/[gentoo]/xml/htdocs/doc/en/migration-to-2.6.xml
Gentoo

Contents of /xml/htdocs/doc/en/migration-to-2.6.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.4 - (show annotations) (download) (as text)
Sat Nov 27 14:19:18 2004 UTC (10 years, 1 month ago) by neysx
Branch: MAIN
Changes since 1.3: +4 -4 lines
File MIME type: application/xml
#71645: use ln -sfn

1 <?xml version='1.0' encoding="UTF-8"?>
2 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3
4 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/migration-to-2.6.xml,v 1.3 2004/11/22 11:13:37 bennyc Exp $ -->
5
6 <guide link="/doc/en/migration-to-2.6.xml">
7
8 <title>The complete Gentoo Linux 2.6 migration guide</title>
9
10 <author title="Author">
11 <mail link="dsd@gentoo.org">Daniel Drake</mail>
12 </author>
13 <author title="Contributor">
14 <mail link="sergey_zlodey@mail.ru">Sergey Galkin</mail>
15 </author>
16 <author title="Contributor">
17 <mail link="svyatogor@gentoo.org">Sergey Kuleshov</mail>
18 </author>
19 <author title="Editor">
20 <mail link="neysx@gentoo.org">Xavier Neys</mail>
21 </author>
22 <author title="Editor">
23 <mail link="bennyc@gentoo.org">Benny Chuang</mail>
24 </author>
25
26 <abstract>
27 This document will aid you in the process of migrating from Linux 2.4 to Linux
28 2.6, devfs to udev and OSS to ALSA.
29 </abstract>
30
31 <version>0.1.2</version>
32 <date>2004-11-27</date>
33
34 <chapter>
35 <title>Introduction</title>
36
37 <section>
38 <title>Status of this document</title>
39 <body>
40
41 <p>
42 The migration processes described in this document are not minor changes. This
43 document is in early stages and may be missing some details but hopefully the
44 main things have been covered. If you do try a migration, please <uri
45 link="http://bugs.gentoo.org">report</uri> any problem you might encounter so
46 that we can refine this guide.
47 </p>
48
49 <p>
50 We are planning on making Linux 2.6 the default kernel for when 2005.0 is
51 released (for some arch's). At the same time, we will encourage all existing
52 users of those arch's to upgrade to Linux 2.6, as many will still be running
53 2.4. Your feedback on this document is much appreciated, so that when this
54 time comes, the document can be in good shape for the mass-migration.
55 </p>
56
57 </body>
58 </section>
59
60 <section>
61 <title>Whats new in Linux 2.6?</title>
62 <body>
63
64 <p>
65 That is no easy question to answer. Linux 2.6 is the result of over 2 years
66 of rapid development and stabilisation of new features, and is architectually
67 quite different from its 2.4 counterpart. Some of the more major changes are
68 listed below:
69 </p>
70
71 <ul>
72 <li>
73 Scheduler/Interactivity improvements: Linux feels very smooth on desktop
74 systems and copes much better than 2.4 while under load
75 </li>
76 <li>
77 Scalability: Linux now scales much better at both ends - on small embedded
78 devices and also systems with many processors
79 </li>
80 <li>Performance: Throughput from common applications is much improved</li>
81 <li>
82 Hardware support: Linux now supports many more architectures and hardware
83 devices out-of-the-box than any other operating system.
84 </li>
85 </ul>
86
87 <p>
88 Joseph Pranevich has written a very detailed document, <uri
89 link="http://www.kniggit.net/wwol26.html">The Wonderful World Of Linux
90 2.6</uri> which you may be interested to glance over. If you are interested in
91 the more technical details, you can refer to <uri
92 link="http://www.linux.org.uk/~davej/docs/post-halloween-2.6.txt">The
93 post-halloween document</uri> - but bear in mind that this is somewhat outdated
94 now.
95 </p>
96
97 </body>
98 </section>
99 <section>
100 <title>What is udev?</title>
101 <body>
102
103 <p>
104 In the past, Gentoo has instructed users to use <e>devfs</e> for managing the
105 /dev directory, which contains a series of device interfaces to allow system
106 applications to communicate with hardware (through the kernel).
107 </p>
108
109 <p>
110 <e>devfs</e>, whilst a good concept, has some internal problems, and has been
111 marked obselete in Linux 2.6.
112 </p>
113
114 <p>
115 <e>udev</e> is the new way of managing device nodes. It addresses issues with
116 previous device managers, and also attempts to solve some other problems.
117 </p>
118
119 <p>
120 The above may not mean much to you, but fear not, the hard working Gentoo
121 developers have put effort into making the migration from devfs very easy.
122 </p>
123
124 </body>
125 </section>
126 <section>
127 <title>What is ALSA?</title>
128 <body>
129
130 <p>
131 With Linux 2.4, chances are that you used OSS (open sound system) drivers to
132 power your sound card. OSS has been replaced by a newer and better set of sound
133 drivers: ALSA.
134 </p>
135
136 <p>
137 ALSA, the Advanced Linux Sound Architecture, is a new set of sound drivers with
138 a new and improved API, present in the Linux 2.6 kernel. It is backwards
139 compatible with OSS applications, provided that you select the right kernel
140 configuration options!
141 </p>
142
143 <note>
144 If you do not have any sound/audio hardware, you can safely skip over any
145 ALSA-related instructions in this document.
146 </note>
147
148 </body>
149 </section>
150 </chapter>
151
152 <chapter>
153 <title>Preparation</title>
154 <section>
155 <title>Get your system up-to-date</title>
156 <body>
157
158 <p>
159 Some of the changes brought in with Linux 2.6 also required some changes in the
160 base system applications. Before continuing, you should ensure that your system
161 is relatively up-to-date, and to be perfectly sure, you should update all world
162 and system packages where updates are available.
163 </p>
164
165 <p>
166 In particular, make sure you have the latest stable versions of the following
167 packages:
168 </p>
169
170 <ul>
171 <li><c>sys-apps/baselayout</c></li>
172 <li><c>sys-apps/util-linux</c></li>
173 <li>
174 <c>sys-kernel/genkernel</c> (only if you wish to use genkernel as opposed
175 to manual configuration)
176 </li>
177 </ul>
178
179 <pre caption="Updating all world packages">
180 # <i>emerge sync</i>
181 # <i>emerge -ua world</i>
182 </pre>
183
184 </body>
185 </section>
186 <section>
187 <title>modutils vs module-init-tools</title>
188 <body>
189
190 <p>
191 <c>sys-apps/modutils</c> is the package that provides tools such as
192 <c>modprobe</c>, <c>rmmod</c> and <c>insmod</c> for Linux 2.4.
193 </p>
194
195 <p>
196 Linux 2.6 introduces a new module format, and therefore requires new tools for
197 handling modules. These are bundled up into the
198 <c>sys-apps/module-init-tools</c> package. </p>
199
200 <p>
201 You should now remove modutils and install module-init-tools:
202 </p>
203
204 <pre caption="Switching from modutils to module-init-tools">
205 # <i>emerge unmerge modutils</i>
206 # <i>emerge module-init-tools</i>
207 </pre>
208
209 <note>
210 Don't worry - even though you have just unmerged modutils, module-init-tools
211 provides backwards compatibility for Linux 2.4, so you will still be
212 able to boot into Linux 2.4 and handle modules for that kernel.
213 </note>
214
215 <note>
216 For the above reason, module-init-tools might already be installed and working
217 with your existing Linux 2.4 kernel. In this case, you don't need to worry
218 about this stage - your system is already ready to deal with Linux 2.6 modules.
219 </note>
220
221 </body>
222 </section>
223 <section>
224 <title>Installing udev</title>
225 <body>
226
227 <p>
228 There is no configuration involved here. Simply use <c>emerge</c> to install
229 udev:
230 </p>
231
232 <pre caption="Installing udev">
233 # <i>emerge -a udev</i>
234 </pre>
235
236 </body>
237 </section>
238 <section>
239 <title>Installing ALSA utilities</title>
240 <body>
241
242 <p>
243 ALSA requires you to have some packages installed, so that applications can use
244 the ALSA API. These packages will also allow you to control the mixer and
245 volume levels. Install the required utilities as follows:
246 </p>
247
248 <pre caption="Installing ALSA utilities and libraries">
249 # <i>emerge -a alsa-lib alsa-utils alsa-tools alsa-headers alsa-oss</i>
250 </pre>
251
252 </body>
253 </section>
254 </chapter>
255
256 <chapter>
257 <title>Installing the Linux 2.6 sources</title>
258
259 <section>
260 <title>Choosing and installing a kernel</title>
261 <body>
262
263 <p>
264 The first thing you need to do is install sources of a 2.6 kernel of your
265 choice. The two Gentoo-supported 2.6 kernels are currently
266 <e>gentoo-dev-sources</e> (for desktops) and <e>hardened-dev-sources</e> (for
267 servers). There are others available, see the <uri
268 link="/doc/en/gentoo-kernel.xml">Gentoo Linux Kernel Guide</uri> for more
269 choices.
270 </p>
271
272 <p>
273 In this guide, we'll use <c>gentoo-dev-sources</c> as an example. Install your
274 chosen set of kernel sources using the <c>emerge</c> utility:
275 </p>
276
277 <pre caption="Installing gentoo-dev-sources">
278 # <i>emerge -a gentoo-dev-sources</i>
279 These are the packages that I would merge, in order:
280 Calculating dependencies ...done!
281 [ebuild N ] sys-kernel/gentoo-dev-sources-2.6.9-r2
282
283 Do you want me to merge these packages? [Yes/No] <i>y</i>
284 </pre>
285
286 </body>
287 </section>
288 <section>
289 <title>Updating the /usr/src/linux symbolic link</title>
290 <body>
291
292 <p>
293 Various components of the Gentoo utilities rely on /usr/src/linux being a
294 symbolic link to the kernel sources that you are running (or wish to compile
295 against).
296 </p>
297
298 <p>
299 We will now update our /usr/src/linux link to point at the kernel sources we
300 just installed. Continuing our example:
301 </p>
302
303 <pre caption="Updating the /usr/src/linux softlink">
304 # <i>cd /usr/src</i>
305 # <i>ln -sfn linux-2.6.9-gentoo-r2 linux</i>
306 </pre>
307
308 </body>
309 </section>
310 </chapter>
311
312 <chapter>
313 <title>Known pitfalls with Linux 2.6 migration</title>
314 <section>
315 <body>
316
317 <p>
318 Before we get stuck into configuring the kernel, I'll attempt to detail the
319 most common errors that people make when migrating to Linux 2.6, as some of
320 these points will influence the way you configure the new kernel.
321 </p>
322
323 <note>
324 Not all of these points are relevant at this stage, but I will detail them all
325 here in one place, and you can refer back at your leisure.
326 </note>
327
328 </body>
329 </section>
330 <section>
331 <title>Don't use "make oldconfig" with a 2.4 .config</title>
332 <body>
333
334 <note>
335 If you don't understand what this means, don't worry, you won't make this
336 mistake if you follow the rest of this guide correctly.
337 </note>
338
339 <p>
340 You'll be asked many many questions, since there have been a large amount of
341 changes. Many people who do try a <c>make oldconfig</c> from a 2.4 config end
342 up creating an unworkable kernel (e.g. no output on-screen, no input from
343 keyboard, etc). Please save yourself the trouble, and use the traditional
344 <c>menuconfig</c> configuration method just this once.
345 </p>
346
347 </body>
348 </section>
349 <section>
350 <title>Don't use ide-scsi for CD/DVD writing</title>
351 <body>
352
353 <p>
354 In Linux 2.4, the only way to achieve good CD/DVD writing results was to enable
355 the (rather ugly) <c>ide-scsi</c> emulation. Thankfully, the IDE layer in Linux
356 2.6 has been extended to support CD/DVD writers much better.
357 </p>
358
359 <p>
360 You don't need to enable any extra options to support CD writing. Just be sure
361 <e>not</e> to enable <c>ide-scsi</c> as you used to.
362 </p>
363
364 </body>
365 </section>
366 <section>
367 <title>PC Speaker is now a configurable option</title>
368 <body>
369
370 <p>
371 You won't get your normal console beeps (or any response from the PC speaker at
372 all) unless you specifically enable the new PC speaker option
373 (<c>CONFIG_INPUT_PCSPKR</c>):
374 </p>
375
376 <pre caption="Location of PC speaker option">
377 Device Drivers ---&gt;
378 Input device support ---&gt;
379 [*] Misc
380 &lt;*&gt; PC Speaker support
381 </pre>
382
383 <note>
384 By "PC speaker", I am referring to the analogue speaker that beeps once when
385 your system is powering up, I am not referring to normal sound hardware used
386 for playing music, etc.
387 </note>
388
389 </body>
390 </section>
391 <section>
392 <title>New USB Storage block device driver sometimes problematic</title>
393 <body>
394
395 <p>
396 Very recently, a new USB storage device driver has been added to the kernel.
397 At the time of writing, this driver ("ub") is still in its early stages and
398 some users find it to be unreliable. If you have problems accessing your USB
399 hard disk, USB flash disk, USB card reader, or USB digital camera, then you
400 could try reverting to the older SCSI-style driver:
401 </p>
402
403 <pre caption="Disabling ub">
404 Device Drivers ---&gt;
405 Block devices ---&gt;
406 &lt; &gt; Low Performance USB Block driver
407 </pre>
408
409 <note>
410 The older SCSI-style driver (USB Mass Storage support) is enabled by default.
411 It can be found under "Device Drivers --&gt; USB support", but will generally
412 not come into effect while ub is also present.
413 </note>
414
415 </body>
416 </section>
417 <section>
418 <title>usbdevfs renamed to usbfs</title>
419 <body>
420
421 <p>
422 If you have edited your <path>/etc/fstab</path> file to customise the way that
423 the USB device filesystem gets mounted, you may have to modify the filesystem
424 type from <e>usbdevfs</e> to <e>usbfs</e>.
425 </p>
426
427 <note>
428 Recent 2.4 kernels will also allow you to use "usbfs" as well as "usbdevfs", so
429 you aren't breaking any backwards compatibility by doing this.
430 </note>
431
432 </body>
433 </section>
434 <section>
435 <title>Don't renice X</title>
436 <body>
437
438 <p>
439 If you are a desktop 2.4 user, you may have hacked your system into running X
440 at a higher priority, as in some cases it seems to provide better desktop
441 performance.
442 </p>
443
444 <p>
445 There have been many scheduler changes in 2.6 which change this behaviour. If
446 you continue to run X at a higher priority, it will do exactly what it is
447 supposed to (run the <e>display server</e> at a very high priority) and you
448 will notice consequences such as sound stuttering and slow application load
449 times because your CPU is spending too long serving X and only X.
450 </p>
451
452 <p>
453 In Linux 2.6, you no longer need to renice desktop applications to get good
454 interactivity. Please remove your "niceness" hacks!
455 </p>
456
457 </body>
458 </section>
459 <section>
460 <title>X11 config file should now use /dev/input/mice</title>
461 <body>
462
463 <p>
464 One of the changes that a default udev configuration introduces is different
465 organisation of the mouse device nodes. Previously, you would have had nodes
466 such as <path>/dev/psaux</path> and <path>/dev/mouse</path>. You will now have
467 nodes such as <path>/dev/input/mouse0</path>, <path>/dev/input/mouse1</path>,
468 and a collective <path>/dev/input/mice</path> node which combines movements
469 from all mice.
470 </p>
471
472 <p>
473 Since the old X configurations typically reference <path>/dev/mouse</path> or
474 <path>/dev/psaux</path> then you may get an error similar to the one shown
475 below when you attempt to start X11:
476 </p>
477
478 <pre caption="Common error when starting X on a udev system for the first time">
479 (EE) xf86OpenSerial: Cannot open device /dev/mouse
480 No such file or directory.
481 (EE) Mouse0: cannot open input device
482 (EE) PreInit failed for input device "Mouse0"
483 No core pointer
484 </pre>
485
486 <p>
487 To correct this, open your X11 config in a text editor, and update the mouse
488 <e>InputDevice</e> section to use the <path>/dev/input/mice</path> device. An
489 example is shown below:
490 </p>
491
492 <pre caption="Opening your X11 config file">
493 # <i>nano -w /etc/X11/xorg.conf</i>
494 </pre>
495
496 <note>
497 If you are still using XFree86, your config file will be
498 <path>/etc/X11/XF86Config</path>
499 </note>
500
501 <pre caption="Sample mouse InputDevice section">
502 Section "InputDevice"
503 Identifier "Mouse0"
504 Driver "mouse"
505 Option "Protocol" "auto"
506 Option "Device" "/dev/input/mice"
507 EndSection
508 </pre>
509
510 </body>
511 </section>
512 </chapter>
513
514 <chapter id="conf">
515 <title>Configuring, building, and installing the kernel</title>
516 <section>
517 <body>
518
519 <p>
520 As with Linux 2.4, you have two options for managing your new kernel build.
521 </p>
522
523 <ol>
524 <li>
525 The default method is to configure your kernel manually. This may seem
526 daunting but is the preferred way as long as you know your system. If you
527 wish to configure your new kernel manually, please continue on to the <uri
528 link="#manual">next chapter</uri>.
529 </li>
530 <li>
531 The alternative option is to use our <c>genkernel</c> utility to
532 automatically configure, compile, and install a kernel for you. If you wish
533 to use <c>genkernel</c> then skip over the next chapter and proceed with
534 <uri link="#genkernel">using genkernel</uri>.
535 </li>
536 </ol>
537
538 </body>
539 </section>
540 </chapter>
541
542 <chapter id="manual">
543 <title>Default: Manual configuration</title>
544 <section>
545 <title>Configuring the kernel</title>
546 <body>
547
548 <p>
549 We'll now get on with configuring the kernel. Open menuconfig in the usual way:
550 </p>
551
552 <pre caption="Invoking menuconfig">
553 # <i>cd /usr/src/linux</i>
554 # <i>make menuconfig</i>
555 </pre>
556
557 <p>
558 You will probably be familiar with using menuconfig from configuring 2.4
559 kernels. Fortunately, the front end has barely changed at all, but you will
560 observe much better organisation of kernel options, plus <e>many</e> new
561 options that weren't present in 2.4.
562 </p>
563
564 <p>
565 Be sure to enable the following important kernel options:
566 </p>
567
568 <pre caption="Required kernel options">
569 File systems ---&gt;
570 Pseudo Filesystems ---&gt;
571 [*] /proc file system support
572 [*] Virtual memory file system support (former shm fs)
573
574 <comment>(the following are required for udev):</comment>
575 General setup ---&gt;
576 [*] Support for hot-pluggable devices
577
578 Device Drivers ---&gt;
579 Block devices ---&gt;
580 &lt;*&gt; RAM disk support
581
582 <comment>(the following are required for ALSA):</comment>
583 Device Drivers ---&gt;
584 Sound ---&gt;
585 &lt;*&gt; Sound card support
586 Advanced Linux Sound Architecture ---&gt;
587 &lt;M&gt; Advanced Linux Sound Architecture
588 &lt;M&gt; Sequencer support
589 &lt;M&gt; OSS Mixer API
590 [*] OSS Sequencer API
591 <comment> (and dont forget to select your soundcard from the submenus!)</comment>
592 </pre>
593
594 <warn>
595 Previously you may have included support for the <path>/dev</path> file system
596 (now marked OBSOLETE). Do not enable devfs support. We have installed udev,
597 which we will be using instead of devfs from now on.
598 </warn>
599
600 <p>
601 Also, remember to enable support for the filesystems that you use, and the
602 hardware present in your system. Be sure to enable support for the IDE
603 controller on your motherboard if you wish to benefit from fast DMA disk
604 access. Refer to the <uri
605 link="/doc/en/handbook/handbook-x86.xml?part=1&amp;chap=7">Configuring the
606 Kernel</uri> section of the <uri link="/doc/en/handbook/index.xml">Gentoo
607 Handbook</uri> for additional guidance here.
608 </p>
609
610 </body>
611 </section>
612 <section>
613 <title>Building the kernel</title>
614 <body>
615
616 <p>
617 Now that we have configured the kernel, we can start the compilation process:
618 </p>
619
620 <pre caption="Compiling the kernel source">
621 # <i>make &amp;&amp; make modules_install</i>
622 </pre>
623
624 <note>
625 You may recall having to run <c>make dep</c> with Linux 2.4 sources. This is no
626 longer required.
627 </note>
628
629 <p>
630 Wait for the kernel compilation to complete (and observe the much more readable
631 compilation output).
632 </p>
633
634 </body>
635 </section>
636 <section>
637 <title>Installing the kernel</title>
638 <body>
639
640 <p>
641 The next step is mounting your <path>/boot</path> partition and copying the
642 kernel image over. You must then update your bootloader config manually.
643 </p>
644
645 <pre caption="Installing the kernel">
646 # <i>mount /boot</i>
647 # <i>cp arch/i386/boot/bzImage /boot/bzImage-2.6.9-gentoo-r2</i>
648 # <i>cp System.map /boot/System.map-2.6.9-gentoo-r2</i>
649 </pre>
650
651 <p>
652 Note that the above instructions are examples only, you should follow your
653 usual procedure of updating kernels by following the instructions in the <uri
654 link="/doc/en/handbook/index.xml">Gentoo Handbook</uri> (see the <uri
655 link="/doc/en/handbook/handbook-x86.xml?part=1&amp;chap=7">Configuring the
656 Kernel</uri> chapter).
657 </p>
658
659 <p>
660 When updating your bootloader config, do not remove the old entry pointing at
661 your 2.4 kernel. This way, you will easily be able to switch between the two if
662 something is not working.
663 </p>
664
665 <p>
666 Now continue onto the <uri link="#modules">Module Configuration</uri> section.
667 </p>
668
669 </body>
670 </section>
671 </chapter>
672
673 <chapter id="genkernel">
674 <title>Alternative: Using genkernel</title>
675 <section>
676 <body>
677
678 <p>
679 If you prefer to use genkernel instead of manually configuring your kernel, you
680 will be happy to hear that using genkernel to produce 2.6 kernels is very
681 similar to the process you performed when producing your previous 2.4 kernel.
682 </p>
683
684 <p>
685 You should invoke genkernel as shown below:
686 </p>
687
688 <pre caption="Invoking genkernel with some common arguments">
689 # <i>genkernel --udev --menuconfig --bootloader=grub all</i>
690 </pre>
691
692 <p>
693 In the above example, we also take advantage of genkernel features to open
694 menuconfig to allow you to customise the kernel configuration (if you wish),
695 and to update the grub bootloader configuration after compilation.
696 </p>
697
698 <p>
699 You should choose genkernel arguments that suit you, but do not forget to
700 include the <c>--udev</c> argument! Refer to the <uri
701 link="/doc/en/genkernel.xml">Gentoo Linux Genkernel Guide</uri> and the <uri
702 link="/doc/en/handbook/handbook-x86.xml?part=1&amp;chap=7">Configuring the
703 Kernel</uri> chapter of the <uri link="/doc/en/handbook/index.xml">Gentoo
704 Handbook</uri> for additional information.
705 </p>
706
707 </body>
708 </section>
709 </chapter>
710
711 <chapter id="modules">
712 <title>Module Configuration</title>
713
714 <section>
715 <title>Installing external modules</title>
716 <body>
717
718 <p>
719 Many users will additionally rely on kernel modules that are built outside of
720 the kernel tree. Common examples are the binary ATI and Nvidia graphics
721 drivers. You now need to install those modules, which will compile against the
722 2.6 sources found at <path>/usr/src/linux</path>. This is the usual case of
723 <c>emerge packagename</c> for all the external modules you are used to using
724 with 2.4.
725 </p>
726
727 <p>
728 Refer again to the <uri
729 link="/doc/en/handbook/handbook-x86.xml?part=1&amp;chap=7">Configuring the
730 Kernel</uri> chapter of the <uri link="/doc/en/handbook/index.xml">Gentoo
731 Handbook</uri> for more info.
732 </p>
733
734 </body>
735 </section>
736 <section>
737 <title>Autoloading modules</title>
738 <body>
739
740 <p>
741 You may have decided to compile some kernel components as modules (as opposed
742 to compiled directly into the kernel) and would like to have them autoloaded on
743 bootup like you did with 2.4. Also, if you installed any external modules from
744 the portage tree (as described above) you will probably want to autoload them
745 too.
746 </p>
747
748 <p>
749 You can achieve this similarly as to how you did with 2.4. Simply open up the
750 file <path>/etc/modules.autoload.d/kernel-2.6</path> in a text editor and list
751 the names of the modules you would like autoloaded.
752 </p>
753
754 <pre caption="Opening the module autoload list in nano">
755 # <i>nano -w /etc/modules.autoload.d/kernel-2.6</i>
756 </pre>
757
758 <pre caption="Sample autoload list to load the 3c59x and nvidia modules">
759 # /etc/modules.autoload.d/kernel-2.6: kernel modules to load when system boots.
760 #
761 # Note that this file is for 2.6 kernels.
762 #
763 # Add the names of modules that you'd like to load when the system
764 # starts into this file, one per line. Comments begin with # and
765 # are ignored. Read man modules.autoload for additional details.
766
767 3c59x
768 nvidia
769 </pre>
770
771 </body>
772 </section>
773 <section>
774 <title>Configuring the ALSA modules</title>
775 <body>
776
777 <p>
778 You will have noticed that we chose to compile ALSA as modules. We can now
779 configure ALSA's behaviour easily. However, we also need to configure which
780 modules are to be loaded. Open up <path>/etc/modules.d/alsa</path> in your text
781 editor:
782 </p>
783
784 <pre caption="Opening /etc/modules.d/alsa in nano">
785 # <i>nano -w /etc/modules.d/alsa</i>
786 </pre>
787
788 <p>
789 Now look for the section marked as <e>IMPORTANT</e>. In most cases, you just
790 need to uncomment and modify the snd-card-0 and snd-slot-0 aliases.
791 </p>
792
793 <pre caption="Sample section of /etc/modules.d/alsa">
794 ## IMPORTANT:
795 ## You need to customise this section for your specific sound card(s)
796 ## and then run `update-modules' command.
797 ## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
798 ##
799 ## ALSA portion
800
801 # My laptop uses the snd-maestro3 driver
802 alias snd-card-0 snd-maestro3
803
804 ## OSS/Free portion
805
806 # Generally all you need to do is uncomment this line:
807 alias sound-slot-0 snd-card-0
808 </pre>
809
810 <p>
811 For more info on which driver name to use, consult the <uri
812 link="/doc/en/alsa-guide.xml">Gentoo Linux ALSA Guide</uri>. Remember to prefix
813 it with <e>snd-</e> in this file.
814 </p>
815
816 <p>
817 Finally, set the <c>alsasound</c> init script to be executed on bootup:
818 </p>
819
820 <pre caption="Adding alsasound to default runlevel">
821 # <i>rc-update add alsasound boot</i>
822 </pre>
823
824 </body>
825 </section>
826 </chapter>
827
828 <chapter>
829 <title>Booting into Linux 2.6</title>
830 <section>
831 <body>
832
833 <p>
834 It's now time to boot into Linux 2.6. Close all applications and reboot:
835 </p>
836
837 <pre caption="Rebooting">
838 # <i>modules-update</i>
839 # <i>umount /boot</i>
840 # <i>reboot</i>
841 </pre>
842
843 <p>
844 When you reboot, if you followed this document correctly so far, you will have
845 the option of either loading Linux 2.4 or Linux 2.6 from your bootloader.
846 Choose Linux 2.6.
847 </p>
848
849 <p>
850 Once the system has booted, check that things are working. If you made a
851 mistake in the kernel configuration, don't worry, you can skip back to the
852 <uri link="#conf">Configuring, building, and installing the kernel</uri>
853 section, make your change, recompile and install new kernel image, reboot, and
854 try again!
855 </p>
856
857 </body>
858 </section>
859 <section>
860 <title>Unmuting ALSA channels</title>
861 <body>
862
863 <p>
864 By default, ALSA channels are muted, so you won't hear anything when you go to
865 play a sound. You need to unmute them now. Run the <c>alsamixer</c> program
866 from a console and use the arrow keys to move around and adjust volumes, and
867 the M key to mute and unmute. Read the <uri
868 link="/doc/en/alsa-guide.xml">Gentoo Linux ALSA Guide</uri> for more complete
869 documentation and other ways to do this.
870 </p>
871
872 <note>
873 The alsasound init script that we put in the default runlevel will save mixer
874 levels on shutdown and restore them on bootup. You won't need to set all these
875 volumes every time you boot!
876 </note>
877
878 </body>
879 </section>
880 </chapter>
881
882 <chapter>
883 <title>Header files and NPTL</title>
884 <section>
885 <body>
886
887 <p>
888 By now you are running Linux 2.6 and hopefully have all issues ironed out. You
889 should now update your Linux kernel header files and re-merge glibc so that
890 userspace applications can take advantage of new Linux 2.6 features.
891 </p>
892
893 <pre caption="Updating to linux26-headers">
894 # <i>emerge unmerge linux-headers</i>
895 # <i>emerge linux26-headers</i>
896 </pre>
897
898 <p>
899 After updating your headers package, you should generally re-merge glibc.
900 There is a new feature here that you may be interested in - NPTL. NPTL is a new
901 threading model present in Linux 2.6, which features much quicker thread create
902 and destroy times. This won't make much of a difference to most systems, but
903 you may wish to enable it during this migration process! To enable NPTL, edit
904 <path>/etc/make.conf</path>, adding <e>nptl</e> to your USE variable.
905 </p>
906
907 <warn>
908 With the current stable glibc ebuilds, you will be unable to boot a 2.4 kernel
909 after compiling glibc with USE="nptl". Be warned, be careful!
910 </warn>
911
912 <p>
913 Now re-merge glibc (you should do this even if you did not choose to enable
914 NPTL).
915 </p>
916
917 <pre caption="Reinstalling glibc against the new kernel headers">
918 # <i>emerge -a glibc</i>
919 </pre>
920
921 <p>
922 If you enabled NPTL, existing binaries will not use it until they are
923 recompiled. However, any binaries compiled from this point onwards <e>will</e>
924 use NPTL. You may wish to recompile all binaries now, e.g.:
925 </p>
926
927 <pre caption="Recompiling all packages on the system">
928 # <i>emerge -e world</i>
929 </pre>
930
931 <p>
932 Alternatively, you can just let your system "naturally" convert itself to NPTL
933 as you update to newer versions of packages when they are released.
934 </p>
935
936 </body>
937 </section>
938 </chapter>
939
940 <chapter>
941 <title>Closing remarks</title>
942 <section>
943 <title>Problems?</title>
944 <body>
945
946 <p>
947 With the incredible amount of work that went into Linux 2.6, it is sometimes
948 inevitable that things which used to work fine, no longer function as expected.
949 </p>
950
951 <p>
952 If you have any problems with your 2.6 kernel, and you can confirm that this
953 problem does not exist with Linux 2.4, then please open a bug with us on our
954 <uri link="http://bugs.gentoo.org">Bugzilla</uri>. We will investigate the
955 issue, and if we find that it is a problem in the mainline kernel, we may then
956 ask you to file a report at the central kernel bugzilla.
957 </p>
958
959 </body>
960 </section>
961 <section>
962 <title>Conclusion</title>
963 <body>
964
965 <p>
966 Hopefully you have just completed a smooth migration and you are enjoying the
967 benefits which Linux 2.6 brings over 2.4. As I mentioned at the start, we are
968 looking for feedback on this document - even if your migration went perfectly
969 smoothly. Please <mail link="dsd@gentoo.org">mail me</mail> your feedback so
970 that we can get this document in perfect shape for when 2005.0 comes around.
971 Thanks!
972 </p>
973
974 </body>
975 </section>
976 </chapter>
977 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20