Eric Lee / linux-smarc-t335x-v3.2

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Commit 4f4e2dc3ce46d279a311e5250ac3cbd394279c31

Authored by Xose Vazquez Perez
Committed by Linus Torvalds
1 parent a462e9ff52
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[PATCH] README updated 

Replace old information with newer from kernel.org

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 1 changed file with 19 additions and 11 deletions Inline Diff

1 Linux kernel release 2.6.xx 1 Linux kernel release 2.6.xx <http://kernel.org>
2 2
3 These are the release notes for Linux version 2.6. Read them carefully, 3 These are the release notes for Linux version 2.6. Read them carefully,
4 as they tell you what this is all about, explain how to install the 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. 5 kernel, and what to do if something goes wrong.
6 6
7 WHAT IS LINUX? 7 WHAT IS LINUX?
8 8
9 Linux is a Unix clone written from scratch by Linus Torvalds with 9 Linux is a clone of the operating system Unix, written from scratch by
10 assistance from a loosely-knit team of hackers across the Net. 10 Linus Torvalds with assistance from a loosely-knit team of hackers across
11 It aims towards POSIX compliance. 11 the Net. It aims towards POSIX and Single UNIX Specification compliance.
12 12
13 It has all the features you would expect in a modern fully-fledged 13 It has all the features you would expect in a modern fully-fledged Unix,
14 Unix, including true multitasking, virtual memory, shared libraries, 14 including true multitasking, virtual memory, shared libraries, demand
15 demand loading, shared copy-on-write executables, proper memory 15 loading, shared copy-on-write executables, proper memory management,
16 management and TCP/IP networking. 16 and multistack networking including IPv4 and IPv6.
17 17
18 It is distributed under the GNU General Public License - see the 18 It is distributed under the GNU General Public License - see the
19 accompanying COPYING file for more details. 19 accompanying COPYING file for more details.
20 20
21 ON WHAT HARDWARE DOES IT RUN? 21 ON WHAT HARDWARE DOES IT RUN?
22 22
23 Linux was first developed for 386/486-based PCs. These days it also 23 Although originally developed first for 32-bit x86-based PCs (386 or higher),
24 runs on ARMs, DEC Alphas, SUN Sparcs, M68000 machines (like Atari and 24 today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and
25 Amiga), MIPS and PowerPC, and others. 25 UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH,
26 IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64, AXIS CRIS,
27 and Renesas M32R architectures.
28
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.
26 34
27 DOCUMENTATION: 35 DOCUMENTATION:
28 36
29 - There is a lot of documentation available both in electronic form on 37 - There is a lot of documentation available both in electronic form on
30 the Internet and in books, both Linux-specific and pertaining to 38 the Internet and in books, both Linux-specific and pertaining to
31 general UNIX questions. I'd recommend looking into the documentation 39 general UNIX questions. I'd recommend looking into the documentation
32 subdirectories on any Linux FTP site for the LDP (Linux Documentation 40 subdirectories on any Linux FTP site for the LDP (Linux Documentation
33 Project) books. This README is not meant to be documentation on the 41 Project) books. This README is not meant to be documentation on the
34 system: there are much better sources available. 42 system: there are much better sources available.
35 43
36 - There are various README files in the Documentation/ subdirectory: 44 - There are various README files in the Documentation/ subdirectory:
37 these typically contain kernel-specific installation notes for some 45 these typically contain kernel-specific installation notes for some
38 drivers for example. See Documentation/00-INDEX for a list of what 46 drivers for example. See Documentation/00-INDEX for a list of what
39 is contained in each file. Please read the Changes file, as it 47 is contained in each file. Please read the Changes file, as it
40 contains information about the problems, which may result by upgrading 48 contains information about the problems, which may result by upgrading
41 your kernel. 49 your kernel.
42 50
43 - The Documentation/DocBook/ subdirectory contains several guides for 51 - The Documentation/DocBook/ subdirectory contains several guides for
44 kernel developers and users. These guides can be rendered in a 52 kernel developers and users. These guides can be rendered in a
45 number of formats: PostScript (.ps), PDF, and HTML, among others. 53 number of formats: PostScript (.ps), PDF, and HTML, among others.
46 After installation, "make psdocs", "make pdfdocs", or "make htmldocs" 54 After installation, "make psdocs", "make pdfdocs", or "make htmldocs"
47 will render the documentation in the requested format. 55 will render the documentation in the requested format.
48 56
49 INSTALLING the kernel: 57 INSTALLING the kernel:
50 58
51 - If you install the full sources, put the kernel tarball in a 59 - If you install the full sources, put the kernel tarball in a
52 directory where you have permissions (eg. your home directory) and 60 directory where you have permissions (eg. your home directory) and
53 unpack it: 61 unpack it:
54 62
55 gzip -cd linux-2.6.XX.tar.gz | tar xvf - 63 gzip -cd linux-2.6.XX.tar.gz | tar xvf -
56 64
57 or 65 or
58 bzip2 -dc linux-2.6.XX.tar.bz2 | tar xvf - 66 bzip2 -dc linux-2.6.XX.tar.bz2 | tar xvf -
59 67
60 68
61 Replace "XX" with the version number of the latest kernel. 69 Replace "XX" with the version number of the latest kernel.
62 70
63 Do NOT use the /usr/src/linux area! This area has a (usually 71 Do NOT use the /usr/src/linux area! This area has a (usually
64 incomplete) set of kernel headers that are used by the library header 72 incomplete) set of kernel headers that are used by the library header
65 files. They should match the library, and not get messed up by 73 files. They should match the library, and not get messed up by
66 whatever the kernel-du-jour happens to be. 74 whatever the kernel-du-jour happens to be.
67 75
68 - You can also upgrade between 2.6.xx releases by patching. Patches are 76 - You can also upgrade between 2.6.xx releases by patching. Patches are
69 distributed in the traditional gzip and the new bzip2 format. To 77 distributed in the traditional gzip and the new bzip2 format. To
70 install by patching, get all the newer patch files, enter the 78 install by patching, get all the newer patch files, enter the
71 top level directory of the kernel source (linux-2.6.xx) and execute: 79 top level directory of the kernel source (linux-2.6.xx) and execute:
72 80
73 gzip -cd ../patch-2.6.xx.gz | patch -p1 81 gzip -cd ../patch-2.6.xx.gz | patch -p1
74 82
75 or 83 or
76 bzip2 -dc ../patch-2.6.xx.bz2 | patch -p1 84 bzip2 -dc ../patch-2.6.xx.bz2 | patch -p1
77 85
78 (repeat xx for all versions bigger than the version of your current 86 (repeat xx for all versions bigger than the version of your current
79 source tree, _in_order_) and you should be ok. You may want to remove 87 source tree, _in_order_) and you should be ok. You may want to remove
80 the backup files (xxx~ or xxx.orig), and make sure that there are no 88 the backup files (xxx~ or xxx.orig), and make sure that there are no
81 failed patches (xxx# or xxx.rej). If there are, either you or me has 89 failed patches (xxx# or xxx.rej). If there are, either you or me has
82 made a mistake. 90 made a mistake.
83 91
84 Unlike patches for the 2.6.x kernels, patches for the 2.6.x.y kernels 92 Unlike patches for the 2.6.x kernels, patches for the 2.6.x.y kernels
85 (also known as the -stable kernels) are not incremental but instead apply 93 (also known as the -stable kernels) are not incremental but instead apply
86 directly to the base 2.6.x kernel. Please read 94 directly to the base 2.6.x kernel. Please read
87 Documentation/applying-patches.txt for more information. 95 Documentation/applying-patches.txt for more information.
88 96
89 Alternatively, the script patch-kernel can be used to automate this 97 Alternatively, the script patch-kernel can be used to automate this
90 process. It determines the current kernel version and applies any 98 process. It determines the current kernel version and applies any
91 patches found. 99 patches found.
92 100
93 linux/scripts/patch-kernel linux 101 linux/scripts/patch-kernel linux
94 102
95 The first argument in the command above is the location of the 103 The first argument in the command above is the location of the
96 kernel source. Patches are applied from the current directory, but 104 kernel source. Patches are applied from the current directory, but
97 an alternative directory can be specified as the second argument. 105 an alternative directory can be specified as the second argument.
98 106
99 - If you are upgrading between releases using the stable series patches 107 - If you are upgrading between releases using the stable series patches
100 (for example, patch-2.6.xx.y), note that these "dot-releases" are 108 (for example, patch-2.6.xx.y), note that these "dot-releases" are
101 not incremental and must be applied to the 2.6.xx base tree. For 109 not incremental and must be applied to the 2.6.xx base tree. For
102 example, if your base kernel is 2.6.12 and you want to apply the 110 example, if your base kernel is 2.6.12 and you want to apply the
103 2.6.12.3 patch, you do not and indeed must not first apply the 111 2.6.12.3 patch, you do not and indeed must not first apply the
104 2.6.12.1 and 2.6.12.2 patches. Similarly, if you are running kernel 112 2.6.12.1 and 2.6.12.2 patches. Similarly, if you are running kernel
105 version 2.6.12.2 and want to jump to 2.6.12.3, you must first 113 version 2.6.12.2 and want to jump to 2.6.12.3, you must first
106 reverse the 2.6.12.2 patch (that is, patch -R) _before_ applying 114 reverse the 2.6.12.2 patch (that is, patch -R) _before_ applying
107 the 2.6.12.3 patch. 115 the 2.6.12.3 patch.
108 116
109 - Make sure you have no stale .o files and dependencies lying around: 117 - Make sure you have no stale .o files and dependencies lying around:
110 118
111 cd linux 119 cd linux
112 make mrproper 120 make mrproper
113 121
114 You should now have the sources correctly installed. 122 You should now have the sources correctly installed.
115 123
116 SOFTWARE REQUIREMENTS 124 SOFTWARE REQUIREMENTS
117 125
118 Compiling and running the 2.6.xx kernels requires up-to-date 126 Compiling and running the 2.6.xx kernels requires up-to-date
119 versions of various software packages. Consult 127 versions of various software packages. Consult
120 Documentation/Changes for the minimum version numbers required 128 Documentation/Changes for the minimum version numbers required
121 and how to get updates for these packages. Beware that using 129 and how to get updates for these packages. Beware that using
122 excessively old versions of these packages can cause indirect 130 excessively old versions of these packages can cause indirect
123 errors that are very difficult to track down, so don't assume that 131 errors that are very difficult to track down, so don't assume that
124 you can just update packages when obvious problems arise during 132 you can just update packages when obvious problems arise during
125 build or operation. 133 build or operation.
126 134
127 BUILD directory for the kernel: 135 BUILD directory for the kernel:
128 136
129 When compiling the kernel all output files will per default be 137 When compiling the kernel all output files will per default be
130 stored together with the kernel source code. 138 stored together with the kernel source code.
131 Using the option "make O=output/dir" allow you to specify an alternate 139 Using the option "make O=output/dir" allow you to specify an alternate
132 place for the output files (including .config). 140 place for the output files (including .config).
133 Example: 141 Example:
134 kernel source code: /usr/src/linux-2.6.N 142 kernel source code: /usr/src/linux-2.6.N
135 build directory: /home/name/build/kernel 143 build directory: /home/name/build/kernel
136 144
137 To configure and build the kernel use: 145 To configure and build the kernel use:
138 cd /usr/src/linux-2.6.N 146 cd /usr/src/linux-2.6.N
139 make O=/home/name/build/kernel menuconfig 147 make O=/home/name/build/kernel menuconfig
140 make O=/home/name/build/kernel 148 make O=/home/name/build/kernel
141 sudo make O=/home/name/build/kernel modules_install install 149 sudo make O=/home/name/build/kernel modules_install install
142 150
143 Please note: If the 'O=output/dir' option is used then it must be 151 Please note: If the 'O=output/dir' option is used then it must be
144 used for all invocations of make. 152 used for all invocations of make.
145 153
146 CONFIGURING the kernel: 154 CONFIGURING the kernel:
147 155
148 Do not skip this step even if you are only upgrading one minor 156 Do not skip this step even if you are only upgrading one minor
149 version. New configuration options are added in each release, and 157 version. New configuration options are added in each release, and
150 odd problems will turn up if the configuration files are not set up 158 odd problems will turn up if the configuration files are not set up
151 as expected. If you want to carry your existing configuration to a 159 as expected. If you want to carry your existing configuration to a
152 new version with minimal work, use "make oldconfig", which will 160 new version with minimal work, use "make oldconfig", which will
153 only ask you for the answers to new questions. 161 only ask you for the answers to new questions.
154 162
155 - Alternate configuration commands are: 163 - Alternate configuration commands are:
156 "make menuconfig" Text based color menus, radiolists & dialogs. 164 "make menuconfig" Text based color menus, radiolists & dialogs.
157 "make xconfig" X windows (Qt) based configuration tool. 165 "make xconfig" X windows (Qt) based configuration tool.
158 "make gconfig" X windows (Gtk) based configuration tool. 166 "make gconfig" X windows (Gtk) based configuration tool.
159 "make oldconfig" Default all questions based on the contents of 167 "make oldconfig" Default all questions based on the contents of
160 your existing ./.config file. 168 your existing ./.config file.
161 "make silentoldconfig" 169 "make silentoldconfig"
162 Like above, but avoids cluttering the screen 170 Like above, but avoids cluttering the screen
163 with questions already answered. 171 with questions already answered.
164 172
165 NOTES on "make config": 173 NOTES on "make config":
166 - having unnecessary drivers will make the kernel bigger, and can 174 - having unnecessary drivers will make the kernel bigger, and can
167 under some circumstances lead to problems: probing for a 175 under some circumstances lead to problems: probing for a
168 nonexistent controller card may confuse your other controllers 176 nonexistent controller card may confuse your other controllers
169 - compiling the kernel with "Processor type" set higher than 386 177 - compiling the kernel with "Processor type" set higher than 386
170 will result in a kernel that does NOT work on a 386. The 178 will result in a kernel that does NOT work on a 386. The
171 kernel will detect this on bootup, and give up. 179 kernel will detect this on bootup, and give up.
172 - A kernel with math-emulation compiled in will still use the 180 - A kernel with math-emulation compiled in will still use the
173 coprocessor if one is present: the math emulation will just 181 coprocessor if one is present: the math emulation will just
174 never get used in that case. The kernel will be slightly larger, 182 never get used in that case. The kernel will be slightly larger,
175 but will work on different machines regardless of whether they 183 but will work on different machines regardless of whether they
176 have a math coprocessor or not. 184 have a math coprocessor or not.
177 - the "kernel hacking" configuration details usually result in a 185 - the "kernel hacking" configuration details usually result in a
178 bigger or slower kernel (or both), and can even make the kernel 186 bigger or slower kernel (or both), and can even make the kernel
179 less stable by configuring some routines to actively try to 187 less stable by configuring some routines to actively try to
180 break bad code to find kernel problems (kmalloc()). Thus you 188 break bad code to find kernel problems (kmalloc()). Thus you
181 should probably answer 'n' to the questions for 189 should probably answer 'n' to the questions for
182 "development", "experimental", or "debugging" features. 190 "development", "experimental", or "debugging" features.
183 191
184 COMPILING the kernel: 192 COMPILING the kernel:
185 193
186 - Make sure you have at least gcc 3.2 available. 194 - Make sure you have at least gcc 3.2 available.
187 For more information, refer to Documentation/Changes. 195 For more information, refer to Documentation/Changes.
188 196
189 Please note that you can still run a.out user programs with this kernel. 197 Please note that you can still run a.out user programs with this kernel.
190 198
191 - Do a "make" to create a compressed kernel image. It is also 199 - Do a "make" to create a compressed kernel image. It is also
192 possible to do "make install" if you have lilo installed to suit the 200 possible to do "make install" if you have lilo installed to suit the
193 kernel makefiles, but you may want to check your particular lilo setup first. 201 kernel makefiles, but you may want to check your particular lilo setup first.
194 202
195 To do the actual install you have to be root, but none of the normal 203 To do the actual install you have to be root, but none of the normal
196 build should require that. Don't take the name of root in vain. 204 build should require that. Don't take the name of root in vain.
197 205
198 - If you configured any of the parts of the kernel as `modules', you 206 - If you configured any of the parts of the kernel as `modules', you
199 will also have to do "make modules_install". 207 will also have to do "make modules_install".
200 208
201 - Keep a backup kernel handy in case something goes wrong. This is 209 - Keep a backup kernel handy in case something goes wrong. This is
202 especially true for the development releases, since each new release 210 especially true for the development releases, since each new release
203 contains new code which has not been debugged. Make sure you keep a 211 contains new code which has not been debugged. Make sure you keep a
204 backup of the modules corresponding to that kernel, as well. If you 212 backup of the modules corresponding to that kernel, as well. If you
205 are installing a new kernel with the same version number as your 213 are installing a new kernel with the same version number as your
206 working kernel, make a backup of your modules directory before you 214 working kernel, make a backup of your modules directory before you
207 do a "make modules_install". 215 do a "make modules_install".
208 Alternatively, before compiling, use the kernel config option 216 Alternatively, before compiling, use the kernel config option
209 "LOCALVERSION" to append a unique suffix to the regular kernel version. 217 "LOCALVERSION" to append a unique suffix to the regular kernel version.
210 LOCALVERSION can be set in the "General Setup" menu. 218 LOCALVERSION can be set in the "General Setup" menu.
211 219
212 - In order to boot your new kernel, you'll need to copy the kernel 220 - In order to boot your new kernel, you'll need to copy the kernel
213 image (e.g. .../linux/arch/i386/boot/bzImage after compilation) 221 image (e.g. .../linux/arch/i386/boot/bzImage after compilation)
214 to the place where your regular bootable kernel is found. 222 to the place where your regular bootable kernel is found.
215 223
216 - Booting a kernel directly from a floppy without the assistance of a 224 - Booting a kernel directly from a floppy without the assistance of a
217 bootloader such as LILO, is no longer supported. 225 bootloader such as LILO, is no longer supported.
218 226
219 If you boot Linux from the hard drive, chances are you use LILO which 227 If you boot Linux from the hard drive, chances are you use LILO which
220 uses the kernel image as specified in the file /etc/lilo.conf. The 228 uses the kernel image as specified in the file /etc/lilo.conf. The
221 kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or 229 kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or
222 /boot/bzImage. To use the new kernel, save a copy of the old image 230 /boot/bzImage. To use the new kernel, save a copy of the old image
223 and copy the new image over the old one. Then, you MUST RERUN LILO 231 and copy the new image over the old one. Then, you MUST RERUN LILO
224 to update the loading map!! If you don't, you won't be able to boot 232 to update the loading map!! If you don't, you won't be able to boot
225 the new kernel image. 233 the new kernel image.
226 234
227 Reinstalling LILO is usually a matter of running /sbin/lilo. 235 Reinstalling LILO is usually a matter of running /sbin/lilo.
228 You may wish to edit /etc/lilo.conf to specify an entry for your 236 You may wish to edit /etc/lilo.conf to specify an entry for your
229 old kernel image (say, /vmlinux.old) in case the new one does not 237 old kernel image (say, /vmlinux.old) in case the new one does not
230 work. See the LILO docs for more information. 238 work. See the LILO docs for more information.
231 239
232 After reinstalling LILO, you should be all set. Shutdown the system, 240 After reinstalling LILO, you should be all set. Shutdown the system,
233 reboot, and enjoy! 241 reboot, and enjoy!
234 242
235 If you ever need to change the default root device, video mode, 243 If you ever need to change the default root device, video mode,
236 ramdisk size, etc. in the kernel image, use the 'rdev' program (or 244 ramdisk size, etc. in the kernel image, use the 'rdev' program (or
237 alternatively the LILO boot options when appropriate). No need to 245 alternatively the LILO boot options when appropriate). No need to
238 recompile the kernel to change these parameters. 246 recompile the kernel to change these parameters.
239 247
240 - Reboot with the new kernel and enjoy. 248 - Reboot with the new kernel and enjoy.
241 249
242 IF SOMETHING GOES WRONG: 250 IF SOMETHING GOES WRONG:
243 251
244 - If you have problems that seem to be due to kernel bugs, please check 252 - If you have problems that seem to be due to kernel bugs, please check
245 the file MAINTAINERS to see if there is a particular person associated 253 the file MAINTAINERS to see if there is a particular person associated
246 with the part of the kernel that you are having trouble with. If there 254 with the part of the kernel that you are having trouble with. If there
247 isn't anyone listed there, then the second best thing is to mail 255 isn't anyone listed there, then the second best thing is to mail
248 them to me (torvalds@osdl.org), and possibly to any other relevant 256 them to me (torvalds@osdl.org), and possibly to any other relevant
249 mailing-list or to the newsgroup. 257 mailing-list or to the newsgroup.
250 258
251 - In all bug-reports, *please* tell what kernel you are talking about, 259 - In all bug-reports, *please* tell what kernel you are talking about,
252 how to duplicate the problem, and what your setup is (use your common 260 how to duplicate the problem, and what your setup is (use your common
253 sense). If the problem is new, tell me so, and if the problem is 261 sense). If the problem is new, tell me so, and if the problem is
254 old, please try to tell me when you first noticed it. 262 old, please try to tell me when you first noticed it.
255 263
256 - If the bug results in a message like 264 - If the bug results in a message like
257 265
258 unable to handle kernel paging request at address C0000010 266 unable to handle kernel paging request at address C0000010
259 Oops: 0002 267 Oops: 0002
260 EIP: 0010:XXXXXXXX 268 EIP: 0010:XXXXXXXX
261 eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx 269 eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx
262 esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx 270 esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx
263 ds: xxxx es: xxxx fs: xxxx gs: xxxx 271 ds: xxxx es: xxxx fs: xxxx gs: xxxx
264 Pid: xx, process nr: xx 272 Pid: xx, process nr: xx
265 xx xx xx xx xx xx xx xx xx xx 273 xx xx xx xx xx xx xx xx xx xx
266 274
267 or similar kernel debugging information on your screen or in your 275 or similar kernel debugging information on your screen or in your
268 system log, please duplicate it *exactly*. The dump may look 276 system log, please duplicate it *exactly*. The dump may look
269 incomprehensible to you, but it does contain information that may 277 incomprehensible to you, but it does contain information that may
270 help debugging the problem. The text above the dump is also 278 help debugging the problem. The text above the dump is also
271 important: it tells something about why the kernel dumped code (in 279 important: it tells something about why the kernel dumped code (in
272 the above example it's due to a bad kernel pointer). More information 280 the above example it's due to a bad kernel pointer). More information
273 on making sense of the dump is in Documentation/oops-tracing.txt 281 on making sense of the dump is in Documentation/oops-tracing.txt
274 282
275 - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump 283 - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump
276 as is, otherwise you will have to use the "ksymoops" program to make 284 as is, otherwise you will have to use the "ksymoops" program to make
277 sense of the dump. This utility can be downloaded from 285 sense of the dump. This utility can be downloaded from
278 ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops. 286 ftp://ftp.<country>.kernel.org/pub/linux/utils/kernel/ksymoops.
279 Alternately you can do the dump lookup by hand: 287 Alternately you can do the dump lookup by hand:
280 288
281 - In debugging dumps like the above, it helps enormously if you can 289 - In debugging dumps like the above, it helps enormously if you can
282 look up what the EIP value means. The hex value as such doesn't help 290 look up what the EIP value means. The hex value as such doesn't help
283 me or anybody else very much: it will depend on your particular 291 me or anybody else very much: it will depend on your particular
284 kernel setup. What you should do is take the hex value from the EIP 292 kernel setup. What you should do is take the hex value from the EIP
285 line (ignore the "0010:"), and look it up in the kernel namelist to 293 line (ignore the "0010:"), and look it up in the kernel namelist to
286 see which kernel function contains the offending address. 294 see which kernel function contains the offending address.
287 295
288 To find out the kernel function name, you'll need to find the system 296 To find out the kernel function name, you'll need to find the system
289 binary associated with the kernel that exhibited the symptom. This is 297 binary associated with the kernel that exhibited the symptom. This is
290 the file 'linux/vmlinux'. To extract the namelist and match it against 298 the file 'linux/vmlinux'. To extract the namelist and match it against
291 the EIP from the kernel crash, do: 299 the EIP from the kernel crash, do:
292 300
293 nm vmlinux | sort | less 301 nm vmlinux | sort | less
294 302
295 This will give you a list of kernel addresses sorted in ascending 303 This will give you a list of kernel addresses sorted in ascending
296 order, from which it is simple to find the function that contains the 304 order, from which it is simple to find the function that contains the
297 offending address. Note that the address given by the kernel 305 offending address. Note that the address given by the kernel
298 debugging messages will not necessarily match exactly with the 306 debugging messages will not necessarily match exactly with the
299 function addresses (in fact, that is very unlikely), so you can't 307 function addresses (in fact, that is very unlikely), so you can't
300 just 'grep' the list: the list will, however, give you the starting 308 just 'grep' the list: the list will, however, give you the starting
301 point of each kernel function, so by looking for the function that 309 point of each kernel function, so by looking for the function that
302 has a starting address lower than the one you are searching for but 310 has a starting address lower than the one you are searching for but
303 is followed by a function with a higher address you will find the one 311 is followed by a function with a higher address you will find the one
304 you want. In fact, it may be a good idea to include a bit of 312 you want. In fact, it may be a good idea to include a bit of
305 "context" in your problem report, giving a few lines around the 313 "context" in your problem report, giving a few lines around the
306 interesting one. 314 interesting one.
307 315
308 If you for some reason cannot do the above (you have a pre-compiled 316 If you for some reason cannot do the above (you have a pre-compiled
309 kernel image or similar), telling me as much about your setup as 317 kernel image or similar), telling me as much about your setup as
310 possible will help. 318 possible will help.
311 319
312 - Alternately, you can use gdb on a running kernel. (read-only; i.e. you 320 - Alternately, you can use gdb on a running kernel. (read-only; i.e. you
313 cannot change values or set break points.) To do this, first compile the 321 cannot change values or set break points.) To do this, first compile the
314 kernel with -g; edit arch/i386/Makefile appropriately, then do a "make 322 kernel with -g; edit arch/i386/Makefile appropriately, then do a "make
315 clean". You'll also need to enable CONFIG_PROC_FS (via "make config"). 323 clean". You'll also need to enable CONFIG_PROC_FS (via "make config").
316 324
317 After you've rebooted with the new kernel, do "gdb vmlinux /proc/kcore". 325 After you've rebooted with the new kernel, do "gdb vmlinux /proc/kcore".
318 You can now use all the usual gdb commands. The command to look up the 326 You can now use all the usual gdb commands. The command to look up the
319 point where your system crashed is "l *0xXXXXXXXX". (Replace the XXXes 327 point where your system crashed is "l *0xXXXXXXXX". (Replace the XXXes
320 with the EIP value.) 328 with the EIP value.)
321 329
322 gdb'ing a non-running kernel currently fails because gdb (wrongly) 330 gdb'ing a non-running kernel currently fails because gdb (wrongly)
323 disregards the starting offset for which the kernel is compiled. 331 disregards the starting offset for which the kernel is compiled.
324 332
325 333