ppc64: add Config.help

arch/ppc64/Config.help

+CONFIG_SMP
+  This enables support for systems with more than one CPU. If you have
+  a system with only one CPU, say N. If you have a system with more
+  than one CPU, say Y.  Note that the kernel does not currently
+  support SMP machines with 603/603e/603ev or PPC750 ("G3") processors
+  since they have inadequate hardware support for multiprocessor
+  operation.
+
+  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 single-processor machines.
+  On a single-processor machine, the kernel will run faster if you say
+  N here.
+
+  If you don't know what to do here, say N.
+
+CONFIG_PREEMPT
+  This option reduces the latency of the kernel when reacting to
+  real-time or interactive events by allowing a low priority process to
+  be preempted even if it is in kernel mode executing a system call.
+  Unfortunately the kernel code has some race conditions if both
+  CONFIG_SMP and CONFIG_PREEMPT are enabled, so this option is
+  currently disabled if you are building an SMP kernel.
+
+  Say Y here if you are building a kernel for a desktop, embedded
+  or real-time system.  Say N if you are unsure.
+
+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 CD-ROM 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.  Quite a number of
+  disks use the IDE interface.
+
+  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
+  CD-ROM 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.
+
+  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 <file:Documentation/modules.txt>. The module
+  will be called ide.o.
+
+  For further information, please read <file:Documentation/ide.txt>.
+
+  If unsure, say Y.
+
+CONFIG_ISA
+  Find out whether you have ISA slots on your motherboard.  ISA is the
+  name of a bus system, i.e. the way the CPU talks to the other stuff
+  inside your box.  If you have an Apple machine, say N here; if you
+  have an IBM RS/6000 or pSeries machine or a PReP machine, say Y.  If
+  you have an embedded board, consult your board documentation.
+
+CONFIG_PCI
+  Find out whether your system includes a PCI bus. PCI is the name of
+  a bus system, i.e. the way the CPU talks to the other stuff inside
+  your box.  If you say Y here, the kernel will include drivers and
+  infrastructure code to support PCI bus devices.
+
+CONFIG_HOTPLUG
+  Say Y here if you want to plug devices into your computer while
+  the system is running, and be able to use them quickly.  In many
+  cases, the devices can likewise be unplugged at any time too.
+
+  One well known example of this is PCMCIA- or PC-cards, credit-card
+  size devices such as network cards, modems or hard drives which are
+  plugged into slots found on all modern laptop computers.  Another
+  example, used on modern desktops as well as laptops, is USB.
+
+  Enable HOTPLUG and KMOD, and build a modular kernel.  Get agent
+  software (at <http://linux-hotplug.sourceforge.net/>) and install it.
+  Then your kernel will automatically call out to a user mode "policy
+  agent" (/sbin/hotplug) to load modules and set up software needed
+  to use devices as you hotplug them.
+
+CONFIG_PCMCIA
+  Say Y here if you want to attach PCMCIA- or PC-cards to your Linux
+  computer.  These are credit-card size devices such as network cards,
+  modems or hard drives often used with laptops computers.  There are
+  actually two varieties of these cards: the older 16 bit PCMCIA cards
+  and the newer 32 bit CardBus cards.  If you want to use CardBus
+  cards, you need to say Y here and also to "CardBus support" below.
+
+  To use your PC-cards, you will need supporting software from David
+  Hinds' pcmcia-cs package (see the file <file:Documentation/Changes>
+  for location).  Please also read the PCMCIA-HOWTO, available from
+  <http://www.linuxdoc.org/docs.html#howto>.
+
+  This driver is also available as a module ( = code which can be
+  inserted in and removed from the running kernel whenever you want).
+  When compiled this way, there will be modules called pcmcia_core.o
+  and ds.o.  If you want to compile it as a module, say M here and
+  read <file:Documentation/modules.txt>.
+
+CONFIG_KCORE_ELF
+  If you enabled support for /proc file system then the file
+  /proc/kcore will contain the kernel core image in ELF format. This
+  can be used in gdb:
+
+  $ cd /usr/src/linux ; gdb vmlinux /proc/kcore
+
+  This is especially useful if you have compiled the kernel with the
+  "-g" option to preserve debugging information. It is mainly used
+  for examining kernel data structures on the live kernel.
+
+CONFIG_BINFMT_ELF
+  ELF (Executable and Linkable Format) is a format for libraries and
+  executables used across different architectures and operating
+  systems.
+
+CONFIG_BINFMT_MISC
+  If you say Y here, it will be possible to plug wrapper-driven binary
+  formats into the kernel. You will like this especially when you use
+  programs that need an interpreter to run like Java, Python or
+  Emacs-Lisp.  It's also useful if you often run DOS executables under
+  the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
+  <http://www.linuxdoc.org/docs.html#howto>).  Once you have
+  registered such a binary class with the kernel, you can start one of
+  those programs simply by typing in its name at a shell prompt; Linux
+  will automatically feed it to the correct interpreter.
+
+  You can do other nice things, too. Read the file
+  <file:Documentation/binfmt_misc.txt> to learn how to use this
+  feature, and <file:Documentation/java.txt> for information about how
+  to include Java support.
+
+  You must say Y to "/proc file system support" (CONFIG_PROC_FS) to
+  use this part of the kernel.
+
+  You may say M here for module support and later load the module when
+  you have use for it; the module is called binfmt_misc.o. If you
+  don't know what to answer at this point, say Y.
+
+CONFIG_VGA_CONSOLE
+  Saying Y here will allow you to use Linux in text mode through a
+  display that complies with the generic VGA standard.  This can be
+  useful on PReP systems and IBM RS/6000 or pSeries machines but is of
+  limited usefulness on Apple machines.
+
+  Say N here if you have an Apple machine.
+
+CONFIG_IRQ_ALL_CPUS
+  This option gives the kernel permission to distribute IRQs across
+  multiple CPUs.  Saying N here will route all IRQs to the first
+  CPU.  Generally saying Y is safe, although some problems have been
+  reported with SMP Power Macintoshes with this option enabled.
+
+CONFIG_FB
+  The frame buffer device provides an abstraction for the graphics
+  hardware. It represents the frame buffer of some video hardware and
+  allows application software to access the graphics hardware through
+  a well-defined interface, so the software doesn't need to know
+  anything about the low-level (hardware register) stuff.
+
+  Frame buffer devices work identically across the different
+  architectures supported by Linux and make the implementation of
+  application programs easier and more portable; at this point, an X
+  server exists which uses the frame buffer device exclusively.
+  On several non-X86 architectures, the frame buffer device is the
+  only way to use the graphics hardware.
+
+  The device is accessed through special device nodes, usually located
+  in the /dev directory, i.e. /dev/fb*.
+
+  You need an utility program called fbset to make full use of frame
+  buffer devices. Please read <file:Documentation/fb/framebuffer.txt>
+  and the Framebuffer-HOWTO at
+  <http://www.tahallah.demon.co.uk/programming/prog.html> for more
+  information.
+
+  Saying Y here is recommended if your machine has graphics hardware,
+  and strongly recommended if you are compiling a kernel for an Apple
+  machine.
+
+CONFIG_SCSI
+  If you want to use a SCSI hard disk, SCSI tape drive, SCSI CD-ROM or
+  any other SCSI device under Linux, say Y and make sure that you know
+  the name of your SCSI host adapter (the card inside your computer
+  that "speaks" the SCSI protocol, also called SCSI controller),
+  because you will be asked for it.
+
+  You also need to say Y here if you want support for the parallel
+  port version of the 100 MB IOMEGA ZIP drive.
+
+  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 scsi_mod.o.  If you want to compile it as
+  a module, say M here and read <file:Documentation/modules.txt> and
+  <file:Documentation/scsi.txt>.  However, do not compile this as a
+  module if your root file system (the one containing the directory /)
+  is located on a SCSI device.
+
+CONFIG_NETDEVICES
+  You can say N here if you don't intend to connect your Linux box to
+  any other computer at all or if all your connections will be over a
+  telephone line with a modem either via UUCP (UUCP is a protocol to
+  forward mail and news between unix hosts over telephone lines; read
+  the UUCP-HOWTO, available from
+  <http://www.linuxdoc.org/docs.html#howto>) or dialing up a shell
+  account or a BBS, even using term (term is a program which gives you
+  almost full Internet connectivity if you have a regular dial up
+  shell account on some Internet connected Unix computer. Read
+  <http://www.bart.nl/~patrickr/term-howto/Term-HOWTO.html>).
+
+  You'll have to say Y if your computer contains a network card that
+  you want to use under Linux (make sure you know its name because you
+  will be asked for it and read the Ethernet-HOWTO (especially if you
+  plan to use more than one network card under Linux)) or if you want
+  to use SLIP (Serial Line Internet Protocol is the protocol used to
+  send Internet traffic over telephone lines or null modem cables) or
+  CSLIP (compressed SLIP) or PPP (Point to Point Protocol, a better
+  and newer replacement for SLIP) or PLIP (Parallel Line Internet
+  Protocol is mainly used to create a mini network by connecting the
+  parallel ports of two local machines) or AX.25/KISS (protocol for
+  sending Internet traffic over amateur radio links).
+
+  Make sure to read the NET-3-HOWTO. Eventually, you will have to read
+  Olaf Kirch's excellent and free book "Network Administrator's
+  Guide", to be found in <http://www.linuxdoc.org/docs.html#guide>. If
+  unsure, say Y.
+
+CONFIG_SERIAL_CONSOLE
+  If you say Y here, it will be possible to use a serial port as the
+  system console (the system console is the device which receives all
+  kernel messages and warnings and which allows logins in single user
+  mode). This could be useful if some terminal or printer is connected
+  to that serial port.
+
+  Even if you say Y here, the currently visible virtual console
+  (/dev/tty0) will still be used as the system console by default, but
+  you can alter that using a kernel command line option such as
+  "console=ttyS1". (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 you don't have a graphics card installed and you say Y here, the
+  kernel will automatically use the first serial line, /dev/ttyS0, as
+  system console.
+
+  If unsure, say N.
+
+CONFIG_MOUSE
+  This is for machines with a mouse which is neither a serial nor a
+  USB nor a bus mouse.  Examples are PS/2 mice (including the track
+  balls on some laptops) and some digitizer pads.  Say Y here if you
+  have a CHRP machine (such as an IBM RS/6000 or pSeries machine) with
+  a PS/2-style mouse.
+
+  Note that the answer to this question won't directly affect the
+  kernel: saying N will just cause the configurator to skip all
+  the questions about non-serial mice. If unsure, say Y.
+
+CONFIG_MAGIC_SYSRQ
+  If you say Y here, you will have some control over the system even
+  if the system crashes for example during kernel debugging (e.g., you
+  will be able to flush the buffer cache to disk, reboot the system
+  immediately or dump some status information). This is accomplished
+  by pressing various keys while holding SysRq (Alt+PrintScreen). It
+  also works on a serial console (on PC hardware at least), if you
+  send a BREAK and then within 5 seconds a command keypress. The
+  keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
+  unless you really know what this hack does.
+
+CONFIG_PROC_DEVICETREE
+  This option adds a device-tree directory under /proc which contains
+  an image of the device tree that the kernel copies from Open
+  Firmware. If unsure, say Y here.
+
+CONFIG_CMDLINE
+  On some platforms, there is currently no way for the boot loader to
+  pass arguments to the kernel. For these platforms, you can supply
+  some command-line options at build time by entering them here.  In
+  most cases you will need to specify the root device here.
+
+CONFIG_XMON
+  Include in-kernel hooks for the xmon kernel monitor/debugger.
+  Unless you are intending to debug the kernel, say N here.