Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/README

  1 
  2         Linux kernel release 2.0.xx
  3 
  4 These are the release notes for linux version 2.0.  Read them carefully,
  5 as they tell you what this is all about, explain how to install the
  6 kernel, and what to do if something goes wrong. 
  7 
  8 WHAT IS LINUX?
  9 
 10   Linux is a Unix clone written from scratch by Linus Torvalds with
 11   assistance from a loosely-knit team of hackers across the Net.
 12   It aims towards POSIX compliance. 
 13 
 14   It has all the features you would expect in a modern fully-fledged
 15   Unix, including true multitasking, virtual memory, shared libraries,
 16   demand loading, shared copy-on-write executables, proper memory
 17   management and TCP/IP networking. 
 18 
 19   It is distributed under the GNU General Public License - see the
 20   accompanying COPYING file for more details. 
 21 
 22 ON WHAT HARDWARE DOES IT RUN?
 23 
 24   Linux was first developed for 386/486-based PCs.  These days it also
 25   runs on DEC Alphas, SUN Sparcs, M68000 machines (like Atari and Amiga),
 26   MIPS and PowerPC.
 27 
 28 DOCUMENTATION:
 29 
 30  - there is a lot of documentation available both in electronic form on
 31    the internet and in books, both Linux-specific and pertaining to
 32    general UNIX questions.  I'd recommend looking into the documentation
 33    subdirectories on any Linux ftp site for the LDP (Linux Documentation
 34    Project) books.  This README is not meant to be documentation on the
 35    system: there are much better sources available.
 36 
 37  - There are various readme's in the kernel Documentation/ subdirectory:
 38    these typically contain kernel-specific installation notes for some 
 39    drivers for example. See ./Documentation/00-INDEX for a list of what
 40    is contained in each file.
 41 
 42 INSTALLING the kernel:
 43 
 44  - If you install the full sources, do a
 45 
 46                 cd /usr/src
 47                 gzip -cd linux-2.0.XX.tar.gz | tar xfv -
 48 
 49    to get it all put in place. Replace "XX" with the version number of the
 50    latest kernel. If you use GNU tar, 
 51 
 52                 cd /usr/src
 53                 tar -xzvf linux-2.0.XX.tar.gz
 54 
 55    is equivalent.
 56 
 57  - You can also upgrade between 2.0.xx releases by patching.  Each
 58    patch that is released for 2.0.xx contains only bugfixes.  No
 59    new features will be added to the Linux kernel 2.0 any more. If
 60    you are interested in new kernel features, you may want to
 61    help developing a more recent kernel.
 62 
 63    To patch to a newer 2.0 kernel version, get all the newer files
 64    (you will find these patches at the kernel FTP servers:
 65     <URL:ftp://ftp.xx.kernel.org/pub/linux/kernel/v2.0/>, replace
 66     xx with your two letter country code here, e.g. se for Sweden),
 67    then do:
 68 
 69                 cd /usr/src/linux
 70                 gzip -cd patchXX.gz | patch -p0
 71 
 72    (repeat xx for all versions bigger than the version of your current
 73    source tree, _in_order_) and you should be ok.  You may want to remove
 74    the backup files (xxx~ or xxx.orig), and make sure that there are no
 75    failed patches (xxx# or xxx.rej). If there are, either you or me has
 76    made a mistake.
 77 
 78    Alternatively, the script patch-kernel can be used to automate this
 79    process.  It determines the current kernel version and applies any
 80    patches found.
 81 
 82                 cd /usr/src
 83                 linux/scripts/patch-kernel
 84 
 85    The default directory for the kernel source is /usr/src/linux, but
 86    can be specified as the first argument.  Patches are applied from
 87    the current directory, but an alternative directory can be specified
 88    as the second argument.
 89 
 90  - make sure you have no stale .o files and dependencies lying around:
 91 
 92                 cd /usr/src/linux
 93                 make mrproper
 94 
 95    You should now have the sources correctly installed.
 96 
 97 CONFIGURING the kernel:
 98 
 99  - do a "make config" to configure the basic kernel.  "make config"
100    needs bash to work: it will search for bash in $BASH, /bin/bash and
101    /bin/sh (in that order), so hopefully one of those is correct. 
102 
103  - Alternate configuration commands are:
104         "make menuconfig"  Text based color menus, radiolists & dialogs.
105         "make xconfig"     X window system based configuration tool.
106    
107         NOTES on "make config":
108         - having unnecessary drivers will make the kernel bigger, and can
109           under some circumstances lead to problems: probing for a
110           nonexistent controller card may confuse your other controllers
111         - compiling the kernel with "Processor type" set higher than 386
112           will result in a kernel that does NOT work on a 386.  The
113           kernel will detect this on bootup, and give up.
114         - A kernel with math-emulation compiled in will still use the
115           coprocessor if one is present: the math emulation will just
116           never get used in that case.  The kernel will be slightly larger,
117           but will work on different machines regardless of whether they
118           have a math coprocessor or not. 
119         - the "kernel hacking" configuration details usually result in a
120           bigger or slower kernel (or both), and can even make the kernel
121           less stable by configuring some routines to actively try to
122           break bad code to find kernel problems (kmalloc()).  Thus you
123           should probably answer 'n' to the questions for a "production"
124           kernel. 
125 
126  - Check the top Makefile for further site-dependent configuration
127    (default SVGA mode etc). 
128 
129  - Finally, do a "make dep" to set up all the dependencies correctly. 
130 
131 COMPILING the kernel:
132 
133  - make sure you have gcc-2.6.3 or newer available.  It seems older gcc
134    versions can have problems compiling newer versions of linux.  If you
135    upgrade your compiler, remember to get the new binutils package too
136    (for as/ld/nm and company).
137 
138  - do a "make zImage" to create a compressed kernel image.  If you want
139    to make a bootdisk (without root filesystem or lilo), insert a floppy
140    in your A: drive, and do a "make zdisk".  It is also possible to do
141    "make zlilo" if you have lilo installed to suit the kernel makefiles,
142    but you may want to check your particular lilo setup first. 
143 
144  - if your kernel is too large for "make zImage", use "make bzImage"
145    instead.
146 
147  - if you configured any of the parts of the kernel as `modules', you
148    will have to do "make modules" followed by "make modules_install".
149    Read Documentation/modules.txt for more information.  For example,
150    an explanation of how to use the modules is included there.
151 
152  - keep a backup kernel handy in case something goes wrong.  This is 
153    especially true for the development releases, since each new release
154    contains new code which has not been debugged. 
155 
156  - In order to boot your new kernel, you'll need to copy the kernel
157    image (found in /usr/src/linux/arch/i386/boot/zImage after compilation)
158    to the place where your regular bootable kernel is found. 
159 
160    For some, this is on a floppy disk, in which case you can "cp
161    /usr/src/linux/arch/i386/boot/zImage /dev/fd0" to make a bootable
162    floppy.  Note that as of Linux 2.0.0, a kernel copied to a 720k
163    double-density 3.5" floppy disk no longer boots.  In this case,
164    it is highly recommended that you install LILO on your
165    double-density bootfloppy or switch to high-density floppies.
166 
167    If you boot Linux from the hard drive, chances are you use LILO which
168    uses the kernel image as specified in the file /etc/lilo.conf.  The
169    kernel image file is usually /vmlinuz, /zImage, or /boot/vmlinuz. 
170    To use the new kernel, copy the new image over the old one (save a
171    backup of the original!).  Then, you MUST RERUN LILO to update the
172    loading map!! If you don't, you won't be able to boot the new kernel
173    image. 
174 
175    Reinstalling LILO is usually a matter of running /sbin/lilo. 
176    You may wish to edit /etc/lilo.conf to specify an entry for your
177    old kernel image (say, /vmlinux.old) in case the new one does not
178    work.  See the LILO docs for more information. 
179 
180    After reinstalling LILO, you should be all set.  Shutdown the system,
181    reboot, and enjoy!
182 
183    If you ever need to change the default root device, video mode,
184    ramdisk size, etc.  in the kernel image, use the 'rdev' program (or
185    alternatively the LILO boot options when appropriate).  No need to
186    recompile the kernel to change these parameters. 
187 
188  - reboot with the new kernel and enjoy. 
189 
190 IF SOMETHING GOES WRONG:
191 
192  - if you have problems that seem to be due to kernel bugs, please check
193    the file MAINTAINERS to see if there is a particular person associated
194    with the part of the kernel that you are having trouble with. If there
195    isn't anyone listed there, then the second best thing is to mail
196    them to me (David Weinehall, tao@kernel.org), and possibly to any other
197    relevant mailing-list or to the newsgroup.
198 
199  - In all bug-reports, *please* tell what kernel you are talking about,
200    how to duplicate the problem, and what your setup is (use your common
201    sense).  If the problem is new, tell me so, and if the problem is
202    old, please try to tell me when you first noticed it.
203 
204  - if the bug results in a message like
205 
206         unable to handle kernel paging request at address C0000010
207         Oops: 0002
208         EIP:   0010:XXXXXXXX
209         eax: xxxxxxxx   ebx: xxxxxxxx   ecx: xxxxxxxx   edx: xxxxxxxx
210         esi: xxxxxxxx   edi: xxxxxxxx   ebp: xxxxxxxx
211         ds: xxxx  es: xxxx  fs: xxxx  gs: xxxx
212         Pid: xx, process nr: xx
213         xx xx xx xx xx xx xx xx xx xx
214 
215    or similar kernel debugging information on your screen or in your
216    system log, please duplicate it *exactly*.  The dump may look
217    incomprehensible to you, but it does contain information that may
218    help debugging the problem.  The text above the dump is also
219    important: it tells something about why the kernel dumped code (in
220    the above example it's due to a bad kernel pointer). More information
221    on making sense of the dump is in Documentation/oops-tracing.txt
222 
223  - You can use the "ksymoops" program to make sense of the dump.  Find
224    the C++ sources under the scripts/ directory to avoid having to do
225    the dump lookup by hand:
226 
227  - in debugging dumps like the above, it helps enormously if you can
228    look up what the EIP value means.  The hex value as such doesn't help
229    me or anybody else very much: it will depend on your particular
230    kernel setup.  What you should do is take the hex value from the EIP
231    line (ignore the "0010:"), and look it up in the kernel namelist to
232    see which kernel function contains the offending address.
233 
234    To find out the kernel function name, you'll need to find the system
235    binary associated with the kernel that exhibited the symptom.  This is
236    the file 'linux/vmlinux'.  To extract the namelist and match it against
237    the EIP from the kernel crash, do:
238 
239                 nm vmlinux | sort | less
240 
241    This will give you a list of kernel addresses sorted in ascending
242    order, from which it is simple to find the function that contains the
243    offending address.  Note that the address given by the kernel
244    debugging messages will not necessarily match exactly with the
245    function addresses (in fact, that is very unlikely), so you can't
246    just 'grep' the list: the list will, however, give you the starting
247    point of each kernel function, so by looking for the function that
248    has a starting address lower than the one you are searching for but
249    is followed by a function with a higher address you will find the one
250    you want.  In fact, it may be a good idea to include a bit of
251    "context" in your problem report, giving a few lines around the
252    interesting one. 
253 
254    If you for some reason cannot do the above (you have a pre-compiled
255    kernel image or similar), telling me as much about your setup as
256    possible will help. 
257 
258  - alternately, you can use gdb on a running kernel. (read-only; i.e. you
259    cannot change values or set break points.) To do this, first compile the
260    kernel with -g; edit arch/i386/Makefile appropriately, then do a "make
261    clean". You'll also need to enable CONFIG_PROC_FS (via "make config").
262 
263    After you've rebooted with the new kernel, do "gdb vmlinux /proc/kcore".
264    You can now use all the usual gdb commands. The command to look up the
265    point where your system crashed is "l *0xXXXXXXXX". (Replace the XXXes
266    with the EIP value.)
267 
268    gdb'ing a non-running kernel currently fails because gdb (wrongly)
269    disregards the starting offset for which the kernel is compiled.
270 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us