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authorMichael Opdenacker <michael.opdenacker@bootlin.com>2022-10-12 11:31:41 +0200
committerRichard Purdie <richard.purdie@linuxfoundation.org>2022-10-19 17:32:57 +0100
commit051e8d83bb27ba0f890609cfd9b080fea7da7ff2 (patch)
tree0925cac0a8de15737016eb8ec59306aa9cf3945a /documentation
parent1cba9417262c74ca80621ab721d2dcaa628e1653 (diff)
downloadpoky-051e8d83bb27ba0f890609cfd9b080fea7da7ff2.tar.gz
ref-manual: faq.rst: reorganize into subsections, contents at top
Reorganize the FAQ into sections and subsections, which allows to have a table of contents at the top. This makes it easier to find relevant questions without having to scroll down the entire page. Reduce the size of questions so that they fit in a subsection title. Merged two redundant questions about fetching sources and working through proxies. Minor updates to other sections. (From yocto-docs rev: 3e24f94e9c2186a6e1d65d82a87323ef2fc6f87d) Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation')
-rw-r--r--documentation/ref-manual/faq.rst612
1 files changed, 314 insertions, 298 deletions
diff --git a/documentation/ref-manual/faq.rst b/documentation/ref-manual/faq.rst
index 84affddd1e..a570c40e7d 100644
--- 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 &MIN_PYTHON_VERSION; 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, make 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
@@ -37,250 +34,33 @@ 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
43**Q:** How do I get support for my board added to the Yocto Project?
44
45**A:** Support for an additional board is added by creating a Board
46Support Package (BSP) layer for it. For more information on how to
47create a BSP layer, see the
48":ref:`dev-manual/common-tasks:understanding and creating layers`"
49section in the Yocto Project Development Tasks Manual and the
50:doc:`/bsp-guide/index`.
51
52Usually, if the board is not completely exotic, adding support in the
53Yocto Project is fairly straightforward.
54 39
55**Q:** Are there any products built using the OpenEmbedded build system? 40Are there any products built using the OpenEmbedded build system?
41-----------------------------------------------------------------
56 42
57**A:** See :yocto_wiki:`Products that use the Yocto Project 43See :yocto_wiki:`Products that use the Yocto Project
58</Project_Users#Products_that_use_the_Yocto_Project>` in the Yocto Project 44</Project_Users#Products_that_use_the_Yocto_Project>` in the Yocto Project
59Wiki. Don't hesitate to contribute to this page if you know other such 45Wiki. Don't hesitate to contribute to this page if you know other such
60products. 46products.
61 47
62**Q:** What does the OpenEmbedded build system produce as output? 48Building environment
63 49====================
64**A:** Because you can use the same set of recipes to create output of
65various formats, the output of an OpenEmbedded build depends on how you
66start it. Usually, the output is a flashable image ready for the target
67device.
68
69**Q:** How do I add my package to the Yocto Project?
70
71**A:** To add a package, you need to create a BitBake recipe. For
72information on how to create a BitBake recipe, see the
73":ref:`dev-manual/common-tasks:writing a new recipe`"
74section in the Yocto Project Development Tasks Manual.
75
76**Q:** Do I have to reflash my entire board with a new Yocto Project
77image when recompiling a package?
78
79**A:** The OpenEmbedded build system can build packages in various
80formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can
81then upgrade the packages using the package tools on the device, much
82like on a desktop distribution such as Ubuntu or Fedora. However,
83package management on the target is entirely optional.
84
85**Q:** I see the error
86'``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``'. What is
87wrong?
88
89**A:** You are probably running the build on an NTFS filesystem. Use
90``ext2``, ``ext3``, or ``ext4`` instead.
91
92**Q:** I see lots of 404 responses for files when the OpenEmbedded build
93system is trying to download sources. Is something wrong?
94
95**A:** Nothing is wrong. The OpenEmbedded build system checks any
96configured source mirrors before downloading from the upstream sources.
97The build system does this searching for both source archives and
98pre-checked out versions of SCM-managed software. These checks help in
99large installations because it can reduce load on the SCM servers
100themselves. The address above is one of the default mirrors configured
101into the build system. Consequently, if an upstream source disappears,
102the team can place sources there so builds continue to work.
103
104**Q:** I have machine-specific data in a package for one machine only
105but the package is being marked as machine-specific in all cases, how do
106I prevent this?
107
108**A:** Set :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` = "0" in the ``.bb`` file
109but make sure the package is manually marked as machine-specific for the
110case that needs it. The code that handles
111:term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` is in the
112``meta/classes-global/base.bbclass`` file.
113
114**Q:** I'm behind a firewall and need to use a proxy server. How do I do
115that?
116
117**A:** Most source fetching by the OpenEmbedded build system is done by
118``wget`` and you therefore need to specify the proxy settings in a
119``.wgetrc`` file, which can be in your home directory if you are a
120single user or can be in ``/usr/local/etc/wgetrc`` as a global user
121file.
122
123Following is the applicable code for setting various proxy types in the
124``.wgetrc`` file. By default, these settings are disabled with comments.
125To use them, remove the comments::
126
127 # You can set the default proxies for Wget to use for http, https, and ftp.
128 # They will override the value in the environment.
129 #https_proxy = http://proxy.yoyodyne.com:18023/
130 #http_proxy = http://proxy.yoyodyne.com:18023/
131 #ftp_proxy = http://proxy.yoyodyne.com:18023/
132
133 # If you do not want to use proxy at all, set this to off.
134 #use_proxy = on
135
136The Yocto Project also includes a
137``meta-poky/conf/templates/default/site.conf.sample`` file that shows
138how to configure CVS and Git proxy servers if needed. For more
139information on setting up various proxy types and configuring proxy
140servers, see the
141":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`"
142Wiki page.
143
144**Q:** What's the difference between ``target`` and ``target-native``?
145
146**A:** The ``*-native`` targets are designed to run on the system being
147used for the build. These are usually tools that are needed to assist
148the build in some way such as ``quilt-native``, which is used to apply
149patches. The non-native version is the one that runs on the target
150device.
151
152**Q:** I'm seeing random build failures. Help?!
153
154**A:** If the same build is failing in totally different and random
155ways, the most likely explanation is:
156
157- The hardware you are running the build on has some problem.
158
159- You are running the build under virtualization, in which case the
160 virtualization probably has bugs.
161
162The OpenEmbedded build system processes a massive amount of data that
163causes lots of network, disk and CPU activity and is sensitive to even
164single-bit failures in any of these areas. True random failures have
165always been traced back to hardware or virtualization issues.
166
167**Q:** When I try to build a native recipe, the build fails with
168``iconv.h`` problems.
169
170**A:** If you get an error message that indicates GNU ``libiconv`` is
171not in use but ``iconv.h`` has been included from ``libiconv``, you need
172to check to see if you have a previously installed version of the header
173file in ``/usr/local/include``.
174::
175
176 #error GNU libiconv not in use but included iconv.h is from libiconv
177
178If you find a previously installed
179file, you should either uninstall it or temporarily rename it and try
180the build again.
181
182This issue is just a single manifestation of "system leakage" issues
183caused when the OpenEmbedded build system finds and uses previously
184installed files during a native build. This type of issue might not be
185limited to ``iconv.h``. Be sure that leakage cannot occur from
186``/usr/local/include`` and ``/opt`` locations.
187
188**Q:** What do we need to ship for license compliance?
189
190**A:** This is a difficult question and you need to consult your lawyer
191for the answer for your specific case. It is worth bearing in mind that
192for GPL compliance, there needs to be enough information shipped to
193allow someone else to rebuild and produce the same end result you are
194shipping. This means sharing the source code, any patches applied to it,
195and also any configuration information about how that package was
196configured and built.
197
198You can find more information on licensing in the
199":ref:`overview-manual/development-environment:licensing`"
200section in the Yocto
201Project Overview and Concepts Manual and also in the
202":ref:`dev-manual/common-tasks:maintaining open source license compliance during your product's lifecycle`"
203section in the Yocto Project Development Tasks Manual.
204
205**Q:** How do I disable the cursor on my touchscreen device?
206
207**A:** You need to create a form factor file as described in the
208":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
209the Yocto Project Board Support Packages (BSP) Developer's Guide. Set
210the ``HAVE_TOUCHSCREEN`` variable equal to one as follows::
211
212 HAVE_TOUCHSCREEN=1
213
214**Q:** How do I make sure connected network interfaces are brought up by
215default?
216
217**A:** The default interfaces file provided by the netbase recipe does
218not automatically bring up network interfaces. Therefore, you will need
219to add a BSP-specific netbase that includes an interfaces file. See the
220":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
221the Yocto Project Board Support Packages (BSP) Developer's Guide for
222information on creating these types of miscellaneous recipe files.
223
224For example, add the following files to your layer::
225
226 meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces
227 meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend
228
229**Q:** How do I create images with more free space?
230
231**A:** By default, the OpenEmbedded build system creates images that are
2321.3 times the size of the populated root filesystem. To affect the image
233size, you need to set various configurations:
234
235- *Image Size:* The OpenEmbedded build system uses the
236 :term:`IMAGE_ROOTFS_SIZE` variable to define
237 the size of the image in Kbytes. The build system determines the size
238 by taking into account the initial root filesystem size before any
239 modifications such as requested size for the image and any requested
240 additional free disk space to be added to the image.
241
242- *Overhead:* Use the
243 :term:`IMAGE_OVERHEAD_FACTOR` variable
244 to define the multiplier that the build system applies to the initial
245 image size, which is 1.3 by default.
246
247- *Additional Free Space:* Use the
248 :term:`IMAGE_ROOTFS_EXTRA_SPACE`
249 variable to add additional free space to the image. The build system
250 adds this space to the image after it determines its
251 :term:`IMAGE_ROOTFS_SIZE`.
252
253**Q:** Why don't you support directories with spaces in the pathnames?
254 50
255**A:** The Yocto Project team has tried to do this before but too many 51Missing dependencies on the development system?
256of the tools the OpenEmbedded build system depends on, such as 52-----------------------------------------------
257``autoconf``, break when they find spaces in pathnames. Until that
258situation changes, the team will not support spaces in pathnames.
259
260**Q:** How do I use an external toolchain?
261 53
262**A:** The toolchain configuration is very flexible and customizable. It 54If your development system does not meet the required Git, tar, and
263is primarily controlled with the :term:`TCMODE` variable. This variable 55Python versions, you can get the required tools on your host development
264controls which ``tcmode-*.inc`` file to include from the 56system in different ways (i.e. building a tarball or downloading a
265``meta/conf/distro/include`` directory within the :term:`Source Directory`. 57tarball). See the ":ref:`ref-manual/system-requirements:required git, tar, python, make and gcc versions`"
266 58section for steps on how to update your build tools.
267The default value of :term:`TCMODE` is "default", which tells the
268OpenEmbedded build system to use its internally built toolchain (i.e.
269``tcmode-default.inc``). However, other patterns are accepted. In
270particular, "external-\*" refers to external toolchains. One example is
271the Sourcery G++ Toolchain. The support for this toolchain resides in
272the separate ``meta-sourcery`` layer at
273https://github.com/MentorEmbedded/meta-sourcery/.
274
275In addition to the toolchain configuration, you also need a
276corresponding toolchain recipe file. This recipe file needs to package
277up any pre-built objects in the toolchain such as ``libgcc``,
278``libstdcc++``, any locales, and ``libc``.
279 59
280**Q:** How does the OpenEmbedded build system obtain source code and 60How does OpenEmbedded fetch source code? Will it work through a firewall or proxy server?
281will it work behind my firewall or proxy server? 61-----------------------------------------------------------------------------------------
282 62
283**A:** The way the build system obtains source code is highly 63The way the build system obtains source code is highly
284configurable. You can setup the build system to get source code in most 64configurable. You can setup the build system to get source code in most
285environments if HTTP transport is available. 65environments if HTTP transport is available.
286 66
@@ -322,16 +102,15 @@ Here is another technique::
322 102
323 BB_FETCH_PREMIRRORONLY = "1" 103 BB_FETCH_PREMIRRORONLY = "1"
324 104
325This statement 105This statement limits the build system to pulling source from the
326limits the build system to pulling source from the :term:`PREMIRRORS` only. 106:term:`PREMIRRORS` only. Again, this technique is useful for reproducing
327Again, this technique is useful for reproducing builds. 107builds.
328 108
329Here is another technique:: 109Here is another technique::
330 110
331 BB_GENERATE_MIRROR_TARBALLS = "1" 111 BB_GENERATE_MIRROR_TARBALLS = "1"
332 112
333This 113This statement tells the build system to generate mirror tarballs. This
334statement tells the build system to generate mirror tarballs. This
335technique is useful if you want to create a mirror server. If not, 114technique is useful if you want to create a mirror server. If not,
336however, the technique can simply waste time during the build. 115however, the technique can simply waste time during the build.
337 116
@@ -350,9 +129,32 @@ These changes would cause the build system to successfully fetch source
350over HTTP and any network accesses to anything other than the 129over HTTP and any network accesses to anything other than the
351:term:`PREMIRRORS` would fail. 130:term:`PREMIRRORS` would fail.
352 131
353The build system also honors the standard shell environment variables 132Most source fetching by the OpenEmbedded build system is done by
354``http_proxy``, ``ftp_proxy``, ``https_proxy``, and ``all_proxy`` to 133``wget`` and you therefore need to specify the proxy settings in a
355redirect requests through proxy servers. 134``.wgetrc`` file, which can be in your home directory if you are a
135single user or can be in ``/usr/local/etc/wgetrc`` as a global user
136file.
137
138Following is the applicable code for setting various proxy types in the
139``.wgetrc`` file. By default, these settings are disabled with comments.
140To use them, remove the comments::
141
142 # You can set the default proxies for Wget to use for http, https, and ftp.
143 # They will override the value in the environment.
144 #https_proxy = http://proxy.yoyodyne.com:18023/
145 #http_proxy = http://proxy.yoyodyne.com:18023/
146 #ftp_proxy = http://proxy.yoyodyne.com:18023/
147
148 # If you do not want to use proxy at all, set this to off.
149 #use_proxy = on
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
155The Yocto Project also includes a
156``meta-poky/conf/templates/default/site.conf.sample`` file that shows
157how to configure CVS and Git proxy servers if needed.
356 158
357.. note:: 159.. note::
358 160
@@ -360,23 +162,199 @@ redirect requests through proxy servers.
360 ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`" 162 ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`"
361 Wiki page. 163 Wiki page.
362 164
363**Q:** Can I get rid of build output so I can start over? 165Using the OpenEmbedded Build system
166===================================
167
168How do I use an external toolchain?
169-----------------------------------
170
171The toolchain configuration is very flexible and customizable. It
172is primarily controlled with the :term:`TCMODE` variable. This variable
173controls which ``tcmode-*.inc`` file to include from the
174``meta/conf/distro/include`` directory within the :term:`Source Directory`.
175
176The default value of :term:`TCMODE` is "default", which tells the
177OpenEmbedded build system to use its internally built toolchain (i.e.
178``tcmode-default.inc``). However, other patterns are accepted. In
179particular, "external-\*" refers to external toolchains. One example is
180the Sourcery G++ Toolchain. The support for this toolchain resides in
181the separate ``meta-sourcery`` layer at
182https://github.com/MentorEmbedded/meta-sourcery/.
183
184In addition to the toolchain configuration, you also need a
185corresponding toolchain recipe file. This recipe file needs to package
186up any pre-built objects in the toolchain such as ``libgcc``,
187``libstdcc++``, any locales, and ``libc``.
188
189Why do I get chmod permission issues?
190-------------------------------------
191
192If you see the error
193``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``,
194you are probably running the build on an NTFS filesystem. Instead,
195run the build system on a partition with a modern Linux filesystem such as
196``ext4``, ``btrfs`` or ``xfs``.
197
198I see many 404 errors trying to download sources. Is anything wrong?
199--------------------------------------------------------------------
200
201Nothing is wrong. The OpenEmbedded build system checks any
202configured source mirrors before downloading from the upstream sources.
203The build system does this searching for both source archives and
204pre-checked out versions of SCM-managed software. These checks help in
205large installations because it can reduce load on the SCM servers
206themselves. This can also allow builds to continue to work if an
207upstream source disappears.
208
209Why do I get random build failures?
210-----------------------------------
211
212If the same build is failing in totally different and random
213ways, the most likely explanation is:
214
215- The hardware you are running the build on has some problem.
216
217- You are running the build under virtualization, in which case the
218 virtualization probably has bugs.
219
220The OpenEmbedded build system processes a massive amount of data that
221causes lots of network, disk and CPU activity and is sensitive to even
222single-bit failures in any of these areas. True random failures have
223always been traced back to hardware or virtualization issues.
224
225Why does the build fail with ``iconv.h`` problems?
226--------------------------------------------------
227
228When you try to build a native recipe, you may get an error message that
229indicates that GNU ``libiconv`` is not in use but ``iconv.h`` has been
230included from ``libiconv``::
231
232 #error GNU libiconv not in use but included iconv.h is from libiconv
233
234When this happens, you need to check whether you have a previously
235installed version of the header file in ``/usr/local/include/``.
236If that's the case, you should either uninstall it or temporarily rename
237it and try the build again.
238
239This issue is just a single manifestation of "system leakage" issues
240caused when the OpenEmbedded build system finds and uses previously
241installed files during a native build. This type of issue might not be
242limited to ``iconv.h``. Make sure that leakage cannot occur from
243``/usr/local/include`` and ``/opt`` locations.
244
245Why don't other recipes find the files provided by my ``*-native`` recipe?
246--------------------------------------------------------------------------
247
248Files provided by your native recipe could be missing from the native
249sysroot, your recipe could also be installing to the wrong place, or you
250could be getting permission errors during the :ref:`ref-tasks-install`
251task in your recipe.
364 252
365**A:** Yes --- you can easily do this. When you use BitBake to build an 253This situation happens when the build system used by a package does not
254recognize the environment variables supplied to it by :term:`BitBake`. The
255incident that prompted this FAQ entry involved a Makefile that used an
256environment variable named ``BINDIR`` instead of the more standard
257variable ``bindir``. The makefile's hardcoded default value of
258"/usr/bin" worked most of the time, but not for the recipe's ``-native``
259variant. For another example, permission errors might be caused by a
260Makefile that ignores ``DESTDIR`` or uses a different name for that
261environment variable. Check the build system of the package to see if
262these kinds of issues exist.
263
264Can I get rid of build output so I can start over?
265--------------------------------------------------
266
267Yes --- you can easily do this. When you use BitBake to build an
366image, all the build output goes into the directory created when you run 268image, all the build output goes into the directory created when you run
367the build environment setup script (i.e. 269the build environment setup script (i.e. :ref:`structure-core-script`).
368:ref:`structure-core-script`). By default, this :term:`Build Directory` 270By default, this :term:`Build Directory` is named ``build`` but can be named
369is named ``build`` but can be named
370anything you want. 271anything you want.
371 272
372Within the Build Directory, is the ``tmp`` directory. To remove all the 273Within the Build Directory, is the ``tmp`` directory. To remove all the
373build output yet preserve any source code or downloaded files from 274build output yet preserve any source code or downloaded files from
374previous builds, simply remove the ``tmp`` directory. 275previous builds, simply remove the ``tmp`` directory.
375 276
376**Q:** Why do ``${bindir}`` and ``${libdir}`` have strange values for 277Customizing generated images
377``-native`` recipes? 278============================
279
280What does the OpenEmbedded build system produce as output?
281----------------------------------------------------------
282
283Because you can use the same set of recipes to create output of
284various formats, the output of an OpenEmbedded build depends on how you
285start it. Usually, the output is a flashable image ready for the target
286device.
287
288How do I make the Yocto Project support my board?
289-------------------------------------------------
290
291Support for an additional board is added by creating a Board
292Support Package (BSP) layer for it. For more information on how to
293create a BSP layer, see the
294":ref:`dev-manual/common-tasks:understanding and creating layers`"
295section in the Yocto Project Development Tasks Manual and the
296:doc:`/bsp-guide/index`.
297
298Usually, if the board is not completely exotic, adding support in the
299Yocto Project is fairly straightforward.
300
301How do I make the Yocto Project support my package?
302---------------------------------------------------
303
304To add a package, you need to create a BitBake recipe. For
305information on how to create a BitBake recipe, see the
306":ref:`dev-manual/common-tasks:writing a new recipe`"
307section in the Yocto Project Development Tasks Manual.
308
309What do I need to ship for license compliance?
310----------------------------------------------
311
312This is a difficult question and you need to consult your lawyer
313for the answer for your specific case. It is worth bearing in mind that
314for GPL compliance, there needs to be enough information shipped to
315allow someone else to rebuild and produce the same end result you are
316shipping. This means sharing the source code, any patches applied to it,
317and also any configuration information about how that package was
318configured and built.
319
320You can find more information on licensing in the
321":ref:`overview-manual/development-environment:licensing`"
322section in the Yocto Project Overview and Concepts Manual and also in the
323":ref:`dev-manual/common-tasks:maintaining open source license compliance during your product's lifecycle`"
324section in the Yocto Project Development Tasks Manual.
325
326Do I have to make a full reflash after recompiling one package?
327---------------------------------------------------------------
378 328
379**A:** Executables and libraries might need to be used from a directory 329The OpenEmbedded build system can build packages in various
330formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can
331then upgrade only the modified packages using the package tools on the device,
332much like on a desktop distribution such as Ubuntu or Fedora. However,
333package management on the target is entirely optional.
334
335How to prevent my package from being marked as machine specific?
336----------------------------------------------------------------
337
338If you have machine-specific data in a package for one machine only
339but the package is being marked as machine-specific in all cases,
340you can set :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` = "0" in the ``.bb`` file.
341However, but make sure the package is manually marked as machine-specific for the
342case that needs it. The code that handles :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH`
343is in the ``meta/classes-global/base.bbclass`` file.
344
345What's the difference between ``target`` and ``target-native``?
346---------------------------------------------------------------
347
348The ``*-native`` targets are designed to run on the system being
349used for the build. These are usually tools that are needed to assist
350the build in some way such as ``quilt-native``, which is used to apply
351patches. The non-native version is the one that runs on the target
352device.
353
354Why do ``${bindir}`` and ``${libdir}`` have strange values for ``-native`` recipes?
355-----------------------------------------------------------------------------------
356
357Executables and libraries might need to be used from a directory
380other than the directory into which they were initially installed. 358other than the directory into which they were initially installed.
381Complicating this situation is the fact that sometimes these executables 359Complicating this situation is the fact that sometimes these executables
382and libraries are compiled with the expectation of being run from that 360and libraries are compiled with the expectation of being run from that
@@ -408,15 +386,9 @@ native program (i.e. one that is intended to run on the build machine),
408that program is never installed directly to the build machine's root 386that program is never installed directly to the build machine's root
409file system. Consequently, the build system uses paths within the Build 387file system. Consequently, the build system uses paths within the Build
410Directory for ``DESTDIR``, ``bindir`` and related variables. To better 388Directory for ``DESTDIR``, ``bindir`` and related variables. To better
411understand this, consider the following two paths where the first is 389understand this, consider the following two paths (artificially broken
412relatively normal and the second is not: 390across lines for readability) where the first is relatively normal and
413 391the second is not::
414.. note::
415
416 Due to these lengthy examples, the paths are artificially broken
417 across lines for readability.
418
419::
420 392
421 /home/maxtothemax/poky-bootchart2/build/tmp/work/i586-poky-linux/zlib/ 393 /home/maxtothemax/poky-bootchart2/build/tmp/work/i586-poky-linux/zlib/
422 1.2.8-r0/sysroot-destdir/usr/bin 394 1.2.8-r0/sysroot-destdir/usr/bin
@@ -425,32 +397,76 @@ relatively normal and the second is not:
425 zlib-native/1.2.8-r0/sysroot-destdir/home/maxtothemax/poky-bootchart2/ 397 zlib-native/1.2.8-r0/sysroot-destdir/home/maxtothemax/poky-bootchart2/
426 build/tmp/sysroots/x86_64-linux/usr/bin 398 build/tmp/sysroots/x86_64-linux/usr/bin
427 399
428Even if the paths look unusual, 400Even if the paths look unusual, they both are correct --- the first for
429they both are correct --- the first for a target and the second for a 401a target and the second for a native recipe. These paths are a consequence
430native recipe. These paths are a consequence of the ``DESTDIR`` 402of the ``DESTDIR`` mechanism and while they appear strange, they are correct
431mechanism and while they appear strange, they are correct and in 403and in practice very effective.
432practice very effective.
433 404
434**Q:** The files provided by my ``*-native`` recipe do not appear to be 405How do I create images with more free space?
435available to other recipes. Files are missing from the native sysroot, 406--------------------------------------------
436my recipe is installing to the wrong place, or I am getting permissions
437errors during the :ref:`ref-tasks-install` task in my recipe! What is wrong?
438 407
439**A:** This situation results when a build system does not recognize the 408By default, the OpenEmbedded build system creates images that are
440environment variables supplied to it by :term:`BitBake`. The 4091.3 times the size of the populated root filesystem. To affect the image
441incident that prompted this FAQ entry involved a Makefile that used an 410size, you need to set various configurations:
442environment variable named ``BINDIR`` instead of the more standard
443variable ``bindir``. The makefile's hardcoded default value of
444"/usr/bin" worked most of the time, but not for the recipe's ``-native``
445variant. For another example, permissions errors might be caused by a
446Makefile that ignores ``DESTDIR`` or uses a different name for that
447environment variable. Check the build system to see if these kinds
448of issues exist.
449 411
450**Q:** I'm adding a binary in a recipe but it's different in the image, what is 412- *Image Size:* The OpenEmbedded build system uses the
451changing it? 413 :term:`IMAGE_ROOTFS_SIZE` variable to define
414 the size of the image in Kbytes. The build system determines the size
415 by taking into account the initial root filesystem size before any
416 modifications such as requested size for the image and any requested
417 additional free disk space to be added to the image.
418
419- *Overhead:* Use the
420 :term:`IMAGE_OVERHEAD_FACTOR` variable
421 to define the multiplier that the build system applies to the initial
422 image size, which is 1.3 by default.
423
424- *Additional Free Space:* Use the
425 :term:`IMAGE_ROOTFS_EXTRA_SPACE`
426 variable to add additional free space to the image. The build system
427 adds this space to the image after it determines its
428 :term:`IMAGE_ROOTFS_SIZE`.
429
430Why aren't spaces in path names supported?
431------------------------------------------
432
433The Yocto Project team has tried to do this before but too many
434of the tools the OpenEmbedded build system depends on, such as
435``autoconf``, break when they find spaces in pathnames. Until that
436situation changes, the team will not support spaces in pathnames.
452 437
453**A:** The first most obvious change is the system stripping debug symbols from 438I'm adding a binary in a recipe. Why is it different in the image?
454it. Setting :term:`INHIBIT_PACKAGE_STRIP` to stop debug symbols being stripped and/or 439------------------------------------------------------------------
455:term:`INHIBIT_PACKAGE_DEBUG_SPLIT` to stop debug symbols being split into a separate 440
456file will ensure the binary is unchanged. 441The first most obvious change is the system stripping debug symbols from
442it. Setting :term:`INHIBIT_PACKAGE_STRIP` to stop debug symbols being
443stripped and/or :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` to stop debug symbols
444being split into a separate file will ensure the binary is unchanged.
445
446Issues on the running system
447============================
448
449How do I disable the cursor on my touchscreen device?
450-----------------------------------------------------
451
452You need to create a form factor file as described in the
453":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
454the Yocto Project Board Support Packages (BSP) Developer's Guide. Set
455the ``HAVE_TOUCHSCREEN`` variable equal to one as follows::
456
457 HAVE_TOUCHSCREEN=1
458
459How to always bring up connected network interfaces?
460----------------------------------------------------
461
462The default interfaces file provided by the netbase recipe does
463not automatically bring up network interfaces. Therefore, you will need
464to add a BSP-specific netbase that includes an interfaces file. See the
465":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in
466the Yocto Project Board Support Packages (BSP) Developer's Guide for
467information on creating these types of miscellaneous recipe files.
468
469For example, add the following files to your layer::
470
471 meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces
472 meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend