From c527fd1f14c27855a37f2e8ac5346ce8d940ced2 Mon Sep 17 00:00:00 2001 From: Tudor Florea Date: Thu, 16 Oct 2014 03:05:19 +0200 Subject: initial commit for Enea Linux 4.0-140929 Migrated from the internal git server on the daisy-enea-point-release branch Signed-off-by: Tudor Florea --- documentation/ref-manual/faq.xml | 685 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 685 insertions(+) create mode 100644 documentation/ref-manual/faq.xml (limited to 'documentation/ref-manual/faq.xml') diff --git a/documentation/ref-manual/faq.xml b/documentation/ref-manual/faq.xml new file mode 100644 index 0000000000..035011f342 --- /dev/null +++ b/documentation/ref-manual/faq.xml @@ -0,0 +1,685 @@ + %poky; ] > + + +FAQ + + + + + How does Poky differ from OpenEmbedded? + + + + + The term "Poky" + refers to the specific reference build system that + the Yocto Project provides. + Poky is based on OE-Core + and BitBake. + Thus, the generic term used here for the build system is + the "OpenEmbedded build system." + Development in the Yocto Project using Poky is closely tied to OpenEmbedded, with + changes always being merged to OE-Core or BitBake first before being pulled back + into Poky. + This practice benefits both projects immediately. + + + + + + + + My development system does not meet the + required Git, tar, and Python versions. + In particular, I do not have Python 2.7.3 or greater, or + I do have Python 3.x, which is specifically not supported by + the Yocto Project. + Can I still use the Yocto Project? + + + + + You can get the required tools on your host development + system a couple different ways (i.e. building a tarball or + downloading a tarball). + See the + "Required Git, tar, and Python Versions" + section for steps on how to update your build tools. + + + + + + + + How can you claim Poky / OpenEmbedded-Core is stable? + + + + + There are three areas that help with stability; + + The Yocto Project team keeps + OE-Core small + and focused, containing around 830 recipes as opposed to the thousands + available in other OpenEmbedded community layers. + Keeping it small makes it easy to test and maintain. + The Yocto Project team runs manual and automated tests + using a small, fixed set of reference hardware as well as emulated + targets. + The Yocto Project uses an autobuilder, + which provides continuous build and integration tests. + + + + + + + + + How do I get support for my board added to the Yocto Project? + + + + + Support for an additional board is added by creating a + Board Support Package (BSP) layer for it. + For more information on how to create a BSP layer, see the + "Understanding and Creating Layers" + section in the Yocto Project Development Manual and the + Yocto Project Board Support Package (BSP) Developer's Guide. + + + Usually, if the board is not completely exotic, adding support in + the Yocto Project is fairly straightforward. + + + + + + + + Are there any products built using the OpenEmbedded build system? + + + + + The software running on the Vernier LabQuest + is built using the OpenEmbedded build system. + See the Vernier LabQuest + website for more information. + There are a number of pre-production devices using the OpenEmbedded build system + and the Yocto Project team + announces them as soon as they are released. + + + + + + + + What does the OpenEmbedded build system produce as output? + + + + + Because you can use the same set of recipes to create output of + various formats, the output of an OpenEmbedded build depends on + how you start it. + Usually, the output is a flashable image ready for the target + device. + + + + + + + + How do I add my package to the Yocto Project? + + + + + To add a package, you need to create a BitBake recipe. + For information on how to create a BitBake recipe, see the + "Writing a New Recipe" + in the Yocto Project Development Manual. + + + + + + + + Do I have to reflash my entire board with a new Yocto Project image when recompiling + a package? + + + + + The OpenEmbedded build system can build packages in various + formats such as IPK for OPKG, Debian package + (.deb), or RPM. + You can then upgrade the packages using the package tools on + the device, much like on a desktop distribution such as + Ubuntu or Fedora. + However, package management on the target is entirely optional. + + + + + + + + What is GNOME Mobile and what is the difference between GNOME Mobile and GNOME? + + + + + GNOME Mobile is a subset of the GNOME + platform targeted at mobile and embedded devices. + The main difference between GNOME Mobile and standard GNOME is that + desktop-orientated libraries have been removed, along with deprecated libraries, + creating a much smaller footprint. + + + + + + + + I see the error 'chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x'. + What is wrong? + + + + + You are probably running the build on an NTFS filesystem. + Use ext2, ext3, or ext4 instead. + + + + + + + + + + I see lots of 404 responses for files on + &YOCTO_HOME_URL;/sources/*. Is something wrong? + + + + + Nothing is wrong. + The OpenEmbedded build system checks any configured source mirrors before downloading + from the upstream sources. + The build system does this searching for both source archives and + pre-checked out versions of SCM-managed software. + These checks help in large installations because it can reduce load on the SCM servers + themselves. + The address above is one of the default mirrors configured into the + build system. + Consequently, if an upstream source disappears, the team + can place sources there so builds continue to work. + + + + + + + + I have machine-specific data in a package for one machine only but the package is + being marked as machine-specific in all cases, how do I prevent this? + + + + + Set SRC_URI_OVERRIDES_PACKAGE_ARCH + = "0" in the .bb file but make sure the package is + manually marked as + machine-specific for the case that needs it. + The code that handles + SRC_URI_OVERRIDES_PACKAGE_ARCH is in + the meta/classes/base.bbclass file. + + + + + + + + I'm behind a firewall and need to use a proxy server. How do I do that? + + + + + Most source fetching by the OpenEmbedded build system is done by wget + and you therefore need to specify the proxy settings in a + .wgetrc file in your home directory. + Here are some example settings: + + http_proxy = http://proxy.yoyodyne.com:18023/ + ftp_proxy = http://proxy.yoyodyne.com:18023/ + + The Yocto Project also includes a + site.conf.sample file that shows how to + configure CVS and Git proxy servers if needed. + + + + + + + + What’s the difference between foo and foo-native? + + + + + The *-native targets are designed to run on the system + being used for the build. + These are usually tools that are needed to assist the build in some way such as + quilt-native, which is used to apply patches. + The non-native version is the one that runs on the target device. + + + + + + + + I'm seeing random build failures. Help?! + + + + + If the same build is failing in totally different and random + ways, the most likely explanation is: + + The hardware you are running the build on + has some problem. + You are running the build under + virtualization, in which case the virtualization + probably has bugs. + + The OpenEmbedded build system processes a massive amount of + data that causes lots of network, disk and CPU activity and + is sensitive to even single-bit failures in any of these areas. + True random failures have always been traced back to hardware + or virtualization issues. + + + + + + + + What do we need to ship for license compliance? + + + + + This is a difficult question and you need to consult your lawyer + for the answer for your specific case. + It is worth bearing in mind that for GPL compliance, there needs + to be enough information shipped to allow someone else to + rebuild and produce the same end result you are shipping. + This means sharing the source code, any patches applied to it, + and also any configuration information about how that package + was configured and built. + + + + You can find more information on licensing in the + "Licensing" + and "Maintaining Open Source License Compliance During Your Product's Lifecycle" + sections, both of which are in the Yocto Project Development + Manual. + + + + + + + + How do I disable the cursor on my touchscreen device? + + + + + You need to create a form factor file as described in the + "Miscellaneous BSP-Specific Recipe Files" + section in the Yocto Project Board Support Packages (BSP) + Developer's Guide. + Set the HAVE_TOUCHSCREEN variable equal to + one as follows: + + HAVE_TOUCHSCREEN=1 + + + + + + + + + How do I make sure connected network interfaces are brought up by default? + + + + + The default interfaces file provided by the netbase recipe does not + automatically bring up network interfaces. + Therefore, you will need to add a BSP-specific netbase that includes an interfaces + file. + See the "Miscellaneous BSP-Specific Recipe Files" + section in the Yocto Project Board Support Packages (BSP) + Developer's Guide for information on creating these types of + miscellaneous recipe files. + + + For example, add the following files to your layer: + + meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces + meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend + + + + + + + + + How do I create images with more free space? + + + + + By default, the OpenEmbedded build system creates images + that are 1.3 times the size of the populated root filesystem. + To affect the image size, you need to set various + configurations: + + Image Size: + The OpenEmbedded build system uses the + IMAGE_ROOTFS_SIZE + variable to define the size of the image in Kbytes. + The build system determines the size by taking into + account the initial root filesystem size before any + modifications such as requested size for the image and + any requested additional free disk space to be + added to the image. + Overhead: + Use the + IMAGE_OVERHEAD_FACTOR + variable to define the multiplier that the build system + applies to the initial image size, which is 1.3 by + default. + Additional Free Space: + Use the + IMAGE_ROOTFS_EXTRA_SPACE + variable to add additional free space to the image. + The build system adds this space to the image after + it determines its + IMAGE_ROOTFS_SIZE. + + + + + + + + + + Why don't you support directories with spaces in the pathnames? + + + + + The Yocto Project team has tried to do this before but too + many of the tools the OpenEmbedded build system depends on, + such as autoconf, break when they find + spaces in pathnames. + Until that situation changes, the team will not support spaces + in pathnames. + + + + + + + + How do I use an external toolchain? + + + + + The toolchain configuration is very flexible and customizable. + It is primarily controlled with the + TCMODE + variable. + This variable controls which tcmode-*.inc + file to include from the + meta/conf/distro/include directory within + the + Source Directory. + + + + The default value of TCMODE is "default", + which tells the OpenEmbedded build system to use its internally + built toolchain (i.e. tcmode-default.inc). + However, other patterns are accepted. + In particular, "external-*" refers to external toolchains. + One example is the Sourcery G++ Toolchain. + The support for this toolchain resides in the separate + meta-sourcery layer at + . + + + + In addition to the toolchain configuration, you also need a + corresponding toolchain recipe file. + This recipe file needs to package up any pre-built objects in + the toolchain such as libgcc, + libstdcc++, any locales, and + libc. + + + + + + + + How does the OpenEmbedded build system obtain source code and + will it work behind my firewall or proxy server? + + + + + The way the build system obtains source code is highly + configurable. + You can setup the build system to get source code in most + environments if HTTP transport is available. + + + When the build system searches for source code, it first + tries the local download directory. + If that location fails, Poky tries + PREMIRRORS, + the upstream source, and then + MIRRORS + in that order. + + + Assuming your distribution is "poky", the OpenEmbedded build + system uses the Yocto Project source + PREMIRRORS by default for SCM-based + sources, upstreams for normal tarballs, and then falls back + to a number of other mirrors including the Yocto Project + source mirror if those fail. + + + As an example, you could add a specific server for the + build system to attempt before any others by adding something + like the following to the local.conf + configuration file: + + PREMIRRORS_prepend = "\ + git://.*/.* http://www.yoctoproject.org/sources/ \n \ + ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ + http://.*/.* http://www.yoctoproject.org/sources/ \n \ + https://.*/.* http://www.yoctoproject.org/sources/ \n" + + + + These changes cause the build system to intercept Git, FTP, + HTTP, and HTTPS requests and direct them to the + http:// sources mirror. + You can use file:// URLs to point to + local directories or network shares as well. + + + Aside from the previous technique, these options also exist: + + BB_NO_NETWORK = "1" + + This statement tells BitBake to issue an error instead of + trying to access the Internet. + This technique is useful if you want to ensure code builds + only from local sources. + + + Here is another technique: + + BB_FETCH_PREMIRRORONLY = "1" + + This statement limits the build system to pulling source + from the PREMIRRORS only. + Again, this technique is useful for reproducing builds. + + + Here is another technique: + + BB_GENERATE_MIRROR_TARBALLS = "1" + + This statement tells the build system to generate mirror + tarballs. + This technique is useful if you want to create a mirror server. + If not, however, the technique can simply waste time during + the build. + + + Finally, consider an example where you are behind an + HTTP-only firewall. + You could make the following changes to the + local.conf configuration file as long as + the PREMIRRORS server is current: + + PREMIRRORS_prepend = "\ + ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ + http://.*/.* http://www.yoctoproject.org/sources/ \n \ + https://.*/.* http://www.yoctoproject.org/sources/ \n" + BB_FETCH_PREMIRRORONLY = "1" + + These changes would cause the build system to successfully + fetch source over HTTP and any network accesses to anything + other than the PREMIRRORS would fail. + + + The build system also honors the standard shell environment + variables http_proxy, + ftp_proxy, + https_proxy, and + all_proxy to redirect requests through + proxy servers. + + + + + + + + Can I get rid of build output so I can start over? + + + + + Yes - you can easily do this. + When you use BitBake to build an image, all the build output + goes into the directory created when you run the + build environment setup script (i.e. + &OE_INIT_FILE; + or + oe-init-build-env-memres). + By default, this Build Directory + is named build but can be named + anything you want. + + + + Within the Build Directory, is the tmp + directory. + To remove all the build output yet preserve any source code or + downloaded files from previous builds, simply remove the + tmp directory. + + + + + + + + -- cgit v1.2.3-54-g00ecf