Lines Matching +full:in +full:- +full:kernel
3 Linux kernel release 4.x <http://kernel.org/>
8 kernel, and what to do if something goes wrong.
11 --------------
14 Linus Torvalds with assistance from a loosely-knit team of hackers across
17 It has all the features you would expect in a modern fully-fledged Unix,
19 loading, shared copy-on-write executables, proper memory management,
22 It is distributed under the GNU General Public License v2 - see the
26 -----------------------------
28 Although originally developed first for 32-bit x86-based PCs (386 or higher),
31 IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 Xtensa, and
34 Linux is easily portable to most general-purpose 32- or 64-bit architectures
39 Linux has also been ported to itself. You can now run the kernel as a
40 userspace application - this is called UserMode Linux (UML).
43 -------------
45 - There is a lot of documentation available both in electronic form on
46 the Internet and in books, both Linux-specific and pertaining to
52 - There are various README files in the Documentation/ subdirectory:
53 these typically contain kernel-specific installation notes for some
54 drivers for example. See Documentation/00-INDEX for a list of what
55 is contained in each file. Please read the
58 your kernel.
60 Installing the kernel source
61 ----------------------------
63 - If you install the full sources, put the kernel tarball in a
67 xz -cd linux-4.X.tar.xz | tar xvf -
69 Replace "X" with the version number of the latest kernel.
72 incomplete) set of kernel headers that are used by the library header
74 whatever the kernel-du-jour happens to be.
76 - You can also upgrade between 4.x releases by patching. Patches are
77 distributed in the xz format. To install by patching, get all the
78 newer patch files, enter the top level directory of the kernel source
79 (linux-4.X) and execute::
81 xz -cd ../patch-4.x.xz | patch -p1
85 the backup files (some-file-name~ or some-file-name.orig), and make sure
86 that there are no failed patches (some-file-name# or some-file-name.rej).
90 (also known as the -stable kernels) are not incremental but instead apply
91 directly to the base 4.x kernel. For example, if your base kernel is 4.0
93 and 4.0.2 patches. Similarly, if you are running kernel version 4.0.2 and
95 patch -R) **before** applying the 4.0.3 patch. You can read more on this in
96 :ref:`Documentation/process/applying-patches.rst <applying_patches>`.
98 Alternatively, the script patch-kernel can be used to automate this
99 process. It determines the current kernel version and applies any
102 linux/scripts/patch-kernel linux
104 The first argument in the command above is the location of the
105 kernel source. Patches are applied from the current directory, but
108 - Make sure you have no stale .o files and dependencies lying around::
116 ---------------------
118 Compiling and running the 4.x kernels requires up-to-date
127 Build directory for the kernel
128 ------------------------------
130 When compiling the kernel, all output files will per default be
131 stored together with the kernel source code.
136 kernel source code: /usr/src/linux-4.X
137 build directory: /home/name/build/kernel
139 To configure and build the kernel, use::
141 cd /usr/src/linux-4.X
142 make O=/home/name/build/kernel menuconfig
143 make O=/home/name/build/kernel
144 sudo make O=/home/name/build/kernel modules_install install
149 Configuring the kernel
150 ----------------------
153 version. New configuration options are added in each release, and
159 - Alternative configuration commands are::
211 and pass it in as a LSMOD parameter.
221 all module options to built in (=y) options.
223 "make kvmconfig" Enable additional options for kvm guest kernel support.
225 "make xenconfig" Enable additional options for xen dom0 guest kernel
228 "make tinyconfig" Configure the tiniest possible kernel.
230 You can find more information on using the Linux kernel config tools
231 in Documentation/kbuild/kconfig.txt.
233 - NOTES on ``make config``:
235 - Having unnecessary drivers will make the kernel bigger, and can
239 - A kernel with math-emulation compiled in will still use the
241 never get used in that case. The kernel will be slightly larger,
245 - The "kernel hacking" configuration details usually result in a
246 bigger or slower kernel (or both), and can even make the kernel
248 break bad code to find kernel problems (kmalloc()). Thus you
252 Compiling the kernel
253 --------------------
255 - Make sure you have at least gcc 3.2 available.
258 Please note that you can still run a.out user programs with this kernel.
260 - Do a ``make`` to create a compressed kernel image. It is also
262 kernel makefiles, but you may want to check your particular lilo setup first.
265 build should require that. Don't take the name of root in vain.
267 - If you configured any of the parts of the kernel as ``modules``, you
270 - Verbose kernel compile/build output:
272 Normally, the kernel build system runs in a fairly quiet mode (but not
273 totally silent). However, sometimes you or other kernel developers need
283 - Keep a backup kernel handy in case something goes wrong. This is
286 backup of the modules corresponding to that kernel, as well. If you
287 are installing a new kernel with the same version number as your
288 working kernel, make a backup of your modules directory before you
291 Alternatively, before compiling, use the kernel config option
292 "LOCALVERSION" to append a unique suffix to the regular kernel version.
293 LOCALVERSION can be set in the "General Setup" menu.
295 - In order to boot your new kernel, you'll need to copy the kernel
297 to the place where your regular bootable kernel is found.
299 - Booting a kernel directly from a floppy without the assistance of a
303 uses the kernel image as specified in the file /etc/lilo.conf. The
304 kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
305 /boot/bzImage. To use the new kernel, save a copy of the old image
308 the new kernel image.
312 old kernel image (say, /vmlinux.old) in case the new one does not
319 ramdisk size, etc. in the kernel image, use the ``rdev`` program (or
321 recompile the kernel to change these parameters.
323 - Reboot with the new kernel and enjoy.
326 -----------------------
328 - If you have problems that seem to be due to kernel bugs, please check
330 with the part of the kernel that you are having trouble with. If there
332 them to me (torvalds@linux-foundation.org), and possibly to any other
333 relevant mailing-list or to the newsgroup.
335 - In all bug-reports, *please* tell what kernel you are talking about,
340 - If the bug results in a message like::
342 unable to handle kernel paging request at address C0000010
351 or similar kernel debugging information on your screen or in your
355 important: it tells something about why the kernel dumped code (in
356 the above example, it's due to a bad kernel pointer). More information
357 on making sense of the dump is in Documentation/admin-guide/bug-hunting.rst
359 - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
363 https://www.kernel.org/pub/linux/utils/kernel/ksymoops/ .
366 - In debugging dumps like the above, it helps enormously if you can
369 kernel setup. What you should do is take the hex value from the EIP
370 line (ignore the ``0010:``), and look it up in the kernel namelist to
371 see which kernel function contains the offending address.
373 To find out the kernel function name, you'll need to find the system
374 binary associated with the kernel that exhibited the symptom. This is
376 the EIP from the kernel crash, do::
380 This will give you a list of kernel addresses sorted in ascending
382 offending address. Note that the address given by the kernel
384 function addresses (in fact, that is very unlikely), so you can't
386 point of each kernel function, so by looking for the function that
389 you want. In fact, it may be a good idea to include a bit of
390 "context" in your problem report, giving a few lines around the
393 If you for some reason cannot do the above (you have a pre-compiled
394 kernel image or similar), telling me as much about your setup as
395 possible will help. Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>`
398 - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you
400 kernel with -g; edit arch/x86/Makefile appropriately, then do a ``make
403 After you've rebooted with the new kernel, do ``gdb vmlinux /proc/kcore``.
408 gdb'ing a non-running kernel currently fails because ``gdb`` (wrongly)
409 disregards the starting offset for which the kernel is compiled.