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author | Richard Purdie <richard.purdie@linuxfoundation.org> | 2014-04-11 17:38:18 +0100 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2014-04-21 23:03:18 +0100 |
commit | 392de9d5685e17aed868eb5659032103748825f4 (patch) | |
tree | df0ea22b9719dbddb374aeb185ec9760eccd74bb /bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml | |
parent | 982aa36251a4a855102575b8a590929787c645fd (diff) | |
download | poky-392de9d5685e17aed868eb5659032103748825f4.tar.gz |
bitbake: doc: Rename user-manual -> bitbake-user-manual
This manual gets combined with other manuals and in that context, it helps
a lot if its seen as the Bitbake User Manual. Renames are a pain but
this is worthwhile so that other docs can correctly be combined with this
one. This also clarifies things like google search results which is helpful.
(Bitbake rev: 452a62ae0c2793e281d6769fd3e45500a74898d6)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml')
-rw-r--r-- | bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml | 622 |
1 files changed, 622 insertions, 0 deletions
diff --git a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml new file mode 100644 index 0000000000..5aa53defc4 --- /dev/null +++ b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-fetching.xml | |||
@@ -0,0 +1,622 @@ | |||
1 | <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | ||
2 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> | ||
3 | |||
4 | <chapter> | ||
5 | <title>File Download Support</title> | ||
6 | |||
7 | <para> | ||
8 | BitBake's fetch module is a standalone piece of library code | ||
9 | that deals with the intricacies of downloading source code | ||
10 | and files from remote systems. | ||
11 | Fetching source code is one of the corner stones of building software. | ||
12 | As such, this module forms an important part of BitBake. | ||
13 | </para> | ||
14 | |||
15 | <para> | ||
16 | The current fetch module is called "fetch2" and refers to the | ||
17 | fact that it is the second major version of the API. | ||
18 | The original version is obsolete and removed from the codebase. | ||
19 | Thus, in all cases, "fetch" refers to "fetch2" in this | ||
20 | manual. | ||
21 | </para> | ||
22 | |||
23 | <section id='the-download-fetch'> | ||
24 | <title>The Download (Fetch)</title> | ||
25 | |||
26 | <para> | ||
27 | BitBake takes several steps when fetching source code or files. | ||
28 | The fetcher codebase deals with two distinct processes in order: | ||
29 | obtaining the files from somewhere (cached or otherwise) | ||
30 | and then unpacking those files into a specific location and | ||
31 | perhaps in a specific way. | ||
32 | Getting and unpacking the files is often optionally followed | ||
33 | by patching. | ||
34 | Patching, however, is not covered by this module. | ||
35 | </para> | ||
36 | |||
37 | <para> | ||
38 | The code to execute the first part of this process, a fetch, | ||
39 | looks something like the following: | ||
40 | <literallayout class='monospaced'> | ||
41 | src_uri = (d.getVar('SRC_URI', True) or "").split() | ||
42 | fetcher = bb.fetch2.Fetch(src_uri, d) | ||
43 | fetcher.download() | ||
44 | </literallayout> | ||
45 | This code sets up an instance of the fetch class. | ||
46 | The instance uses a space-separated list of URLs from the | ||
47 | <link linkend='var-SRC_URI'><filename>SRC_URI</filename></link> | ||
48 | variable and then calls the <filename>download</filename> | ||
49 | method to download the files. | ||
50 | </para> | ||
51 | |||
52 | <para> | ||
53 | The instantiation of the fetch class is usually followed by: | ||
54 | <literallayout class='monospaced'> | ||
55 | rootdir = l.getVar('WORKDIR', True) | ||
56 | fetcher.unpack(rootdir) | ||
57 | </literallayout> | ||
58 | This code unpacks the downloaded files to the | ||
59 | specified by <filename>WORKDIR</filename>. | ||
60 | <note> | ||
61 | For convenience, the naming in these examples matches | ||
62 | the variables used by OpenEmbedded. | ||
63 | </note> | ||
64 | The <filename>SRC_URI</filename> and <filename>WORKDIR</filename> | ||
65 | variables are not coded into the fetcher. | ||
66 | They variables can (and are) called with different variable names. | ||
67 | In OpenEmbedded for example, the shared state (sstate) code uses | ||
68 | the fetch module to fetch the sstate files. | ||
69 | </para> | ||
70 | |||
71 | <para> | ||
72 | When the <filename>download()</filename> method is called, | ||
73 | BitBake tries to fulfill the URLs by looking for source files | ||
74 | in a specific search order: | ||
75 | <itemizedlist> | ||
76 | <listitem><para><emphasis>Pre-mirror Sites:</emphasis> | ||
77 | BitBake first uses pre-mirrors to try and find source files. | ||
78 | These locations are defined using the | ||
79 | <link linkend='var-PREMIRRORS'><filename>PREMIRRORS</filename></link> | ||
80 | variable. | ||
81 | </para></listitem> | ||
82 | <listitem><para><emphasis>Source URI:</emphasis> | ||
83 | If pre-mirrors fail, BitBake uses the original URL (e.g from | ||
84 | <filename>SRC_URI</filename>). | ||
85 | </para></listitem> | ||
86 | <listitem><para><emphasis>Mirror Sites:</emphasis> | ||
87 | If fetch failures occur, BitBake next uses mirror location as | ||
88 | defined by the | ||
89 | <link linkend='var-MIRRORS'><filename>MIRRORS</filename></link> | ||
90 | variable. | ||
91 | </para></listitem> | ||
92 | </itemizedlist> | ||
93 | </para> | ||
94 | |||
95 | <para> | ||
96 | For each URL passed to the fetcher, the fetcher | ||
97 | calls the submodule that handles that particular URL type. | ||
98 | This behavior can be the source of some confusion when you | ||
99 | are providing URLs for the <filename>SRC_URI</filename> | ||
100 | variable. | ||
101 | Consider the following two URLs: | ||
102 | <literallayout class='monospaced'> | ||
103 | http://git.yoctoproject.org/git/poky;protocol=git | ||
104 | git://git.yoctoproject.org/git/poky;protocol=http | ||
105 | </literallayout> | ||
106 | In the former case, the URL is passed to the | ||
107 | <filename>wget</filename> fetcher, which does not | ||
108 | understand "git". | ||
109 | Therefore, the latter case is the correct form since the | ||
110 | Git fetcher does know how to use HTTP as a transport. | ||
111 | </para> | ||
112 | |||
113 | <para> | ||
114 | Here are some examples that show commonly used mirror | ||
115 | definitions: | ||
116 | <literallayout class='monospaced'> | ||
117 | PREMIRRORS ?= "\ | ||
118 | bzr://.*/.* http://somemirror.org/sources/ \n \ | ||
119 | cvs://.*/.* http://somemirror.org/sources/ \n \ | ||
120 | git://.*/.* http://somemirror.org/sources/ \n \ | ||
121 | hg://.*/.* http://somemirror.org/sources/ \n \ | ||
122 | osc://.*/.* http://somemirror.org/sources/ \n \ | ||
123 | p4://.*/.* http://somemirror.org/sources/ \n \ | ||
124 | svn://.*/.* http://somemirror.org/sources/ \n" | ||
125 | |||
126 | MIRRORS =+ "\ | ||
127 | ftp://.*/.* http://somemirror.org/sources/ \n \ | ||
128 | http://.*/.* http://somemirror.org/sources/ \n \ | ||
129 | https://.*/.* http://somemirror.org/sources/ \n" | ||
130 | </literallayout> | ||
131 | It is useful to note that BitBake supports | ||
132 | cross-URLs. | ||
133 | It is possible to mirror a Git repository on an HTTP | ||
134 | server as a tarball. | ||
135 | This is what the <filename>git://</filename> mapping in | ||
136 | the previous example does. | ||
137 | </para> | ||
138 | |||
139 | <para> | ||
140 | Since network accesses are slow, Bitbake maintains a | ||
141 | cache of files downloaded from the network. | ||
142 | Any source files that are not local (i.e. | ||
143 | downloaded from the Internet) are placed into the download | ||
144 | directory, which is specified by the | ||
145 | <link linkend='var-DL_DIR'><filename>DL_DIR</filename></link> | ||
146 | variable. | ||
147 | </para> | ||
148 | |||
149 | <para> | ||
150 | File integrity is of key importance for reproducing builds. | ||
151 | For non-local archive downloads, the fetcher code can verify | ||
152 | sha256 and md5 checksums to ensure the archives have been | ||
153 | downloaded correctly. | ||
154 | You can specify these checksums by using the | ||
155 | <filename>SRC_URI</filename> variable with the appropriate | ||
156 | varflags as follows: | ||
157 | <literallayout class='monospaced'> | ||
158 | SRC_URI[md5sum] = "value" | ||
159 | SRC_URI[sha256sum] = "value" | ||
160 | </literallayout> | ||
161 | You can also specify the checksums as parameters on the | ||
162 | <filename>SRC_URI</filename> as shown below: | ||
163 | <literallayout class='monospaced'> | ||
164 | SRC_URI = "http://example.com/foobar.tar.bz2;md5sum=4a8e0f237e961fd7785d19d07fdb994d" | ||
165 | </literallayout> | ||
166 | If multiple URIs exist, you can specify the checksums either | ||
167 | directly as in the previous example, or you can name the URLs. | ||
168 | The following syntax shows how you name the URIs: | ||
169 | <literallayout class='monospaced'> | ||
170 | SRC_URI = "http://example.com/foobar.tar.bz2;name=foo" | ||
171 | SRC_URI[foo.md5sum] = 4a8e0f237e961fd7785d19d07fdb994d | ||
172 | </literallayout> | ||
173 | After a file has been downloaded and has had its checksum checked, | ||
174 | a ".done" stamp is placed in <filename>DL_DIR</filename>. | ||
175 | BitBake uses this stamp during subsequent builds to avoid | ||
176 | downloading or comparing a checksum for the file again. | ||
177 | <note> | ||
178 | It is assumed that local storage is safe from data corruption. | ||
179 | If this were not the case, there would be bigger issues to worry about. | ||
180 | </note> | ||
181 | </para> | ||
182 | |||
183 | <para> | ||
184 | If | ||
185 | <link linkend='var-BB_STRICT_CHECKSUM'><filename>BB_STRICT_CHECKSUM</filename></link> | ||
186 | is set, any download without a checksum triggers an | ||
187 | error message. | ||
188 | The | ||
189 | <link linkend='var-BB_NO_NETWORK'><filename>BB_NO_NETWORK</filename></link> | ||
190 | variable can be used to make any attempted network access a fatal | ||
191 | error, which is useful for checking that mirrors are complete | ||
192 | as well as other things. | ||
193 | </para> | ||
194 | </section> | ||
195 | |||
196 | <section id='bb-the-unpack'> | ||
197 | <title>The Unpack</title> | ||
198 | |||
199 | <para> | ||
200 | The unpack process usually immediately follows the download. | ||
201 | For all URLs except Git URLs, BitBake uses the common | ||
202 | <filename>unpack</filename> method. | ||
203 | </para> | ||
204 | |||
205 | <para> | ||
206 | A number of parameters exist that you can specify within the | ||
207 | URL to govern the behavior of the unpack stage: | ||
208 | <itemizedlist> | ||
209 | <listitem><para><emphasis>unpack:</emphasis> | ||
210 | Controls whether the URL components are unpacked. | ||
211 | If set to "1", which is the default, the components | ||
212 | are unpacked. | ||
213 | If set to "0", the unpack stage leaves the file alone. | ||
214 | This parameter is useful when you want an archive to be | ||
215 | copied in and not be unpacked. | ||
216 | </para></listitem> | ||
217 | <listitem><para><emphasis>dos:</emphasis> | ||
218 | Applies to <filename>.zip</filename> and | ||
219 | <filename>.jar</filename> files and specifies whether to | ||
220 | use DOS line ending conversion on text files. | ||
221 | </para></listitem> | ||
222 | <listitem><para><emphasis>basepath:</emphasis> | ||
223 | Instructs the unpack stage to strip the specified | ||
224 | directories from the source path when unpacking. | ||
225 | </para></listitem> | ||
226 | <listitem><para><emphasis>subdir:</emphasis> | ||
227 | Unpacks the specific URL to the specified subdirectory | ||
228 | within the root directory. | ||
229 | </para></listitem> | ||
230 | </itemizedlist> | ||
231 | The unpack call automatically decompresses and extracts files | ||
232 | with ".Z", ".z", ".gz", ".xz", ".zip", ".jar", ".ipk", ".rpm". | ||
233 | ".srpm", ".deb" and ".bz2" extensions as well as various combinations | ||
234 | of tarball extensions. | ||
235 | </para> | ||
236 | |||
237 | <para> | ||
238 | As mentioned, the Git fetcher has its own unpack method that | ||
239 | is optimized to work with Git trees. | ||
240 | Basically, this method works by cloning the tree into the final | ||
241 | directory. | ||
242 | The process is completed using references so that there is | ||
243 | only one central copy of the Git metadata needed. | ||
244 | </para> | ||
245 | </section> | ||
246 | |||
247 | <section id='bb-fetchers'> | ||
248 | <title>Fetchers</title> | ||
249 | |||
250 | <para> | ||
251 | As mentioned earlier, the URL prefix determines which | ||
252 | fetcher submodule BitBake uses. | ||
253 | Each submodule can support different URL parameters, | ||
254 | which are described in the following sections. | ||
255 | </para> | ||
256 | |||
257 | <section id='local-file-fetcher'> | ||
258 | <title>Local file fetcher (<filename>file://</filename>)</title> | ||
259 | |||
260 | <para> | ||
261 | This submodule handles URLs that begin with | ||
262 | <filename>file://</filename>. | ||
263 | The filename you specify with in the URL can | ||
264 | either be an absolute or relative path to a file. | ||
265 | If the filename is relative, the contents of the | ||
266 | <link linkend='var-FILESPATH'><filename>FILESPATH</filename></link> | ||
267 | variable is used in the same way | ||
268 | <filename>PATH</filename> is used to find executables. | ||
269 | Failing that, | ||
270 | <link linkend='var-FILESDIR'><filename>FILESDIR</filename></link> | ||
271 | is used to find the appropriate relative file. | ||
272 | <note> | ||
273 | <filename>FILESDIR</filename> is deprecated and can | ||
274 | be replaced with <filename>FILESPATH</filename>. | ||
275 | Because <filename>FILESDIR</filename> is likely to be | ||
276 | removed, you should not use this variable in any new code. | ||
277 | </note> | ||
278 | If the file cannot be found, it is assumed that it is available in | ||
279 | <link linkend='var-DL_DIR'><filename>DL_DIR</filename></link> | ||
280 | by the time the <filename>download()</filename> method is called. | ||
281 | </para> | ||
282 | |||
283 | <para> | ||
284 | If you specify a directory, the entire directory is | ||
285 | unpacked. | ||
286 | </para> | ||
287 | |||
288 | <para> | ||
289 | Here are some example URLs: | ||
290 | <literallayout class='monospaced'> | ||
291 | SRC_URI = "file://relativefile.patch" | ||
292 | SRC_URI = "file://relativefile.patch;this=ignored" | ||
293 | SRC_URI = "file:///Users/ich/very_important_software" | ||
294 | </literallayout> | ||
295 | </para> | ||
296 | </section> | ||
297 | |||
298 | <section id='cvs-fetcher'> | ||
299 | <title>CVS fetcher (<filename>(cvs://</filename>)</title> | ||
300 | |||
301 | <para> | ||
302 | This submodule handles checking out files from the | ||
303 | CVS version control system. | ||
304 | You can configure it using a number of different variables: | ||
305 | <itemizedlist> | ||
306 | <listitem><para><emphasis><filename>FETCHCMD_cvs</filename>:</emphasis> | ||
307 | The name of the executable to use when running | ||
308 | the <filename>cvs</filename> command. | ||
309 | This name is usually "cvs". | ||
310 | </para></listitem> | ||
311 | <listitem><para><emphasis><filename>SRCDATE</filename>:</emphasis> | ||
312 | The date to use when fetching the CVS source code. | ||
313 | A special value of "now" causes the checkout to | ||
314 | be updated on every build. | ||
315 | </para></listitem> | ||
316 | <listitem><para><emphasis><filename>CVSDIR</filename>:</emphasis> | ||
317 | Specifies where a temporary checkout is saved. | ||
318 | The location is often <filename>DL_DIR/cvs</filename>. | ||
319 | </para></listitem> | ||
320 | <listitem><para><emphasis><filename>CVS_PROXY_HOST</filename>:</emphasis> | ||
321 | The name to use as a "proxy=" parameter to the | ||
322 | <filename>cvs</filename> command. | ||
323 | </para></listitem> | ||
324 | <listitem><para><emphasis><filename>CVS_PROXY_PORT</filename>:</emphasis> | ||
325 | The port number to use as a "proxyport=" parameter to | ||
326 | the <filename>cvs</filename> command. | ||
327 | </para></listitem> | ||
328 | </itemizedlist> | ||
329 | As well as the standard username and password URL syntax, | ||
330 | you can also configure the fetcher with various URL parameters: | ||
331 | </para> | ||
332 | |||
333 | <para> | ||
334 | The supported parameters are as follows: | ||
335 | <itemizedlist> | ||
336 | <listitem><para><emphasis>"method":</emphasis> | ||
337 | The protocol over which to communicate with the cvs server. | ||
338 | By default, this protocol is "pserver". | ||
339 | If "method" is set to "ext", BitBake examines the | ||
340 | "rsh" parameter and sets <filename>CVS_RSH</filename>. | ||
341 | You can use "dir" for local directories. | ||
342 | </para></listitem> | ||
343 | <listitem><para><emphasis>"module":</emphasis> | ||
344 | Specifies the module to check out. | ||
345 | You must supply this parameter. | ||
346 | </para></listitem> | ||
347 | <listitem><para><emphasis>"tag":</emphasis> | ||
348 | Describes which CVS TAG should be used for | ||
349 | the checkout. | ||
350 | By default, the TAG is empty. | ||
351 | </para></listitem> | ||
352 | <listitem><para><emphasis>"date":</emphasis> | ||
353 | Specifies a date. | ||
354 | If no "date" is specified, the | ||
355 | <link linkend='var-SRCDATE'><filename>SRCDATE</filename></link> | ||
356 | of the configuration is used to checkout a specific date. | ||
357 | The special value of "now" causes the checkout to be | ||
358 | updated on every build. | ||
359 | </para></listitem> | ||
360 | <listitem><para><emphasis>"localdir":</emphasis> | ||
361 | Used to rename the module. | ||
362 | Effectively, you are renaming the output directory | ||
363 | to which the module is unpacked. | ||
364 | You are forcing the module into a special | ||
365 | directory relative to <filename>CVSDIR</filename>. | ||
366 | </para></listitem> | ||
367 | <listitem><para><emphasis>"rsh"</emphasis> | ||
368 | Used in conjunction with the "method" parameter. | ||
369 | </para></listitem> | ||
370 | <listitem><para><emphasis>"scmdata":</emphasis> | ||
371 | Causes the CVS metadata to be maintained in the tarball | ||
372 | the fetcher creates when set to "keep". | ||
373 | The tarball is expanded into the work directory. | ||
374 | By default, the CVS metadata is removed. | ||
375 | </para></listitem> | ||
376 | <listitem><para><emphasis>"fullpath":</emphasis> | ||
377 | Controls whether the resulting checkout is at the | ||
378 | module level, which is the default, or is at deeper | ||
379 | paths. | ||
380 | </para></listitem> | ||
381 | <listitem><para><emphasis>"norecurse":</emphasis> | ||
382 | Causes the fetcher to only checkout the specified | ||
383 | directory with no recurse into any subdirectories. | ||
384 | </para></listitem> | ||
385 | <listitem><para><emphasis>"port":</emphasis> | ||
386 | The port to which the CVS server connects. | ||
387 | </para></listitem> | ||
388 | </itemizedlist> | ||
389 | Some example URLs are as follows: | ||
390 | <literallayout class='monospaced'> | ||
391 | SRC_URI = "cvs://CVSROOT;module=mymodule;tag=some-version;method=ext" | ||
392 | SRC_URI = "cvs://CVSROOT;module=mymodule;date=20060126;localdir=usethat" | ||
393 | </literallayout> | ||
394 | </para> | ||
395 | </section> | ||
396 | |||
397 | <section id='http-ftp-fetcher'> | ||
398 | <title>HTTP/FTP wget fetcher (<filename>http://</filename>, <filename>ftp://</filename>, <filename>https://</filename>)</title> | ||
399 | |||
400 | <para> | ||
401 | This fetcher obtains files from web and FTP servers. | ||
402 | Internally, the fetcher uses the wget utility. | ||
403 | </para> | ||
404 | |||
405 | <para> | ||
406 | The executable and parameters used are specified by the | ||
407 | <filename>FETCHCMD_wget</filename> variable, which defaults | ||
408 | to a sensible values. | ||
409 | The fetcher supports a parameter "downloadfilename" that | ||
410 | allows the name of the downloaded file to be specified. | ||
411 | Specifying the name of the downloaded file is useful | ||
412 | for avoiding collisions in | ||
413 | <link linkend='var-DL_DIR'><filename>DL_DIR</filename></link> | ||
414 | when dealing with multiple files that have the same name. | ||
415 | </para> | ||
416 | |||
417 | <para> | ||
418 | Some example URLs are as follows: | ||
419 | <literallayout class='monospaced'> | ||
420 | SRC_URI = "http://oe.handhelds.org/not_there.aac" | ||
421 | SRC_URI = "ftp://oe.handhelds.org/not_there_as_well.aac" | ||
422 | SRC_URI = "ftp://you@oe.handheld.sorg/home/you/secret.plan" | ||
423 | </literallayout> | ||
424 | </para> | ||
425 | </section> | ||
426 | |||
427 | <section id='svn-fetcher'> | ||
428 | <title>Subversion (SVN) Fetcher (<filename>svn://</filename>)</title> | ||
429 | |||
430 | <para> | ||
431 | This fetcher submodule fetches code from the | ||
432 | Subversion source control system. | ||
433 | The executable used is specified by | ||
434 | <filename>FETCHCMD_svn</filename>, which defaults | ||
435 | to "svn". | ||
436 | The fetcher's temporary working directory is set | ||
437 | by <filename>SVNDIR</filename>, which is usually | ||
438 | <filename>DL_DIR/svn</filename>. | ||
439 | </para> | ||
440 | |||
441 | <para> | ||
442 | The supported parameters are as follows: | ||
443 | <itemizedlist> | ||
444 | <listitem><para><emphasis>"module":</emphasis> | ||
445 | The name of the svn module to checkout. | ||
446 | You must provide this parameter. | ||
447 | You can think of this parameter as the top-level | ||
448 | directory of the repository data you want. | ||
449 | </para></listitem> | ||
450 | <listitem><para><emphasis>"protocol":</emphasis> | ||
451 | The protocol to use, which defaults to "svn". | ||
452 | Other options are "svn+ssh" and "rsh". | ||
453 | For "rsh", the "rsh" parameter is also used. | ||
454 | </para></listitem> | ||
455 | <listitem><para><emphasis>"rev":</emphasis> | ||
456 | The revision of the source code to checkout. | ||
457 | </para></listitem> | ||
458 | <listitem><para><emphasis>"date":</emphasis> | ||
459 | The date of the source code to checkout. | ||
460 | Specific revisions are generally much safer to checkout | ||
461 | rather than by date as they do not involve timezones | ||
462 | (e.g. they are much more deterministic). | ||
463 | </para></listitem> | ||
464 | <listitem><para><emphasis>"scmdata":</emphasis> | ||
465 | Causes the “.svn” directories to be available during | ||
466 | compile-time when set to "keep". | ||
467 | By default, these directories are removed. | ||
468 | </para></listitem> | ||
469 | </itemizedlist> | ||
470 | Following are two examples using svn: | ||
471 | <literallayout class='monospaced'> | ||
472 | SRC_URI = "svn://svn.oe.handhelds.org/svn;module=vip;proto=http;rev=667" | ||
473 | SRC_URI = "svn://svn.oe.handhelds.org/svn/;module=opie;proto=svn+ssh;date=20060126" | ||
474 | </literallayout> | ||
475 | </para> | ||
476 | </section> | ||
477 | |||
478 | <section id='git-fetcher'> | ||
479 | <title>GIT Fetcher (<filename>git://</filename>)</title> | ||
480 | |||
481 | <para> | ||
482 | This fetcher submodule fetches code from the Git | ||
483 | source control system. | ||
484 | The fetcher works by creating a bare clone of the | ||
485 | remote into <filename>GITDIR</filename>, which is | ||
486 | usually <filename>DL_DIR/git</filename>. | ||
487 | This bare clone is then cloned into the work directory during the | ||
488 | unpack stage when a specific tree is checked out. | ||
489 | This is done using alternates and by reference to | ||
490 | minimize the amount of duplicate data on the disk and | ||
491 | make the unpack process fast. | ||
492 | The executable used can be set with | ||
493 | <filename>FETCHCMD_git</filename>. | ||
494 | </para> | ||
495 | |||
496 | <para> | ||
497 | This fetcher supports the following parameters: | ||
498 | <itemizedlist> | ||
499 | <listitem><para><emphasis>"protocol":</emphasis> | ||
500 | The protocol used to fetch the files. | ||
501 | The default is "git" when a hostname is set. | ||
502 | If a hostname is not set, the Git protocol is "file". | ||
503 | You can also use "http", "https", "ssh" and "rsync". | ||
504 | </para></listitem> | ||
505 | <listitem><para><emphasis>"nocheckout":</emphasis> | ||
506 | Tells the fetcher to not checkout source code when | ||
507 | unpacking when set to "1". | ||
508 | Set this option for the URL where there is a custom | ||
509 | routine to checkout code. | ||
510 | The default is "0". | ||
511 | </para></listitem> | ||
512 | <listitem><para><emphasis>"rebaseable":</emphasis> | ||
513 | Indicates that the upstream Git repository can be rebased. | ||
514 | You should set this parameter to "1" if | ||
515 | revisions can become detached from branches. | ||
516 | In this case, the source mirror tarball is done per | ||
517 | revision, which has a loss of efficiency. | ||
518 | Rebasing the upstream Git repository could cause the | ||
519 | current revision to disappear from the upstream repository. | ||
520 | This option reminds the fetcher to preserve the local cache | ||
521 | carefully for future use. | ||
522 | The default value for this parameter is "0". | ||
523 | </para></listitem> | ||
524 | <listitem><para><emphasis>"nobranch":</emphasis> | ||
525 | Tells the fetcher to not check the SHA validation | ||
526 | for the branch when set to "1". | ||
527 | The default is "0". | ||
528 | Set this option for the recipe that refers to | ||
529 | the commit that is valid for a tag instead of | ||
530 | the branch. | ||
531 | </para></listitem> | ||
532 | <listitem><para><emphasis>"bareclone":</emphasis> | ||
533 | Tells the fetcher to clone a bare clone into the | ||
534 | destination directory without checking out a working tree. | ||
535 | Only the raw Git metadata is provided. | ||
536 | This parameter implies the "nocheckout" parameter as well. | ||
537 | </para></listitem> | ||
538 | <listitem><para><emphasis>"branch":</emphasis> | ||
539 | The branch(es) of the Git tree to clone. | ||
540 | If unset, this is assumed to be "master". | ||
541 | The number of branch parameters much match the number of | ||
542 | name parameters. | ||
543 | </para></listitem> | ||
544 | <listitem><para><emphasis>"rev":</emphasis> | ||
545 | The revision to use for the checkout. | ||
546 | The default is "master". | ||
547 | </para></listitem> | ||
548 | <listitem><para><emphasis>"tag":</emphasis> | ||
549 | Specifies a tag to use for the checkout. | ||
550 | To correctly resolve tags, BitBake must access the | ||
551 | network. | ||
552 | For that reason, tags are often not used. | ||
553 | As far as Git is concerned, the "tag" parameter behaves | ||
554 | effectively the same as the "revision" parameter. | ||
555 | </para></listitem> | ||
556 | <listitem><para><emphasis>"subpath":</emphasis> | ||
557 | Limits the checkout to a specific subpath of the tree. | ||
558 | By default, the whole tree is checked out. | ||
559 | </para></listitem> | ||
560 | <listitem><para><emphasis>"destsuffix":</emphasis> | ||
561 | The name of the path in which to place the checkout. | ||
562 | By default, the path is <filename>git/</filename>. | ||
563 | </para></listitem> | ||
564 | </itemizedlist> | ||
565 | Here are some example URLs: | ||
566 | <literallayout class='monospaced'> | ||
567 | SRC_URI = "git://git.oe.handhelds.org/git/vip.git;tag=version-1" | ||
568 | SRC_URI = "git://git.oe.handhelds.org/git/vip.git;protocol=http" | ||
569 | </literallayout> | ||
570 | </para> | ||
571 | </section> | ||
572 | |||
573 | <section id='other-fetchers'> | ||
574 | <title>Other Fetchers</title> | ||
575 | |||
576 | <para> | ||
577 | Fetch submodules also exist for the following: | ||
578 | <itemizedlist> | ||
579 | <listitem><para> | ||
580 | Bazaar (<filename>bzr://</filename>) | ||
581 | </para></listitem> | ||
582 | <listitem><para> | ||
583 | Perforce (<filename>p4://</filename>) | ||
584 | </para></listitem> | ||
585 | <listitem><para> | ||
586 | Git Submodules (<filename>gitsm://</filename>) | ||
587 | </para></listitem> | ||
588 | <listitem><para> | ||
589 | Trees using Git Annex (<filename>gitannex://</filename>) | ||
590 | </para></listitem> | ||
591 | <listitem><para> | ||
592 | Secure FTP (<filename>sftp://</filename>) | ||
593 | </para></listitem> | ||
594 | <listitem><para> | ||
595 | Secure Shell (<filename>ssh://</filename>) | ||
596 | </para></listitem> | ||
597 | <listitem><para> | ||
598 | Repo (<filename>repo://</filename>) | ||
599 | </para></listitem> | ||
600 | <listitem><para> | ||
601 | OSC (<filename>osc://</filename>) | ||
602 | </para></listitem> | ||
603 | <listitem><para> | ||
604 | Mercurial (<filename>hg://</filename>) | ||
605 | </para></listitem> | ||
606 | </itemizedlist> | ||
607 | No documentation currently exists for these lesser used | ||
608 | fetcher submodules. | ||
609 | However, you might find the code helpful and readable. | ||
610 | </para> | ||
611 | </section> | ||
612 | </section> | ||
613 | |||
614 | <section id='auto-revisions'> | ||
615 | <title>Auto Revisions</title> | ||
616 | |||
617 | <para> | ||
618 | We need to document <filename>AUTOREV</filename> and | ||
619 | <filename>SRCREV_FORMAT</filename> here. | ||
620 | </para> | ||
621 | </section> | ||
622 | </chapter> | ||