PC Online 1996 November/PCO96_11.ISO/linux/docs/kernel-2.0/config~1.hel

Text File | 1996-09-21 | 14.0 KB | 275 lines

# Maintained by Axel Boldt ([e-mail])
#
# This version of the Linux kernel configuration help texts
# corresponds to the kernel versions 2.0.x.
#
# Information about what a kernel is, what it does, how to patch and
# compile it and much more is contained in the Kernel-HOWTO, available
# via ftp (user: anonymous) from sunsite.unc.edu in the directory
# /pub/Linux/docs/HOWTO.
#
# Format of this file: description<nl>variable<nl>helptext<nl><nl>.
# If the question being documented is of type "choice", we list
# only the first occurring config variable. The help texts
# must not contain empty lines. No variable should occur twice; if it
# does, only the first occurrence will be used by Configure. The lines
# in a help text should be indented two positions. Lines starting with
# `#' are ignored. To be nice to menuconfig, limit your lines to 70
# characters. Use emacs' kfill.el to edit this file or you lose.
#
# If you add a help text to this file, please try to be as gentle as
# possible. Don't use unexplained acronyms and generally write for the
# hypothetical user who has just bought a PC, removed Windows,
# installed Linux and is now recompiling the kernel for the first
# time. Tell them what to do if they're unsure. Technical information
# should go in a README in the Documentation directory. Mention all
# the relevant READMEs and HOWTOs in the help text.
#
# All this was shamelessly stolen from several different sources. Many
# thanks to all the contributors.  Feel free to use these help texts
# in your own kernel configuration tools. The texts are copyrighted
# (c) 1995,1996 by Axel Boldt and governed by the GNU Public License.

Prompt for development and/or incomplete code/drivers
CONFIG_EXPERIMENTAL
  Some of the various things that Linux supports (such as network
  drivers, filesystems, network protocols, etc.) can be in a state
  of development where the functionality, stability, or the level of
  testing is not yet high enough for general use. This is usually
  known as the "alpha-test" phase amongst developers. If a feature is
  currently in alpha-test, then the developers usually discourage
  uninformed widespread use of this feature by the general public to
  avoid "Why doesn't this work?" type mail messages. However, active
  testing and use of these systems is welcomed. Just be aware that it
  may not meet the normal level of reliability or it may fail to work
  in some special cases. Detailed bug reports from people familiar with
  the kernel internals are usually welcomed by the developers.
  Unless you intend to help test and develop a feature or driver that
  falls into this category, or you have a situation that requires using
  these features you should probably say N here, which will cause this
  configure script to present you with fewer choices. If you say Y here,
  you will be offered the choice of using features or drivers that are
  currently considered to be in the alpha-test phase.

Kernel math emulation
CONFIG_MATH_EMULATION
  Linux can emulate a math coprocessor (used for floating point
  operations) if you don't have one. 486DX and Pentium processors have
  a math coprocessor built in, 486SX and 386 do not, unless you added
  a 487DX or 387, respectively.  (The messages during boot time can
  give you some hints here ["man dmesg"]) Everyone needs either a
  coprocessor or this emulation. If you enable this emulation even
  though you have a coprocessor, the coprocessor will be used
  nevertheless. (This behavior can be changed with the kernel command
  line option "no387", which comes handy if your coprocessor is
  broken. See the documentation of your boot loader (lilo or loadlin)
  about how to pass options to the kernel at boot time. The lilo
  procedure is also explained in the SCSI-HOWTO, available via ftp
  (user: anonymous) in sunsite.unc.edu:/pub/Linux/docs/HOWTO.) This
  means that it is a good idea to say Y here if you intend to use this
  kernel on different machines. More information about the internals
  of Linux math coprocessor emulation can be found in
  arch/i386/math-emu/README. If you are not sure, say Y; apart from
  resulting in a 45kB bigger kernel, it won't hurt.

Normal floppy disk support
CONFIG_BLK_DEV_FD
  If you want to use your floppy disk drive(s) under Linux, say
  Y. Information about this driver, especially important for IBM
  Thinkpad users, is contained in drivers/block/README.fd.  This
  driver is also available as a module ( = code which can be inserted
  in and removed from the running kernel whenever you want). If you
  want to compile it as a module, say M here and read
  Documentation/modules.txt.

RAM disk support
CONFIG_BLK_DEV_RAM
  Enabling this option will allow you to use a portion of your RAM
  memory as a block device, so that you can make filesystems on it,
  read and write to it and do all the other things that normal block
  devices (such as harddrives) can do.  It is usually used to load and
  store a copy of a minimal root file system off of a floppy into RAM
  during the initial install of Linux.  Note that the kernel command
  line option "ramdisk=XX" is now obsolete.  For details, read
  Documentation/ramdisk.txt. If you want to compile this as a module (
  = code which can be inserted in and removed from the running kernel
  whenever you want), say M and read Documentation/modules.txt.  Most
  normal users won't need the RAM disk functionality, and can thus say
  N here.

Initial RAM disk (initrd) support
CONFIG_BLK_DEV_INITRD
  The initial RAM disk is a RAM disk that is loaded by the boot loader
  (LOADLIN or LILO) and that is mounted as root before the normal boot
  procedure. It is typically used to load modules needed to mount the
  "real" root file system, etc. See Documentation/initrd.txt for
  details.

Loop device support
CONFIG_BLK_DEV_LOOP
  Enabling this option will allow you to mount a file as a file system.
  This is useful if you want to check an ISO9660 file system before
  burning the CD, or want to use floppy images without first writing
  them to floppy.
  This option also allows one to mount a filesystem with encryption.
  To use these features, you need a recent version of mount, such as
  the one found at ftp.win.tue.nl:/pub/linux/util/mount-2.5X.tar.gz.
  If you want to use encryption, you might also be interested in the
  (old) DES package ftp.funet.fi:/pub/OS/Linux/BETA/loop/des.1.tar.gz.
  Note that this loop device has nothing to do with the loopback
  device used for network connections from the machine to itself.
  Most users will answer N here.

Enhanced IDE/MFM/RLL disk/cdrom/tape support
CONFIG_BLK_DEV_IDE
  This will use the full-featured IDE driver to control up to four IDE
  interfaces, for a combination of up to eight IDE disk/cdrom/tape
  drives.  Useful information about large (>540MB) IDE disks,
  soundcard IDE ports, and other topics, is all contained in
  Documentation/ide.txt.  If you have one or more IDE drives, say Y
  here.  If your system has no IDE drives, or if memory requirements
  are really tight, you could say N here, and select the Old harddisk
  driver instead to save about 13kB of memory in the kernel.  To
  fine-tune IDE drive/interface parameters for improved performance,
  look for the hdparm package at
  sunsite.unc.edu:/pub/Linux/kernel/patches/diskdrives/

Old harddisk (MFM/RLL/IDE) driver
CONFIG_BLK_DEV_HD_ONLY
  There are two drivers for MFM/RLL/IDE disks.  Most people use the
  newer enhanced driver, but the old one is still around for two
  reasons.  Some older systems have strange timing problems and seem
  to work only with the old driver (which itself does not work with
  some newer systems).  The other reason is that the old driver is
  smaller, since it lacks the enhanced functionality of the new one.
  This makes it a good choice for systems with very tight memory
  restrictions, or for systems with only older MFM/RLL/ESDI drives.
  Choosing the old driver can save 13kB or so of kernel memory.  If
  you are unsure, then just choose the Enhanced IDE/MFM/RLL driver
  instead of this one.

Use old disk-only driver on primary interface
CONFIG_BLK_DEV_HD_IDE
  There are two drivers for MFM/RLL/IDE disks.  Most people use just
  the new enhanced driver by itself.  This option installs the old
  harddisk driver to control the primary IDE/disk interface in the
  system, leaving the new enhanced IDE driver take care of only the
  2nd/3rd/4th IDE interfaces. Doing this will prevent you from having
  an IDE/ATAPI CDROM or tape drive connected to the primary IDE
  interface. Choosing this option may be useful for older systems
  which have MFM/RLL/ESDI controller+drives at the primary port
  address (0x1f0), along with IDE drives at the secondary/3rd/4th port
  addresses.  Normally, just say N here; you will then use the new
  driver for all 4 interfaces.

Include IDE/ATAPI CDROM support
CONFIG_BLK_DEV_IDECD
  If you have a CDROM drive using the ATAPI protocol, say Y.  ATAPI is
  a new protocol used by IDE CDROM and TAPE drives, similar to the
  SCSI protocol.  Most new CDROM drives use ATAPI, including the
  NEC-260, Mitsumi FX400, Sony 55E, and just about all non-SCSI
  double(2X), quad(4X), and six(6X) speed drives.  At boot time, the
  TAPE drive will be identified along with other IDE devices, as "hdb"
  or "hdc", or something similar.
  If this is your only CDROM drive, you can say N to all other CDROM
  options, but be sure to say Y to the ISO9660 filesystem.  Read the
  CDROM-HOWTO, available via ftp (user: anonymous) in
  sunsite.unc.edu:/pub/Linux/docs/HOWTO and the file
  Documentation/cdrom/ide-cd.  Note that older versions of lilo (the
  linux boot loader) cannot properly deal with IDE/ATAPI CDROMs, so
  install lilo-16 or higher, available from
  sunsite.unc.edu:/pub/Linux/system/Linux-boot/lilo.

Include IDE/ATAPI TAPE support
CONFIG_BLK_DEV_IDETAPE
  If you have an IDE tape drive using the ATAPI protocol, say Y.
  ATAPI is a new protocol used by IDE TAPE and ATAPI drives,
  similar to the SCSI protocol.  At boot time, the TAPE drive will
  be identified along with other IDE devices, as "hdb" or "hdc",
  or something similar.  Be sure to consult the drivers/block/ide-tape.c
  and Documentation/ide.txt files for usage information.

Support removable IDE interfaces (PCMCIA)
CONFIG_BLK_DEV_IDE_PCMCIA
  This option adds code to the IDE driver to handle hot insertion
  and removal of IDE interfaces and drives, under direction of an
  external utility (?).  Normally, just say N here.

CMD640 chipset bugfix/support
CONFIG_BLK_DEV_CMD640
  The CMD-Technologies CMD640 chip is used on many common 486 and
  Pentium motherboards, usually in combination with a "Neptune" or
  "SiS" chipset.  Unfortunately, it has a number of rather nasty
  design flaws that can cause severe data corruption under many common
  conditions.  Say Y here to include code which tries to automatically
  detect and correct the problems under Linux.  This also provides
  support for the enhanced features of the CMD640, for improved
  support/operation under linux, including access to the secondary IDE
  ports in some systems.  This driver will work automatically in PCI
  based systems (most new systems have PCI slots).  But if your system
  uses VESA local bus (VLB) instead of PCI, you must also supply a
  kernel boot parameter to enable the CMD640 bugfix/support:
  "ide0=cmd640_vlb" The CMD640 chip is also used on add-in cards by
  Acculogic, and on the "CSA-6400E PCI to IDE controller" that some
  people have. If unsure, say Y.

RZ1000 chipset bugfix/support
CONFIG_BLK_DEV_RZ1000
  The PC-Technologies RZ1000 chip is used on many common 486 and
  Pentium motherboards, usually along with the "Neptune" chipset.
  Unfortunately, it has a rather nasty design flaw that can cause
  severe data corruption under many conditions.  Say Y here to include
  code which automatically detects and corrects the problem under
  Linux.  This may slow disk throughput by a few percent, but at least
  things will operate 100% reliably. If unsure, say Y.

Other IDE chipset support
CONFIG_IDE_CHIPSETS
  Say Y here if you want to include enhanced support for various IDE
  interface chipsets used on motherboards and add-on cards.  This
  enhanced support may be necessary for linux to be able to access the
  3rd/4th drives in some systems.  It may also enable setting of
  higher speed I/O rates to improve system performance with these
  chipsets.  Most of these also require special kernel boot parameters
  to actually turn on the support at runtime.

DTC-2278 support
CONFIG_BLK_DEV_DTC2278
  This driver is enabled at runtime using the "ide0=dtc2278" kernel
  boot parameter.  It enables support for the secondary IDE interface
  of the DTC-2278 card, and permits faster I/O speeds to be set as
  well.  See the README.ide and dtc2278.c files for more info.

Holtek HT6560B support
CONFIG_BLK_DEV_HT6560B
  This driver is enabled at runtime using the "ide0=ht6560b" kernel
  boot parameter.  It enables support for the secondary IDE interface
  of the Holtek card, and permits faster I/O speeds to be set as well.
  See the README.ide and ht6560b.c files for more info.

QDI QD6580 support
CONFIG_BLK_DEV_QD6580
  This driver is enabled at runtime using the "ide0=qd6580" kernel
  boot parameter.  It permits faster I/O speeds to be set.
  See the README.ide and qd6580.c files for more info.

UMC 8672 support
CONFIG_BLK_DEV_UMC8672
  This driver is enabled at runtime using the "ide0=umc8672" kernel
  boot parameter.  It enables support for the secondary IDE interface
  of the UMC-8672, and permits faster I/O speeds to be set as well.
  See the README.ide and umc8672.c files for more info.

ALI M1439/M1445 support
CONFIG_BLK_DEV_ALI14XX
  This driver is enabled at runtime using the "ide0=ali14xx" kernel
  boot parameter.  It enables support for the secondary IDE interface
  of the chipset, and permits faster I/O speeds to be set as well.
  See the README.ide and ali14xx.c files for more info.

PROMISE DC4030 support (EXPERIMENTAL)
CONFIG_BLK_DEV_PROMISE
  This driver is enabled at runtime using the "ide0=dc4030" kernel
  boot parameter.  It enables support for the secondary IDE interface
  of the chipset, and takes advantage of the caching features of the
  ca