The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)

[ source navigation ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

Name Size Last modified (GMT) Description
Folder Documentation/ 2013-02-02 13:13:18
Folder arch/ 2013-02-02 13:09:22
Folder block/ 2013-02-02 13:09:20
Folder crypto/ 2013-02-02 13:09:20
Folder drivers/ 2013-02-02 13:04:39
Folder firmware/ 2013-02-02 13:02:29
Folder fs/ 2013-02-02 13:04:12
Folder include/ 2013-02-02 13:03:28
Folder init/ 2013-02-02 13:03:28
Folder ipc/ 2013-02-02 13:03:28
Folder kernel/ 2013-02-02 13:03:25
Folder lib/ 2013-02-02 13:03:23
Folder mm/ 2013-02-02 13:03:22
Folder net/ 2013-02-02 13:03:03
Folder samples/ 2013-02-02 13:02:33
Folder scripts/ 2013-02-02 13:03:02
Folder security/ 2013-02-02 13:02:58
Folder sound/ 2013-02-02 13:02:34
Folder tools/ 2013-02-02 13:02:17
Folder usr/ 2013-02-02 13:02:34
Folder virt/ 2008-02-17 11:07:38
File COPYING 18693 bytes 2006-12-13 11:48:09
File CREDITS 95054 bytes 2012-12-25 01:40:34
File Kbuild 2536 bytes 2012-12-25 01:40:49
File Kconfig 252 bytes 2011-08-10 17:02:09
File MAINTAINERS 239910 bytes 2013-02-02 13:01:38
File Makefile 48021 bytes 2013-02-02 13:01:38
File README 18736 bytes 2012-12-25 01:40:50
File REPORTING-BUGS 3371 bytes 2009-10-05 12:43:25

    1         Linux kernel release 3.x <>
    3 These are the release notes for Linux version 3.  Read them carefully,
    4 as they tell you what this is all about, explain how to install the
    5 kernel, and what to do if something goes wrong. 
    9   Linux is a clone of the operating system Unix, written from scratch by
   10   Linus Torvalds with assistance from a loosely-knit team of hackers across
   11   the Net. It aims towards POSIX and Single UNIX Specification compliance.
   13   It has all the features you would expect in a modern fully-fledged Unix,
   14   including true multitasking, virtual memory, shared libraries, demand
   15   loading, shared copy-on-write executables, proper memory management,
   16   and multistack networking including IPv4 and IPv6.
   18   It is distributed under the GNU General Public License - see the
   19   accompanying COPYING file for more details. 
   23   Although originally developed first for 32-bit x86-based PCs (386 or higher),
   24   today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
   25   UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell,
   26   IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64, AXIS CRIS,
   27   Xtensa, Tilera TILE, AVR32 and Renesas M32R architectures.
   29   Linux is easily portable to most general-purpose 32- or 64-bit architectures
   30   as long as they have a paged memory management unit (PMMU) and a port of the
   31   GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has
   32   also been ported to a number of architectures without a PMMU, although
   33   functionality is then obviously somewhat limited.
   34   Linux has also been ported to itself. You can now run the kernel as a
   35   userspace application - this is called UserMode Linux (UML).
   39  - There is a lot of documentation available both in electronic form on
   40    the Internet and in books, both Linux-specific and pertaining to
   41    general UNIX questions.  I'd recommend looking into the documentation
   42    subdirectories on any Linux FTP site for the LDP (Linux Documentation
   43    Project) books.  This README is not meant to be documentation on the
   44    system: there are much better sources available.
   46  - There are various README files in the Documentation/ subdirectory:
   47    these typically contain kernel-specific installation notes for some 
   48    drivers for example. See Documentation/00-INDEX for a list of what
   49    is contained in each file.  Please read the Changes file, as it
   50    contains information about the problems, which may result by upgrading
   51    your kernel.
   53  - The Documentation/DocBook/ subdirectory contains several guides for
   54    kernel developers and users.  These guides can be rendered in a
   55    number of formats:  PostScript (.ps), PDF, HTML, & man-pages, among others.
   56    After installation, "make psdocs", "make pdfdocs", "make htmldocs",
   57    or "make mandocs" will render the documentation in the requested format.
   59 INSTALLING the kernel source:
   61  - If you install the full sources, put the kernel tarball in a
   62    directory where you have permissions (eg. your home directory) and
   63    unpack it:
   65      gzip -cd linux-3.X.tar.gz | tar xvf -
   67    or
   69      bzip2 -dc linux-3.X.tar.bz2 | tar xvf -
   71    Replace "X" with the version number of the latest kernel.
   73    Do NOT use the /usr/src/linux area! This area has a (usually
   74    incomplete) set of kernel headers that are used by the library header
   75    files.  They should match the library, and not get messed up by
   76    whatever the kernel-du-jour happens to be.
   78  - You can also upgrade between 3.x releases by patching.  Patches are
   79    distributed in the traditional gzip and the newer bzip2 format.  To
   80    install by patching, get all the newer patch files, enter the
   81    top level directory of the kernel source (linux-3.X) and execute:
   83      gzip -cd ../patch-3.x.gz | patch -p1
   85    or
   87      bzip2 -dc ../patch-3.x.bz2 | patch -p1
   89    Replace "x" for all versions bigger than the version "X" of your current
   90    source tree, _in_order_, and you should be ok.  You may want to remove
   91    the backup files (some-file-name~ or some-file-name.orig), and make sure
   92    that there are no failed patches (some-file-name# or some-file-name.rej).
   93    If there are, either you or I have made a mistake.
   95    Unlike patches for the 3.x kernels, patches for the 3.x.y kernels
   96    (also known as the -stable kernels) are not incremental but instead apply
   97    directly to the base 3.x kernel.  For example, if your base kernel is 3.0
   98    and you want to apply the 3.0.3 patch, you must not first apply the 3.0.1
   99    and 3.0.2 patches. Similarly, if you are running kernel version 3.0.2 and
  100    want to jump to 3.0.3, you must first reverse the 3.0.2 patch (that is,
  101    patch -R) _before_ applying the 3.0.3 patch. You can read more on this in
  102    Documentation/applying-patches.txt
  104    Alternatively, the script patch-kernel can be used to automate this
  105    process.  It determines the current kernel version and applies any
  106    patches found.
  108      linux/scripts/patch-kernel linux
  110    The first argument in the command above is the location of the
  111    kernel source.  Patches are applied from the current directory, but
  112    an alternative directory can be specified as the second argument.
  114  - Make sure you have no stale .o files and dependencies lying around:
  116      cd linux
  117      make mrproper
  119    You should now have the sources correctly installed.
  123    Compiling and running the 3.x kernels requires up-to-date
  124    versions of various software packages.  Consult
  125    Documentation/Changes for the minimum version numbers required
  126    and how to get updates for these packages.  Beware that using
  127    excessively old versions of these packages can cause indirect
  128    errors that are very difficult to track down, so don't assume that
  129    you can just update packages when obvious problems arise during
  130    build or operation.
  132 BUILD directory for the kernel:
  134    When compiling the kernel, all output files will per default be
  135    stored together with the kernel source code.
  136    Using the option "make O=output/dir" allow you to specify an alternate
  137    place for the output files (including .config).
  138    Example:
  140      kernel source code: /usr/src/linux-3.X
  141      build directory:    /home/name/build/kernel
  143    To configure and build the kernel, use:
  145      cd /usr/src/linux-3.X
  146      make O=/home/name/build/kernel menuconfig
  147      make O=/home/name/build/kernel
  148      sudo make O=/home/name/build/kernel modules_install install
  150    Please note: If the 'O=output/dir' option is used, then it must be
  151    used for all invocations of make.
  153 CONFIGURING the kernel:
  155    Do not skip this step even if you are only upgrading one minor
  156    version.  New configuration options are added in each release, and
  157    odd problems will turn up if the configuration files are not set up
  158    as expected.  If you want to carry your existing configuration to a
  159    new version with minimal work, use "make oldconfig", which will
  160    only ask you for the answers to new questions.
  162  - Alternative configuration commands are:
  164      "make config"      Plain text interface.
  166      "make menuconfig"  Text based color menus, radiolists & dialogs.
  168      "make nconfig"     Enhanced text based color menus.
  170      "make xconfig"     X windows (Qt) based configuration tool.
  172      "make gconfig"     X windows (Gtk) based configuration tool.
  174      "make oldconfig"   Default all questions based on the contents of
  175                         your existing ./.config file and asking about
  176                         new config symbols.
  178      "make silentoldconfig"
  179                         Like above, but avoids cluttering the screen
  180                         with questions already answered.
  181                         Additionally updates the dependencies.
  183      "make olddefconfig"
  184                         Like above, but sets new symbols to their default
  185                         values without prompting.
  187      "make defconfig"   Create a ./.config file by using the default
  188                         symbol values from either arch/$ARCH/defconfig
  189                         or arch/$ARCH/configs/${PLATFORM}_defconfig,
  190                         depending on the architecture.
  192      "make ${PLATFORM}_defconfig"
  193                         Create a ./.config file by using the default
  194                         symbol values from
  195                         arch/$ARCH/configs/${PLATFORM}_defconfig.
  196                         Use "make help" to get a list of all available
  197                         platforms of your architecture.
  199      "make allyesconfig"
  200                         Create a ./.config file by setting symbol
  201                         values to 'y' as much as possible.
  203      "make allmodconfig"
  204                         Create a ./.config file by setting symbol
  205                         values to 'm' as much as possible.
  207      "make allnoconfig" Create a ./.config file by setting symbol
  208                         values to 'n' as much as possible.
  210      "make randconfig"  Create a ./.config file by setting symbol
  211                         values to random values.
  213      "make localmodconfig" Create a config based on current config and
  214                            loaded modules (lsmod). Disables any module
  215                            option that is not needed for the loaded modules.
  217                            To create a localmodconfig for another machine,
  218                            store the lsmod of that machine into a file
  219                            and pass it in as a LSMOD parameter.
  221                    target$ lsmod > /tmp/mylsmod
  222                    target$ scp /tmp/mylsmod host:/tmp
  224                    host$ make LSMOD=/tmp/mylsmod localmodconfig
  226                            The above also works when cross compiling.
  228      "make localyesconfig" Similar to localmodconfig, except it will convert
  229                            all module options to built in (=y) options.
  231    You can find more information on using the Linux kernel config tools
  232    in Documentation/kbuild/kconfig.txt.
  234  - NOTES on "make config":
  236     - Having unnecessary drivers will make the kernel bigger, and can
  237       under some circumstances lead to problems: probing for a
  238       nonexistent controller card may confuse your other controllers
  240     - Compiling the kernel with "Processor type" set higher than 386
  241       will result in a kernel that does NOT work on a 386.  The
  242       kernel will detect this on bootup, and give up.
  244     - A kernel with math-emulation compiled in will still use the
  245       coprocessor if one is present: the math emulation will just
  246       never get used in that case.  The kernel will be slightly larger,
  247       but will work on different machines regardless of whether they
  248       have a math coprocessor or not.
  250     - The "kernel hacking" configuration details usually result in a
  251       bigger or slower kernel (or both), and can even make the kernel
  252       less stable by configuring some routines to actively try to
  253       break bad code to find kernel problems (kmalloc()).  Thus you
  254       should probably answer 'n' to the questions for "development",
  255       "experimental", or "debugging" features.
  257 COMPILING the kernel:
  259  - Make sure you have at least gcc 3.2 available.
  260    For more information, refer to Documentation/Changes.
  262    Please note that you can still run a.out user programs with this kernel.
  264  - Do a "make" to create a compressed kernel image. It is also
  265    possible to do "make install" if you have lilo installed to suit the
  266    kernel makefiles, but you may want to check your particular lilo setup first.
  268    To do the actual install, you have to be root, but none of the normal
  269    build should require that. Don't take the name of root in vain.
  271  - If you configured any of the parts of the kernel as `modules', you
  272    will also have to do "make modules_install".
  274  - Verbose kernel compile/build output:
  276    Normally, the kernel build system runs in a fairly quiet mode (but not
  277    totally silent).  However, sometimes you or other kernel developers need
  278    to see compile, link, or other commands exactly as they are executed.
  279    For this, use "verbose" build mode.  This is done by inserting
  280    "V=1" in the "make" command.  E.g.:
  282      make V=1 all
  284    To have the build system also tell the reason for the rebuild of each
  285    target, use "V=2".  The default is "V=0".
  287  - Keep a backup kernel handy in case something goes wrong.  This is 
  288    especially true for the development releases, since each new release
  289    contains new code which has not been debugged.  Make sure you keep a
  290    backup of the modules corresponding to that kernel, as well.  If you
  291    are installing a new kernel with the same version number as your
  292    working kernel, make a backup of your modules directory before you
  293    do a "make modules_install".
  295    Alternatively, before compiling, use the kernel config option
  296    "LOCALVERSION" to append a unique suffix to the regular kernel version.
  297    LOCALVERSION can be set in the "General Setup" menu.
  299  - In order to boot your new kernel, you'll need to copy the kernel
  300    image (e.g. .../linux/arch/i386/boot/bzImage after compilation)
  301    to the place where your regular bootable kernel is found. 
  303  - Booting a kernel directly from a floppy without the assistance of a
  304    bootloader such as LILO, is no longer supported.
  306    If you boot Linux from the hard drive, chances are you use LILO, which
  307    uses the kernel image as specified in the file /etc/lilo.conf.  The
  308    kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
  309    /boot/bzImage.  To use the new kernel, save a copy of the old image
  310    and copy the new image over the old one.  Then, you MUST RERUN LILO
  311    to update the loading map!! If you don't, you won't be able to boot
  312    the new kernel image.
  314    Reinstalling LILO is usually a matter of running /sbin/lilo. 
  315    You may wish to edit /etc/lilo.conf to specify an entry for your
  316    old kernel image (say, /vmlinux.old) in case the new one does not
  317    work.  See the LILO docs for more information. 
  319    After reinstalling LILO, you should be all set.  Shutdown the system,
  320    reboot, and enjoy!
  322    If you ever need to change the default root device, video mode,
  323    ramdisk size, etc.  in the kernel image, use the 'rdev' program (or
  324    alternatively the LILO boot options when appropriate).  No need to
  325    recompile the kernel to change these parameters. 
  327  - Reboot with the new kernel and enjoy. 
  331  - If you have problems that seem to be due to kernel bugs, please check
  332    the file MAINTAINERS to see if there is a particular person associated
  333    with the part of the kernel that you are having trouble with. If there
  334    isn't anyone listed there, then the second best thing is to mail
  335    them to me (, and possibly to any other
  336    relevant mailing-list or to the newsgroup.
  338  - In all bug-reports, *please* tell what kernel you are talking about,
  339    how to duplicate the problem, and what your setup is (use your common
  340    sense).  If the problem is new, tell me so, and if the problem is
  341    old, please try to tell me when you first noticed it.
  343  - If the bug results in a message like
  345      unable to handle kernel paging request at address C0000010
  346      Oops: 0002
  347      EIP:   0010:XXXXXXXX
  348      eax: xxxxxxxx   ebx: xxxxxxxx   ecx: xxxxxxxx   edx: xxxxxxxx
  349      esi: xxxxxxxx   edi: xxxxxxxx   ebp: xxxxxxxx
  350      ds: xxxx  es: xxxx  fs: xxxx  gs: xxxx
  351      Pid: xx, process nr: xx
  352      xx xx xx xx xx xx xx xx xx xx
  354    or similar kernel debugging information on your screen or in your
  355    system log, please duplicate it *exactly*.  The dump may look
  356    incomprehensible to you, but it does contain information that may
  357    help debugging the problem.  The text above the dump is also
  358    important: it tells something about why the kernel dumped code (in
  359    the above example, it's due to a bad kernel pointer). More information
  360    on making sense of the dump is in Documentation/oops-tracing.txt
  362  - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
  363    as is, otherwise you will have to use the "ksymoops" program to make
  364    sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred).
  365    This utility can be downloaded from
  366    ftp://ftp.<country> .
  367    Alternatively, you can do the dump lookup by hand:
  369  - In debugging dumps like the above, it helps enormously if you can
  370    look up what the EIP value means.  The hex value as such doesn't help
  371    me or anybody else very much: it will depend on your particular
  372    kernel setup.  What you should do is take the hex value from the EIP
  373    line (ignore the "0010:"), and look it up in the kernel namelist to
  374    see which kernel function contains the offending address.
  376    To find out the kernel function name, you'll need to find the system
  377    binary associated with the kernel that exhibited the symptom.  This is
  378    the file 'linux/vmlinux'.  To extract the namelist and match it against
  379    the EIP from the kernel crash, do:
  381      nm vmlinux | sort | less
  383    This will give you a list of kernel addresses sorted in ascending
  384    order, from which it is simple to find the function that contains the
  385    offending address.  Note that the address given by the kernel
  386    debugging messages will not necessarily match exactly with the
  387    function addresses (in fact, that is very unlikely), so you can't
  388    just 'grep' the list: the list will, however, give you the starting
  389    point of each kernel function, so by looking for the function that
  390    has a starting address lower than the one you are searching for but
  391    is followed by a function with a higher address you will find the one
  392    you want.  In fact, it may be a good idea to include a bit of
  393    "context" in your problem report, giving a few lines around the
  394    interesting one. 
  396    If you for some reason cannot do the above (you have a pre-compiled
  397    kernel image or similar), telling me as much about your setup as
  398    possible will help.  Please read the REPORTING-BUGS document for details.
  400  - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
  401    cannot change values or set break points.) To do this, first compile the
  402    kernel with -g; edit arch/i386/Makefile appropriately, then do a "make
  403    clean". You'll also need to enable CONFIG_PROC_FS (via "make config").
  405    After you've rebooted with the new kernel, do "gdb vmlinux /proc/kcore".
  406    You can now use all the usual gdb commands. The command to look up the
  407    point where your system crashed is "l *0xXXXXXXXX". (Replace the XXXes
  408    with the EIP value.)
  410    gdb'ing a non-running kernel currently fails because gdb (wrongly)
  411    disregards the starting offset for which the kernel is compiled.

[ source navigation ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.