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--- a/documentation/ref-manual/faq.rst
+++ b/documentation/ref-manual/faq.rst
@@ -4,9 +4,15 @@
4FAQ 4FAQ
5*** 5***
6 6
7**Q:** How does Poky differ from :oe_home:`OpenEmbedded <>`? 7.. contents::
8 8
9**A:** The term ``Poky`` refers to the specific reference build 9General questions
10=================
11
12How does Poky differ from OpenEmbedded?
13---------------------------------------
14
15The term ``Poky`` refers to the specific reference build
10system that the Yocto Project provides. Poky is based on 16system that the Yocto Project provides. Poky is based on
11:term:`OpenEmbedded-Core (OE-Core)` and :term:`BitBake`. Thus, the 17:term:`OpenEmbedded-Core (OE-Core)` and :term:`BitBake`. Thus, the
12generic term used here for the build system is the "OpenEmbedded build 18generic term used here for the build system is the "OpenEmbedded build
@@ -15,19 +21,10 @@ OpenEmbedded, with changes always being merged to OE-Core or BitBake
15first before being pulled back into Poky. This practice benefits both 21first before being pulled back into Poky. This practice benefits both
16projects immediately. 22projects immediately.
17 23
18**Q:** My development system does not meet the required Git, tar, and 24How can you claim Poky / OpenEmbedded-Core is stable?
19Python versions. In particular, I do not have Python 3.5.0 or greater. 25-----------------------------------------------------
20Can I still use the Yocto Project?
21
22**A:** You can get the required tools on your host development system a
23couple different ways (i.e. building a tarball or downloading a
24tarball). See the
25":ref:`ref-manual/system-requirements:required git, tar, python and gcc versions`"
26section for steps on how to update your build tools.
27
28**Q:** How can you claim Poky / OpenEmbedded-Core is stable?
29 26
30**A:** There are three areas that help with stability; 27There are three areas that help with stability;
31 28
32- The Yocto Project team keeps :term:`OpenEmbedded-Core (OE-Core)` small and 29- The Yocto Project team keeps :term:`OpenEmbedded-Core (OE-Core)` small and
33 focused, containing around 830 recipes as opposed to the thousands 30 focused, containing around 830 recipes as opposed to the thousands
@@ -37,95 +34,110 @@ section for steps on how to update your build tools.
37- The Yocto Project team runs manual and automated tests using a small, 34- The Yocto Project team runs manual and automated tests using a small,
38 fixed set of reference hardware as well as emulated targets. 35 fixed set of reference hardware as well as emulated targets.
39 36
40- The Yocto Project uses an autobuilder, which provides continuous 37- The Yocto Project uses an :yocto_ab:`autobuilder <>`, which provides
41 build and integration tests. 38 continuous build and integration tests.
42 39
43**Q:** How do I get support for my board added to the Yocto Project? 40Are there any products built using the OpenEmbedded build system?
41-----------------------------------------------------------------
44 42
45**A:** Support for an additional board is added by creating a Board 43See :yocto_wiki:`Products that use the Yocto Project
46Support Package (BSP) layer for it. For more information on how to 44</Project_Users#Products_that_use_the_Yocto_Project>` in the Yocto Project
47create a BSP layer, see the 45Wiki. Don't hesitate to contribute to this page if you know other such
48":ref:`dev-manual/common-tasks:understanding and creating layers`" 46products.
49section in the Yocto Project Development Tasks Manual and the
50:doc:`/bsp-guide/index`.
51 47
52Usually, if the board is not completely exotic, adding support in the 48Building environment
53Yocto Project is fairly straightforward. 49====================
54 50
55**Q:** Are there any products built using the OpenEmbedded build system? 51Missing dependencies on the development system?
52-----------------------------------------------
56 53
57**A:** The software running on the `Vernier 54If your development system does not meet the required Git, tar, and
58LabQuest <https://vernier.com/labquest/>`__ is built using the 55Python versions, you can get the required tools on your host development
59OpenEmbedded build system. See the `Vernier 56system in different ways (i.e. building a tarball or downloading a
60LabQuest <https://www.vernier.com/products/interfaces/labq/>`__ website 57tarball). See the ":ref:`ref-manual/system-requirements:required git, tar, python, make and gcc versions`"
61for more information. There are a number of pre-production devices using 58section for steps on how to update your build tools.
62the OpenEmbedded build system and the Yocto Project team announces them
63as soon as they are released.
64 59
65**Q:** What does the OpenEmbedded build system produce as output? 60How does OpenEmbedded fetch source code? Will it work through a firewall or proxy server?
61-----------------------------------------------------------------------------------------
66 62
67**A:** Because you can use the same set of recipes to create output of 63The way the build system obtains source code is highly
68various formats, the output of an OpenEmbedded build depends on how you 64configurable. You can setup the build system to get source code in most
69start it. Usually, the output is a flashable image ready for the target 65environments if HTTP transport is available.
70device.
71 66
72**Q:** How do I add my package to the Yocto Project? 67When the build system searches for source code, it first tries the local
68download directory. If that location fails, Poky tries
69:term:`PREMIRRORS`, the upstream source, and then
70:term:`MIRRORS` in that order.
73 71
74**A:** To add a package, you need to create a BitBake recipe. For 72Assuming your distribution is "poky", the OpenEmbedded build system uses
75information on how to create a BitBake recipe, see the 73the Yocto Project source :term:`PREMIRRORS` by default for SCM-based
76":ref:`dev-manual/common-tasks:writing a new recipe`" 74sources, upstreams for normal tarballs, and then falls back to a number
77section in the Yocto Project Development Tasks Manual. 75of other mirrors including the Yocto Project source mirror if those
76fail.
77
78As an example, you could add a specific server for the build system to
79attempt before any others by adding something like the following to the
80``local.conf`` configuration file::
78 81
79**Q:** Do I have to reflash my entire board with a new Yocto Project 82 PREMIRRORS:prepend = "\
80image when recompiling a package? 83 git://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
84 ftp://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
85 http://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
86 https://.*/.* &YOCTO_DL_URL;/mirror/sources/"
81 87
82**A:** The OpenEmbedded build system can build packages in various 88These changes cause the build system to intercept Git, FTP, HTTP, and
83formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can 89HTTPS requests and direct them to the ``http://`` sources mirror. You
84then upgrade the packages using the package tools on the device, much 90can use ``file://`` URLs to point to local directories or network shares
85like on a desktop distribution such as Ubuntu or Fedora. However, 91as well.
86package management on the target is entirely optional.
87 92
88**Q:** I see the error 93Another option is to set::
89'``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``'. What is
90wrong?
91 94
92**A:** You are probably running the build on an NTFS filesystem. Use 95 BB_NO_NETWORK = "1"
93``ext2``, ``ext3``, or ``ext4`` instead.
94 96
95**Q:** I see lots of 404 responses for files when the OpenEmbedded build 97This statement tells BitBake to issue an error
96system is trying to download sources. Is something wrong? 98instead of trying to access the Internet. This technique is useful if
99you want to ensure code builds only from local sources.
97 100
98**A:** Nothing is wrong. The OpenEmbedded build system checks any 101Here is another technique::
99configured source mirrors before downloading from the upstream sources. 102
100The build system does this searching for both source archives and 103 BB_FETCH_PREMIRRORONLY = "1"
101pre-checked out versions of SCM-managed software. These checks help in
102large installations because it can reduce load on the SCM servers
103themselves. The address above is one of the default mirrors configured
104into the build system. Consequently, if an upstream source disappears,
105the team can place sources there so builds continue to work.
106 104
107**Q:** I have machine-specific data in a package for one machine only 105This statement limits the build system to pulling source from the
108but the package is being marked as machine-specific in all cases, how do 106:term:`PREMIRRORS` only. Again, this technique is useful for reproducing
109I prevent this? 107builds.
110 108
111**A:** Set ``SRC_URI_OVERRIDES_PACKAGE_ARCH`` = "0" in the ``.bb`` file 109Here is yet another technique::
112but make sure the package is manually marked as machine-specific for the
113case that needs it. The code that handles
114``SRC_URI_OVERRIDES_PACKAGE_ARCH`` is in the
115``meta/classes/base.bbclass`` file.
116 110
117**Q:** I'm behind a firewall and need to use a proxy server. How do I do 111 BB_GENERATE_MIRROR_TARBALLS = "1"
118that? 112
113This statement tells the build system to generate mirror tarballs. This
114technique is useful if you want to create a mirror server. If not,
115however, the technique can simply waste time during the build.
119 116
120**A:** Most source fetching by the OpenEmbedded build system is done by 117Finally, consider an example where you are behind an HTTP-only firewall.
118You could make the following changes to the ``local.conf`` configuration
119file as long as the :term:`PREMIRRORS` server is current::
120
121 PREMIRRORS:prepend = "\
122 git://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
123 ftp://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
124 http://.*/.* &YOCTO_DL_URL;/mirror/sources/ \
125 https://.*/.* &YOCTO_DL_URL;/mirror/sources/"
126 BB_FETCH_PREMIRRORONLY = "1"
127
128These changes would cause the build system to successfully fetch source
129over HTTP and any network accesses to anything other than the
130:term:`PREMIRRORS` would fail.
131
132Most source fetching by the OpenEmbedded build system is done by
121``wget`` and you therefore need to specify the proxy settings in a 133``wget`` and you therefore need to specify the proxy settings in a
122``.wgetrc`` file, which can be in your home directory if you are a 134``.wgetrc`` file, which can be in your home directory if you are a
123single user or can be in ``/usr/local/etc/wgetrc`` as a global user 135single user or can be in ``/usr/local/etc/wgetrc`` as a global user
124file. 136file.
125 137
126Following is the applicable code for setting various proxy types in the 138Here is the applicable code for setting various proxy types in the
127``.wgetrc`` file. By default, these settings are disabled with comments. 139``.wgetrc`` file. By default, these settings are disabled with comments.
128To use them, remove the comments: :: 140To use them, remove the comments::
129 141
130 # You can set the default proxies for Wget to use for http, https, and ftp. 142 # You can set the default proxies for Wget to use for http, https, and ftp.
131 # They will override the value in the environment. 143 # They will override the value in the environment.
@@ -136,24 +148,53 @@ To use them, remove the comments: ::
136 # If you do not want to use proxy at all, set this to off. 148 # If you do not want to use proxy at all, set this to off.
137 #use_proxy = on 149 #use_proxy = on
138 150
151The build system also accepts ``http_proxy``, ``ftp_proxy``, ``https_proxy``,
152and ``all_proxy`` set as to standard shell environment variables to redirect
153requests through proxy servers.
154
139The Yocto Project also includes a 155The Yocto Project also includes a
140``meta-poky/conf/site.conf.sample`` file that shows how to configure CVS 156``meta-poky/conf/templates/default/site.conf.sample`` file that shows
141and Git proxy servers if needed. For more information on setting up 157how to configure CVS and Git proxy servers if needed.
142various proxy types and configuring proxy servers, see the
143":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`"
144Wiki page.
145 158
146**Q:** What's the difference between target and target\ ``-native``? 159.. note::
147 160
148**A:** The ``*-native`` targets are designed to run on the system being 161 You can find more information on the
149used for the build. These are usually tools that are needed to assist 162 ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`"
150the build in some way such as ``quilt-native``, which is used to apply 163 Wiki page.
151patches. The non-native version is the one that runs on the target 164
152device. 165Using the OpenEmbedded Build system
166===================================
167
168How do I use an external toolchain?
169-----------------------------------
170
171See the ":ref:`dev-manual/external-toolchain:optionally using an external toolchain`"
172section in the Development Task manual.
173
174Why do I get chmod permission issues?
175-------------------------------------
153 176
154**Q:** I'm seeing random build failures. Help?! 177If you see the error
178``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``,
179you are probably running the build on an NTFS filesystem. Instead,
180run the build system on a partition with a modern Linux filesystem such as
181``ext4``, ``btrfs`` or ``xfs``.
155 182
156**A:** If the same build is failing in totally different and random 183I see many 404 errors trying to download sources. Is anything wrong?
184--------------------------------------------------------------------
185
186Nothing is wrong. The OpenEmbedded build system checks any
187configured source mirrors before downloading from the upstream sources.
188The build system does this searching for both source archives and
189pre-checked out versions of SCM-managed software. These checks help in
190large installations because it can reduce load on the SCM servers
191themselves. This can also allow builds to continue to work if an
192upstream source disappears.
193
194Why do I get random build failures?
195-----------------------------------
196
197If the same build is failing in totally different and random
157ways, the most likely explanation is: 198ways, the most likely explanation is:
158 199
159- The hardware you are running the build on has some problem. 200- The hardware you are running the build on has some problem.
@@ -166,222 +207,139 @@ causes lots of network, disk and CPU activity and is sensitive to even
166single-bit failures in any of these areas. True random failures have 207single-bit failures in any of these areas. True random failures have
167always been traced back to hardware or virtualization issues. 208always been traced back to hardware or virtualization issues.
168 209
169**Q:** When I try to build a native recipe, the build fails with 210Why does the build fail with ``iconv.h`` problems?
170``iconv.h`` problems. 211--------------------------------------------------
171 212
172**A:** If you get an error message that indicates GNU ``libiconv`` is 213When you try to build a native recipe, you may get an error message that
173not in use but ``iconv.h`` has been included from ``libiconv``, you need 214indicates that GNU ``libiconv`` is not in use but ``iconv.h`` has been
174to check to see if you have a previously installed version of the header 215included from ``libiconv``::
175file in ``/usr/local/include``.
176::
177 216
178 #error GNU libiconv not in use but included iconv.h is from libiconv 217 #error GNU libiconv not in use but included iconv.h is from libiconv
179 218
180If you find a previously installed 219When this happens, you need to check whether you have a previously
181file, you should either uninstall it or temporarily rename it and try 220installed version of the header file in ``/usr/local/include/``.
182the build again. 221If that's the case, you should either uninstall it or temporarily rename
222it and try the build again.
183 223
184This issue is just a single manifestation of "system leakage" issues 224This issue is just a single manifestation of "system leakage" issues
185caused when the OpenEmbedded build system finds and uses previously 225caused when the OpenEmbedded build system finds and uses previously
186installed files during a native build. This type of issue might not be 226installed files during a native build. This type of issue might not be
187limited to ``iconv.h``. Be sure that leakage cannot occur from 227limited to ``iconv.h``. Make sure that leakage cannot occur from
188``/usr/local/include`` and ``/opt`` locations. 228``/usr/local/include`` and ``/opt`` locations.
189 229
190**Q:** What do we need to ship for license compliance? 230Why don't other recipes find the files provided by my ``*-native`` recipe?
191 231--------------------------------------------------------------------------
192**A:** This is a difficult question and you need to consult your lawyer
193for the answer for your specific case. It is worth bearing in mind that
194for GPL compliance, there needs to be enough information shipped to
195allow someone else to rebuild and produce the same end result you are
196shipping. This means sharing the source code, any patches applied to it,
197and also any configuration information about how that package was
198configured and built.
199
200You can find more information on licensing in the
201":ref:`overview-manual/development-environment:licensing`"
202section in the Yocto
203Project Overview and Concepts Manual and also in the
204":ref:`dev-manual/common-tasks:maintaining open source license compliance during your product's lifecycle`"
205section in the Yocto Project Development Tasks Manual.
206
207**Q:** How do I disable the cursor on my touchscreen device?
208
209**A:** You need to create a form factor file as described in the
210":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
211the Yocto Project Board Support Packages (BSP) Developer's Guide. Set
212the ``HAVE_TOUCHSCREEN`` variable equal to one as follows:
213::
214
215 HAVE_TOUCHSCREEN=1
216
217**Q:** How do I make sure connected network interfaces are brought up by
218default?
219
220**A:** The default interfaces file provided by the netbase recipe does
221not automatically bring up network interfaces. Therefore, you will need
222to add a BSP-specific netbase that includes an interfaces file. See the
223":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
224the Yocto Project Board Support Packages (BSP) Developer's Guide for
225information on creating these types of miscellaneous recipe files.
226
227For example, add the following files to your layer: ::
228
229 meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces
230 meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend
231
232**Q:** How do I create images with more free space?
233
234**A:** By default, the OpenEmbedded build system creates images that are
2351.3 times the size of the populated root filesystem. To affect the image
236size, you need to set various configurations:
237
238- *Image Size:* The OpenEmbedded build system uses the
239 :term:`IMAGE_ROOTFS_SIZE` variable to define
240 the size of the image in Kbytes. The build system determines the size
241 by taking into account the initial root filesystem size before any
242 modifications such as requested size for the image and any requested
243 additional free disk space to be added to the image.
244
245- *Overhead:* Use the
246 :term:`IMAGE_OVERHEAD_FACTOR` variable
247 to define the multiplier that the build system applies to the initial
248 image size, which is 1.3 by default.
249
250- *Additional Free Space:* Use the
251 :term:`IMAGE_ROOTFS_EXTRA_SPACE`
252 variable to add additional free space to the image. The build system
253 adds this space to the image after it determines its
254 ``IMAGE_ROOTFS_SIZE``.
255
256**Q:** Why don't you support directories with spaces in the pathnames?
257
258**A:** The Yocto Project team has tried to do this before but too many
259of the tools the OpenEmbedded build system depends on, such as
260``autoconf``, break when they find spaces in pathnames. Until that
261situation changes, the team will not support spaces in pathnames.
262
263**Q:** How do I use an external toolchain?
264
265**A:** The toolchain configuration is very flexible and customizable. It
266is primarily controlled with the ``TCMODE`` variable. This variable
267controls which ``tcmode-*.inc`` file to include from the
268``meta/conf/distro/include`` directory within the :term:`Source Directory`.
269
270The default value of ``TCMODE`` is "default", which tells the
271OpenEmbedded build system to use its internally built toolchain (i.e.
272``tcmode-default.inc``). However, other patterns are accepted. In
273particular, "external-\*" refers to external toolchains. One example is
274the Sourcery G++ Toolchain. The support for this toolchain resides in
275the separate ``meta-sourcery`` layer at
276https://github.com/MentorEmbedded/meta-sourcery/.
277
278In addition to the toolchain configuration, you also need a
279corresponding toolchain recipe file. This recipe file needs to package
280up any pre-built objects in the toolchain such as ``libgcc``,
281``libstdcc++``, any locales, and ``libc``.
282
283**Q:** How does the OpenEmbedded build system obtain source code and
284will it work behind my firewall or proxy server?
285 232
286**A:** The way the build system obtains source code is highly 233Files provided by your native recipe could be missing from the native
287configurable. You can setup the build system to get source code in most 234sysroot, your recipe could also be installing to the wrong place, or you
288environments if HTTP transport is available. 235could be getting permission errors during the :ref:`ref-tasks-install`
289 236task in your recipe.
290When the build system searches for source code, it first tries the local
291download directory. If that location fails, Poky tries
292:term:`PREMIRRORS`, the upstream source, and then
293:term:`MIRRORS` in that order.
294
295Assuming your distribution is "poky", the OpenEmbedded build system uses
296the Yocto Project source ``PREMIRRORS`` by default for SCM-based
297sources, upstreams for normal tarballs, and then falls back to a number
298of other mirrors including the Yocto Project source mirror if those
299fail.
300 237
301As an example, you could add a specific server for the build system to 238This situation happens when the build system used by a package does not
302attempt before any others by adding something like the following to the 239recognize the environment variables supplied to it by :term:`BitBake`. The
303``local.conf`` configuration file: :: 240incident that prompted this FAQ entry involved a Makefile that used an
241environment variable named ``BINDIR`` instead of the more standard
242variable ``bindir``. The makefile's hardcoded default value of
243"/usr/bin" worked most of the time, but not for the recipe's ``-native``
244variant. For another example, permission errors might be caused by a
245Makefile that ignores ``DESTDIR`` or uses a different name for that
246environment variable. Check the build system of the package to see if
247these kinds of issues exist.
304 248
305 PREMIRRORS_prepend = "\ 249Can I get rid of build output so I can start over?
306 git://.*/.* http://www.yoctoproject.org/sources/ \n \ 250--------------------------------------------------
307 ftp://.*/.* http://www.yoctoproject.org/sources/ \n \
308 http://.*/.* http://www.yoctoproject.org/sources/ \n \
309 https://.*/.* http://www.yoctoproject.org/sources/ \n"
310 251
311These changes cause the build system to intercept Git, FTP, HTTP, and 252Yes --- you can easily do this. When you use BitBake to build an
312HTTPS requests and direct them to the ``http://`` sources mirror. You 253image, all the build output goes into the directory created when you run
313can use ``file://`` URLs to point to local directories or network shares 254the build environment setup script (i.e. :ref:`structure-core-script`).
314as well. 255By default, this :term:`Build Directory` is named ``build`` but can be named
256anything you want.
315 257
316Aside from the previous technique, these options also exist: 258Within the :term:`Build Directory`, is the ``tmp`` directory. To remove all the
317:: 259build output yet preserve any source code or downloaded files from
260previous builds, simply remove the ``tmp`` directory.
318 261
319 BB_NO_NETWORK = "1" 262Customizing generated images
263============================
320 264
321This statement tells BitBake to issue an error 265What does the OpenEmbedded build system produce as output?
322instead of trying to access the Internet. This technique is useful if 266----------------------------------------------------------
323you want to ensure code builds only from local sources.
324 267
325Here is another technique: 268Because you can use the same set of recipes to create output of
326:: 269various formats, the output of an OpenEmbedded build depends on how you
270start it. Usually, the output is a flashable image ready for the target
271device.
327 272
328 BB_FETCH_PREMIRRORONLY = "1" 273How do I make the Yocto Project support my board?
274-------------------------------------------------
329 275
330This statement 276Support for an additional board is added by creating a Board
331limits the build system to pulling source from the ``PREMIRRORS`` only. 277Support Package (BSP) layer for it. For more information on how to
332Again, this technique is useful for reproducing builds. 278create a BSP layer, see the
279":ref:`dev-manual/layers:understanding and creating layers`"
280section in the Yocto Project Development Tasks Manual and the
281:doc:`/bsp-guide/index`.
333 282
334Here is another technique: 283Usually, if the board is not completely exotic, adding support in the
335:: 284Yocto Project is fairly straightforward.
336 285
337 BB_GENERATE_MIRROR_TARBALLS = "1" 286How do I make the Yocto Project support my package?
287---------------------------------------------------
338 288
339This 289To add a package, you need to create a BitBake recipe. For
340statement tells the build system to generate mirror tarballs. This 290information on how to create a BitBake recipe, see the
341technique is useful if you want to create a mirror server. If not, 291":ref:`dev-manual/new-recipe:writing a new recipe`"
342however, the technique can simply waste time during the build. 292section in the Yocto Project Development Tasks Manual.
343 293
344Finally, consider an example where you are behind an HTTP-only firewall. 294What do I need to ship for license compliance?
345You could make the following changes to the ``local.conf`` configuration 295----------------------------------------------
346file as long as the ``PREMIRRORS`` server is current: ::
347 296
348 PREMIRRORS_prepend = "\ 297This is a difficult question and you need to consult your lawyer
349 ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ 298for the answer for your specific case. It is worth bearing in mind that
350 http://.*/.* http://www.yoctoproject.org/sources/ \n \ 299for GPL compliance, there needs to be enough information shipped to
351 https://.*/.* http://www.yoctoproject.org/sources/ \n" 300allow someone else to rebuild and produce the same end result you are
352 BB_FETCH_PREMIRRORONLY = "1" 301shipping. This means sharing the source code, any patches applied to it,
302and also any configuration information about how that package was
303configured and built.
353 304
354These changes would cause the build system to successfully fetch source 305You can find more information on licensing in the
355over HTTP and any network accesses to anything other than the 306":ref:`overview-manual/development-environment:licensing`"
356``PREMIRRORS`` would fail. 307section in the Yocto Project Overview and Concepts Manual and also in the
308":ref:`dev-manual/licenses:maintaining open source license compliance during your product's lifecycle`"
309section in the Yocto Project Development Tasks Manual.
357 310
358The build system also honors the standard shell environment variables 311Do I have to make a full reflash after recompiling one package?
359``http_proxy``, ``ftp_proxy``, ``https_proxy``, and ``all_proxy`` to 312---------------------------------------------------------------
360redirect requests through proxy servers.
361 313
362.. note:: 314The OpenEmbedded build system can build packages in various
315formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can
316then upgrade only the modified packages using the package tools on the device,
317much like on a desktop distribution such as Ubuntu or Fedora. However,
318package management on the target is entirely optional.
363 319
364 You can find more information on the 320How to prevent my package from being marked as machine specific?
365 ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`" 321----------------------------------------------------------------
366 Wiki page.
367 322
368**Q:** Can I get rid of build output so I can start over? 323If you have machine-specific data in a package for one machine only
324but the package is being marked as machine-specific in all cases,
325you can set :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` = "0" in the ``.bb`` file.
326However, but make sure the package is manually marked as machine-specific for the
327case that needs it. The code that handles :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH`
328is in the ``meta/classes-global/base.bbclass`` file.
369 329
370**A:** Yes - you can easily do this. When you use BitBake to build an 330What's the difference between ``target`` and ``target-native``?
371image, all the build output goes into the directory created when you run 331---------------------------------------------------------------
372the build environment setup script (i.e.
373:ref:`structure-core-script`). By default, this :term:`Build Directory`
374is named ``build`` but can be named
375anything you want.
376 332
377Within the Build Directory, is the ``tmp`` directory. To remove all the 333The ``*-native`` targets are designed to run on the system being
378build output yet preserve any source code or downloaded files from 334used for the build. These are usually tools that are needed to assist
379previous builds, simply remove the ``tmp`` directory. 335the build in some way such as ``quilt-native``, which is used to apply
336patches. The non-native version is the one that runs on the target
337device.
380 338
381**Q:** Why do ``${bindir}`` and ``${libdir}`` have strange values for 339Why do ``${bindir}`` and ``${libdir}`` have strange values for ``-native`` recipes?
382``-native`` recipes? 340-----------------------------------------------------------------------------------
383 341
384**A:** Executables and libraries might need to be used from a directory 342Executables and libraries might need to be used from a directory
385other than the directory into which they were initially installed. 343other than the directory into which they were initially installed.
386Complicating this situation is the fact that sometimes these executables 344Complicating this situation is the fact that sometimes these executables
387and libraries are compiled with the expectation of being run from that 345and libraries are compiled with the expectation of being run from that
@@ -408,20 +366,13 @@ system of that image. Thus, the build system provides a value of
408forth. 366forth.
409 367
410Meanwhile, ``DESTDIR`` is a path within the :term:`Build Directory`. 368Meanwhile, ``DESTDIR`` is a path within the :term:`Build Directory`.
411However, when the recipe builds a 369However, when the recipe builds a native program (i.e. one that is
412native program (i.e. one that is intended to run on the build machine), 370intended to run on the build machine), that program is never installed
413that program is never installed directly to the build machine's root 371directly to the build machine's root file system. Consequently, the build
414file system. Consequently, the build system uses paths within the Build 372system uses paths within the Build Directory for ``DESTDIR``, ``bindir``
415Directory for ``DESTDIR``, ``bindir`` and related variables. To better 373and related variables. To better understand this, consider the following
416understand this, consider the following two paths where the first is 374two paths (artificially broken across lines for readability) where the
417relatively normal and the second is not: 375first is relatively normal and the second is not::
418
419.. note::
420
421 Due to these lengthy examples, the paths are artificially broken
422 across lines for readability.
423
424::
425 376
426 /home/maxtothemax/poky-bootchart2/build/tmp/work/i586-poky-linux/zlib/ 377 /home/maxtothemax/poky-bootchart2/build/tmp/work/i586-poky-linux/zlib/
427 1.2.8-r0/sysroot-destdir/usr/bin 378 1.2.8-r0/sysroot-destdir/usr/bin
@@ -430,35 +381,76 @@ relatively normal and the second is not:
430 zlib-native/1.2.8-r0/sysroot-destdir/home/maxtothemax/poky-bootchart2/ 381 zlib-native/1.2.8-r0/sysroot-destdir/home/maxtothemax/poky-bootchart2/
431 build/tmp/sysroots/x86_64-linux/usr/bin 382 build/tmp/sysroots/x86_64-linux/usr/bin
432 383
433Even if the paths look unusual, 384Even if the paths look unusual, they both are correct --- the first for
434they both are correct - the first for a target and the second for a 385a target and the second for a native recipe. These paths are a consequence
435native recipe. These paths are a consequence of the ``DESTDIR`` 386of the ``DESTDIR`` mechanism and while they appear strange, they are correct
436mechanism and while they appear strange, they are correct and in 387and in practice very effective.
437practice very effective.
438 388
439**Q:** The files provided by my ``*-native`` recipe do not appear to be 389How do I create images with more free space?
440available to other recipes. Files are missing from the native sysroot, 390--------------------------------------------
441my recipe is installing to the wrong place, or I am getting permissions
442errors during the do_install task in my recipe! What is wrong?
443 391
444**A:** This situation results when a build system does not recognize the 392By default, the OpenEmbedded build system creates images that are
445environment variables supplied to it by :term:`BitBake`. The 3931.3 times the size of the populated root filesystem. To affect the image
446incident that prompted this FAQ entry involved a Makefile that used an 394size, you need to set various configurations:
447environment variable named ``BINDIR`` instead of the more standard 395
448variable ``bindir``. The makefile's hardcoded default value of 396- *Image Size:* The OpenEmbedded build system uses the
449"/usr/bin" worked most of the time, but not for the recipe's ``-native`` 397 :term:`IMAGE_ROOTFS_SIZE` variable to define
450variant. For another example, permissions errors might be caused by a 398 the size of the image in Kbytes. The build system determines the size
451Makefile that ignores ``DESTDIR`` or uses a different name for that 399 by taking into account the initial root filesystem size before any
452environment variable. Check the the build system to see if these kinds 400 modifications such as requested size for the image and any requested
453of issues exist. 401 additional free disk space to be added to the image.
454 402
455**Q:** I'm adding a binary in a recipe but it's different in the image, what is 403- *Overhead:* Use the
456changing it? 404 :term:`IMAGE_OVERHEAD_FACTOR` variable
457 405 to define the multiplier that the build system applies to the initial
458**A:** The first most obvious change is the system stripping debug symbols from 406 image size, which is 1.3 by default.
459it. Setting :term:`INHIBIT_PACKAGE_STRIP` to stop debug symbols being stripped and/or 407
460:term:`INHIBIT_PACKAGE_DEBUG_SPLIT` to stop debug symbols being split into a separate 408- *Additional Free Space:* Use the
461file will ensure the binary is unchanged. The other less obvious thing that can 409 :term:`IMAGE_ROOTFS_EXTRA_SPACE`
462happen is prelinking of the image. This is set by default in local.conf via 410 variable to add additional free space to the image. The build system
463:term:`USER_CLASSES` which can contain 'image-prelink'. If you remove that, the 411 adds this space to the image after it determines its
464image will not be prelinked meaning the binaries would be unchanged. 412 :term:`IMAGE_ROOTFS_SIZE`.
413
414Why aren't spaces in path names supported?
415------------------------------------------
416
417The Yocto Project team has tried to do this before but too many
418of the tools the OpenEmbedded build system depends on, such as
419``autoconf``, break when they find spaces in pathnames. Until that
420situation changes, the team will not support spaces in pathnames.
421
422I'm adding a binary in a recipe. Why is it different in the image?
423------------------------------------------------------------------
424
425The first most obvious change is the system stripping debug symbols from
426it. Setting :term:`INHIBIT_PACKAGE_STRIP` to stop debug symbols being
427stripped and/or :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` to stop debug symbols
428being split into a separate file will ensure the binary is unchanged.
429
430Issues on the running system
431============================
432
433How do I disable the cursor on my touchscreen device?
434-----------------------------------------------------
435
436You need to create a form factor file as described in the
437":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
438the Yocto Project Board Support Packages (BSP) Developer's Guide. Set
439the ``HAVE_TOUCHSCREEN`` variable equal to one as follows::
440
441 HAVE_TOUCHSCREEN=1
442
443How to always bring up connected network interfaces?
444----------------------------------------------------
445
446The default interfaces file provided by the netbase recipe does
447not automatically bring up network interfaces. Therefore, you will need
448to add a BSP-specific netbase that includes an interfaces file. See the
449":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
450the Yocto Project Board Support Packages (BSP) Developer's Guide for
451information on creating these types of miscellaneous recipe files.
452
453For example, add the following files to your layer::
454
455 meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces
456 meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend