configure.help

嵌入式系统设计与实验教材二源码linux内核移植与编译

# Maintained by:
#	Eric S. Raymond <mailto:[e-mail]>
#	Steven Cole <mailto:[e-mail]>
#
# Merged version 2.69: current with 2.4.17-pre8/2.5.1-pre10.
#
# This version of the Linux kernel configuration help texts
# corresponds to kernel versions 2.4.x and 2.5.x.
#
# Translations of this file available on the WWW:
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#     <http://home.elka.pw.edu.pl/~dmierzej/linux/kernel/>
#   - German, by SuSE, at <http://www.suse.de/~ke/kernel/>. This patch
#     also includes infrastructure to support different languages.
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# Format of this file: description<nl>variable<nl>help text<nl><nl>.
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# 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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# Explain why someone configuring a kernel might want to select your
# option.
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# All this was shamelessly stolen from numerous 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 among 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
  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  <file:Documentation/BUG-HUNTING>, and
  <file: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 the configurator 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.

Prompt for drivers for obsolete features and hardware
CONFIG_OBSOLETE
  Obsolete drivers have usually been replaced by more recent software
  that can talk to the same hardware.  Obsolete hardware is things
  like MGA monitors that you are very unlikely to see on today's
  systems.

Symmetric Multi-Processing support
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 <file:Documentation/smp.tex>,
  <file:Documentation/smp.txt>, <file:Documentation/i386/IO-APIC.txt>,
  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  <http://www.linuxdoc.org/docs.html#howto>.

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

Intel or compatible 80x86 processor
CONFIG_X86
  This is Linux's home port.  Linux was originally native to the Intel
  386, and runs on all the later x86 processors including the Intel
  486, 586, Pentiums, and various instruction-set-compatible chips by
  AMD, Cyrix, and others.

Alpha processor
CONFIG_ALPHA
  The Alpha is a 64-bit general-purpose processor designed and
  marketed by the Digital Equipment Corporation of blessed memory, now
  Compaq.  Alpha Linux dates from 1995-1996 and was the first non-x86
  port. The Alpha Linux project has a home page at
  <http://www.alphalinux.org/>.

32-bit Sun Sparc
CONFIG_SPARC32
  SPARC is a family of RISC microprocessors designed and marketed by
  Sun Microsystems, incorporated.  They are very widely found in Sun
  workstations and clones. This port covers the original 32-bit SPARC;
  it is old and stable and usually considered one of the "big three"
  along with the Intel and Alpha ports.  The UltraLinux project
  maintains both the SPARC32 and SPARC64 ports; its web page is
  available at <http://www.ultralinux.org/>.

64-bit Sun Sparc
CONFIG_SPARC64
  SPARC is a family of RISC microprocessors designed and marketed by
  Sun Microsystems, incorporated.  This port covers the newer 64-bit
  UltraSPARC.  The UltraLinux project maintains both the SPARC32 and
  SPARC64 ports; its web page is available at
  <http://www.ultralinux.org/>.

Power PC processor
CONFIG_PPC
  The PowerPC is a very capable 32-bit RISC processor from Motorola,
  the successor to their 68000 and 88000 series.  It powers recent
  Macintoshes and also a widely-used series of single-board computers
  from Motorola.  The Linux PowerPC port has a home page at
  <http://penguinppc.org/>.

Motorola 68K processors
CONFIG_M68K
  The Motorola 68K microprocessors are now obsolete, having been
  superseded by the PowerPC line also from Motorola.  But they powered
  the first wave of workstation hardware in the 1980s, including Sun
  workstations; they were also the basis of the original Amiga and
  later Atari personal computers.  A lot of this hardware is still
  around.  The m68k project has a home page at
  <http://www.linux-m68k.org/>.

ARM processors
CONFIG_ARM
  The ARM series is a line of low-power-consumption RISC chip designs
  licensed by ARM ltd and targeted at embedded applications and
  handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
  manufactured, but  legacy ARM-based PC hardware remains popular in
  Europe.  There is an ARM Linux project with a web page at
  <http://www.arm.linux.org.uk/>.

SuperH processors
CONFIG_SUPERH
  The SuperH is a RISC processor targeted for use in embedded systems
  and consumer electronics; it was also used in the Sega Dreamcast
  gaming console.  The SuperH port has a home page at
  <http://www.sh-linux.org/>.

IA64 processors, including Intel Itanium
CONFIG_IA64
  The Itanium is Intel's 64-bit successor to the 32-bit X86 line.  As
  of early 2001 it is not yet in widespread production use.  The Linux
  IA-64 project has a home page at <http://www.linuxia64.org/>.

HP PA-RISC processor
CONFIG_PARISC
  The PA-RISC microprocessor is a RISC chip designed by
  Hewlett-Packard and used in their line of workstations.  The PA-RISC
  Linux project has a home page at <www.parisc-linux.org>.

IBM System/390
CONFIG_S390
  Linux now runs on the venerable System/390 mainframe from IBM, in a
  guest partition under VM.  In fact, over 40,000 simultaneous Linux
  images have been run on a single mainframe!  The S390 Linux project
  has a home page at <http://linux.s390.org/>.

Axis Communications ETRAX 100LX embedded network CPU
CONFIG_CRIS
  Linux has been ported to run on the Axis Communications ETRAX 100LX
  CPU and the single-board computers built around it, targeted for
  network and embedded applications.  For more information see the
  Axis Communication site, <http://developer.axis.com/>.

Multiquad support for NUMA systems
CONFIG_MULTIQUAD
  This option is used for getting Linux to run on a (IBM/Sequent) NUMA 
  multiquad box. This changes the way that processors are bootstrapped,
  and uses Clustered Logical APIC addressing mode instead of Flat Logical.
  You will need a new lynxer.elf file to flash your firmware with - send
  email to [e-mail]

IO-APIC support on uniprocessors
CONFIG_X86_UP_IOAPIC
  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  SMP-capable replacement for PC-style interrupt controllers. Most
  SMP systems and a small number of uniprocessor systems have one.
  If you have a single-CPU system with an IO-APIC, you can say Y here
  to use it. If you say Y here even though your machine doesn't have
  an IO-APIC, then the kernel will still run with no slowdown at all.

  If you have a system with several CPUs, you do not need to say Y
  here: the IO-APIC will be used automatically.

Local APIC Support on Uniprocessors
CONFIG_X86_UP_APIC
  A local APIC (Advanced Programmable Interrupt Controller) is an
  integrated interrupt controller in the CPU. If you have a single-CPU
  system which has a processor with a local APIC, you can say Y here to
  enable and use it. If you say Y here even though your machine doesn't
  have a local APIC, then the kernel will still run with no slowdown at
  all. The local APIC supports CPU-generated self-interrupts (timer,
  performance counters), and the NMI watchdog which detects hard lockups.

  If you have a system with several CPUs, you do not need to say Y
  here: the local 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 <file: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