the same value. 1382.It Cd options LIMITMEM=value 1383If there, limit the part of the first memory bank used by 1384.Nx 1385to value megabytes. 1386Default is unlimited. 1387.It Cd options NKPTADD=addvalue 1388.It Cd options NKPTADDSHIFT=shiftvalue 1389The 1390.Tn CPU 1391specific 1392.Tn MMU 1393table for the kernel is pre-allocated at kernel startup time. 1394Part of it is scaled with 1395.Va maxproc , 1396to have enough room to hold the user program 1397.Tn MMU 1398tables; the second part is a fixed amount for the kernel itself. 1399.Pp 1400The third part accounts for the size of the file buffer cache. 1401Its size is either 1402.Dv NKPTADD 1403pages (if defined) or memory size in bytes divided by two to 1404the power of 1405.Dv NKPTADDSHIFT . 1406The default is undefined 1407.Dv NKPTADD 1408and 1409.Dv NKPTADDSHIFT=24 , 1410allowing for 16 buffers per megabyte of main memory (while 1411a GENERIC kernel allocates about half of that). 1412When you get "can't get KPT page" panics, you should increase 1413.Dv NKPTADD 1414(if defined), or decrease 1415.Dv NKPTADDSHIFT 1416by one. 1417.It Cd options P5PPC68KBOARD 1418Add special support for Phase5 mixed 68k+PPC boards. Currently, this only 1419affects rebooting from NetBSD and is only needed on 68040+PPC, not on 142068060+PPC; without this, affected machines will hang after NetBSD has shut 1421down and will only restart after a keyboard reset or a power cycle. 1422.El 1423.Ss arm32-specific Options 1424.Bl -ohang 1425.It Cd options FRENCH_KEYBOARD 1426Include translation for French keyboards when using 1427.Xr pccons 4 1428on a Shark. 1429.It Cd options FINNISH_KEYBOARD 1430Include translation for Finnish keyboards when using 1431.Xr pccons 4 1432on a Shark. 1433.It Cd options GERMAN_KEYBOARD 1434Include translation for German keyboards when using 1435.Xr pccons 4 1436on a Shark. 1437.It Cd options NORWEGIAN_KEYBOARD 1438Include translation for French keyboards when using 1439.Xr pccons 4 1440on a Shark. 1441.El 1442.Ss atari-specific Options 1443.Bl -ohang 1444.It Cd options DISKLABEL_AHDI 1445Include support for AHDI (native Atari) disklabels. 1446.It Cd options DISKLABEL_NBDA 1447Include support for 1448.Nx Ns Tn /atari 1449labels. 1450If you don't set this option, it will be set automatically. 1451.Nx Ns Tn /atari 1452will not work without it. 1453.It Cd options FALCON_SCSI 1454Include support for the 5380-SCSI configuration as found on the Falcon. 1455.It Cd options RELOC_KERNEL 1456If set, the kernel will relocate itself to TT-RAM, if possible. 1457This will give you a slightly faster system. 1458.Em Beware 1459that on some TT030 systems, 1460the system will frequently dump with MMU-faults with this option enabled. 1461.It Cd options SERCONSOLE 1462Allow the modem1-port to act as the system-console. 1463A carrier should be active on modem1 during system boot to active 1464the console functionality. 1465.It Cd options TT_SCSI 1466Include support for the 5380-SCSI configuration as found on the TT030 1467and Hades. 1468.El 1469.Ss i386-specific Options 1470.Bl -ohang 1471.It Cd options I386_CPU,I486_CPU,I586_CPU,I686_CPU 1472Include support for a particular class of 1473.Tn CPU 1474.Po 1475.Tn i386 , 1476.Tn i486 , 1477.Tn Pentium , 1478or 1479.Tn Pentium Pro 1480.Pc . 1481If the appropriate class for your 1482.Tn CPU 1483is not configured, the kernel will use the highest class available 1484that will work. 1485In general, using the correct 1486.Tn CPU 1487class will result in the best performance. 1488At least one of these options must be present. 1489.It Cd options CPURESET_DELAY=value 1490specifies the time (in millisecond) to wait before doing a hardware reset 1491in the last phase of a reboot. This gives the user a chance to see error 1492messages from the shutdown operations (like NFS unmounts, buffer cache flush, 1493etc ...). Setting this to 0 will disable the delay. Default is 2 seconds. 1494.It Cd options MATH_EMULATE 1495Include the floating point emulator. 1496This is useful only for 1497.Tn CPU Ns s 1498that lack an 1499internal Floating Point Unit 1500.Pq Tn FPU 1501or co-processor. 1502.It Cd options VM86 1503Include support for virtual 8086 mode, used by 1504.Tn DOS 1505emulators and X servers to run BIOS code, e.g. for some VESA routines. 1506.It Cd options USER_LDT 1507Include i386-specific system calls for modifying the local descriptor table, 1508used by Windows emulators. 1509.It Cd options REALBASEMEM=integer 1510Overrides the base memory size passed in from the boot block. 1511(Value given in kilobytes.) 1512Use this option only if the boot block reports the size incorrectly. 1513(Note that some 1514.Tn BIOS Ns es 1515put the extended 1516.Tn BIOS 1517data area at the top of base memory, and therefore report a smaller 1518base memory size to prevent programs overwriting it. 1519This is correct behavior, and you should not use the 1520.Em REALBASEMEM 1521option to access this memory). 1522.It Cd options REALEXTMEM=integer 1523Overrides the extended memory size passed in from the boot block. 1524(Value given in kilobytes. Extended memory does not include the first megabyte.) 1525Use this option only if the boot block reports the size incorrectly. 1526.It Cd options FRENCH_KBD,FINNISH_KBD,GERMAN_KBD,NORWEGIAN_KBD 1527Select a non-US keyboard layout for the 1528.Em pccons 1529console driver. 1530.It Cd options CYRIX_CACHE_WORKS 1531Relevant only to the Cyrix 486DLC cpu. This option is used to turn on 1532the cache in hold-flush mode. It is not turned on by default because it 1533is known to have problems in certain motherboard implementations. 1534.It Cd options CYRIX_CACHE_REALLY_WORKS 1535Relevant only to the Cyrix 486DLC cpu. This option is used to turn on 1536the cache in write-back mode. It is not turned on by default because it 1537is known to have problems in certain motherboard implementations. In order 1538for this option to take effect, option 1539.Em CYRIX_CACHE_WORKS 1540must also be specified. 1541.It Cd options PCIBIOS 1542Enable support for initializing the 1543.Tn PCI 1544bus using information from the 1545.Tn BIOS . 1546See 1547.Xr pcibios 4 1548for details. 1549.El 1550.Ss isa-specific Options 1551Options specific to 1552.Xr isa 4 1553busses. 1554.Bl -ohang 1555.It Cd options PCIC_ISA_ALLOC_IOBASE=address, PCIC_ISA_ALLOC_IOSIZE=size 1556Control the section of IO bus space used for PCMCIA bus space mapping. 1557Ideally the probed defaults are satisfactory, however in practice 1558that is not always the case. See 1559.Xr pcmcia 4 1560for details. 1561.It Cd options PCIC_ISA_INTR_ALLOC_MASK=mask 1562Controls the allowable interrupts that may be used for 1563.Tn PCMCIA 1564devices. This mask is a logical-or of power-of-2s of allowable 1565interrupts: 1566.Bd -literal -offset 04n 1567.Em "IRQ Val IRQ Val IRQ Val IRQ Val" 1568 0 0x0001 4 0x0010 8 0x0100 12 0x1000 1569 1 0x0002 5 0x0020 9 0x0200 13 0x2000 1570 2 0x0004 6 0x0040 10 0x0400 14 0x4000 1571 3 0x0008 7 0x0080 11 0x0800 15 0x8000 1572.Ed 1573.El 1574.Ss m68k-specific Options 1575.Bl -ohang 1576.It Cd options FPU_EMULATE 1577Include support for MC68881/MC68882 emulator. 1578.It Cd options FPSP 1579Include support for 68040 floating point. 1580.It Cd options M68020,M68030,M68040,M68060 1581Include support for a specific 1582.Tn CPU , 1583at least one (the one you are using) should be specified. 1584.It Cd options M060SP 1585Include software support for 68060. 1586This provides emulation of unimplemented 1587integer instructions as well as emulation of unimplemented floating point 1588instructions and data types and software support for floating point traps. 1589.El 1590.Ss sparc-specific Options 1591.Bl -ohang 1592.It Cd options AUDIO_DEBUG 1593Enable simple event debugging of the logging of the 1594.Xr audio 4 1595device. 1596.It Cd options BLINK 1597Enable blinking of LED. Blink rate is full cycle every N seconds for 1598N < then current load average. See 1599.Xr getloadavg 3 . 1600.\" .It Cd options COLORFONT_CACHE 1601.\" this is totally fucked up.. what does this do? 1602.It Cd options COUNT_SW_LEFTOVERS 1603Count how many times the sw SCSI device has left 3, 2, 1 and 0 in the 1604sw_3_leftover, sw_2_leftover, sw_1_leftover, and sw_0_leftover 1605variables accessable from 1606.Xr ddb 4 . 1607See 1608.Xr sw 4 . 1609.It Cd options DEBUG_ALIGN 1610Adds debugging messages calls when user-requested alignment fault 1611handling happens. 1612.It Cd options DEBUG_EMUL 1613Adds debugging messages calls for emulated floating point and 1614alignment fixing operations. 1615.It Cd options DEBUG_SVR4 1616Prints registers messages calls for emulated SVR4 getcontext and 1617setcontext operations. See 1618.Em options COMPAT_SVR4 . 1619.It Cd options EXTREME_DEBUG 1620Adds debugging functions callable from 1621.Xr ddb 4 . The debug_pagetables, test_region and print_fe_map 1622functions print information about page tables for the SUN4M 1623platforms only. 1624.It Cd options EXTREME_EXTREME_DEBUG 1625Adds extra info to 1626.Em options EXTREME_DEBUG . 1627.It Cd options FPU_CONTEXT 1628Make 1629.Em options COMPAT_SVR4 1630getcontext and setcontext include floating point registers. 1631.It Cd options MAGMA_DEBUG 1632Adds debugging messages to the 1633.Xr magma 4 1634device. 1635.It Cd options RASTERCONS_FULLSCREEN 1636Use the entire screen for the console. 1637.It Cd options RASTERCONS_SMALLFONT 1638Use a the fixed font on the console, instead of the normal font. 1639.It Cd options SUN4 1640Support sun4 class machines. 1641.It Cd options SUN4C 1642Support sun4c class machines. 1643.It Cd options SUN4M 1644Support sun4m class machines. 1645.It Cd options SUN4_MMU3L 1646.\" XXX ??? 1647Enable support for sun4 3-level MMU machines. 1648.It Cd options V9 1649Enable SPARC V9 assembler in 1650.Xr ddb 4 . 1651.El 1652.Ss x68k-specific Options 1653.Bl -ohang 1654.It Cd options EXTENDED_MEMORY 1655Include support for extended memory e.g. TS-6BE16 and 060turbo on-board. 1656.It Cd options JUPITER 1657Include support for Jupiter-X MPU accelerator 1658.It Cd options ZSCONSOLE,ZSCN_SPEED=value 1659Use the built-in serial port as the system-console. 1660Speed is specified in bps, defaults to 9600. 1661.It Cd options ITE_KERNEL_ATTR=value 1662Set the kernel message attribute for ITE. 1663Value, an integer, is a logical or of the following values: 1664.Bl -tag -width 4n -compact -offset indent 1665.It 1 1666color inversed 1667.It 2 1668underlined 1669.It 4 1670bolded 1671.El 1672.El 1673.\" The following requests should be uncommented and used where appropriate. 1674.\" .Sh FILES 1675.\" .Sh EXAMPLES 1676.Sh SEE ALSO 1677.Xr gdb 1 , 1678.Xr ktrace 1 , 1679.Xr quota 1 , 1680.Xr gettimeofday 2 , 1681.Xr i386_iopl 2 , 1682.Xr msgctl 2 , 1683.Xr msgget 2 , 1684.Xr msgrcv 2 , 1685.Xr msgsnd 2 , 1686.Xr ntp_adjtime 2 , 1687.Xr ntp_gettime 2 , 1688.Xr semctl 2 , 1689.Xr semget 2 , 1690.Xr semop 2 , 1691.Xr shmat 2 , 1692.Xr shmctl 2 , 1693.Xr shmdt 2 , 1694.Xr shmget 2 , 1695.Xr sysctl 3 , 1696.Xr apm 4 , 1697.Xr ddb 4 , 1698.Xr inet 4 , 1699.Xr iso 4 , 1700.Xr lkm 4 , 1701.Xr ns 4 , 1702.Xr pcibios 4 , 1703.Xr pcmcia 4 , 1704.Xr config 8 , 1705.Xr edquota 8 , 1706.Xr init 8 , 1707.Xr mount_cd9660 8 , 1708.Xr mount_fdesc 8 , 1709.Xr mount_kernfs 8 , 1710.Xr mount_lfs 8 , 1711.Xr mount_mfs 8 , 1712.Xr mount_msdos 8 , 1713.Xr mount_nfs 8 , 1714.Xr mount_ntfs 8 , 1715.Xr mount_null 8 , 1716.Xr mount_portal 8 , 1717.Xr mount_procfs 8 , 1718.Xr mount_umap 8 , 1719.Xr mount_union 8 , 1720.Xr mrouted 8 , 1721.Xr newfs_lfs 8 , 1722.Xr quotaon 8 , 1723.Xr rpc.rquotad 8 , 1724.Xr sysctl 8 , 1725.Xr ntpd 8 1726.Sh HISTORY 1727The 1728.Nm 1729man page first appeared in 1730.Nx 1.3 . 1731.Sh BUGS 1732The 1733.Em INET 1734and the 1735.Em VNODEPAGER 1736options should not be required. 1737The 1738.Em EON 1739option should be a pseudo-device, and is also very fragile. 1740