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1 <?xml version="1.0" encoding="UTF-8"?>
2 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/gentoo-alpha-faq.xml,v 1.9 2011/09/04 17:53:40 swift Exp $ -->
3
4 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
5 <guide>
6
7 <title>Gentoo Linux/Alpha Frequently Asked Questions</title>
8 <author title="Author">
9 <mail link="tcort@gentoo.org">Thomas Cort</mail>
10 </author>
11 <author title="Author">
12 <mail link="grknight2k@bluebottle.com">Brian Evans</mail>
13 </author>
14 <author title="Editor">
15 <mail link="nightmorph"/>
16 </author>
17 <author title="Author">
18 <mail link="mattst88">Matt Turner</mail>
19 </author>
20
21 <abstract>
22 This FAQ is intended to answer some of the most frequently asked questions
23 relating to Gentoo/Alpha and Linux/Alpha in general.
24 </abstract>
25
26 <!-- The content of this document is licensed under the CC-BY-SA license -->
27 <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
28 <license/>
29
30 <version>3</version>
31 <date>2013-07-22</date>
32
33 <faqindex>
34 <title>About this Document</title>
35
36 <section>
37 <title>Introduction</title>
38 <body>
39
40 <p>
41 This document contains answers to the most commonly asked questions about
42 Gentoo/Alpha and Alpha/Linux. It's aimed at both new users and experienced
43 users alike.
44 </p>
45
46 </body>
47 </section>
48 </faqindex>
49
50 <chapter>
51 <title>About the Gentoo/Alpha Project</title>
52 <section id="what">
53 <title>What is Gentoo/Alpha?</title>
54 <body>
55
56 <p>
57 The Gentoo/Alpha project is responsible for keeping the Gentoo distribution
58 updated and current for the Alpha platform. This primarily includes keywording
59 packages, porting software, and making new releases. The Gentoo/Alpha project
60 aims to provide a usable environment for both desktops and servers.
61 </p>
62
63 </body>
64 </section>
65 </chapter>
66
67 <chapter>
68 <title>The Alpha Architecture</title>
69 <section id="dead">
70 <title>Isn't the Alpha architecture dead?</title>
71 <body>
72
73 <p>
74 Kind of, yes. HP stopped taking orders for new Alpha systems on April 27, 2007.
75 and for Alpha options and upgrades on April 25, 2008. See their <uri
76 link="http://h18002.www1.hp.com/alphaserver/evolution.html">planning page</uri>
77 for more details.
78 </p>
79
80 </body>
81 </section>
82 <section id="bitapps">
83 <title>Can I run 32-bit applications?</title>
84 <body>
85
86 <p>
87 No, all Alpha systems use a pure 64 bit kernel and a pure 64 bit userland. You
88 cannot even force gcc to output 32 bit code using the <c>-m32</c> compiler
89 flag.
90 </p>
91
92 </body>
93 </section>
94 <section id="endian">
95 <title>Is Alpha big endian or little endian?</title>
96 <body>
97
98 <p>
99 Alpha systems are little endian. A large Cray system using Alphas was big
100 endian, but Linux will never support it.
101 </p>
102
103 </body>
104 </section>
105 <section id="i386">
106 <title>Can I run Linux/x86 applications on Alpha?</title>
107 <body>
108
109 <p>
110 No, not without a x86 emulator like <uri
111 link="http://wiki.qemu.org/Main_Page">qemu</uri>. In the past DEC/Compaq/HP
112 maintained a program called <c>em86</c> which allowed Linux/x86 applications to
113 be run on Linux/Alpha systems. However, the program is closed source and no
114 longer maintained upstream. There are no <c>em86</c> binaries available that
115 are compatible with gcc-3's ABI.
116 </p>
117
118 </body>
119 </section>
120 <section id="why">
121 <title>Why install Gentoo on Alpha?</title>
122 <body>
123
124 <p>
125 Admittedly, you can find faster 64-bit systems out there, like amd64. However,
126 that doesn't mean that Alpha systems are useless. The following are a few good
127 reasons why you'd want to install Linux on this sort of hardware:
128 </p>
129
130 <ul>
131 <li>
132 You can turn an old computer into something useful. Older Alphas make great
133 routers and servers. Their desktop performance isn't that bad either.
134 </li>
135 <li>You will learn about unusual computer hardware.</li>
136 <li>
137 It's cool. How many people can say they've got Linux running on an Alpha?
138 </li>
139 </ul>
140
141 </body>
142 </section>
143 <section id="where">
144 <title>Where can I buy Alpha hardware?</title>
145 <body>
146
147 <p>
148 Alpha hardware generally isn't available at your local computer store.
149 <uri link="http://ebay.com">eBay</uri> is usually a
150 good option, assuming that the shipping doesn't cost you too much. There are
151 several used equipment dealers that can be found via Google, however most of
152 them charge too much.
153 </p>
154
155 </body>
156 </section>
157 </chapter>
158
159 <chapter>
160 <title>Hardware</title>
161 <section id="ascase">
162 <title>I opened up the case on an AlphaServer and now it won't power
163 on, what do I do?</title>
164 <body>
165
166 <p>
167 Make sure the top panel of the case is on and properly in place. The middle of
168 the top panel of the case has a small piece of metal oriented downwards. When
169 the top panel is put back in place properly, the small piece of metal will
170 press down on a switch. When the switch isn't pressed down, the system will
171 refuse to power on.
172 </p>
173
174 </body>
175 </section>
176 </chapter>
177
178 <chapter>
179 <title>Alpha Specific Compiler Flags</title>
180 <section id="CFLAGS">
181 <title>Is the use of Alpha specific compiler flags recommended?</title>
182 <body>
183
184 <p>
185 As with all compiler optimizations, don't over do it. Use these flags with care
186 and they will give you a stable, speedy system; use them too aggressively and
187 you could seriously break your system. When in doubt, leave it out. If you need
188 further clarification, check the <c>gcc</c> man page.
189 </p>
190
191 </body>
192 </section>
193 <section id="MCPU">
194 <title>
195 How do I optimize for a specific instruction set and scheduling model?
196 </title>
197 <body>
198
199 <p>
200 You can optimize for a specific instruction set and scheduling model with
201 <c>-mcpu=XXX</c>, where XXX is your cpu type. Valid cpu types are <c>ev4</c>,
202 <c>ev45</c>, <c>ev5</c>, <c>ev56</c>, <c>pca56</c>, <c>ev6</c> and <c>ev67</c>.
203 If you do not use the <c>-mcpu=XXX</c> flag, then <c>gcc</c> will default to
204 the cpu type of the machine it was compiled on. <c>-mcpu=</c> is equivalent to
205 the <c>-march=</c> flag on x86.
206 </p>
207
208 <note>
209 AlphaServer 800 users should set <c>ev5</c>. There are known issues setting
210 <c>ev56</c> particularly with Xorg causing a full system lock up.
211 </note>
212
213 </body>
214 </section>
215 <section id="MTUNE">
216 <title>
217 How do I specify the scheduling model without changing the instruction set?
218 </title>
219 <body>
220
221 <p>
222 You can specify the scheduling model without changing the instruction set with
223 <c>-mtune=XXX</c>, where XXX is your cpu type. Valid cpu types are <c>ev4</c>,
224 <c>ev45</c>, <c>ev5</c>, <c>ev56</c>, <c>pca56</c>, <c>ev6</c> and <c>ev67</c>.
225 <c>-mtune=</c> is implied by <c>-mcpu=</c>, so you don't need to specify this
226 with if you set <c>-mcpu=</c>. <c>-mtune=</c> is equivalent to the
227 <c>-mcpu=</c> flag on x86.
228 </p>
229
230 </body>
231 </section>
232 <section id="mieee">
233 <title>How do I enable software assisted floating point numbers?</title>
234 <body>
235
236 <p>
237 You can enable software assisted floating point numbers with <c>-mieee</c>.
238 This will enable software assistance to correctly support denormalized numbers
239 and exceptional IEEE values such as not-a-number and plus/minus infinity.
240 </p>
241
242 <p>
243 This should be in your global <c>CFLAGS</c> unless you really know what you are
244 doing.
245 </p>
246
247 </body>
248 </section>
249 <section id="MEMLAT">
250 <title>How do I specify the memory latency of my system?</title>
251 <body>
252
253 <p>
254 You can specify the memory latency of your system with
255 <c>-mmemory-latency=XXX</c>, where XXX is the number of clock cycles. This sets
256 the latency time that the scheduler should assume for memory references.
257 <c>gcc</c> has some predefined "typical" values that are also accepted by
258 <c>-mmemory-latency=XXX</c>. Those values are <c>L1</c> for Dcache, <c>L2</c>
259 for Scache, <c>L3</c> for Bcache, and <c>main</c> for main memory.
260 </p>
261
262 <p>
263 This flag should probably not be use in your global <c>CFLAGS</c> as the value
264 you choose is highly dependent on the memory access pattern of the application
265 you are compiling.
266 </p>
267
268 </body>
269 </section>
270 <section id="SMALLDATA">
271 <title>
272 How do I specify that static data should be placed in the small data area?
273 </title>
274 <body>
275
276 <p>
277 You can specify that static data should be placed in the small data area with
278 <c>-msmall-data</c>. This will cause <c>gcc</c> to take advantage of some
279 features of the Alpha architecture by storing heavily used pieces of data in
280 specific sections called the small memory sections. The sections are limited to
281 64KiB which means accessing anything stored in them will only take one
282 instruction.
283 </p>
284
285 <p>
286 <c>-fPIC</c> will override <c>-msmall-data</c>, so you should use the
287 <c>-fpic</c> flag instead if you do not want <c>-msmall-data</c> to be
288 overridden.
289 </p>
290
291 <p>
292 This flag should probably not be used in your global <c>CFLAGS</c> as some
293 objects require more than 64KiB to be stored, and this will cause a gp_overflow
294 ld error.
295 </p>
296
297 </body>
298 </section>
299 <section id="SMALLTEXT">
300 <title>
301 How do I specify that object code should be placed in the small text area?
302 </title>
303 <body>
304
305 <p>
306 You can specify that object code should be placed in the small text area with
307 <c>-msmall-text</c>. This will cause <c>gcc</c> to assume that the entire
308 program (or library) fits in 4MB, and is thus reachable with a branch
309 instruction. This reduces the number of instructions required for a function
310 call from 4 to 1.
311 </p>
312
313 <p>
314 This flag should probably not be used in your global <c>CFLAGS</c> as some
315 programs (or libraries) are larger than 4MB, and this will cause an ld error.
316 </p>
317
318 </body>
319 </section>
320 <section id="CFLAGSERR">
321 <title>
322 What do I do if any of these compiler flags cause a compile, linker, or
323 runtime error?
324 </title>
325 <body>
326
327 <p>
328 As <uri link="#CFLAGS">already mentioned</uri>, please use these <c>CFLAGS</c>
329 cautiously. They may break your system. If you experience problems, try using
330 less aggressive <c>CFLAGS</c> before <uri link="#bugs">filing a bug
331 report</uri>.
332 </p>
333
334 </body>
335 </section>
336 </chapter>
337
338 <chapter>
339 <title>Alpha Booting and Bootloaders</title>
340 <section id="SRM">
341 <title>What is SRM?</title>
342 <body>
343
344 <p>
345 SRM is based on the Alpha Console Subsystem specification, which provides an
346 operating environment for OpenVMS, Tru64 UNIX, and Linux operating systems. See
347 the <uri link="http://www.alphalinux.org/faq/SRM-HOWTO/"> SRM Howto</uri> for
348 more information about SRM.
349 </p>
350
351 </body>
352 </section>
353 <section id="ARC">
354 <title>What is ARC?</title>
355 <body>
356
357 <p>
358 ARC is based on the Advanced RISC Computing (ARC) specification, which provides
359 an operating environment for Windows NT.
360 </p>
361
362 </body>
363 </section>
364 <section id="ARCvsSRM">
365 <title>How can I tell if which firmware my Alpha has, ARC or SRM?</title>
366 <body>
367
368 <p>
369 When you power your system on you will see a screen with a blue background and
370 white text if it is using SRM. You will see a graphical boot system if it is
371 using ARC.
372 </p>
373
374 </body>
375 </section>
376 <section id="whichbootloader">
377 <title>Which bootloader do I use?</title>
378 <body>
379
380 <p>
381 If your Alpha system supports SRM, then you should use aboot. If your system
382 supports both SRM and ARCs (ARC, AlphaBIOS, ARCSBIOS), then you should follow
383 <uri link="http://www.alphalinux.org/faq/x31.html">the SRM Firmware Howto</uri>
384 for switching to SRM and use aboot. If your system can only use ARCs (Ruffian,
385 xl, etc.) then you will need to choose milo.
386 </p>
387
388 </body>
389 </section>
390 <section id="abootfs">
391 <title>Can aboot boot kernels from EXT4, XFS, ReiserFS, or JFS partitions?</title>
392 <body>
393
394 <p>
395 No, <c>aboot</c> only supports booting kernels from <c>ext2</c> and <c>ext3</c>
396 partitions. You may still use other files systems for your root partition, you
397 just need to create a <path>/boot</path> partition with either <c>ext2</c> or
398 <c>ext3</c> on it.
399 </p>
400
401 <p>
402 Support for ext4 is planned. In fact, there are patches floating
403 around that add support for <uri
404 link="https://bugs.gentoo.org/show_bug.cgi?id=106855">ReiserFS</uri>, <uri
405 link="https://bugs.gentoo.org/show_bug.cgi?id=107103">XFS</uri>, and <uri
406 link="http://alphalinux.org/wiki/index.php/Aboot_EXT4_support">ext4</uri>.
407 </p>
408
409 </body>
410 </section>
411 </chapter>
412 <chapter>
413 <title>Software</title>
414
415 <section id="javasupport">
416 <title>How is Java support in Gentoo/Alpha?</title>
417 <body>
418
419 <p>
420 Compaq/HP offered binary packages, called <c>compaq-jre</c> and <c>compaq-jdk</c>.
421 They stopped all support, and the packages were removed from Gentoo on October
422 11, 2006. Since then, we haven't supported Java.
423 </p>
424
425 </body>
426 </section>
427
428 <section id="currentjava">
429 <title>Will there ever be working Java support?</title>
430 <body>
431
432 <p>
433 It's possible to use <c>icedtea</c> on Alpha, but we have no plans to
434 support it, due to the high maintenance costs involved with testing hundreds of
435 additional packages.
436 </p>
437
438 </body>
439 </section>
440 <section id="dotnetsupport">
441 <title>How is .NET support in Gentoo/Alpha?</title>
442 <body>
443
444 <p>
445 Neither of the two main open source efforts, <uri
446 link="http://www.mono-project.com/Main_Page">mono</uri> nor <uri
447 link="http://www.dotgnu.org/">DotGNU</uri>, support the alpha architecture.
448 </p>
449
450 </body>
451 </section>
452 <section id="dotnetneeded">
453 <title>What is needed for .NET support?</title>
454 <body>
455
456 <p>
457 Bringing .NET to Alpha isn't a simple task. It requires coding all of the
458 assembly language code generation macros for the JIT (just in time) compiler
459 and coding architecture specific functions (register allocators, etc).
460 </p>
461
462 </body>
463 </section>
464 </chapter>
465
466 <chapter>
467 <title>Alpha Linux Kernel</title>
468 <section id="whichkernel">
469 <title>Which kernel sources should I use?</title>
470 <body>
471
472 <p>
473 We recommend using <c>gentoo-sources</c> but <c>vanilla-sources</c> is
474 also supported by Gentoo/Alpha. You should read the <uri
475 link="/doc/en/gentoo-kernel.xml">Gentoo Kernel Guide</uri> to determine which
476 one is right for your needs.
477 </p>
478
479 </body>
480 </section>
481 <section id="kernel24">
482 <title>My system is broken with kernel-2.6, Can I build a 2.4 bassed system?</title>
483 <body>
484
485 <p>
486 Gentoo/Alpha stopped supporting 2.4 kernel and profile in January 2008.
487 Technically you can build a 2.4 Gentoo System (the kernel is in the tree) but
488 you will have to mask all the 2.6 only packages by yourself and you won't have
489 support from developers.
490 </p>
491
492 <p>
493 Gentoo/Alpha will review all bug reports about non-working 2.6 systems and
494 will try to help as much as we can.
495 </p>
496
497 </body>
498 </section>
499
500 <section id="selinux">
501 <title>Are hardened-sources supported?</title>
502 <body>
503
504 <p>
505 Short answer is no. They were supported some time ago, but we lost the hardware
506 and the maintainer so now they are not supported. If you are interested
507 and want to continue the initial work, please let us know.
508 </p>
509
510 </body>
511 </section>
512 <section id="smpkernel">
513 <title>Does the 2.6 kernel support Alpha SMP?</title>
514 <body>
515
516 <p>
517 There were some times in the past when it was broken. However, modern kernel
518 versions are known to work well.
519 </p>
520
521 </body>
522 </section>
523 </chapter>
524
525 <chapter>
526 <title>Helping out the Gentoo/Alpha Project</title>
527 <section id="bugs">
528 <title>How do I report bugs?</title>
529 <body>
530
531 <p>
532 If you find a bug or you want to send us patches, then you need to file a bug
533 report. It only takes you a little bit of your time, and your help is really
534 appreciated. Please follow the <uri
535 link="https://wiki.gentoo.org/wiki/Bugzilla_HOWTO">Gentoo Bug Reporting Guide</uri>.
536 </p>
537
538 </body>
539 </section>
540 <section id="project">
541 <title>How can I help the Gentoo/Alpha Project?</title>
542 <body>
543
544 <p>
545 Users can help us by:
546 </p>
547
548 <ul>
549 <li>Filing clear and concise <uri link="#bugs">bug reports</uri>.</li>
550 <li>Testing software that does not yet have the <c>~alpha</c> keyword.</li>
551 <li>
552 Answering questions on the <uri link="/main/en/lists.xml">mailing
553 lists</uri>, <uri link="http://forums.gentoo.org/viewforum-f-32.html">
554 forum</uri> and IRC channel.
555 </li>
556 <li>Sending patches</li>
557 <li>Becoming an <uri
558 link="http://www.gentoo.org/proj/en/base/alpha/AT/index.xml">AT</uri>
559 </li>
560 </ul>
561
562 </body>
563 </section>
564 <section id="archtest">
565 <title>Is there an Alpha Arch Testers Project?</title>
566 <body>
567
568 <p>
569 Yes, see the <uri link="http://www.gentoo.org/proj/en/base/alpha/AT/index.xml">
570 Gentoo Linux Alpha Arch Testers Project</uri> page for details.
571 </p>
572
573 </body>
574 </section>
575 </chapter>
576
577 <chapter>
578 <title>Troubleshooting</title>
579 <section id="tshoot-xorg">
580 <title>Why is Xorg locking up my Alpha?</title>
581 <body>
582
583 <p>
584 This is usually caused by a bad -mcpu setting. For example, the AlphaServer
585 800 needs to be compiled with the <c>ev5</c> flag for xorg <b>and</b> glibc.
586 Failing to do so will cause undesired results.
587 </p>
588
589 </body>
590 </section>
591 </chapter>
592
593 <chapter>
594 <title>Other Resources</title>
595 <section id="noforum">
596 <title>Why is there no Gentoo on Alpha forum?</title>
597 <body>
598
599 <p>
600 On the <uri link="http://forums.gentoo.org">Gentoo Forums</uri> there are
601 several arch specific categories like <uri
602 link="http://forums.gentoo.org/viewforum-f-24.html">Gentoo on PPC</uri> and
603 <uri link="http://forums.gentoo.org/viewforum-f-24.html">Gentoo on
604 Sparc</uri>. There is no Gentoo on Alpha category because there simply isn't
605 enough Gentoo/Alpha activity on the forums to warrant one. All Alpha related
606 posts should go in the <uri
607 link="http://forums.gentoo.org/viewforum-f-32.html"> Gentoo on Alternative
608 Architectures</uri> category.
609 </p>
610
611 </body>
612 </section>
613 <section id="othergentoo">
614 <title>Where can I get more help or information about Gentoo/Alpha?</title>
615 <body>
616
617 <p>
618 If any of your questions weren't answered here, you can try other resources
619 like the <uri link="/doc/en/handbook/handbook-alpha.xml">Alpha Handbook</uri>
620 or <uri link="/proj/en/base/alpha/">our project homepage</uri>. You can also
621 ask us at <c>#gentoo-alpha</c> on <c>irc.freenode.net</c>, <uri
622 link="http://forums.gentoo.org/viewforum-f-32.html">Gentoo on Alternative
623 Architectures Forum</uri>, or on the <mail>gentoo-alpha@lists.gentoo.org</mail>
624 mailing list.
625 </p>
626
627 </body>
628 </section>
629 <section id="other">
630 <title>Where can I get more help or information about Alpha/Linux?</title>
631 <body>
632
633 <p>
634 <uri link="http://alphalinux.org/wiki/index.php/Main_Page">AlphaLinux.org</uri>
635 is a central repository for all things Alpha/Linux.
636 </p>
637
638 </body>
639 </section>
640 </chapter>
641 </guide>

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