Re: [yocto] How does bitbake work
Hi Tim - this sounds quite correct to me, and a good way to represent the process. Further, the elinux.org wiki page is coming along very well, and I would encourage you to add this to the page. I'd be glad to help with it if I can. On Tue, Aug 21, 2012 at 11:23 AM, Tim Bird tim.b...@am.sony.com wrote: On 08/21/2012 01:11 AM, Liu wrote: Hi all, In order to learn to use poky,I am wondering how bitbake works with so many recipes. When I bitbake target, I want to know how bitbake collect the providers of target . Then bitbake will prepare the runqueue tasks to build the target.So I need to know which tasks to assign to build the target.And bitbake run these tasks in what order.In other words according to the characteristics of what to decided to implement which task first and then next. I am very eager to know the answers. I'm not an expert, but here's some information that I believe is correct. (If someone else knows better, please correct this...) bitbake reads the entire set of recipe files that are specified by the local configuration, and parses them all into a global task namespace. This includes all the class files and include files as well. These are specified by the BBFILES and BBLAYERS variables in the conf/bblayers.conf file. Within the layers directories, the layer-dir/conf/layer.conf file is used to indicate the set of .bb files to parse for that layer. Note that this global parse of the entire set of recipe files is quite different from 'make', which usually operated on a single Makefile. (This is also why bitbake startup is a little slow). Information in the meta-data (the DEPENDS and PROVIDES lines) determine package ordering. Where packages are independent of each other, the build order is dependent (I believe) on file parse order. In this case, processing is not required to be in any particular order (and, in fact, can be parallelized). You can have bitbake produce the dependency graph of the packages for your build by using the -g option. This produces output in 'dot' syntax (suitable for processing using some graphviz visualizer). The list of tasks to perform within a package appears to come from the common class meta-data (see meta/classes/utility-tasks.bbclass, for example) and the meta-data for the individual package These are added by the 'addtask' keyword. You can see a list of tasks for an individual package with: bitbake pkg -c listtasks I have started to put together an overview introduction of Yocto at: http://elinux.org/Yocto_Project_Introduction I haven't gotten much completed yet, but I do discuss bitbake there a bit. Hopefully what I've got so far will be helpful. -- Tim P.S. someone correct me if I'm wrong. Thanks , -- Yu Liu Following is the some output of bitbake busybox and in this example I want to know why first do the task of (quilt-native_0.51.bb, do_fetch) : Parsing recipes...done. Parsing of 830 .bb files complete (0 cached, 830 parsed). 1106 targets, 34 skipped, 0 masked, 0 errors. OE Build Configuration: BB_VERSION= 1.15.2 TARGET_ARCH = arm TARGET_OS = linux-gnueabi MACHINE = qemuarm DISTRO= poky DISTRO_VERSION= 1.2.1 TUNE_FEATURES = armv5 dsp thumb arm926ejs TARGET_FPU= soft meta meta-yocto= unknown:unknown NOTE: Resolving any missing task queue dependencies NOTE: multiple providers are available for virtual/arm-none-linux-gnueabi-g++ (external-csl-toolchain, gcc-cross) NOTE: consider defining a PREFERRED_PROVIDER entry to match virtual/arm-none-linux-gnueabi-g++ NOTE: multiple providers are available for runtime linux-libc-headers-dev (linux-libc-headers, linux-libc-headers-yocto, linux-libc-headers-yocto-nativesdk) NOTE: consider defining a PREFERRED_PROVIDER entry to match linux-libc-headers-dev NOTE: Preparing runqueue NOTE: Executing SetScene Tasks NOTE: Executing RunQueue Tasks NOTE: Running task 1 of 706 (ID: 18, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/quilt/quilt-native_0.51.bb, do_fetch) NOTE: Running task 2 of 706 (ID: 228, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/gnu-config/gnu-config_2011.bb, do_fetch) NOTE: Running task 3 of 706 (ID: 189, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/autoconf/autoconf_2.68.bb, do_fetch) NOTE: Running task 4 of 706 (ID: 515, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/m4/m4-native_1.4.16.bb, do_fetch) NOTE: package gnu-config-native-2011-r1: task do_fetch: Started NOTE: package m4-native-1.4.16-r2: task do_fetch: Started NOTE: package quilt-native-0.51-r1: task do_fetch: Started NOTE: package autoconf-native-2.68-r7: task do_fetch: Started NOTE: package gnu-config-native-2011-r1: task do_fetch: Succeeded NOTE: Running task 5 of 706 (ID: 224,
Re: [yocto] How does bitbake work
I like the chapter Beth Flanagan wrote recently about the architecture of the Yocto Project. Check it out at the following link, and I think you might learn a lot. I do suspect that what's happening for you is that certain native tools like quilt need to be built first so that other parts of the build will run. (Quilt is used to manage the patches that applied in the build process). Dave http://www.aosabook.org/en/yocto.html From: yocto-boun...@yoctoproject.org [mailto:yocto-boun...@yoctoproject.org] On Behalf Of Liu Sent: Tuesday, August 21, 2012 1:11 AM To: yocto Subject: [yocto] How does bitbake work Hi all, In order to learn to use poky,I am wondering how bitbake works with so many recipes. When I bitbake target, I want to know how bitbake collect the providers of target . Then bitbake will prepare the runqueue tasks to build the target.So I need to know which tasks to assign to build the target.And bitbake run these tasks in what order.In other words according to the characteristics of what to decided to implement which task first and then next. I am very eager to know the answers. Thanks , -- Yu Liu Following is the some output of bitbake busybox and in this example I want to know why first do the task of (quilt-native_0.51.bb, do_fetch) : Parsing recipes...done. Parsing of 830 .bb files complete (0 cached, 830 parsed). 1106 targets, 34 skipped, 0 masked, 0 errors. OE Build Configuration: BB_VERSION= 1.15.2 TARGET_ARCH = arm TARGET_OS = linux-gnueabi MACHINE = qemuarm DISTRO= poky DISTRO_VERSION= 1.2.1 TUNE_FEATURES = armv5 dsp thumb arm926ejs TARGET_FPU= soft meta meta-yocto= unknown:unknown NOTE: Resolving any missing task queue dependencies NOTE: multiple providers are available for virtual/arm-none-linux-gnueabi-g++ (external-csl-toolchain, gcc-cross) NOTE: consider defining a PREFERRED_PROVIDER entry to match virtual/arm-none-linux-gnueabi-g++ NOTE: multiple providers are available for runtime linux-libc-headers-dev (linux-libc-headers, linux-libc-headers-yocto, linux-libc-headers-yocto-nativesdk) NOTE: consider defining a PREFERRED_PROVIDER entry to match linux-libc-headers-dev NOTE: Preparing runqueue NOTE: Executing SetScene Tasks NOTE: Executing RunQueue Tasks NOTE: Running task 1 of 706 (ID: 18, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/quilt/quilt-native_0.51.bb, do_fetch) NOTE: Running task 2 of 706 (ID: 228, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/gnu-config/gnu-config_2011.bb, do_fetch) NOTE: Running task 3 of 706 (ID: 189, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/autoconf/autoconf_2.68.bb, do_fetch) NOTE: Running task 4 of 706 (ID: 515, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/m4/m4-native_1.4.16.bb, do_fetch) NOTE: package gnu-config-native-2011-r1: task do_fetch: Started NOTE: package m4-native-1.4.16-r2: task do_fetch: Started NOTE: package quilt-native-0.51-r1: task do_fetch: Started NOTE: package autoconf-native-2.68-r7: task do_fetch: Started NOTE: package gnu-config-native-2011-r1: task do_fetch: Succeeded NOTE: Running task 5 of 706 (ID: 224, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/gnu-config/gnu-config_2011.bb, do_unpack) NOTE: package gnu-config-native-2011-r1: task do_unpack: Started NOTE: package gnu-config-native-2011-r1: task do_unpack: Succeeded NOTE: Running task 6 of 706 (ID: 202, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/automake/automake_1.11.2.bb, do_fetch) NOTE: package automake-native-1.11.2-r3: task do_fetch: Started NOTE: package m4-native-1.4.16-r2: task do_fetch: Succeeded NOTE: Running task 7 of 706 (ID: 511, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/m4/m4-native_1.4.16.bb, do_unpack) NOTE: package m4-native-1.4.16-r2: task do_unpack: Started NOTE: package m4-native-1.4.16-r2: task do_unpack: Succeeded NOTE: Running task 8 of 706 (ID: 215, /home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/libtool/libtool-native_2.4.2.bb, do_fetch) NOTE: package autoconf-native-2.68-r7: task do_fetch: Succeeded NOTE: Running task 9 of 706 (ID: 185, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/autoconf/autoconf_2.68.bb, do_unpack) NOTE: package libtool-native-2.4.2-r2.0: task do_fetch: Started NOTE: package autoconf-native-2.68-r7: task do_unpack: Started NOTE: package autoconf-native-2.68-r7: task do_unpack: Succeeded NOTE: Running task 10 of 706 (ID: 254, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-core/zlib/zlib_1.2.6.bb, do_fetch) NOTE: package automake-native-1.11.2-r3: task do_fetch: Succeeded NOTE: Running task 11 of 706 (ID: 198, virtual:native:/home/ly/yocto/poky-denzil-7.0.1/meta/recipes-devtools/automake/automake_1.11.2.bb, do_unpack) NOTE: package zlib-native-1.2.6-r1: task do_fetch: Started NOTE: package
