Linux kernel release 3.x <http://kernel.org/>

These are the release notes for Linux version 3.  Read them carefully,
as they tell you what this is all about, explain how to install the
kernel, and what to do if something goes wrong. 

WHAT IS LINUX?

  Linux is a clone of the operating system Unix, written from scratch by
  Linus Torvalds with assistance from a loosely-knit team of hackers across
  the Net. It aims towards POSIX and Single UNIX Specification compliance.

  It has all the features you would expect in a modern fully-fledged Unix,
  including true multitasking, virtual memory, shared libraries, demand
  loading, shared copy-on-write executables, proper memory management,
  and multistack networking including IPv4 and IPv6.

  It is distributed under the GNU General Public License - see the
  accompanying COPYING file for more details. 

ON WHAT HARDWARE DOES IT RUN?

  Although originally developed first for 32-bit x86-based PCs (386 or higher),
  today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
  UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
  IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64, AXIS CRIS,
  Xtensa, Tilera TILE, AVR32 and Renesas M32R architectures.

  Linux is easily portable to most general-purpose 32- or 64-bit architectures
  as long as they have a paged memory management unit (PMMU) and a port of the
  GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
  also been ported to a number of architectures without a PMMU, although
  functionality is then obviously somewhat limited.
  Linux has also been ported to itself. You can now run the kernel as a
  userspace application - this is called UserMode Linux (UML).

DOCUMENTATION:

 - There is a lot of documentation available both in electronic form on
   the Internet and in books, both Linux-specific and pertaining to
   general UNIX questions.  I'd recommend looking into the documentation
   subdirectories on any Linux FTP site for the LDP (Linux Documentation
   Project) books.  This README is not meant to be documentation on the
   system: there are much better sources available.

 - There are various README files in the Documentation/ subdirectory:
   these typically contain kernel-specific installation notes for some 
   drivers for example. See Documentation/00-INDEX for a list of what
   is contained in each file.  Please read the Changes file, as it
   contains information about the problems, which may result by upgrading
   your kernel.

 - The Documentation/DocBook/ subdirectory contains several guides for
   kernel developers and users.  These guides can be rendered in a
   number of formats:  PostScript (.ps), PDF, HTML, & man-pages, among others.
   After installation, "make psdocs", "make pdfdocs", "make htmldocs",
   or "make mandocs" will render the documentation in the requested format.

INSTALLING the kernel source:

 - If you install the full sources, put the kernel tarball in a
   directory where you have permissions (eg. your home directory) and
   unpack it:

     gzip -cd linux-3.X.tar.gz | tar xvf -

   or

     bzip2 -dc linux-3.X.tar.bz2 | tar xvf -

   Replace "X" with the version number of the latest kernel.

   Do NOT use the /usr/src/linux area! This area has a (usually
   incomplete) set of kernel headers that are used by the library header
   files.  They should match the library, and not get messed up by
   whatever the kernel-du-jour happens to be.

 - You can also upgrade between 3.x releases by patching.  Patches are
   distributed in the traditional gzip and the newer bzip2 format.  To
   install by patching, get all the newer patch files, enter the
   top level directory of the kernel source (linux-3.X) and execute:

     gzip -cd ../patch-3.x.gz | patch -p1

   or

     bzip2 -dc ../patch-3.x.bz2 | patch -p1

   Replace "x" for all versions bigger than the version "X" of your current
   source tree, _in_order_, and you should be ok.  You may want to remove
   the backup files (some-file-name~ or some-file-name.orig), and make sure
   that there are no failed patches (some-file-name# or some-file-name.rej).
   If there are, either you or I have made a mistake.

   Unlike patches for the 3.x kernels, patches for the 3.x.y kernels
   (also known as the -stable kernels) are not incremental but instead apply
   directly to the base 3.x kernel.  For example, if your base kernel is 3.0
   and you want to apply the 3.0.3 patch, you must not first apply the 3.0.1
   and 3.0.2 patches. Similarly, if you are running kernel version 3.0.2 and
   want to jump to 3.0.3, you must first reverse the 3.0.2 patch (that is,
   patch -R) _before_ applying the 3.0.3 patch. You can read more on this in
   Documentation/applying-patches.txt

   Alternatively, the script patch-kernel can be used to automate this
   process.  It determines the current kernel version and applies any
   patches found.

     linux/scripts/patch-kernel linux

   The first argument in the command above is the location of the
   kernel source.  Patches are applied from the current directory, but
   an alternative directory can be specified as the second argument.

 - Make sure you have no stale .o files and dependencies lying around:

     cd linux
     make mrproper

   You should now have the sources correctly installed.

SOFTWARE REQUIREMENTS

   Compiling and running the 3.x kernels requires up-to-date
   versions of various software packages.  Consult
   Documentation/Changes for the minimum version numbers required
   and how to get updates for these packages.  Beware that using
   excessively old versions of these packages can cause indirect
   errors that are very difficult to track down, so don't assume that
   you can just update packages when obvious problems arise during
   build or operation.

BUILD directory for the kernel:

   When compiling the kernel, all output files will per default be
   stored together with the kernel source code.
   Using the option "make O=output/dir" allow you to specify an alternate
   place for the output files (including .config).
   Example:

     kernel source code: /usr/src/linux-3.X
     build directory:    /home/name/build/kernel

   To configure and build the kernel, use:

     cd /usr/src/linux-3.X
     make O=/home/name/build/kernel menuconfig
     make O=/home/name/build/kernel
     sudo make O=/home/name/build/kernel modules_install install

   Please note: If the 'O=output/dir' option is used, then it must be
   used for all invocations of make.

CONFIGURING the kernel:

   Do not skip this step even if you are only upgrading one minor
   version.  New configuration options are added in each release, and
   odd problems will turn up if the configuration files are not set up
   as expected.  If you want to carry your existing configuration to a
   new version with minimal work, use "make oldconfig", which will
   only ask you for the answers to new questions.

 - Alternative configuration commands are:

     "make config"      Plain text interface.

     "make menuconfig"  Text based color menus, radiolists & dialogs.

     "make nconfig"     Enhanced text based color menus.

     "make xconfig"     X windows (Qt) based configuration tool.

     "make gconfig"     X windows (Gtk) based configuration tool.

     "make oldconfig"   Default all questions based on the contents of
                        your existing ./.config file and asking about
                        new config symbols.

     "make silentoldconfig"
                        Like above, but avoids cluttering the screen
                        with questions already answered.
                        Additionally updates the dependencies.

     "make olddefconfig"
                        Like above, but sets new symbols to their default
                        values without prompting.

     "make defconfig"   Create a ./.config file by using the default
                        symbol values from either arch/$ARCH/defconfig
                        or arch/$ARCH/configs/${PLATFORM}_defconfig,
                        depending on the architecture.

     "make ${PLATFORM}_defconfig"
                        Create a ./.config file by using the default
                        symbol values from
                        arch/$ARCH/configs/${PLATFORM}_defconfig.
                        Use "make he