| 1 |
<?xml version='1.0' encoding="UTF-8"?> |
| 2 |
<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/genkernel.xml,v 1.13 2004/12/22 22:47:01 swift Exp $ --> |
| 3 |
<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> |
| 4 |
|
| 5 |
<guide link="/doc/en/genkernel.xml"> |
| 6 |
<title>Gentoo Linux Genkernel Guide</title> |
| 7 |
|
| 8 |
<author title="Author"> |
| 9 |
<mail link="plasmaroo@gentoo.org">Tim Yamin</mail> |
| 10 |
</author> |
| 11 |
|
| 12 |
<abstract> |
| 13 |
This guide intends to provide a reference of all the functions |
| 14 |
provided by genkernel. |
| 15 |
</abstract> |
| 16 |
|
| 17 |
<license/> |
| 18 |
|
| 19 |
<version>1.1.2.1</version> |
| 20 |
<date>June 11, 2005</date> |
| 21 |
|
| 22 |
<chapter> |
| 23 |
<title>Introduction</title> |
| 24 |
<section> |
| 25 |
<title>Introduction</title> |
| 26 |
<body> |
| 27 |
|
| 28 |
<p> |
| 29 |
Genkernel is designed to allow users who are not previously used to |
| 30 |
compiling a kernel to use a similar setup to that one that is used on |
| 31 |
the Gentoo LiveCDs which auto-detects your hardware. |
| 32 |
</p> |
| 33 |
|
| 34 |
<p> |
| 35 |
Some users may also be interested in using genkernel for hardware |
| 36 |
which requires initialization and a working kernel before it can be |
| 37 |
booted. Because genkernel also automatically compiles your kernel modules, |
| 38 |
thus allowing hardware which needs to be loaded with module parameters |
| 39 |
to be used. |
| 40 |
</p> |
| 41 |
|
| 42 |
</body> |
| 43 |
</section> |
| 44 |
<section> |
| 45 |
<title>Is genkernel for me?</title> |
| 46 |
<body> |
| 47 |
|
| 48 |
<p> |
| 49 |
Genkernel is often a good choice to those who are unused to compiling |
| 50 |
their own kernel or those who are not certain about their hardware |
| 51 |
configurations. |
| 52 |
</p> |
| 53 |
|
| 54 |
<p> |
| 55 |
Because genkernel is designed to use a generic configuration, it |
| 56 |
should be able to support all of your hardware - however, because all |
| 57 |
the drivers and modules have to be compiled as well, compiling a |
| 58 |
kernel by yourself is often much faster provided you know what you need. |
| 59 |
</p> |
| 60 |
|
| 61 |
<p> |
| 62 |
Genkernel does not however, currently support booting the sytem from |
| 63 |
LVM2/EVMS2 partitions. Users are recommended to use a manually compiled |
| 64 |
kernel for the time being. |
| 65 |
</p> |
| 66 |
|
| 67 |
</body> |
| 68 |
</section> |
| 69 |
<section> |
| 70 |
<title>Getting genkernel</title> |
| 71 |
<body> |
| 72 |
|
| 73 |
<p> |
| 74 |
You can obtain genkernel by simply running <c>emerge genkernel</c>. Don't |
| 75 |
forget to use the <c>-k</c> flag for emerge if you are using binary packages, |
| 76 |
i.e. GRP. Due to the GRP packages having an older version of genkernel, the |
| 77 |
flags are different. As a result, you should consult the <uri |
| 78 |
link="/doc/en/handbook/handbook-x86.xml?part=1&chap=10"> |
| 79 |
Gentoo Handbook</uri> and <path>genkernel --help</path>. |
| 80 |
</p> |
| 81 |
|
| 82 |
</body> |
| 83 |
</section> |
| 84 |
<section> |
| 85 |
<title>Supported platforms</title> |
| 86 |
<body> |
| 87 |
|
| 88 |
<p> |
| 89 |
As of genkernel 3.0.2, the following platforms should be |
| 90 |
supported: alpha, amd64, parisc, parisc64, ppc, ppc64, sparc, sparc64, and x86. |
| 91 |
</p> |
| 92 |
|
| 93 |
</body> |
| 94 |
</section> |
| 95 |
</chapter> |
| 96 |
|
| 97 |
<chapter> |
| 98 |
<title>Genkernel usage</title> |
| 99 |
<section> |
| 100 |
<title>Introduction</title> |
| 101 |
<body> |
| 102 |
|
| 103 |
<p> |
| 104 |
Genkernel is designed to work in three modes: |
| 105 |
</p> |
| 106 |
|
| 107 |
<ul> |
| 108 |
<li>"all" mode: this builds the kernel and the initrd</li> |
| 109 |
<li>"kernel" mode: this only builds the kernel image</li> |
| 110 |
<li>"initrd" mode: this only builds the initrd</li> |
| 111 |
</ul> |
| 112 |
|
| 113 |
<p> |
| 114 |
Most users will only want the "all" mode, which runs the "kernel" mode |
| 115 |
and the "initrd" mode for you. <b>Note</b> that the "kernel" and "initrd" |
| 116 |
modes are currently just aliases for the "all" mode, so they will |
| 117 |
currently give you no special effect. |
| 118 |
</p> |
| 119 |
|
| 120 |
<p> |
| 121 |
Although genkernel is mainly a command to make your life easier when |
| 122 |
you need to compile a kernel, genkernel is also packed full of |
| 123 |
different flags which allow you to customize how your kernel is |
| 124 |
compiled or configured. |
| 125 |
</p> |
| 126 |
|
| 127 |
</body> |
| 128 |
</section> |
| 129 |
<section> |
| 130 |
<title>Genkernel compiler flags</title> |
| 131 |
<body> |
| 132 |
|
| 133 |
<p> |
| 134 |
Genkernel supports the following flags which are passed to the |
| 135 |
relevant applications when your kernel is assembled: |
| 136 |
</p> |
| 137 |
|
| 138 |
<ul> |
| 139 |
<li> |
| 140 |
<b>--kernel-as=<c>someAssembler</c></b>: This specifies an assembler which |
| 141 |
would be used for compiling your kernel. |
| 142 |
</li> |
| 143 |
<li> |
| 144 |
<b>--kernel-cc=<c>someCompiler</c></b>: This specifies a compiler which |
| 145 |
would be used for compiling your kernel. |
| 146 |
</li> |
| 147 |
<li> |
| 148 |
<b>--kernel-ld=<c>someLinker</c></b>: This specifies a linker which would |
| 149 |
be used for compiling your kernel. |
| 150 |
</li> |
| 151 |
<li> |
| 152 |
<b>--kernel-make=<c>someMake</c></b>: This specifies an alternate GNU make |
| 153 |
which would be used for compiling your kernel. |
| 154 |
</li> |
| 155 |
</ul> |
| 156 |
|
| 157 |
<ul> |
| 158 |
<li> |
| 159 |
<b>--utils-as=<c>someAssembler</c></b>: This specifies an assembler which |
| 160 |
would be used for compiling the support utilities. |
| 161 |
</li> |
| 162 |
<li> |
| 163 |
<b>--utils-cc=<c>someCompiler</c></b>: This specifies a compiler which |
| 164 |
would be used for compiling the support utilities. |
| 165 |
</li> |
| 166 |
<li> |
| 167 |
<b>--utils-ld=<c>someLinker</c></b>: This specifies a linker which would be |
| 168 |
used for compiling the support utilities. |
| 169 |
</li> |
| 170 |
<li> |
| 171 |
<b>--utils-make=<c>someMake</c></b>: This specifies an alternate GNU make |
| 172 |
which would be used for compiling the support utilities. |
| 173 |
</li> |
| 174 |
</ul> |
| 175 |
|
| 176 |
<ul> |
| 177 |
<li> |
| 178 |
<b>--makeopts=<c>-jJobs</c></b>: This specifies the flags which would be |
| 179 |
passed to GNU make when the kernel and utilities are being compiled. |
| 180 |
</li> |
| 181 |
</ul> |
| 182 |
|
| 183 |
</body> |
| 184 |
</section> |
| 185 |
<section> |
| 186 |
<title>Genkernel kernel flags</title> |
| 187 |
<body> |
| 188 |
|
| 189 |
<p> |
| 190 |
Genkernel supports the following flags, some of which have |
| 191 |
<c>--<b>no-</b>option</c> equivalents that influence |
| 192 |
kernel compilation: |
| 193 |
</p> |
| 194 |
|
| 195 |
<ul> |
| 196 |
<li> |
| 197 |
<b>--callback="echo Hello"</b>: This routine calls the specified |
| 198 |
arguments after the kernel and the relevant modules have been built; but |
| 199 |
before the initrd has been built. This is useful where you might want |
| 200 |
external modules installed to the initrd by emerging the relevant item |
| 201 |
using the callback and then redefinining a genkernel module group. |
| 202 |
</li> |
| 203 |
<li> |
| 204 |
<b>--<c>no-</c>clean</b>: This runs <e>or does not |
| 205 |
run</e> <c>make clean</c> before compiling your kernel. This |
| 206 |
causes all object files and dependencies to be removed. |
| 207 |
</li> |
| 208 |
<li> |
| 209 |
<b>--<c>no-</c>mrproper</b>: This runs <e>or does not |
| 210 |
run</e> <c>make mrproper</c> before compiling your kernel. This |
| 211 |
causes all object files, dependencies <b>and your |
| 212 |
configuration</b> to be removed. |
| 213 |
</li> |
| 214 |
</ul> |
| 215 |
|
| 216 |
<ul> |
| 217 |
<li> |
| 218 |
<b>--kerneldir=<path>/path/to/sources</path></b>: This specifies an |
| 219 |
alternative kernel source location, instead of the default location of |
| 220 |
<path>/usr/src/linux</path>. |
| 221 |
</li> |
| 222 |
<li> |
| 223 |
<b>--kernel-config=<path>/path/to/config-file</path></b>: This specifies an |
| 224 |
alternative kernel configuration which would be used; rather than the |
| 225 |
inpersistant <path>/path/to/sources/.config</path> which is used by |
| 226 |
default. |
| 227 |
</li> |
| 228 |
</ul> |
| 229 |
|
| 230 |
<ul> |
| 231 |
<li> |
| 232 |
<b>--<c>no-</c>bootsplash</b>: This adds <e>or does not add</e> bootsplash |
| 233 |
support in the initrd which genkernel builds. Not all architectures |
| 234 |
currently support bootsplash, and a kernel that supports bootsplash is |
| 235 |
also required. |
| 236 |
</li> |
| 237 |
<li> |
| 238 |
<b>--<c>no-</c>menuconfig</b>: This runs <e>or does not run</e> the kernel |
| 239 |
menu-based configurator before building your kernel, after <c>make |
| 240 |
oldconfig</c> has run. |
| 241 |
</li> |
| 242 |
</ul> |
| 243 |
|
| 244 |
<ul> |
| 245 |
<li> |
| 246 |
<b>--no-initrdmodules</b>: This doesn't copy any modules to the initrd |
| 247 |
which genkernel creates. |
| 248 |
</li> |
| 249 |
<li> |
| 250 |
<b>--<c>no-</c>install</b>: This installs <e>or does not install</e> your |
| 251 |
kernel, modules, and initrd once the compilation has finished. |
| 252 |
</li> |
| 253 |
</ul> |
| 254 |
|
| 255 |
</body> |
| 256 |
</section> |
| 257 |
<section> |
| 258 |
<title>Genkernel miscellaneous flags</title> |
| 259 |
<body> |
| 260 |
|
| 261 |
<p> |
| 262 |
Genkernel also supports some miscellaneous flags which do not fit into |
| 263 |
the other two categories: |
| 264 |
</p> |
| 265 |
|
| 266 |
<ul> |
| 267 |
<li> |
| 268 |
<b>--arch-override=<c>someArch</c></b>: This flag can be used to override |
| 269 |
what architecture genkernel thinks you're on, if the auto-detection |
| 270 |
mechanism fails (please file a bug if it does!) or if you wish to |
| 271 |
cross-compile a kernel. |
| 272 |
</li> |
| 273 |
</ul> |
| 274 |
|
| 275 |
<ul> |
| 276 |
<li> |
| 277 |
<b>--busybox-config=<path>/path/to/busybox-config</path></b>: This |
| 278 |
overrides the default busybox configuration with the specifid file |
| 279 |
</li> |
| 280 |
<li> |
| 281 |
<b>--busybox-bin=<path>/path/to/busybox-binary.tar.bz2</path></b>: Using |
| 282 |
this option means that a busybox binary would not be compiled, and the |
| 283 |
specified tarball would be used. Note that busybox <e>must</e> be compiled |
| 284 |
statically! |
| 285 |
</li> |
| 286 |
</ul> |
| 287 |
|
| 288 |
<ul> |
| 289 |
<li> |
| 290 |
<b>--minkernpackage=<path>/output/to/yourkernel.tar.bz2</path></b>: This |
| 291 |
flag outputs a tarball of the kernel, named as <path>kernel</path> and the |
| 292 |
initrd named as <path>initrd</path> to the specified file. No path |
| 293 |
information or modules will be included in the tarball. |
| 294 |
</li> |
| 295 |
</ul> |
| 296 |
|
| 297 |
</body> |
| 298 |
</section> |
| 299 |
<section> |
| 300 |
<title>Running genkernel</title> |
| 301 |
<body> |
| 302 |
|
| 303 |
<p> |
| 304 |
All that is needed to run genkernel is just genkernel with the |
| 305 |
necessary flags as root. For example: |
| 306 |
</p> |
| 307 |
|
| 308 |
<pre caption="Running genkernel"> |
| 309 |
# genkernel --menuconfig --no-clean --no-install --bootsplash all |
| 310 |
<comment>(Would produce a kernel, asking you how to configure it |
| 311 |
to your desire, leaving alone any compiled object files, enabling |
| 312 |
bootsplash support but not installing anything.)</comment> |
| 313 |
</pre> |
| 314 |
|
| 315 |
<p> |
| 316 |
If you want genkernel to install your kernel as well, you must ensure |
| 317 |
that your <path>/boot</path> partition is mounted - recent genkernels |
| 318 |
would automatically attempt to do this for you if MOUNTBOOT is set to |
| 319 |
"yes" in <path>/etc/genkernel.conf</path>. |
| 320 |
</p> |
| 321 |
|
| 322 |
<pre caption="Mounting your /boot manually"> |
| 323 |
<comment>(If /boot is a valid entry in /etc/fstab:)</comment> |
| 324 |
# mount /boot |
| 325 |
<comment>(... otherwise for IDE disks:)</comment> |
| 326 |
# mount /dev/hda1 /boot |
| 327 |
<comment>(... and for SCSI disks:)</comment> |
| 328 |
# mount /dev/sda1 /boot |
| 329 |
</pre> |
| 330 |
|
| 331 |
</body> |
| 332 |
</section> |
| 333 |
<section> |
| 334 |
<title>Setting up genkernel to work with your bootloader</title> |
| 335 |
<body> |
| 336 |
|
| 337 |
<p> |
| 338 |
To set up genkernel to work with your bootloader, three or four changes are |
| 339 |
required to your bootloader configuration. |
| 340 |
</p> |
| 341 |
|
| 342 |
<ol> |
| 343 |
<li> |
| 344 |
Add <c>root=/dev/ram0</c> and <c>init=/linuxrc</c> to the |
| 345 |
kernel parameters passed to the kernel image. |
| 346 |
</li> |
| 347 |
<li> |
| 348 |
Add <c>real_root=/dev/hda3</c>, for example, to the kernel parameters |
| 349 |
passed to the kernel image, if <path>/dev/hda3</path> contains your root |
| 350 |
partition. |
| 351 |
</li> |
| 352 |
<li> |
| 353 |
If you are using bootsplash, add a suitable modeline such as |
| 354 |
<c>vga=0x317</c> to the parameters passed to the kernel and also add |
| 355 |
<c>splash=verbose</c> or <c>splash=silent</c> depending on the verboseness |
| 356 |
you require from your bootsplash. |
| 357 |
</li> |
| 358 |
<li> |
| 359 |
Add the initrd according to how your bootloader requires it: see the <uri |
| 360 |
link="/doc/en/handbook/handbook-x86.xml?part=1&chap=10">Gentoo |
| 361 |
Handbook</uri> for details on how you would do it for your bootloader. |
| 362 |
</li> |
| 363 |
</ol> |
| 364 |
|
| 365 |
</body> |
| 366 |
</section> |
| 367 |
<section> |
| 368 |
<title>Kernel Configuration Files</title> |
| 369 |
<body> |
| 370 |
|
| 371 |
<p> |
| 372 |
Genkernel will save your kernel config in <path>/etc/kernels</path> and use that |
| 373 |
config whenever you issue <c>genkernel</c> again. If you want to start off again |
| 374 |
with the defaults, rename the file in <path>/etc/kernels</path>. Genkernel will |
| 375 |
then use the kernel config located in |
| 376 |
<path>/usr/share/genkernel/<arch></path> instead. |
| 377 |
</p> |
| 378 |
|
| 379 |
</body> |
| 380 |
</section> |
| 381 |
</chapter> |
| 382 |
|
| 383 |
<chapter> |
| 384 |
<title>Porting genkernel</title> |
| 385 |
<section> |
| 386 |
<title>Introduction</title> |
| 387 |
<body> |
| 388 |
|
| 389 |
<p> |
| 390 |
Provided your architecture has all the required libraries and utilties |
| 391 |
which genkernel requires, which includes but it is not limited to a |
| 392 |
working kernel for your architecture, working compiler suite, GNU |
| 393 |
make, and a working busybox distribution, you're all set to go! |
| 394 |
</p> |
| 395 |
|
| 396 |
<p> |
| 397 |
For each architecture, genkernel uses |
| 398 |
<path>/usr/share/genkernel/$archName</path> for configuration files for |
| 399 |
that architecture. |
| 400 |
</p> |
| 401 |
|
| 402 |
</body> |
| 403 |
</section> |
| 404 |
<section> |
| 405 |
<title>How the system bootstrapping works</title> |
| 406 |
<body> |
| 407 |
|
| 408 |
<ol> |
| 409 |
<li> |
| 410 |
The bootloader loads the genkernel image, built to the specification of the |
| 411 |
configuration files in the genkernel directories as well as the initrd |
| 412 |
which is prepared by genkernel. |
| 413 |
</li> |
| 414 |
<li> |
| 415 |
The kernel boots up, allocates a small amount of RAM in which busybox is |
| 416 |
initialized, which probes the system with the modules in the modules_load |
| 417 |
list for the architecture. |
| 418 |
</li> |
| 419 |
<li> |
| 420 |
Once done, and providing that the <c>real_root</c> parameter which is the |
| 421 |
root boot device as busybox sees things is found, the system is booted from |
| 422 |
the device. |
| 423 |
</li> |
| 424 |
</ol> |
| 425 |
|
| 426 |
</body> |
| 427 |
</section> |
| 428 |
<section> |
| 429 |
<title>The configuration files</title> |
| 430 |
<body> |
| 431 |
|
| 432 |
<ul> |
| 433 |
<li> |
| 434 |
<path>busy-config</path>: This is the configuration which is used to build |
| 435 |
busybox for your architecture. |
| 436 |
</li> |
| 437 |
<li> |
| 438 |
<path>config.sh</path>: This is a shell script which sets various internal |
| 439 |
genkernel variables. See one of the <path>config.sh</path> files for an |
| 440 |
example. |
| 441 |
</li> |
| 442 |
<li> |
| 443 |
<path>modules_load</path>: This is a file containing a space-delimited list |
| 444 |
of modules which are loaded for SCSI, FireWire, ATARAID and PCMCIA support. |
| 445 |
If none are available for your platform, leave the fields blank. See one of |
| 446 |
the <path>modules_load</path> files for an example. |
| 447 |
</li> |
| 448 |
</ul> |
| 449 |
|
| 450 |
<ul> |
| 451 |
<li> |
| 452 |
<path>kernel-config</path>: A default kernel configuration used for any |
| 453 |
kernel version. |
| 454 |
</li> |
| 455 |
<li> |
| 456 |
<path>kernel-config-2.4</path>: A default kernel configuration used for 2.4 |
| 457 |
series kernels. |
| 458 |
</li> |
| 459 |
<li> |
| 460 |
<path>kernel-config-2.6</path>: A default kernel configuration used for 2.6 |
| 461 |
series kernels. |
| 462 |
</li> |
| 463 |
</ul> |
| 464 |
|
| 465 |
</body> |
| 466 |
</section> |
| 467 |
</chapter> |
| 468 |
</guide> |
Parent Directory
| 
Revision Log