Configure.help - Documentation/Configure.help - Linux source code 2.4.6.3

# Maintained by Axel Boldt (axel@uni-paderborn.de)
#
# This version of the Linux kernel configuration help texts
# corresponds to the kernel versions 2.4.x.
#
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# Format of this file: description<nl>variable<nl>help text<nl><nl>. If
# the question being documented is of type "choice", we list only the
# first occurring config variable. The help texts may contain empty
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# Order of the help texts does not matter, however, no variable should
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# hypothetical ignorant but intelligent 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
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# Mention all the relevant READMEs and HOWTOs in the help text.
# Repetitions are fine since the help texts are not meant to be read
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# 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)
# 1995-2000 by Axel Boldt and many others and are governed by the GNU
# General Public License.

Prompt for development and/or incomplete code/drivers
CONFIG_EXPERIMENTAL
Some of the various things that Linux supports (such as network
drivers, file systems, 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
(before submitting bug reports, please read the documents README,
MAINTAINERS, REPORTING-BUGS, Documentation/BUG-HUNTING, and
Documentation/oops-tracing.txt in the kernel source).

This option will also make obsoleted drivers available. These are
drivers that have been replaced by something else, and/or are
scheduled to be removed in a future kernel release.

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.

Symmetric Multi Processing
CONFIG_SMP
This enables support for systems with more than one CPU. If you have
a system with only one CPU, like most personal computers, say N. If
you have a system with more than one CPU, say Y.

If you say N here, the kernel will run on single and multiprocessor
machines, but will use only one CPU of a multiprocessor machine. If
you say Y here, the kernel will run on many, but not all,
singleprocessor machines. On a singleprocessor machine, the kernel
will run faster if you say N here.

Note that if you say Y here and choose architecture "586" or
"Pentium" under "Processor family", the kernel will not work on 486
architectures. Similarly, multiprocessor kernels for the "PPro"
architecture may not work on all Pentium based boards.

People using multiprocessor machines who say Y here should also say
Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
Management" code will be disabled if you say Y here.

See also the files Documentation/smp.tex, Documentation/smp.txt,
Documentation/i386/IO-APIC.txt, Documentation/nmi_watchdog.txt and the
SMP-FAQ on the WWW at http://www.irisa.fr/prive/mentre/smp-faq/ .

If you don't know what to do here, say N.

APIC and IO-APIC Support on Uniprocessors
CONFIG_X86_UP_IOAPIC
APIC (Advanced Programmable Interrupt Controller) is a scheme for
delivering hardware interrupt requests to the CPU. It is commonly
used on systems with several CPU's. If you have a single-CPU system
which uses APIC, you can say Y here to use it. If you say Y here
even though your machine doesn't have APIC, then the kernel will
still run with no slowdown at all.

If you have system with several CPU's, you do not need to say Y
here: APIC will be used automatically.

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 don't have a math coprocessor, you need to say Y here; if you
say Y here 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. Try "man bootparam" or see the documentation of your boot
loader (lilo or loadlin) about how to pass options to the kernel at
boot time.) 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 the 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 66 KB bigger
kernel, it won't hurt.

Timer and CPU usage LEDs
CONFIG_LEDS
If you say Y here, the LEDs on your machine will be used
to provide useful information about your current system status.

If you are compiling a kernel for a NetWinder or EBSA-285, you will
be able to select which LEDs are active using the options below. If
you are compiling a kernel for the EBSA-110 or the LART however, the
red LED will simply flash regularly to indicate that the system is
still functional. It is safe to say Y here if you have a CATS
system, but the driver will do nothing.

Timer LED
CONFIG_LEDS_TIMER
If you say Y here, one of the system LEDs (the green one on the
NetWinder, the amber one on the EBSA285, or the red one on the LART)
will flash regularly to indicate that the system is still
operational. This is mainly useful to kernel hackers who are
debugging unstable kernels.

The LART uses the same LED for both Timer LED and CPU usage LED
functions. You may choose to use both, but the Timer LED function
will overrule the CPU usage LED.

CPU usage LED
CONFIG_LEDS_CPU
If you say Y here, the red LED will be used to give a good real
time indication of CPU usage, by lighting whenever the idle task
is not currently executing.

The LART uses the same LED for both Timer LED and CPU usage LED
functions. You may choose to use both, but the Timer LED function
will overrule the CPU usage LED.

Kernel FP software completion (EXPERIMENTAL)
CONFIG_MATHEMU
This option is required for IEEE compliant floating point arithmetic
on the Alpha. The only time you would ever not say Y is to say M in
order to debug the code. Say Y unless you know what you are doing.

High Memory support
CONFIG_NOHIGHMEM
Linux can use up to 64 Gigabytes of physical memory on x86 systems.
However, the address space of 32-bit x86 processors is only 4
Gigabytes large. That means that, if you have a large amount of
physical memory, not all of it can be "permanently mapped" by the
kernel. The physical memory that's not permanently mapped is called
"high memory".

If you are compiling a kernel which will never run on a machine with
more than 1 Gigabyte total physical RAM, answer "off" here (default
choice and suitable for most users). This will result in a "3GB/1GB"
split: 3GB are mapped so that each process sees a 3GB virtual memory
space and the remaining part of the 4GB virtual memory space is used
by the kernel to permanently map as much physical memory as
possible.

If the machine has between 1 and 4 Gigabytes physical RAM, then
answer "4GB" here.

If more than 4 Gigabytes is used then answer "64GB" here. This
selection turns Intel PAE (Physical Address Extension) mode on.
PAE implements 3-level paging on IA32 processors. PAE is fully
supported by Linux, PAE mode is implemented on all recent Intel
processors (Pentium Pro and better). NOTE: If you say "64GB" here,
then the kernel will not boot on CPUs that don't support PAE!

The actual amount of total physical memory will either be
auto detected or can be forced by using a kernel command line option
such as "mem=256M". (Try "man bootparam" or see the documentation of
your boot loader (lilo or loadlin) about how to pass options to the
kernel at boot time.)

If unsure, say "off".

Normal PC floppy disk support
CONFIG_BLK_DEV_FD
If you want to use the floppy disk drive(s) of your PC under Linux,
say Y. Information about this driver, especially important for IBM
Thinkpad users, is contained in Documentation/floppy.txt. That file
also contains the location of the Floppy driver FAQ as well as
location of the fdutils package used to configure additional
parameters of the driver at run time.

This driver is also available as a module ( = code which can be
inserted in and removed from the running kernel whenever you want).
The module will be called floppy.o. If you want to compile it as a
module, say M here and read Documentation/modules.txt.

Support for PowerMac floppy
CONFIG_MAC_FLOPPY
If you have a SWIM-3 (Super Woz Integrated Machine 3; from Apple)
floppy controller, say Y here. Most commonly found in PowerMacs.

RAM disk support
CONFIG_BLK_DEV_RAM
Saying Y here will allow you to use a portion of your RAM memory as
a block device, so that you can make file systems on it, read and
write to it and do all the other things that you can do with normal
block devices (such as hard drives). 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. The module will be called
rd.o.

Most normal users won't need the RAM disk functionality, and can
thus say N here.

Default RAM disk size
CONFIG_BLK_DEV_RAM_SIZE
The default value is 4096. Only change this if you know what are
you doing. If you are using IBM S/390, then set this to 8192.

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
Saying Y here will allow you to use a regular file as a block
device; you can then create a file system on that block device and
mount it just as you would mount other block devices such as hard
drive partitions, CDROM drives or floppy drives. The loop devices
are block special device files with major number 7 and typically
called /dev/loop0, /dev/loop1 etc.

This is useful if you want to check an ISO 9660 file system before
burning the CD, or if you want to use floppy images without first
writing them to floppy. Furthermore, some Linux distributions avoid
the need for a dedicated Linux partition by keeping their complete
root file system inside a DOS FAT file using this loop device
driver.

The loop device driver can also be used to "hide" a file system in a
disk partition, floppy, or regular file, either using encryption
(scrambling the data) or steganography (hiding the data in the low
bits of, say, a sound file). This is also safe if the file resides
on a remote file server. If you want to do this, you will first have
to acquire and install a kernel patch from
ftp://ftp.kerneli.org/pub/kerneli/ , and then you need to
say Y to this option.

Note that alternative ways to use encrypted file systems are
provided by the cfs package, which can be gotten from
ftp://ftp.kerneli.org/pub/kerneli/net-source/ , and the newer tcfs
package, available at http://tcfs.dia.unisa.it/ . You do not need to
say Y here if you want to use one of these. However, using cfs
requires saying Y to "NFS file system support" below while using
tcfs requires applying a kernel patch. An alternative steganography
solution is provided by StegFS, also available from
ftp://ftp.kerneli.org/pub/kerneli/net-source/ .

To use the loop device, you need the losetup utility and a recent
version of the mount program, both contained in the util-linux
package. The location and current version number of util-linux is
contained in the file Documentation/Changes.

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.

Network Block Device support
CONFIG_BLK_DEV_NBD
Saying Y here will allow your computer to be a client for network
block devices, i.e. it will be able to use block devices exported by
servers (mount file systems on them etc.). Communication between
client and server works over TCP/IP networking, but to the client
program this is hidden: it looks like a regular local file access to
a block device special file such as /dev/nd0.

Network block devices also allows you to run a block-device in
userland (making server and client physically the same computer,
communicating using the loopback network device).

Read Documentation/nbd.txt for more information, especially about
where to find the server code, which runs in user space and does not
need special kernel support.

Note that this has nothing to do with the network file systems NFS
or Coda; you can say N here even if you intend to use NFS or Coda.

If unsure, say N.

ATA/IDE/MFM/RLL support
CONFIG_IDE
If you say Y here, your kernel will be able to manage low cost mass
storage units such as ATA/(E)IDE and ATAPI units. The most common
cases are IDE hard drives and ATAPI CDROM drives.

If your system is pure SCSI and doesn't use these interfaces, you
can say N here.

Integrated Disk Electronics (IDE aka ATA-1) is a connecting standard
for mass storage units such as hard disks. It was designed by
Western Digital and Compaq Computer in 1984. It was then named
ST506. Quite a number of disks use the IDE interface.

AT Attachment (ATA) is the superset of the IDE specifications.
ST506 was also called ATA-1.

Fast-IDE is ATA-2 (also named Fast ATA), Enhanced IDE (EIDE) is
ATA-3. It provides support for larger disks (up to 8.4GB by means of
the LBA standard), more disks (4 instead of 2) and for other mass
storage units such as tapes and cdrom. UDMA/33 (aka UltraDMA/33) is
ATA-4 and provides faster (and more CPU friendly) transfer modes
than previous PIO (Programmed processor Input/Output) from previous
ATA/IDE standards by means of fast DMA controllers.

ATA Packet Interface (ATAPI) is a protocol used by EIDE tape and
CDROM drives, similar in many respects to the SCSI protocol.

SMART IDE (Self Monitoring, Analysis and Reporting Technology) was
designed in order to prevent data corruption and disk crash by
detecting pre hardware failure conditions (heat, access time, and
the like...). Disks built since June 1995 may follow this
standard. The kernel itself don't manage this; however there are
quite a number of user programs such as smart that can query the
status of SMART parameters disk.

For further information, please read Documentation/ide.txt.

If unsure, say Y.

Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support
CONFIG_BLK_DEV_IDE
If you say Y here, you will use the full-featured IDE driver to
control up to ten ATA/IDE interfaces, each being able to serve a
"master" and a "slave" device, for a total of up to twenty ATA/IDE
disk/cdrom/tape/floppy drives.

Useful information about large (>540 MB) IDE disks, multiple
interfaces, what to do if ATA/IDE devices are not automatically
detected, sound card ATA/IDE ports, module support, and other
topics, is contained in Documentation/ide.txt. For detailed
information about hard drives, consult the Disk-HOWTO and the
Multi-Disk-HOWTO, available from
http://www.linuxdoc.org/docs.html#howto .

To fine-tune ATA/IDE drive/interface parameters for improved
performance, look for the hdparm package at
http://www.ibiblio.org/pub/Linux/system/hardware .

If you want to compile this driver as a module ( = code which can be
inserted in and removed from the running kernel whenever you want),
say M here and read Documentation/modules.txt and
Documentation/ide.txt. The module will be called ide-mod.o. Do not
compile this driver as a module if your root file system (the one
containing the directory /) is located on an IDE device.

If you have one or more IDE drives, say Y or M here. If your system
has no IDE drives, or if memory requirements are really tight, you
could say N here, and select the "Old hard disk driver" below
instead to save about 13 KB of memory in the kernel.

Old hard disk (MFM/RLL/IDE) driver
CONFIG_BLK_DEV_HD_ONLY
There are two drivers for MFM/RLL/IDE hard disks. Most people use
the newer enhanced driver, but this 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 13 KB or so of kernel memory.

If you are unsure, then just choose the Enhanced IDE/MFM/RLL driver
instead of this one. For more detailed information, read the
Disk-HOWTO, available from
http://www.linuxdoc.org/docs.html#howto .

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 however installs the
old hard disk driver to control the primary IDE/disk interface in
the system, leaving the new enhanced IDE driver to 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/ATA-2 DISK support
CONFIG_BLK_DEV_IDEDISK
This will include enhanced support for MFM/RLL/IDE hard disks. If
you have a MFM/RLL/IDE disk, and there is no special reason to use
the old hard disk driver instead, say Y. If you have an SCSI-only
system, you can say N here.

If you want to compile this driver as a module ( = code which can be
inserted in and removed from the running kernel whenever you want),
say M here and read Documentation/modules.txt. The module will be
called ide-disk.o. Do not compile this driver as a module if your
root file system (the one containing the directory /) is located on
the IDE disk. If unsure, say Y.

Use multi-mode by default
CONFIG_IDEDISK_MULTI_MODE
If you get this error, try to say Y here:

hda: set_multmode: status=0x51 { DriveReady SeekComplete Error }
hda: set_multmode: error=0x04 { DriveStatusError }

If in doubt, say N.

Include IDE/ATAPI CDROM support
CONFIG_BLK_DEV_IDECD
If you have a CDROM drive using the ATAPI protocol, say Y. ATAPI is
a newer 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) or better speed drives.

If you say Y here, the CDROM drive will be identified at boot time
along with other IDE devices, as "hdb" or "hdc", or something
similar (check the boot messages with dmesg). If this is your only
CDROM drive, you can say N to all other CDROM options, but be sure
to say Y or M to "ISO 9660 CDROM file system support".

Read the CDROM-HOWTO, available from
http://www.linuxdoc.org/docs.html#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
ftp://metalab.unc.edu/pub/Linux/system/boot/lilo .

If you want to compile the driver as a module ( = code which can be
inserted in and removed from the running kernel whenever you want),
say M here and read Documentation/modules.txt. The module will be
called ide-cd.o.

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 newer protocol used by IDE tape and CDROM drives, similar
to the SCSI protocol. If you have an SCSI tape drive however, you
can say N here.

You should also say Y if you have an OnStream DI-30 tape drive; this
will not work with the SCSI protocol, until there is support for the
SC-30 and SC-50 versions.

If you say Y here, the tape drive will be identified at boot time
along with other IDE devices, as "hdb" or "hdc", or something
similar, and will be mapped to a character device such as "ht0"
(check the boot messages with dmesg). Be sure to consult the
drivers/ide/ide-tape.c and Documentation/ide.txt files for usage
information.

Include IDE/ATAPI FLOPPY support
CONFIG_BLK_DEV_IDEFLOPPY
If you have an IDE floppy drive which uses the ATAPI protocol,
answer Y. ATAPI is a newer protocol used by IDE CDROM/tape/floppy
drives, similar to the SCSI protocol.

The LS-120 and the IDE/ATAPI Iomega ZIP drive are also supported by
this driver. For information about jumper settings and the question
of when a ZIP drive uses a partition table, see
http://www.win.tue.nl/~aeb/linux/zip/zip-1.html .
(ATAPI PD-CD/CDR drives are not supported by this driver; support
for PD-CD/CDR drives is available if you answer Y to
"SCSI emulation support", below).

If you say Y here, the FLOPPY drive will be identified along with
other IDE devices, as "hdb" or "hdc", or something similar (check
the boot messages with dmesg).

SCSI emulation support
CONFIG_BLK_DEV_IDESCSI
This will provide SCSI host adapter emulation for IDE ATAPI devices,
and will allow you to use a SCSI device driver instead of a native
ATAPI driver.

This is useful if you have an ATAPI device for which no native
driver has been written (for example, an ATAPI PD-CD or CDR drive);
you can then use this emulation together with an appropriate SCSI
device driver. In order to do this, say Y here and to "SCSI support"
and "SCSI generic support", below. You must then provide the kernel
command line "hdx=scsi" (try "man bootparam" or see the
documentation of your boot loader (lilo or loadlin) about how to
pass options to the kernel at boot time) for devices if you want the
native EIDE sub-drivers to skip over the native support, so that
this SCSI emulation can be used instead. This is required for use of
CD-RW's.

Note that this option does NOT allow you to attach SCSI devices to a
box that doesn't have a SCSI host adapter installed.

If both this SCSI emulation and native ATAPI support are compiled
into the kernel, the native support will be used.

ISA-PNP EIDE support
CONFIG_BLK_DEV_ISAPNP
If you have an ISA EIDE card that is PnP (Plug and Play) and
requires setup first before scanning for devices, say Y here.

If unsure, say N.

CMD640 chipset bugfix/support
CONFIG_BLK_DEV_CMD640
The CMD-Technologies CMD640 IDE 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 option also
enables access to the secondary IDE ports in some CMD640 based
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". (Try "man
bootparam" or see the documentation of your boot loader about how to
pass options to the kernel.)

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. For
details, read Documentation/ide.txt.

CMD640 enhanced support
CONFIG_BLK_DEV_CMD640_ENHANCED
This option includes support for setting/autotuning PIO modes and
prefetch on CMD640 IDE interfaces. For details, read
Documentation/ide.txt. If you have a CMD640 IDE interface and your
BIOS does not already do this for you, then say Y here. Otherwise
say N.

RZ1000 chipset bugfix/support
CONFIG_BLK_DEV_RZ1000
The PC-Technologies RZ1000 IDE 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.

Generic PCI IDE chipset support
CONFIG_BLK_DEV_IDEPCI
Say Y here for PCI systems which use IDE drive(s).
This option helps the IDE driver to automatically detect and
configure all PCI-based IDE interfaces in your system.

Support for sharing PCI IDE interrupts
CONFIG_IDEPCI_SHARE_IRQ
Some ATA/IDE chipsets have hardware support which allows for
sharing a single IRQ with other cards. To enable support for
this in the ATA/IDE driver, say Y here.

It is safe to say Y to this question, in most cases.
If unsure, say N.

Generic PCI bus-master DMA support
CONFIG_BLK_DEV_IDEDMA_PCI
If your PCI system uses IDE drive(s) (as opposed to SCSI, say) and
is capable of bus-master DMA operation (most Pentium PCI systems),
you will want to say Y here to reduce CPU overhead. You can then use
the "hdparm" utility to enable DMA for drives for which it was not
enabled automatically. By default, DMA is not enabled automatically
for these drives, but you can change that by saying Y to the
following question "Use DMA by default when available". You can get
the latest version of the hdparm utility from
ftp://metalab.unc.edu/pub/Linux/system/hardware/ .

Read the comments at the beginning of drivers/ide/ide-dma.c and
the file Documentation/ide.txt for more information.

It is safe to say Y to this question.

Good-Bad DMA Model-Firmware (EXPERIMENTAL)
CONFIG_IDEDMA_NEW_DRIVE_LISTINGS
If you say Y here, the model and firmware revision of your drive
will be compared against a blacklist of buggy drives that claim to
be (U)DMA capable but aren't. This is a blanket on/off test with no
speed limit options.

Straight GNU GCC 2.7.3/2.8.X compilers are known to be safe;
whereas, many versions of EGCS have a problem and miscompile if you
say Y here.

If in doubt, say N.

Boot off-board chipsets first support
CONFIG_BLK_DEV_OFFBOARD
Normally, IDE controllers built into the motherboard (on-board
controllers) are assigned to ide0 and ide1 while those on add-in PCI
cards (off-board controllers) are relegated to ide2 and ide3.
Answering Y here will allow you to reverse the situation, with
off-board controllers on ide0/1 and on-board controllers on ide2/3.
This can improve the usability of some boot managers such as lilo
when booting from a drive on an off-board controller.

If you say Y here, and you actually want to reverse the device scan
order as explained above, you also need to issue the kernel command
line option "ide=reverse". (Try "man bootparam" or see the
documentation of your boot loader (lilo or loadlin) about how to
pass options to the kernel at boot time.)

Note that, if you do this, the order of the hd* devices will be
rearranged which may require modification of fstab and other files.

If in doubt, say N.

Use DMA by default when available
CONFIG_IDEDMA_PCI_AUTO
Prior to kernel version 2.1.112, Linux used to automatically use
DMA for IDE drives and chipsets which support it. Due to concerns
about a couple of cases where buggy hardware may have caused damage,
the default is now to NOT use DMA automatically. To revert to the
previous behaviour, say Y to this question.

If you suspect your hardware is at all flakey, say N here.
Do NOT email the IDE kernel people regarding this issue!

It is normally safe to answer Y to this question unless your
motherboard uses a VIA VP2 chipset, in which case you should say N.

IGNORE word93 Validation BITS
CONFIG_IDEDMA_IVB
Since various rules were applied and created ... et al. as it relates
the detection of valid cable signals. This is a result of unclear terms
in ATA-4 and ATA-5 standards.

It is normally safe to answer Y; however, the default is N.

Various ATA, Work(s) In Progress (EXPERIMENTAL)
CONFIG_IDEDMA_PCI_WIP
If you enable this you will be able to use and test highly
developmental projects. If you say N, this configure script will
simply skip those options.

It is SAFEST to say N to this question.

3ware Hardware ATA-RAID support
CONFIG_BLK_DEV_3W_XXXX_RAID
3ware is the only hardware ATA-Raid product in Linux to date.
This card is 2,4, or 8 channel master mode support only.
SCSI support required!!!

http://www.3ware.com/

Please read the comments at the top of drivers/scsi/3w-xxxx.c

AEC62XX chipset support
CONFIG_BLK_DEV_AEC62XX
This driver adds up to 4 more EIDE devices sharing a single
interrupt. This add-on card is a bootable PCI UDMA controller. In
order to get this card to initialize correctly in some cases, you
should say Y here, and preferably also to "Use DMA by default when
available".

The ATP850U/UF is an UltraDMA 33 chipset base.
The ATP860 is an UltraDMA 66 chipset base.
The ATP860M(acintosh) version is an UltraDMA 66 chipset base.

Please read the comments at the top of drivers/ide/aec62xx.c
If you say Y here, then say Y to "Use DMA by default when available" as
well.

AEC62XX Tuning support
CONFIG_AEC62XX_TUNING
Please read the comments at the top of drivers/ide/aec62xx.c
If unsure, say N.

ALI M15x3 chipset support
CONFIG_BLK_DEV_ALI15X3
This driver ensures (U)DMA support for ALI 1533, 1543 and 1543C
onboard chipsets. It also tests for Simplex mode and enables
normal dual channel support.

If you say Y here, you also need to say Y to "Use DMA by default
when available", above.
Please read the comments at the top of drivers/ide/alim15x3.c

If unsure, say N.

ALI M15x3 WDC support (DANGEROUS)
CONFIG_WDC_ALI15X3
This allows for UltraDMA support for WDC drives that ignore CRC
checking. You are a fool for enabling this option, but there have
been requests. DO NOT COMPLAIN IF YOUR DRIVE HAS FS CORRUPTION, IF
YOU ENABLE THIS! No one will listen, just laugh for ignoring this
SERIOUS WARNING.

Using this option can allow WDC drives to run at ATA-4/5 transfer
rates with only an ATA-2 support structure.

SAY NO!

AMD7409 chipset support
CONFIG_BLK_DEV_AMD7409
This driver ensures (U)DMA support for the AMD756 Viper chipset.

If you say Y here, you also need to say Y to "Use DMA by default
when available", above.
Please read the comments at the top of drivers/ide/amd7409.c

If unsure, say N.

AMD Viper ATA-66 Override support (WIP)
CONFIG_AMD7409_OVERRIDE
This option auto-forces the ata66 flag.
This effect can be also invoked by calling "idex=ata66"
If unsure, say N.

CMD64X chipset support
CONFIG_BLK_DEV_CMD64X
Say Y here if you have an IDE controller which uses any of these
chipsets: CMD643, CMD646, or CMD648.

CY82C693 chipset support
CONFIG_BLK_DEV_CY82C693
This driver adds detection and support for the CY82C693 chipset
used on Digital's PC-Alpha 164SX boards.

If you say Y here, you need to say Y to "Use DMA by default
when available" as well.

Cyrix CS5530 MediaGX chipset support
CONFIG_BLK_DEV_CS5530
Include support for UDMA on the Cyrix MediaGX 5530 chipset. This
will automatically be detected and configured if found.

It is safe to say Y to this question.

People with SCSI-only systems should say N here. If unsure, say Y.

HPT34X chipset support
CONFIG_BLK_DEV_HPT34X
This driver adds up to 4 more EIDE devices sharing a single
interrupt. The HPT343 chipset in its current form is a non-bootable
controller; the HPT345/HPT363 chipset is a bootable (needs BIOS FIX)
PCI UDMA controllers. This driver requires dynamic tuning of the
chipset during the ide-probe at boot time. It is reported to support
DVD II drives, by the manufacturer.

HPT34X AUTODMA support (WIP)
CONFIG_HPT34X_AUTODMA
This is a dangerous thing to attempt currently! Please read the
comments at the top of drivers/ide/hpt34x.c If you say Y here,
then say Y to "Use DMA by default when available" as well.

If unsure, say N.

HPT366 chipset support
CONFIG_BLK_DEV_HPT366
HPT366 is an Ultra DMA chipset for ATA-66.
HPT368 is an Ultra DMA chipset for ATA-66 RAID Based.
HPT370 is an Ultra DMA chipset for ATA-100.

This driver adds up to 4 more EIDE devices sharing a single
interrupt.

The HPT366 chipset in its current form is bootable. One solution
for this problem are special LILO commands for redirecting the
reference to device 0x80. The other solution is to say Y to "Boot
off-board chipsets first support" (CONFIG_BLK_DEV_OFFBOARD) unless
your mother board has the chipset natively mounted. Regardless one
should use the fore mentioned option and call at LILO or include
"ide=reverse" in LILO's append-line.

This driver requires dynamic tuning of the chipset during the
ide-probe at boot. It is reported to support DVD II drives, by the
manufacturer.

NS87415 support (EXPERIMENTAL)
CONFIG_BLK_DEV_NS87415
This driver adds detection and support for the NS87415 chip
(used in SPARC64, among others).

Please read the comments at the top of drivers/ide/ns87415.c.

OPTi 82C621 enhanced support (EXPERIMENTAL)
CONFIG_BLK_DEV_OPTI621
This is a driver for the OPTi 82C621 EIDE controller.
Please read the comments at the top of drivers/ide/opti621.c.

ServerWorks OSB4 chipset support (EXPERIMENTAL)
CONFIG_BLK_DEV_OSB4
This driver adds PIO/DMA support for the Serverworks OSB4 chipset

Intel PIIXn chipsets support
CONFIG_BLK_DEV_PIIX
This driver adds PIO mode setting and tuning for all PIIX IDE
controllers by Intel. Since the BIOS can sometimes improperly tune
PIO 0-4 mode settings, this allows dynamic tuning of the chipset
via the standard end-user tool 'hdparm'.

Please read the comments at the top of drivers/ide/piix.c.

If you say Y here, you should also say Y to "PIIXn Tuning support",
below.

If unsure, say N.

PIIXn Tuning support
CONFIG_PIIX_TUNING
This driver extension adds DMA mode setting and tuning for all PIIX
IDE controllers by Intel. Since the BIOS can sometimes improperly
set up the device/adapter combination and speed limits, it has
become a necessity to back/forward speed devices as needed.

Case 430HX/440FX PIIX3 need speed limits to reduce UDMA to DMA mode
2 if the BIOS can not perform this task at initialization.

If unsure, say N.

PROMISE PDC20246/PDC20262/PDC20267 support
CONFIG_BLK_DEV_PDC202XX
Promise Ultra33 or PDC20246
Promise Ultra66 or PDC20262
Promise Ultra100 or PDC20265/PDC20267

This driver adds up to 4 more EIDE devices sharing a single
interrupt. This add-on card is a bootable PCI UDMA controller. Since
multiple cards can be installed and there are BIOS ROM problems that
happen if the BIOS revisions of all installed cards (three-max) do
not match, the driver attempts to do dynamic tuning of the chipset
at boot-time for max-speed. Ultra33 BIOS 1.25 or newer is required
for more than one card. This card may require that you say Y to
"Special UDMA Feature (EXPERIMENTAL)".

If you say Y here, you need to say Y to "Use DMA by default when
available" as well.

Please read the comments at the top of drivers/ide/pdc202xx.c

If unsure, say N.

Special UDMA Feature (EXPERIMENTAL)
CONFIG_PDC202XX_BURST
For PDC20246, PDC20262, PDC20265 and PDC20267 Ultra DMA chipsets.
Designed originally for PDC20246/Ultra33 that has BIOS setup
failures when using 3 or more cards.

Unknown for PDC20265/PDC20267 Ultra DMA 100.

Please read the comments at the top of drivers/ide/pdc202xx.c

If unsure, say N.

SiS5513 chipset support
CONFIG_BLK_DEV_SIS5513
This driver ensures (U)DMA support for SIS5513 chipset based
mainboards. SiS620/530 UDMA mode 4, SiS5600/5597 UDMA mode 2, all
other DMA mode 2 limited chipsets are unsupported to date.

If you say Y here, you need to say Y to "Use DMA by default when
available" as well.

Please read the comments at the top of drivers/ide/sis5513.c

SLC90E66 chipset support
CONFIG_BLK_DEV_SLC90E66
This driver ensures (U)DMA support for Victroy66 SouthBridges for
SMsC with Intel NorthBridges. This is an Ultra66 based chipset.
The nice thing about it is that you can mix Ultra/DMA/PIO devices
and it will handle timing cycles. Since this is an improved look-a-like
to the PIIX4 it should be a nice addition.

If you say Y here, you need to say Y to "Use DMA by default when
available" as well.

Please read the comments at the top of drivers/ide/slc90e66.c

Winbond SL82c105 support
CONFIG_BLK_DEV_SL82C105
If you have a Winbond SL82c105 IDE controller, say Y here to enable
special configuration for this chip. This is common on various CHRP
motherboards, but could be used elsewhere. If in doubt, say Y.

Tekram TRM290 chipset support (EXPERIMENTAL)
CONFIG_BLK_DEV_TRM290
This driver adds support for bus master DMA transfers
using the Tekram TRM290 PCI IDE chip. Volunteers are
needed for further tweaking and development.
Please read the comments at the top of drivers/ide/trm290.c.

VIA82CXXX chipset support
CONFIG_BLK_DEV_VIA82CXXX
This allows you to configure your chipset for a better use while
running (U)DMA: it will allow you to enable efficiently the second
channel dma usage, as it may not be set by BIOS. It allows you to
pass a kernel command line at boot time in order to set fifo
config. If no command line is provided, it will try to set fifo
configuration at its best. It will allow you to get information from
/proc/ide/via provided you enabled "proc" support.

Please read the comments at the top of drivers/ide/via82cxxx.c

If you say Y here, then say Y to "Use DMA by default when available"
as well.

If unsure, say N.

VIA82CXXX Tuning support (WIP)
CONFIG_VIA82CXXX_TUNING
Please read the comments at the top of drivers/ide/via82cxxx.c

If unsure, say N.

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. You can
then pick your particular IDE chip from among the following options.
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; you can find
a list of these in the file Documentation/ide.txt.

People with SCSI-only systems can say N here.

Generic 4 drives/port support
CONFIG_BLK_DEV_4DRIVES
Certain older chipsets, including the Tekram 690CD, use a single set
of I/O ports at 0x1f0 to control up to four drives, instead of the
customary two drives per port. Support for this can be enabled at
runtime using the "ide0=four" kernel boot parameter if you say Y
here.

ALI M14xx 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 ALI M1439/1443/1445/1487/1489 chipsets, and permits faster
I/O speeds to be set as well. See the files Documentation/ide.txt
and drivers/ide/ali14xx.c for more info.

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 Documentation/ide.txt and drivers/ide/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 Documentation/ide.txt and drivers/ide/ht6560b.c files for
more info.

PROMISE DC4030 support (EXPERIMENTAL)
CONFIG_BLK_DEV_PDC4030
This driver provides support for the secondary IDE interface and
cache of Promise IDE chipsets, e.g. DC4030 and DC5030. This driver
is known to incur timeouts/retries during heavy I/O to drives
attached to the secondary interface. CDROM and TAPE devices are not
supported yet. This driver is enabled at runtime using the
"ide0=dc4030" kernel boot parameter. See the Documentation/ide.txt
and drivers/ide/pdc4030.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
files Documentation/ide.txt and drivers/ide/qd6580.c 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 files Documentation/ide.txt and drivers/ide/umc8672.c for
more info.

Amiga builtin Gayle IDE interface support
CONFIG_BLK_DEV_GAYLE
This is the IDE driver for the builtin IDE interface on some Amiga
models. It supports both the `A1200 style' (used in A600 and A1200)
and `A4000 style' (used in A4000 and A4000T) of the Gayle IDE
interface. Say Y if you have such an Amiga model and want to use IDE
devices (hard disks, CD-ROM drives, etc.) that are connected to the
builtin IDE interface.

Falcon IDE interface support
CONFIG_BLK_DEV_FALCON_IDE
This is the IDE driver for the builtin IDE interface on the Atari
Falcon. Say Y if you have a Falcon and want to use IDE devices (hard
disks, CD-ROM drives, etc.) that are connected to the builtin IDE
interface.

Amiga Buddha/Catweasel IDE interface support (EXPERIMENTAL)
CONFIG_BLK_DEV_BUDDHA
This is the IDE driver for the IDE interfaces on the Buddha and
Catweasel expansion boards. It supports up to two interfaces on the
Buddha and three on the Catweasel.

Say Y if you have a Buddha or Catweasel expansion board and want to
use IDE devices (hard disks, CD-ROM drives, etc.) that are connected
to one of its IDE interfaces.

Amiga IDE Doubler support (EXPERIMENTAL)
CONFIG_BLK_DEV_IDEDOUBLER
This driver provides support for the so-called `IDE doublers' (made
by various manufacturers, e.g. Eyetech) that can be connected to the
builtin IDE interface of some Amiga models. Using such an IDE
doubler, you can connect up to four instead of two IDE devices on
the Amiga's builtin IDE interface.

Note that the normal Amiga Gayle IDE driver may not work correctly
if you have an IDE doubler and don't enable this driver!

Say Y if you have an IDE doubler. The driver is enabled at kernel
runtime using the "ide=doubler" kernel boot parameter.

Support for PowerMac IDE devices (must also enable IDE)
CONFIG_BLK_DEV_IDE_PMAC
This driver provides support for the built-in IDE controller on most
of the recent Apple Power Macintoshes and PowerBooks.
If unsure, say Y.

PowerMac IDE DMA support
CONFIG_BLK_DEV_IDEDMA_PMAC
This option allows the driver for the built-in IDE controller on
Power Macintoshes and PowerBooks to use DMA (direct memory access)
to transfer data to and from memory. Saying Y is safe and improves
performance.

Use DMA by default
CONFIG_BLK_DEV_IDEDMA_PMAC_AUTO
This option allows the driver for the built-in IDE controller on
Power Macintoshes and PowerBooks to use DMA automatically, without
it having to be explicitly enabled. This option is provided because
of concerns about a couple of cases where using DMA on buggy PC
hardware may have caused damage. Saying Y should be safe on all
Apple machines.

Macintosh Quadra/Powerbook IDE interface support
CONFIG_BLK_DEV_MAC_IDE
This is the IDE driver for the builtin IDE interface on some m68k
Macintosh models. It supports both the `Quadra style' (used in
Quadra/ Centris 630 and Performa 588 models) and `Powerbook style'
(used in the Powerbook 150 and 190 models) IDE interface.

Say Y if you have such an Macintosh model and want to use IDE
devices (hard disks, CD-ROM drives, etc.) that are connected to the
builtin IDE interface.

ICS IDE interface support
CONFIG_BLK_DEV_IDE_ICSIDE
On Acorn systems, say Y here if you wish to use the ICS IDE
interface card. This is not required for ICS partition support.
If you are unsure, say N to this.

ICS DMA support
CONFIG_BLK_DEV_IDEDMA_ICS
Say Y here if you want to add DMA (Direct Memory Access) support to
the ICS IDE driver.

Use ICS DMA by default
CONFIG_IDEDMA_ICS_AUTO
Prior to kernel version 2.1.112, Linux used to automatically use
DMA for IDE drives and chipsets which support it. Due to concerns
about a couple of cases where buggy hardware may have caused damage,
the default is now to NOT use DMA automatically. To revert to the
previous behaviour, say Y to this question.

If you suspect your hardware is at all flakey, say N here.
Do NOT email the IDE kernel people regarding this issue!

XT hard disk support
CONFIG_BLK_DEV_XD
Very old 8 bit hard disk controllers used in the IBM XT computer
will be supported if you say Y here.

It's pretty unlikely that you have one of these: say N.

PS/2 ESDI hard disk support
CONFIG_BLK_DEV_PS2
Say Y here if you have a PS/2 machine with a MCA bus and an ESDI
hard disk.

Mylex DAC960/DAC1100 PCI RAID Controller support
CONFIG_BLK_DEV_DAC960
This driver adds support for the Mylex DAC960, AcceleRAID, and
eXtremeRAID PCI RAID controllers. See the file
Documentation/README.DAC960 for further information about this
driver.

Parallel port IDE device support
CONFIG_PARIDE
There are many external CD-ROM and disk devices that connect through
your computer's parallel port. Most of them are actually IDE devices
using a parallel port IDE adapter. This option enables the PARIDE
subsystem which contains drivers for many of these external drives.
Read Documentation/paride.txt for more information.

If you have said Y to the "Parallel-port support" configuration
option, you may share a single port between your printer and other
parallel port devices. Answer Y to build PARIDE support into your
kernel, or M if you would like to build it as a loadable module. If
your parallel port support is in a loadable module, you must build
PARIDE as a module. If you built PARIDE support into your kernel,
you may still build the individual protocol modules and high-level
drivers as loadable modules. If you build this support as a module,
it will be called paride.o.

To use the PARIDE support, you must say Y or M here and also to at
least one high-level driver (e.g. "Parallel port IDE disks",
"Parallel port ATAPI CD-ROMs", "Parallel port ATAPI disks" etc.) and
to at least one protocol driver (e.g. "ATEN EH-100 protocol",
"MicroSolutions backpack protocol", "DataStor Commuter protocol"
etc.).

Parallel port IDE disks
CONFIG_PARIDE_PD
This option enables the high-level driver for IDE-type disk devices
connected through a parallel port. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
parallel port IDE driver, otherwise you should answer M to build
it as a loadable module. The module will be called pd.o. You
must also have at least one parallel port protocol driver in your
system. Among the devices supported by this driver are the SyQuest
EZ-135, EZ-230 and SparQ drives, the Avatar Shark and the backpack
hard drives from MicroSolutions.

Parallel port ATAPI CD-ROMs
CONFIG_PARIDE_PCD
This option enables the high-level driver for ATAPI CD-ROM devices
connected through a parallel port. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
parallel port ATAPI CD-ROM driver, otherwise you should answer M to
build it as a loadable module. The module will be called pcd.o. You
must also have at least one parallel port protocol driver in your
system. Among the devices supported by this driver are the
MicroSolutions backpack CD-ROM drives and the Freecom Power CD. If
you have such a CD-ROM drive, you should also say Y or M to "ISO
9660 CDROM file system support" below, because that's the file
system used on CDROMs.

Parallel port ATAPI disks
CONFIG_PARIDE_PF
This option enables the high-level driver for ATAPI disk devices
connected through a parallel port. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
parallel port ATAPI disk driver, otherwise you should answer M
to build it as a loadable module. The module will be called pf.o.
You must also have at least one parallel port protocol driver in
your system. Among the devices supported by this driver are the
MicroSolutions backpack PD/CD drive and the Imation Superdisk
LS-120 drive.

Parallel port ATAPI tapes
CONFIG_PARIDE_PT
This option enables the high-level driver for ATAPI tape devices
connected through a parallel port. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
parallel port ATAPI disk driver, otherwise you should answer M
to build it as a loadable module. The module will be called pt.o.
You must also have at least one parallel port protocol driver in
your system. Among the devices supported by this driver is the
parallel port version of the HP 5GB drive.

Parallel port generic ATAPI devices
CONFIG_PARIDE_PG
This option enables a special high-level driver for generic ATAPI
devices connected through a parallel port. The driver allows user
programs, such as cdrecord, to send ATAPI commands directly to a
device.

If you chose to build PARIDE support into your kernel, you may
answer Y here to build in the parallel port generic ATAPI driver,
otherwise you should answer M to build it as a loadable module. The
module will be called pg.o.

You must also have at least one parallel port protocol driver in
your system.

This driver implements an API loosely related to the generic SCSI
driver. See include/linux/pg.h for details.

You can obtain the most recent version of cdrecord from
ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ . Versions 1.6.1a3 and
later fully support this driver.

ATEN EH-100 protocol
CONFIG_PARIDE_ATEN
This option enables support for the ATEN EH-100 parallel port IDE
protocol. This protocol is used in some inexpensive low performance
parallel port kits made in Hong Kong. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
protocol driver, otherwise you should answer M to build it as a
loadable module. The module will be called aten.o. You must also
have a high-level driver for the type of device that you want to
support.

Micro Solutions BACKPACK Series 5 protocol
CONFIG_PARIDE_BPCK
This option enables support for the Micro Solutions BACKPACK parallel
port Series 5 IDE protocol. (Most BACKPACK drives made before 1999 were
Series 5) Series 5 drives will NOT always have the Series noted on the
bottom of the drive. Series 6 drivers will.

In other words, if your BACKPACK drive dosen't say "Series 6" on the
bottom, enable this option.

If you chose to build PARIDE support into your kernel, you may answer Y
here to build in the protocol driver, otherwise you should answer M to
build it as a loadable module. The module will be called bpck.o. You
must also have a high-level driver for the type of device that you want
to support.

Micro Solutions BACKPACK Series 6 protocol
CONFIG_PARIDE_BPCK6
This option enables support for the Micro Solutions BACKPACK parallel
port Series 6 IDE protocol. (Most BACKPACK drives made after 1999 were
Series 6) Series 6 drives will have the Series noted on the bottom of
the drive. Series 5 drivers don't always have it noted.

In other words, if your BACKPACK drive says "Series 6" on the bottom,
enable this option.

If you chose to build PARIDE support into your kernel, you may answer Y
here to build in the protocol driver, otherwise you should answer M to
build it as a loadable module. The module will be called bpck6.o. You
must also have a high-level driver for the type of device that you want
to support.

DataStor Commuter protocol
CONFIG_PARIDE_COMM
This option enables support for the Commuter parallel port IDE
protocol from DataStor. If you chose to build PARIDE support
into your kernel, you may answer Y here to build in the protocol
driver, otherwise you should answer M to build it as a loadable
module. The module will be called comm.o. You must also have
a high-level driver for the type of device that you want to support.

DataStor EP-2000 protocol
CONFIG_PARIDE_DSTR
This option enables support for the EP-2000 parallel port IDE
protocol from DataStor. If you chose to build PARIDE support
into your kernel, you may answer Y here to build in the protocol
driver, otherwise you should answer M to build it as a loadable
module. The module will be called dstr.o. You must also have
a high-level driver for the type of device that you want to support.

Shuttle EPAT/EPEZ protocol
CONFIG_PARIDE_EPAT
This option enables support for the EPAT parallel port IDE protocol.
EPAT is a parallel port IDE adapter manufactured by Shuttle
Technology and widely used in devices from major vendors such as
Hewlett-Packard, SyQuest, Imation and Avatar. If you chose to build
PARIDE support into your kernel, you may answer Y here to build in
the protocol driver, otherwise you should answer M to build it as a
loadable module. The module will be called epat.o. You must also
have a high-level driver for the type of device that you want to
support.

Shuttle EPIA protocol
CONFIG_PARIDE_EPIA
This option enables support for the (obsolete) EPIA parallel port
IDE protocol from Shuttle Technology. This adapter can still be
found in some no-name kits. If you chose to build PARIDE support
into your kernel, you may answer Y here to build in the protocol
driver, otherwise you should answer M to build it as a loadable
module. The module will be called epia.o. You must also have a
high-level driver for the type of device that you want to support.

FIT TD-2000 protocol
CONFIG_PARIDE_FIT2
This option enables support for the TD-2000 parallel port IDE
protocol from Fidelity International Technology. This is a simple
(low speed) adapter that is used in some portable hard drives. If
you chose to build PARIDE support into your kernel, you may answer Y
here to build in the protocol driver, otherwise you should answer M
to build it as a loadable module. The module will be called ktti.o.
You must also have a high-level driver for the type of device that
you want to support.

FIT TD-3000 protocol
CONFIG_PARIDE_FIT3
This option enables support for the TD-3000 parallel port IDE
protocol from Fidelity International Technology. This protocol is
used in newer models of their portable disk, CD-ROM and PD/CD
devices. If you chose to build PARIDE support into your kernel, you
may answer Y here to build in the protocol driver, otherwise you
should answer M to build it as a loadable module. The module will be
called fit3.o. You must also have a high-level driver for the type
of device that you want to support.

Freecom IQ ASIC-2 protocol
CONFIG_PARIDE_FRIQ
This option enables support for version 2 of the Freecom IQ parallel
port IDE adapter. This adapter is used by the Maxell Superdisk
drive. If you chose to build PARIDE support into your kernel, you
may answer Y here to build in the protocol driver, otherwise you
should answer M to build it as a loadable module. The module will be
called friq.o. You must also have a high-level driver for the type
of device that you want to support.

FreeCom power protocol
CONFIG_PARIDE_FRPW
This option enables support for the Freecom power parallel port IDE
protocol. If you chose to build PARIDE support into your kernel, you
may answer Y here to build in the protocol driver, otherwise you
should answer M to build it as a loadable module. The module will be
called frpw.o. You must also have a high-level driver for the type
of device that you want to support.

KingByte KBIC-951A/971A protocols
CONFIG_PARIDE_KBIC
This option enables support for the KBIC-951A and KBIC-971A parallel
port IDE protocols from KingByte Information Corp. KingByte's
adapters appear in many no-name portable disk and CD-ROM products,
especially in Europe. If you chose to build PARIDE support into your
kernel, you may answer Y here to build in the protocol driver,
otherwise you should answer M to build it as a loadable module. The
module will be called kbic.o. You must also have a high-level driver
for the type of device that you want to support.

KT PHd protocol
CONFIG_PARIDE_KTTI
This option enables support for the "PHd" parallel port IDE protocol
from KT Technology. This is a simple (low speed) adapter that is
used in some 2.5" portable hard drives. If you chose to build PARIDE
support into your kernel, you may answer Y here to build in the
protocol driver, otherwise you should answer M to build it as a
loadable module. The module will be called ktti.o. You must also
have a high-level driver for the type of device that you want to
support.

OnSpec 90c20 protocol
CONFIG_PARIDE_ON20
This option enables support for the (obsolete) 90c20 parallel port
IDE protocol from OnSpec (often marketed under the ValuStore brand
name). If you chose to build PARIDE support into your kernel, you
may answer Y here to build in the protocol driver, otherwise you
should answer M to build it as a loadable module. The module will
be called on20.o. You must also have a high-level driver for the
type of device that you want to support.

OnSpec 90c26 protocol
CONFIG_PARIDE_ON26
This option enables support for the 90c26 parallel port IDE protocol
from OnSpec Electronics (often marketed under the ValuStore brand
name). If you chose to build PARIDE support into your kernel, you
may answer Y here to build in the protocol driver, otherwise you
should answer M to build it as a loadable module. The module will be
called on26.o. You must also have a high-level driver for the type
of device that you want to support.

Logical Volume Manager (LVM) support
CONFIG_BLK_DEV_LVM
This driver lets you combine several hard disks, hard disk
partitions, multiple devices or even loop devices (for evaluation
purposes) into a volume group. Imagine a volume group as a kind of
virtual disk. Logical volumes, which can be thought of as virtual
partitions, can be created in the volume group. You can resize
volume groups and logical volumes after creation time, corresponding
to new capacity needs. Logical volumes are accessed as block
devices named /dev/VolumeGroupName/LogicalVolumeName.

For details see Documentation/LVM-HOWTO. You will need supporting
user space software; location is in Documentation/Changes.

If you want to compile this support as a module ( = code which can
be inserted in and removed from the running kernel whenever you
want), say M here and read Documentation/modules.txt. The module
will be called lvm-mod.o.

Multiple devices driver support
CONFIG_BLK_DEV_MD
This driver lets you combine several hard disk partitions into one
logical block device. This can be used to simply append one
partition to another one or to combine several redundant hard disks
into a RAID1/4/5 device so as to provide protection against hard
disk failures. This is called "Software RAID" since the combining of
the partitions is done by the kernel. "Hardware RAID" means that the
combining is done by a dedicated controller; if you have such a
controller, you do not need to say Y here.

More information about Software RAID on Linux is contained in the
Software-RAID mini-HOWTO, available from
http://www.linuxdoc.org/docs.html#howto . There you will also
learn where to get the supporting user space utilities raidtools.

If unsure, say N.

Linear (append) mode
CONFIG_MD_LINEAR
If you say Y here, then your multiple devices driver will be able to
use the so-called linear mode, i.e. it will combine the hard disk
partitions by simply appending one to the other.

If unsure, say Y.

RAID-0 (striping) mode
CONFIG_MD_RAID0
If you say Y here, then your multiple devices driver will be able to
use the so-called raid0 mode, i.e. it will combine the hard disk
partitions into one logical device in such a fashion as to fill them
up evenly, one chunk here and one chunk there. This will increase
the throughput rate if the partitions reside on distinct disks.

Information about Software RAID on Linux is contained in the
Software-RAID mini-HOWTO, available from
http://www.linuxdoc.org/docs.html#howto . There you will also
learn where to get the supporting user space utilities raidtools.

If unsure, say Y.

RAID-1 (mirroring) mode
CONFIG_MD_RAID1
A RAID-1 set consists of several disk drives which are exact copies
of each other. In the event of a mirror failure, the RAID driver
will continue to use the operational mirrors in the set, providing
an error free MD (multiple device) to the higher levels of the
kernel. In a set with N drives, the available space is the capacity
of a single drive, and the set protects against a failure of (N - 1)
drives.

If you want to use such a RAID-1 set, say Y. This code is also
available as a module called raid1.o ( = 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.

If unsure, say Y.

RAID-4/RAID-5 mode
CONFIG_MD_RAID5
A RAID-5 set of N drives with a capacity of C MB per drive provides
the capacity of C * (N - 1) MB, and protects against a failure
of a single drive. For a given sector (row) number, (N - 1) drives
contain data sectors, and one drive contains the parity protection.
For a RAID-4 set, the parity blocks are present on a single drive,
while a RAID-5 set distributes the parity across the drives in one
of the available parity distribution methods.

If you want to use such a RAID-4/RAID-5 set, say Y. This code is
also available as a module called raid5.o ( = 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.

If unsure, say Y.

Support for Acer PICA 1 chipset
CONFIG_ACER_PICA_61
This is a machine with a R4400 133/150 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
the MIPS architecture, check out the Linux/MIPS FAQ on the WWW at
http://oss.sgi.com/mips .

Support for Algorithmics P4032 (EXPERIMENTAL)
CONFIG_ALGOR_P4032
This is an evaluation board of the British company Algorithmics. The
board uses the R4300 and a R5230 CPUs. For more information about
this board see http://www.algor.co.uk .

Support for BAGET MIPS series
CONFIG_BAGET_MIPS
This enables support for the Baget, a Russian embedded system. For
more details about the Baget see the Linux/MIPS FAQ on
http://oss.sgi.com/mips .

Support for DECstations
CONFIG_DECSTATION
This enables support for DEC's MIPS based workstations. For details
see the Linux/MIPS FAQ on http://oss.sgi.com/mips and the
DECstation porting pages on http://decstation.unix-ag.org .

If you have one of the following DECstation Models you definitely
want to choose R4xx0 for the CPU Type:

DECstation 5000/50
DECstation 5000/150
DECstation 5000/260
DECsystem 5900/260

otherwise choose R3000.

Support for NEC DDB Vrc-5074
CONFIG_DDB5074
This enables support for the VR5000-based NEC DDB Vrc-5074
evaluation board.

Support for NEC DDB Vrc-5476
CONFIG_DDB5476
This enables support for the R5432-based NEC DDB Vrc-5476
evaluation board.

Features : kernel debugging, serial terminal, NFS root fs, on-board
ether port (with a patch to tulip driver), IDE controller, PS2 keyboard
PS2 mouse, etc.

TODO : USB, Compact-PCI interface.

Support for MIPS Atlas board
CONFIG_MIPS_ATLAS
This enables support for the QED R5231-based MIPS Atlas evaluation
board.

Support for MIPS Malta board
CONFIG_MIPS_MALTA
This enables support for the VR5000-based MIPS Malta evaluation
board.

Support for Mips Magnum 4000
CONFIG_MIPS_MAGNUM_4000
This is a machine with a R4000 100 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
the MIPS architecture, check out the Linux/MIPS FAQ on the WWW at
http://oss.sgi.com/mips.

Support for Olivetti M700
CONFIG_OLIVETTI_M700
This is a machine with a R4000 100 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
the MIPS architecture, check out the Linux/MIPS FAQ on the WWW at
http://oss.sgi.com/mips.

Support for SGI IP22
CONFIG_SGI_IP22
This are the SGI Indy, Challenge S and Indigo2, as well as certain
OEM variants like the Tandem CMN B006S. To compile a Linux kernel
that runs on these, say Y here.

Support for SGI IP27
This are the SGI Origin 200, Origin 2000 and Onyx 2 Graphics
workstations. To compile a Linux kernel that runs on these, say Y
here.

IP27 N-Mode
CONFIG_SGI_SN0_N_MODE
The nodes of Origin 200, Origin 2000 and Onyx 2 systems can be
configured in either N-Modes which allows for more nodes or M-Mode
which allows for more memory. Your system is most probably
running in M-Mode, so you should say N here.

MIPS JAZZ onboard SONIC Ethernet support
CONFIG_MIPS_JAZZ_SONIC
This is the driver for the onboard card of MIPS Magnum 4000,
Acer PICA, Olivetti M700-10 and a few other identical OEM systems.

MIPS JAZZ FAS216 SCSI support
CONFIG_JAZZ_ESP
This is the driver for the onboard SCSI host adapter of MIPS Magnum
4000, Acer PICA, Olivetti M700-10 and a few other identical OEM
systems.

Kernel floating-point instruction emulation
CONFIG_MIPS_FPU_EMULATOR
This option enables the MIPS software floatingpoint support. Due to the
way floatingpoint works you should always enable this option unless
you exactly know what you're doing.

PCMCIA SCSI adapter support
CONFIG_SCSI_PCMCIA
Say Y here if you intend to attach a PCMCIA or CardBus card to your
computer which acts as a SCSI host adapter. These are credit card
size devices often used with laptops.

Note that the answer to this question won't directly affect the
kernel: saying N will just cause this configure script to skip all
the questions PCMCIA SCSI host adapters.

Adaptec AHA152X PCMCIA support
CONFIG_PCMCIA_AHA152X
Say Y here if you intend to attach this type of PCMCIA SCSI host
adapter to your computer.

This driver is also available as a module called aha152x_cs.o ( =
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.

Qlogic PCMCIA support
CONFIG_PCMCIA_QLOGIC
Say Y here if you intend to attach this type of PCMCIA SCSI host
adapter to your computer.

This driver is also available as a module called qlogic_cs.o ( =
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.

Future Domain PCMCIA support
CONFIG_PCMCIA_FDOMAIN
Say Y here if you intend to attach this type of PCMCIA SCSI host
adapter to your computer.

This driver is also available as a module called fdomain_cs.o ( =
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.

Adaptec APA1480 CardBus support
CONFIG_PCMCIA_APA1480
Say Y here if you intend to attach this type of CardBus SCSI host
adapter to your computer.

This driver is also available as a module called apa1480_cb.o ( =
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.

CPU type
CONFIG_CPU_R3000
Please make sure to pick the right CPU type. Linux/MIPS is not
designed to be generic, i.e. Kernels compiled for R3000 CPUs will
*not* work on R4000 Machines and vice versa.
However, since most the supported Machines have an R4000 (or
similar) CPU, R4xx0 might be a safe bet.
If the resulting Kernel does not work try to recompile with R3000.

Support for large 64-bit configurations
CONFIG_MIPS_INSANE_LARGE
MIPS R10000 does support a 44 bit / 16TB address space as opposed to
previous 64-bit processors which only supported 40 bit / 1TB. If you
need processes of more than 1TB virtual address space, say Y here.
This will result in additional memory usage, so it is not
recommended for normal users.

Generate little endian code
CONFIG_CPU_LITTLE_ENDIAN
Some MIPS machines can be configured for either little or big endian
byte order. These modes require different kernels. Say Y if your
machine is little endian, N if it's a big endian machine.

Networking support
CONFIG_NET
Unless you really know what you are doing, you should say Y here.
The reason is that some programs need kernel networking support even
when running on a stand-alone machine that isn't connected to any
other computer. If you are upgrading from an older kernel, you
should consider updating your networking tools too because changes
in the kernel and the tools often go hand in hand. The tools are
contained in the package net-tools, the location and version number
of which are given in Documentation/Changes.

For a general introduction to Linux networking, it is highly
recommended to read the NET-3-HOWTO, available from
http://www.linuxdoc.org/docs.html#howto .

Socket filtering
CONFIG_FILTER
The Linux Socket Filter is derived from the Berkeley Packet Filter.
If you say Y here, user-space programs can attach a filter to any
socket and thereby tell the kernel that it should allow or disallow
certain types of data to get through the socket. Linux Socket
Filtering works on all socket types except TCP for now. See the text
file Documentation/networking/filter.txt for more information.

You need to say Y here if you want to use PPP packet filtering
(see the CONFIG_PPP_FILTER option below).

If unsure, say N.

Network packet filtering
CONFIG_NETFILTER
Netfilter is a framework for filtering and mangling network packets
that pass through your Linux box.

The most common use of packet filtering is to run your Linux box as
a firewall protecting a local network from the Internet. The type of
firewall provided by this kernel support is called a "packet
filter", which means that it can reject individual network packets
based on type, source, destination etc. The other kind of firewall,
a "proxy-based" one, is more secure but more intrusive and more
bothersome to set up; it inspects the network traffic much more
closely, modifies it and has knowledge about the higher level
protocols, which a packet filter lacks. Moreover, proxy-based
firewalls often require changes to the programs running on the local
clients. Proxy-based firewalls don't need support by the kernel, but
they are often combined with a packet filter, which only works if
you say Y here.

You should also say Y here if you intend to use your Linux box as
the gateway to the Internet for a local network of machines without
globally valid IP addresses. This is called "masquerading": if one
of the computers on your local network wants to send something to
the outside, your box can "masquerade" as that computer, i.e. it
forwards the traffic to the intended outside destination, but
modifies the packets to make it look like they came from the
firewall box itself. It works both ways: if the outside host
replies, the Linux box will silently forward the traffic to the
correct local computer. This way, the computers on your local net
are completely invisible to the outside world, even though they can
reach the outside and can receive replies. It is even possible to
run globally visible servers from within a masqueraded local network
using a mechanism called portforwarding. Masquerading is also often
called NAT (Network Address Translation).

Another use of Netfilter is in transparent proxying: if a machine on
the local network tries to connect to an outside host, your Linux
box can transparently forward the traffic to a local server,
typically a caching proxy server.

Various modules exist for netfilter which replace the previous
masquerading (ipmasqadm), packet filtering (ipchains), transparent
proxying, and portforwarding mechanisms. Please see
Documentation/Changes under "iptables" for the location of these
packages.

Make sure to say N to "Fast switching" below if you intend to say Y
here, as Fast switching currently bypasses netfilter.

Chances are that you should say Y here if you compile a kernel which
will run as a router and N for regular hosts. If unsure, say N.

Network packet filtering debugging
CONFIG_NETFILTER_DEBUG
You can say Y here if you want to get additional messages useful in
debugging the netfilter code.

IP: connection tracking (required for masq/NAT)
CONFIG_IP_NF_CONNTRACK
Connection tracking keeps a record of what packets have passed
through your machine, in order to figure out how they are related
into connections.

This is required to do Masquerading or other kinds of Network
Address Translation (except for Fast NAT). It can also be used to
enhance packet filtering (see `Connection state match support'
below).