- Linux kernel release 2.6.xx
+ Linux kernel release 3.x <http://kernel.org/>
-These are the release notes for Linux version 2.6. Read them carefully,
+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 Unix clone written from scratch by Linus Torvalds with
- assistance from a loosely-knit team of hackers across the Net.
- It aims towards POSIX compliance.
+ 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 TCP/IP networking.
+ 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?
- Linux was first developed for 386/486-based PCs. These days it also
- runs on ARMs, DEC Alphas, SUN Sparcs, M68000 machines (like Atari and
- Amiga), MIPS and PowerPC, and others.
+ 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:
- 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, and HTML, among others.
- After installation, "make psdocs", "make pdfdocs", or "make htmldocs"
- will render the documentation in the requested format.
+ 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:
+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-2.6.XX.tar.gz | tar xvf -
+ gzip -cd linux-3.X.tar.gz | tar xvf -
+
+ or
- Replace "XX" with the version number of the latest kernel.
+ 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 2.6.xx releases by patching. Patches are
- distributed in the traditional gzip and the new bzip2 format. To
+ - 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-2.6.xx) and execute:
+ top level directory of the kernel source (linux-3.X) and execute:
- gzip -cd ../patch-2.6.xx.gz | patch -p1
+ gzip -cd ../patch-3.x.gz | patch -p1
or
- bzip2 -dc ../patch-2.6.xx.bz2 | patch -p1
- (repeat xx for all versions bigger than the version of your current
- source tree, _in_order_) and you should be ok. You may want to remove
- the backup files (xxx~ or xxx.orig), and make sure that there are no
- failed patches (xxx# or xxx.rej). If there are, either you or me has
- made a mistake.
+ 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
+ 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.
- - If you are upgrading between releases using the stable series patches
- (for example, patch-2.6.xx.y), note that these "dot-releases" are
- not incremental and must be applied to the 2.6.xx base tree. For
- example, if your base kernel is 2.6.12 and you want to apply the
- 2.6.12.3 patch, you do not and indeed must not first apply the
- 2.6.12.1 and 2.6.12.2 patches. Similarly, if you are running kernel
- version 2.6.12.2 and want to jump to 2.6.12.3, you must first
- reverse the 2.6.12.2 patch (that is, patch -R) _before_ applying
- the 2.6.12.3 patch.
-
- Make sure you have no stale .o files and dependencies lying around:
- cd linux
- make mrproper
+ cd linux
+ make mrproper
You should now have the sources correctly installed.
SOFTWARE REQUIREMENTS
- Compiling and running the 2.6.xx kernels requires up-to-date
+ 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
BUILD directory for the kernel:
- When compiling the kernel all output files will per default be
+ 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-2.6.N
- build directory: /home/name/build/kernel
- To configure and build the kernel use:
- cd /usr/src/linux-2.6.N
- make O=/home/name/build/kernel menuconfig
- make O=/home/name/build/kernel
- sudo make O=/home/name/build/kernel modules_install install
+ kernel source code: /usr/src/linux-3.X
+ build directory: /home/name/build/kernel
+
+ To configure and build the kernel, use:
- Please note: If the 'O=output/dir' option is used then it must be
+ 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:
new version with minimal work, use "make oldconfig", which will
only ask you for the answers to new questions.
- - Alternate configuration commands are:
- "make menuconfig" Text based color menus, radiolists & dialogs.
- "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.
- "make silentoldconfig"
- Like above, but avoids cluttering the screen
- with question already answered.
-
- NOTES on "make config":
- - having unnecessary drivers will make the kernel bigger, and can
- under some circumstances lead to problems: probing for a
- nonexistent controller card may confuse your other controllers
- - compiling the kernel with "Processor type" set higher than 386
- will result in a kernel that does NOT work on a 386. The
- kernel will detect this on bootup, and give up.
- - A kernel with math-emulation compiled in will still use the
- coprocessor if one is present: the math emulation will just
- never get used in that case. The kernel will be slightly larger,
- but will work on different machines regardless of whether they
- have a math coprocessor or not.
- - the "kernel hacking" configuration details usually result in a
- bigger or slower kernel (or both), and can even make the kernel
- less stable by configuring some routines to actively try to
- break bad code to find kernel problems (kmalloc()). Thus you
- should probably answer 'n' to the questions for
- "development", "experimental", or "debugging" features.
+ - 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/${PLATFORM}_defconfig.
+ Use "make help" to get a list of all available
+ platforms of your architecture.
+
+ "make allyesconfig"
+ Create a ./.config file by setting symbol
+ values to 'y' as much as possible.
+
+ "make allmodconfig"
+ Create a ./.config file by setting symbol
+ values to 'm' as much as possible.
+
+ "make allnoconfig" Create a ./.config file by setting symbol
+ values to 'n' as much as possible.
+
+ "make randconfig" Create a ./.config file by setting symbol
+ values to random values.
+
+ "make localmodconfig" Create a config based on current config and
+ loaded modules (lsmod). Disables any module
+ option that is not needed for the loaded modules.
+
+ To create a localmodconfig for another machine,
+ store the lsmod of that machine into a file
+ and pass it in as a LSMOD parameter.
+
+ target$ lsmod > /tmp/mylsmod
+ target$ scp /tmp/mylsmod host:/tmp
+
+ host$ make LSMOD=/tmp/mylsmod localmodconfig
+
+ The above also works when cross compiling.
+
+ "make localyesconfig" Similar to localmodconfig, except it will convert
+ all module options to built in (=y) options.
+
+ You can find more information on using the Linux kernel config tools
+ in Documentation/kbuild/kconfig.txt.
+
+ - NOTES on "make config":
+
+ - Having unnecessary drivers will make the kernel bigger, and can
+ under some circumstances lead to problems: probing for a
+ nonexistent controller card may confuse your other controllers
+
+ - Compiling the kernel with "Processor type" set higher than 386
+ will result in a kernel that does NOT work on a 386. The
+ kernel will detect this on bootup, and give up.
+
+ - A kernel with math-emulation compiled in will still use the
+ coprocessor if one is present: the math emulation will just
+ never get used in that case. The kernel will be slightly larger,
+ but will work on different machines regardless of whether they
+ have a math coprocessor or not.
+
+ - The "kernel hacking" configuration details usually result in a
+ bigger or slower kernel (or both), and can even make the kernel
+ less stable by configuring some routines to actively try to
+ break bad code to find kernel problems (kmalloc()). Thus you
+ should probably answer 'n' to the questions for "development",
+ "experimental", or "debugging" features.
COMPILING the kernel:
- - Make sure you have gcc 2.95.3 available.
- gcc 2.91.66 (egcs-1.1.2), and gcc 2.7.2.3 are known to miscompile
- some parts of the kernel, and are *no longer supported*.
- Also remember to upgrade your binutils package (for as/ld/nm and company)
- if necessary. For more information, refer to Documentation/Changes.
+ - Make sure you have at least gcc 3.2 available.
+ For more information, refer to Documentation/Changes.
Please note that you can still run a.out user programs with this kernel.
possible to do "make install" if you have lilo installed to suit the
kernel makefiles, but you may want to check your particular lilo setup first.
- To do the actual install you have to be root, but none of the normal
+ To do the actual install, you have to be root, but none of the normal
build should require that. Don't take the name of root in vain.
- If you configured any of the parts of the kernel as `modules', you
will also have to do "make modules_install".
+ - Verbose kernel compile/build output:
+
+ Normally, the kernel build system runs in a fairly quiet mode (but not
+ totally silent). However, sometimes you or other kernel developers need
+ to see compile, link, or other commands exactly as they are executed.
+ For this, use "verbose" build mode. This is done by inserting
+ "V=1" in the "make" command. E.g.:
+
+ make V=1 all
+
+ To have the build system also tell the reason for the rebuild of each
+ target, use "V=2". The default is "V=0".
+
- Keep a backup kernel handy in case something goes wrong. This is
especially true for the development releases, since each new release
contains new code which has not been debugged. Make sure you keep a
are installing a new kernel with the same version number as your
working kernel, make a backup of your modules directory before you
do a "make modules_install".
- In alternative, before compiling, edit your Makefile and change the
- "EXTRAVERSION" line - its content is appended to the regular kernel
- version.
+
+ Alternatively, before compiling, use the kernel config option
+ "LOCALVERSION" to append a unique suffix to the regular kernel version.
+ LOCALVERSION can be set in the "General Setup" menu.
- In order to boot your new kernel, you'll need to copy the kernel
image (e.g. .../linux/arch/i386/boot/bzImage after compilation)
- Booting a kernel directly from a floppy without the assistance of a
bootloader such as LILO, is no longer supported.
- If you boot Linux from the hard drive, chances are you use LILO which
+ If you boot Linux from the hard drive, chances are you use LILO, which
uses the kernel image as specified in the file /etc/lilo.conf. The
kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
/boot/bzImage. To use the new kernel, save a copy of the old image
the file MAINTAINERS to see if there is a particular person associated
with the part of the kernel that you are having trouble with. If there
isn't anyone listed there, then the second best thing is to mail
- them to me (torvalds@osdl.org), and possibly to any other relevant
- mailing-list or to the newsgroup.
+ them to me (torvalds@linux-foundation.org), and possibly to any other
+ relevant mailing-list or to the newsgroup.
- In all bug-reports, *please* tell what kernel you are talking about,
how to duplicate the problem, and what your setup is (use your common
- If the bug results in a message like
- unable to handle kernel paging request at address C0000010
- Oops: 0002
- EIP: 0010:XXXXXXXX
- eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx
- esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx
- ds: xxxx es: xxxx fs: xxxx gs: xxxx
- Pid: xx, process nr: xx
- xx xx xx xx xx xx xx xx xx xx
+ unable to handle kernel paging request at address C0000010
+ Oops: 0002
+ EIP: 0010:XXXXXXXX
+ eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx
+ esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx
+ ds: xxxx es: xxxx fs: xxxx gs: xxxx
+ Pid: xx, process nr: xx
+ xx xx xx xx xx xx xx xx xx xx
or similar kernel debugging information on your screen or in your
system log, please duplicate it *exactly*. The dump may look
incomprehensible to you, but it does contain information that may
help debugging the problem. The text above the dump is also
important: it tells something about why the kernel dumped code (in
- the above example it's due to a bad kernel pointer). More information
+ the above example, it's due to a bad kernel pointer). More information
on making sense of the dump is in Documentation/oops-tracing.txt
- If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
as is, otherwise you will have to use the "ksymoops" program to make
- sense of the dump. This utility can be downloaded from
- ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops.
- Alternately you can do the dump lookup by hand:
+ sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred).
+ This utility can be downloaded from
+ ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops/ .
+ Alternatively, you can do the dump lookup by hand:
- In debugging dumps like the above, it helps enormously if you can
look up what the EIP value means. The hex value as such doesn't help
the file 'linux/vmlinux'. To extract the namelist and match it against
the EIP from the kernel crash, do:
- nm vmlinux | sort | less
+ nm vmlinux | sort | less
This will give you a list of kernel addresses sorted in ascending
order, from which it is simple to find the function that contains the
If you for some reason cannot do the above (you have a pre-compiled
kernel image or similar), telling me as much about your setup as
- possible will help.
+ possible will help. Please read the REPORTING-BUGS document for details.
- - Alternately, you can use gdb on a running kernel. (read-only; i.e. you
+ - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
cannot change values or set break points.) To do this, first compile the
kernel with -g; edit arch/i386/Makefile appropriately, then do a "make
clean". You'll also need to enable CONFIG_PROC_FS (via "make config").
Code Review / linux-3.10.git / blobdiff