%poky; ] > 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. I only have Python 2.4 or 2.5 but BitBake requires Python 2.6 or 2.7. Can I still use the Yocto Project? You can use a stand-alone tarball to provide Python 2.6. You can find pre-built 32 and 64-bit versions of Python 2.6 at the following locations: 32-bit tarball 64-bit tarball These tarballs are self-contained with all required libraries and should work on most Linux systems. To use the tarballs extract them into the root directory and run the appropriate command: $ export PATH=/opt/poky/sysroots/i586-pokysdk-linux/usr/bin/:$PATH $ export PATH=/opt/poky/sysroots/x86_64-pokysdk-linux/usr/bin/:$PATH Once you run the command, BitBake uses Python 2.6. 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 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 add a package, see the section "Writing a Recipe to Add a Package to Your Image" 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 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. How do I make the Yocto Project work in RHEL/CentOS? To get the Yocto Project working under RHEL/CentOS 5.1 you need to first install some required packages. The standard CentOS packages needed are: "Development tools" (selected during installation) texi2html compat-gcc-34 On top of these, you need the following external packages: python-sqlite2 from DAG repository help2man from Karan repository Once these packages are installed, the OpenEmbedded build system will be able to build standard images. However, there might be a problem with the QEMU emulator segfaulting. You can either disable the generation of binary locales by setting ENABLE_BINARY_LOCALE_GENERATION to "0" or by removing the linux-2.6-execshield.patch from the kernel and rebuilding it since that is the patch that causes the problems with QEMU. For information on distributions that the Yocto Project uses during validation, see the Distribution Support Wiki page. For notes about using the Yocto Project on a RHEL 4-based host, see the Building on RHEL4 Wiki page. 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" (i.e. tcmode-default.inc). However, other patterns are accepted. In particular, "external-*" refers to external toolchains of which there are some basic examples included in the OpenEmbedded Core (meta). You can use your own custom toolchain definition in your own layer (or as defined in the local.conf file) at the location conf/distro/include/tcmode-*.inc. 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. An example is the external-sourcery-toolchain.bb, which is located in meta/recipes-core/meta/ within the Source Directory. For information on installing and using cross-development toolchains, see the "Installing the ADT and Toolchains" section in the Yocto Project Application Developer's Guide. For general information on cross-development toolchains, see the "Cross-Development Toolchain Generation" section. 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 source the &OE_INIT_FILE; setup script. 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.