diff options
author | Nicolas Dechesne <nicolas.dechesne@linaro.org> | 2020-10-05 16:30:32 +0200 |
---|---|---|
committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2020-10-06 13:56:17 +0100 |
commit | 43d07a285181e64c30d98d10ff93ef50391efe59 (patch) | |
tree | 78918fc94d55d44d35e1e3e61c7a6fccc28bca24 /documentation/ref-manual/ref-features.xml | |
parent | 1fd9c4b2c0ae927df29f7a0d34c3e595bcf48e89 (diff) | |
download | poky-43d07a285181e64c30d98d10ff93ef50391efe59.tar.gz |
sphinx: remove DocBook files
The Yocto Project documentation was migrated to Sphinx. Let's remove
the deprecated DocBook files.
(From yocto-docs rev: 28fb0e63b2fbfd6426b00498bf2682bb53fdd862)
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/ref-manual/ref-features.xml')
-rw-r--r-- | documentation/ref-manual/ref-features.xml | 461 |
1 files changed, 0 insertions, 461 deletions
diff --git a/documentation/ref-manual/ref-features.xml b/documentation/ref-manual/ref-features.xml deleted file mode 100644 index 8cab5ec3a8..0000000000 --- a/documentation/ref-manual/ref-features.xml +++ /dev/null | |||
@@ -1,461 +0,0 @@ | |||
1 | <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | ||
2 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" | ||
3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > | ||
4 | <!--SPDX-License-Identifier: CC-BY-2.0-UK--> | ||
5 | |||
6 | <chapter id='ref-features'> | ||
7 | <title>Features</title> | ||
8 | |||
9 | <para> | ||
10 | This chapter provides a reference of shipped machine and distro features | ||
11 | you can include as part of your image, a reference on image features you can | ||
12 | select, and a reference on feature backfilling. | ||
13 | </para> | ||
14 | |||
15 | <para> | ||
16 | Features provide a mechanism for working out which packages | ||
17 | should be included in the generated images. | ||
18 | Distributions can select which features they want to support through the | ||
19 | <filename><link linkend='var-DISTRO_FEATURES'>DISTRO_FEATURES</link></filename> | ||
20 | variable, which is set or appended to in a distribution's configuration file such as | ||
21 | <filename>poky.conf</filename>, | ||
22 | <filename>poky-tiny.conf</filename>, | ||
23 | <filename>poky-lsb.conf</filename> and so forth. | ||
24 | Machine features are set in the | ||
25 | <filename><link linkend='var-MACHINE_FEATURES'>MACHINE_FEATURES</link></filename> | ||
26 | variable, which is set in the machine configuration file and | ||
27 | specifies the hardware features for a given machine. | ||
28 | </para> | ||
29 | |||
30 | <para> | ||
31 | These two variables combine to work out which kernel modules, | ||
32 | utilities, and other packages to include. | ||
33 | A given distribution can support a selected subset of features so some machine features might not | ||
34 | be included if the distribution itself does not support them. | ||
35 | </para> | ||
36 | |||
37 | <para> | ||
38 | One method you can use to determine which recipes are checking to see if a | ||
39 | particular feature is contained or not is to <filename>grep</filename> through | ||
40 | the <link linkend='metadata'>Metadata</link> | ||
41 | for the feature. | ||
42 | Here is an example that discovers the recipes whose build is potentially | ||
43 | changed based on a given feature: | ||
44 | <literallayout class='monospaced'> | ||
45 | $ cd poky | ||
46 | $ git grep 'contains.*MACHINE_FEATURES.*<replaceable>feature</replaceable>' | ||
47 | </literallayout> | ||
48 | </para> | ||
49 | |||
50 | <section id='ref-features-machine'> | ||
51 | <title>Machine Features</title> | ||
52 | |||
53 | <para> | ||
54 | The items below are features you can use with | ||
55 | <link linkend='var-MACHINE_FEATURES'><filename>MACHINE_FEATURES</filename></link>. | ||
56 | Features do not have a one-to-one correspondence to packages, and they can | ||
57 | go beyond simply controlling the installation of a package or packages. | ||
58 | Sometimes a feature can influence how certain recipes are built. | ||
59 | For example, a feature might determine whether a particular configure option | ||
60 | is specified within the | ||
61 | <link linkend='ref-tasks-configure'><filename>do_configure</filename></link> | ||
62 | task for a particular recipe. | ||
63 | </para> | ||
64 | |||
65 | <para> | ||
66 | This feature list only represents features as shipped with the Yocto Project metadata: | ||
67 | <itemizedlist> | ||
68 | <listitem><para><emphasis>acpi:</emphasis> Hardware has ACPI (x86/x86_64 only) | ||
69 | </para></listitem> | ||
70 | <listitem><para><emphasis>alsa:</emphasis> Hardware has ALSA audio drivers | ||
71 | </para></listitem> | ||
72 | <listitem><para><emphasis>apm:</emphasis> Hardware uses APM (or APM emulation) | ||
73 | </para></listitem> | ||
74 | <listitem><para><emphasis>bluetooth:</emphasis> Hardware has integrated BT | ||
75 | </para></listitem> | ||
76 | <listitem><para><emphasis>efi:</emphasis> Support for booting through EFI | ||
77 | </para></listitem> | ||
78 | <listitem><para><emphasis>ext2:</emphasis> Hardware HDD or Microdrive | ||
79 | </para></listitem> | ||
80 | <listitem><para><emphasis>keyboard:</emphasis> Hardware has a keyboard | ||
81 | </para></listitem> | ||
82 | <listitem><para><emphasis>pcbios:</emphasis> Support for booting through BIOS | ||
83 | </para></listitem> | ||
84 | <listitem><para><emphasis>pci:</emphasis> Hardware has a PCI bus | ||
85 | </para></listitem> | ||
86 | <listitem><para><emphasis>pcmcia:</emphasis> Hardware has PCMCIA or CompactFlash sockets | ||
87 | </para></listitem> | ||
88 | <listitem><para><emphasis>phone:</emphasis> Mobile phone (voice) support | ||
89 | </para></listitem> | ||
90 | <listitem><para><emphasis>qvga:</emphasis> Machine has a QVGA (320x240) display | ||
91 | </para></listitem> | ||
92 | <listitem><para><emphasis>rtc:</emphasis> Machine has a Real-Time Clock | ||
93 | </para></listitem> | ||
94 | <listitem><para><emphasis>screen:</emphasis> Hardware has a screen | ||
95 | </para></listitem> | ||
96 | <listitem><para><emphasis>serial:</emphasis> Hardware has serial support (usually RS232) | ||
97 | </para></listitem> | ||
98 | <listitem><para><emphasis>touchscreen:</emphasis> Hardware has a touchscreen | ||
99 | </para></listitem> | ||
100 | <listitem><para><emphasis>usbgadget:</emphasis> Hardware is USB gadget device capable | ||
101 | </para></listitem> | ||
102 | <listitem><para><emphasis>usbhost:</emphasis> Hardware is USB Host capable | ||
103 | </para></listitem> | ||
104 | <listitem><para><emphasis>vfat:</emphasis> FAT file system support | ||
105 | </para></listitem> | ||
106 | <listitem><para><emphasis>wifi:</emphasis> Hardware has integrated WiFi | ||
107 | </para></listitem> | ||
108 | </itemizedlist> | ||
109 | </para> | ||
110 | </section> | ||
111 | |||
112 | <section id='ref-features-distro'> | ||
113 | <title>Distro Features</title> | ||
114 | |||
115 | <para> | ||
116 | The items below are features you can use with | ||
117 | <link linkend='var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></link> | ||
118 | to enable features across your distribution. | ||
119 | Features do not have a one-to-one correspondence to packages, | ||
120 | and they can go beyond simply controlling the installation of a | ||
121 | package or packages. | ||
122 | In most cases, the presence or absence of a feature translates to | ||
123 | the appropriate option supplied to the configure script during the | ||
124 | <link linkend='ref-tasks-configure'><filename>do_configure</filename></link> | ||
125 | task for the recipes that optionally | ||
126 | support the feature. | ||
127 | </para> | ||
128 | |||
129 | <para> | ||
130 | Some distro features are also machine features. | ||
131 | These select features make sense to be controlled both at | ||
132 | the machine and distribution configuration level. | ||
133 | See the | ||
134 | <link linkend='var-COMBINED_FEATURES'><filename>COMBINED_FEATURES</filename></link> | ||
135 | variable for more information. | ||
136 | </para> | ||
137 | |||
138 | <para> | ||
139 | This list only represents features as shipped with the Yocto Project metadata: | ||
140 | <itemizedlist> | ||
141 | <listitem><para><emphasis>alsa:</emphasis> Include ALSA support | ||
142 | (OSS compatibility kernel modules installed if available). | ||
143 | </para></listitem> | ||
144 | <listitem><para><emphasis>api-documentation:</emphasis> | ||
145 | Enables generation of API documentation during recipe | ||
146 | builds. | ||
147 | The resulting documentation is added to SDK tarballs | ||
148 | when the | ||
149 | <filename>bitbake -c populate_sdk</filename> command | ||
150 | is used. | ||
151 | See the | ||
152 | "<ulink url='&YOCTO_DOCS_SDK_URL;#adding-api-documentation-to-the-standard-sdk'>Adding API Documentation to the Standard SDK</ulink>" | ||
153 | section in the Yocto Project Application Development and | ||
154 | the Extensible Software Development Kit (eSDK) manual. | ||
155 | </para></listitem> | ||
156 | <listitem><para><emphasis>bluetooth:</emphasis> Include | ||
157 | bluetooth support (integrated BT only).</para></listitem> | ||
158 | <listitem><para><emphasis>cramfs:</emphasis> Include CramFS | ||
159 | support.</para></listitem> | ||
160 | <listitem><para><emphasis>directfb:</emphasis> | ||
161 | Include DirectFB support. | ||
162 | </para></listitem> | ||
163 | <listitem><para><emphasis>ext2:</emphasis> Include tools for | ||
164 | supporting for devices with internal HDD/Microdrive for | ||
165 | storing files (instead of Flash only devices). | ||
166 | </para></listitem> | ||
167 | <listitem><para><emphasis>ipsec:</emphasis> Include IPSec | ||
168 | support.</para></listitem> | ||
169 | <listitem><para><emphasis>ipv6:</emphasis> Include IPv6 support. | ||
170 | </para></listitem> | ||
171 | <listitem><para><emphasis>keyboard:</emphasis> Include keyboard | ||
172 | support (e.g. keymaps will be loaded during boot). | ||
173 | </para></listitem> | ||
174 | <listitem><para><emphasis>ldconfig:</emphasis> | ||
175 | Include support for ldconfig and | ||
176 | <filename>ld.so.conf</filename> on the target. | ||
177 | </para></listitem> | ||
178 | <listitem><para><emphasis>nfs:</emphasis> Include NFS client | ||
179 | support (for mounting NFS exports on device). | ||
180 | </para></listitem> | ||
181 | <listitem><para><emphasis>opengl:</emphasis> | ||
182 | Include the Open Graphics Library, which is a | ||
183 | cross-language, multi-platform application programming | ||
184 | interface used for rendering two and three-dimensional | ||
185 | graphics.</para></listitem> | ||
186 | <listitem><para><emphasis>pci:</emphasis> Include PCI bus | ||
187 | support.</para></listitem> | ||
188 | <listitem><para><emphasis>pcmcia:</emphasis> Include | ||
189 | PCMCIA/CompactFlash support.</para></listitem> | ||
190 | <listitem><para><emphasis>ppp:</emphasis> Include PPP dialup | ||
191 | support.</para></listitem> | ||
192 | <listitem><para><emphasis>ptest:</emphasis> Enables building | ||
193 | the package tests where supported by individual recipes. | ||
194 | For more information on package tests, see the | ||
195 | "<ulink url='&YOCTO_DOCS_DEV_URL;#testing-packages-with-ptest'>Testing Packages With ptest</ulink>" | ||
196 | section in the Yocto Project Development Tasks Manual. | ||
197 | </para></listitem> | ||
198 | <listitem><para><emphasis>smbfs:</emphasis> Include SMB networks | ||
199 | client support (for mounting Samba/Microsoft Windows shares | ||
200 | on device).</para></listitem> | ||
201 | <listitem><para><emphasis>systemd:</emphasis> Include support | ||
202 | for this <filename>init</filename> manager, which is a full | ||
203 | replacement of for <filename>init</filename> with parallel | ||
204 | starting of services, reduced shell overhead, and other | ||
205 | features. | ||
206 | This <filename>init</filename> manager is used by many | ||
207 | distributions.</para></listitem> | ||
208 | <listitem><para><emphasis>usbgadget:</emphasis> Include USB | ||
209 | Gadget Device support (for USB networking/serial/storage). | ||
210 | </para></listitem> | ||
211 | <listitem><para><emphasis>usbhost:</emphasis> Include USB Host | ||
212 | support (allows to connect external keyboard, mouse, | ||
213 | storage, network etc).</para></listitem> | ||
214 | <listitem><para><emphasis>usrmerge:</emphasis> Merges the | ||
215 | <filename>/bin</filename>, <filename>/sbin</filename>, | ||
216 | <filename>/lib</filename>, and <filename>/lib64</filename> | ||
217 | directories into their respective counterparts in the | ||
218 | <filename>/usr</filename> directory to provide better package | ||
219 | and application compatibility.</para></listitem> | ||
220 | <listitem><para><emphasis>wayland:</emphasis> Include the | ||
221 | Wayland display server protocol and the library that | ||
222 | supports it.</para></listitem> | ||
223 | <listitem><para><emphasis>wifi:</emphasis> Include WiFi support | ||
224 | (integrated only).</para></listitem> | ||
225 | <listitem><para><emphasis>x11:</emphasis> Include the X server | ||
226 | and libraries.</para></listitem> | ||
227 | </itemizedlist> | ||
228 | </para> | ||
229 | </section> | ||
230 | |||
231 | <section id='ref-features-image'> | ||
232 | <title>Image Features</title> | ||
233 | |||
234 | <para> | ||
235 | The contents of images generated by the OpenEmbedded build system | ||
236 | can be controlled by the | ||
237 | <link linkend='var-IMAGE_FEATURES'><filename>IMAGE_FEATURES</filename></link> | ||
238 | and | ||
239 | <link linkend='var-EXTRA_IMAGE_FEATURES'><filename>EXTRA_IMAGE_FEATURES</filename></link> | ||
240 | variables that you typically configure in your image recipes. | ||
241 | Through these variables, you can add several different | ||
242 | predefined packages such as development utilities or packages with | ||
243 | debug information needed to investigate application problems or | ||
244 | profile applications. | ||
245 | </para> | ||
246 | |||
247 | <para> | ||
248 | The following image features are available for all images: | ||
249 | <itemizedlist> | ||
250 | <listitem><para><emphasis>allow-empty-password:</emphasis> | ||
251 | Allows Dropbear and OpenSSH to accept root logins | ||
252 | and logins from accounts having an empty password string. | ||
253 | </para></listitem> | ||
254 | <listitem><para><emphasis>dbg-pkgs:</emphasis> | ||
255 | Installs debug symbol packages for all packages installed | ||
256 | in a given image. | ||
257 | </para></listitem> | ||
258 | <listitem><para><emphasis>debug-tweaks:</emphasis> | ||
259 | Makes an image suitable for development (e.g. | ||
260 | allows root logins without passwords and enables | ||
261 | post-installation logging). | ||
262 | See the 'allow-empty-password', 'empty-root-password', | ||
263 | and 'post-install-logging' features in this list for | ||
264 | additional information. | ||
265 | </para></listitem> | ||
266 | <listitem><para><emphasis>dev-pkgs:</emphasis> | ||
267 | Installs development packages (headers and extra library | ||
268 | links) for all packages installed in a given image. | ||
269 | </para></listitem> | ||
270 | <listitem><para><emphasis>doc-pkgs:</emphasis> Installs | ||
271 | documentation packages for all packages installed in a | ||
272 | given image. | ||
273 | </para></listitem> | ||
274 | <listitem><para><emphasis>empty-root-password:</emphasis> | ||
275 | Sets the root password to an empty string, which allows | ||
276 | logins with a blank password. | ||
277 | </para></listitem> | ||
278 | <listitem><para><emphasis>package-management:</emphasis> | ||
279 | Installs package management tools and preserves the package | ||
280 | manager database. | ||
281 | </para></listitem> | ||
282 | <listitem><para><emphasis>post-install-logging:</emphasis> | ||
283 | Enables logging postinstall script runs to | ||
284 | the <filename>/var/log/postinstall.log</filename> file | ||
285 | on first boot of the image on the target system. | ||
286 | <note> | ||
287 | To make the <filename>/var/log</filename> directory | ||
288 | on the target persistent, use the | ||
289 | <link linkend='var-VOLATILE_LOG_DIR'><filename>VOLATILE_LOG_DIR</filename></link> | ||
290 | variable by setting it to "no". | ||
291 | </note> | ||
292 | </para></listitem> | ||
293 | <listitem><para><emphasis>ptest-pkgs:</emphasis> | ||
294 | Installs ptest packages for all ptest-enabled recipes. | ||
295 | </para></listitem> | ||
296 | <listitem><para><emphasis>read-only-rootfs:</emphasis> | ||
297 | Creates an image whose root filesystem is read-only. | ||
298 | See the | ||
299 | "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-read-only-root-filesystem'>Creating a Read-Only Root Filesystem</ulink>" | ||
300 | section in the Yocto Project Development Tasks Manual for | ||
301 | more information. | ||
302 | </para></listitem> | ||
303 | <listitem><para><emphasis>splash:</emphasis> | ||
304 | Enables showing a splash screen during boot. | ||
305 | By default, this screen is provided by | ||
306 | <filename>psplash</filename>, which does allow | ||
307 | customization. | ||
308 | If you prefer to use an alternative splash screen package, | ||
309 | you can do so by setting the <filename>SPLASH</filename> | ||
310 | variable to a different package name (or names) within the | ||
311 | image recipe or at the distro configuration level. | ||
312 | </para></listitem> | ||
313 | <listitem><para><emphasis>staticdev-pkgs:</emphasis> | ||
314 | Installs static development packages, which are | ||
315 | static libraries (i.e. <filename>*.a</filename> files), for | ||
316 | all packages installed in a given image. | ||
317 | </para></listitem> | ||
318 | </itemizedlist> | ||
319 | </para> | ||
320 | |||
321 | <para> | ||
322 | Some image features are available only when you inherit the | ||
323 | <link linkend='ref-classes-core-image'><filename>core-image</filename></link> | ||
324 | class. | ||
325 | The current list of these valid features is as follows: | ||
326 | <itemizedlist> | ||
327 | <listitem><para><emphasis>hwcodecs:</emphasis> Installs | ||
328 | hardware acceleration codecs. | ||
329 | </para></listitem> | ||
330 | <listitem><para><emphasis>nfs-server:</emphasis> | ||
331 | Installs an NFS server. | ||
332 | </para></listitem> | ||
333 | <listitem><para><emphasis>perf:</emphasis> | ||
334 | Installs profiling tools such as | ||
335 | <filename>perf</filename>, <filename>systemtap</filename>, | ||
336 | and <filename>LTTng</filename>. | ||
337 | For general information on user-space tools, see the | ||
338 | <ulink url='&YOCTO_DOCS_SDK_URL;'>Yocto Project Application Development and the Extensible Software Development Kit (eSDK)</ulink> | ||
339 | manual. | ||
340 | </para></listitem> | ||
341 | <listitem><para><emphasis>ssh-server-dropbear:</emphasis> | ||
342 | Installs the Dropbear minimal SSH server. | ||
343 | </para></listitem> | ||
344 | <listitem><para><emphasis>ssh-server-openssh:</emphasis> | ||
345 | Installs the OpenSSH SSH server, which is more | ||
346 | full-featured than Dropbear. | ||
347 | Note that if both the OpenSSH SSH server and the Dropbear | ||
348 | minimal SSH server are present in | ||
349 | <filename>IMAGE_FEATURES</filename>, then OpenSSH will take | ||
350 | precedence and Dropbear will not be installed. | ||
351 | </para></listitem> | ||
352 | <listitem><para><emphasis>tools-debug:</emphasis> | ||
353 | Installs debugging tools such as | ||
354 | <filename>strace</filename> and <filename>gdb</filename>. | ||
355 | For information on GDB, see the | ||
356 | "<ulink url='&YOCTO_DOCS_DEV_URL;#platdev-gdb-remotedebug'>Debugging With the GNU Project Debugger (GDB) Remotely</ulink>" | ||
357 | section in the Yocto Project Development Tasks Manual. | ||
358 | For information on tracing and profiling, see the | ||
359 | <ulink url='&YOCTO_DOCS_PROF_URL;'>Yocto Project Profiling and Tracing Manual</ulink>. | ||
360 | </para></listitem> | ||
361 | <listitem><para><emphasis>tools-sdk:</emphasis> | ||
362 | Installs a full SDK that runs on the device. | ||
363 | </para></listitem> | ||
364 | <listitem><para><emphasis>tools-testapps:</emphasis> | ||
365 | Installs device testing tools (e.g. touchscreen debugging). | ||
366 | </para></listitem> | ||
367 | <listitem><para><emphasis>x11:</emphasis> | ||
368 | Installs the X server. | ||
369 | </para></listitem> | ||
370 | <listitem><para><emphasis>x11-base:</emphasis> | ||
371 | Installs the X server with a minimal environment. | ||
372 | </para></listitem> | ||
373 | <listitem><para><emphasis>x11-sato:</emphasis> | ||
374 | Installs the OpenedHand Sato environment. | ||
375 | </para></listitem> | ||
376 | </itemizedlist> | ||
377 | </para> | ||
378 | |||
379 | </section> | ||
380 | |||
381 | <section id='ref-features-backfill'> | ||
382 | <title>Feature Backfilling</title> | ||
383 | |||
384 | <para> | ||
385 | Sometimes it is necessary in the OpenEmbedded build system to extend | ||
386 | <link linkend='var-MACHINE_FEATURES'><filename>MACHINE_FEATURES</filename></link> | ||
387 | or <link linkend='var-DISTRO_FEATURES'><filename>DISTRO_FEATURES</filename></link> | ||
388 | to control functionality that was previously enabled and not able | ||
389 | to be disabled. | ||
390 | For these cases, we need to add an | ||
391 | additional feature item to appear in one of these variables, | ||
392 | but we do not want to force developers who have existing values | ||
393 | of the variables in their configuration to add the new feature | ||
394 | in order to retain the same overall level of functionality. | ||
395 | Thus, the OpenEmbedded build system has a mechanism to | ||
396 | automatically "backfill" these added features into existing | ||
397 | distro or machine configurations. | ||
398 | You can see the list of features for which this is done by | ||
399 | finding the | ||
400 | <link linkend='var-DISTRO_FEATURES_BACKFILL'><filename>DISTRO_FEATURES_BACKFILL</filename></link> | ||
401 | and <link linkend='var-MACHINE_FEATURES_BACKFILL'><filename>MACHINE_FEATURES_BACKFILL</filename></link> | ||
402 | variables in the <filename>meta/conf/bitbake.conf</filename> file. | ||
403 | </para> | ||
404 | |||
405 | <para> | ||
406 | Because such features are backfilled by default into all | ||
407 | configurations as described in the previous paragraph, developers | ||
408 | who wish to disable the new features need to be able to selectively | ||
409 | prevent the backfilling from occurring. | ||
410 | They can do this by adding the undesired feature or features to the | ||
411 | <link linkend='var-DISTRO_FEATURES_BACKFILL_CONSIDERED'><filename>DISTRO_FEATURES_BACKFILL_CONSIDERED</filename></link> | ||
412 | or <link linkend='var-MACHINE_FEATURES_BACKFILL_CONSIDERED'><filename>MACHINE_FEATURES_BACKFILL_CONSIDERED</filename></link> | ||
413 | variables for distro features and machine features respectively. | ||
414 | </para> | ||
415 | |||
416 | <para> | ||
417 | Here are two examples to help illustrate feature backfilling: | ||
418 | <itemizedlist> | ||
419 | <listitem><para><emphasis>The "pulseaudio" distro feature option</emphasis>: | ||
420 | Previously, PulseAudio support was enabled within the Qt and | ||
421 | GStreamer frameworks. | ||
422 | Because of this, the feature is backfilled and thus | ||
423 | enabled for all distros through the | ||
424 | <filename>DISTRO_FEATURES_BACKFILL</filename> | ||
425 | variable in the <filename>meta/conf/bitbake.conf</filename> file. | ||
426 | However, your distro needs to disable the feature. | ||
427 | You can disable the feature without affecting | ||
428 | other existing distro configurations that need PulseAudio support | ||
429 | by adding "pulseaudio" to | ||
430 | <filename>DISTRO_FEATURES_BACKFILL_CONSIDERED</filename> | ||
431 | in your distro's <filename>.conf</filename> file. | ||
432 | Adding the feature to this variable when it also | ||
433 | exists in the <filename>DISTRO_FEATURES_BACKFILL</filename> | ||
434 | variable prevents the build system from adding the feature to | ||
435 | your configuration's <filename>DISTRO_FEATURES</filename>, effectively disabling | ||
436 | the feature for that particular distro.</para></listitem> | ||
437 | <listitem><para><emphasis>The "rtc" machine feature option</emphasis>: | ||
438 | Previously, real time clock (RTC) support was enabled for all | ||
439 | target devices. | ||
440 | Because of this, the feature is backfilled and thus enabled | ||
441 | for all machines through the <filename>MACHINE_FEATURES_BACKFILL</filename> | ||
442 | variable in the <filename>meta/conf/bitbake.conf</filename> file. | ||
443 | However, your target device does not have this capability. | ||
444 | You can disable RTC support for your device without | ||
445 | affecting other machines that need RTC support | ||
446 | by adding the feature to your machine's | ||
447 | <filename>MACHINE_FEATURES_BACKFILL_CONSIDERED</filename> | ||
448 | list in the machine's <filename>.conf</filename> file. | ||
449 | Adding the feature to this variable when it also | ||
450 | exists in the <filename>MACHINE_FEATURES_BACKFILL</filename> | ||
451 | variable prevents the build system from adding the feature to | ||
452 | your configuration's <filename>MACHINE_FEATURES</filename>, effectively | ||
453 | disabling RTC support for that particular machine.</para></listitem> | ||
454 | </itemizedlist> | ||
455 | </para> | ||
456 | </section> | ||
457 | </chapter> | ||
458 | |||
459 | <!-- | ||
460 | vim: expandtab tw=80 ts=4 spell spelllang=en_gb | ||
461 | --> | ||