diff options
Diffstat (limited to 'documentation/overview-manual')
-rw-r--r-- | documentation/overview-manual/overview-manual-concepts.xml | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/documentation/overview-manual/overview-manual-concepts.xml b/documentation/overview-manual/overview-manual-concepts.xml index 2a3d62c32a..3fc810d21a 100644 --- a/documentation/overview-manual/overview-manual-concepts.xml +++ b/documentation/overview-manual/overview-manual-concepts.xml | |||
@@ -1830,8 +1830,8 @@ | |||
1830 | 1830 | ||
1831 | <para> | 1831 | <para> |
1832 | The description of tasks so far assumes that BitBake needs | 1832 | The description of tasks so far assumes that BitBake needs |
1833 | to build everything and there are no prebuilt objects | 1833 | to build everything and no available prebuilt objects |
1834 | available. | 1834 | exist. |
1835 | BitBake does support skipping tasks if prebuilt objects are | 1835 | BitBake does support skipping tasks if prebuilt objects are |
1836 | available. | 1836 | available. |
1837 | These objects are usually made available in the form of a | 1837 | These objects are usually made available in the form of a |
@@ -1856,34 +1856,33 @@ | |||
1856 | variant (e.g. generating package files in the | 1856 | variant (e.g. generating package files in the |
1857 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-package_write_deb'><filename>do_package_write_*</filename></ulink> | 1857 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-package_write_deb'><filename>do_package_write_*</filename></ulink> |
1858 | task). | 1858 | task). |
1859 | In other cases, it does not make sense, (e.g. a | 1859 | In other cases, it does not make sense (e.g. a |
1860 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-patch'><filename>do_patch</filename></ulink> | 1860 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-patch'><filename>do_patch</filename></ulink> |
1861 | task or | 1861 | task or a |
1862 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-unpack'><filename>do_unpack</filename></ulink> | 1862 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-unpack'><filename>do_unpack</filename></ulink> |
1863 | task) since the work involved would be equal to or greater | 1863 | task) since the work involved would be equal to or greater |
1864 | than the underlying task. | 1864 | than the underlying task. |
1865 | </para> | 1865 | </para> |
1866 | 1866 | ||
1867 | <para> | 1867 | <para> |
1868 | In the OpenEmbedded build system, the common tasks that | 1868 | In the build system, the common tasks that have setscene |
1869 | have setscene variants are | 1869 | variants are |
1870 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-package'><filename>do_package</filename></ulink>, | 1870 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-package'><filename>do_package</filename></ulink>, |
1871 | <filename>do_package_write_*</filename>, | 1871 | <filename>do_package_write_*</filename>, |
1872 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-deploy'><filename>do_deploy</filename></ulink>, | 1872 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-deploy'><filename>do_deploy</filename></ulink>, |
1873 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-packagedata'><filename>do_packagedata</filename></ulink>, | 1873 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-packagedata'><filename>do_packagedata</filename></ulink>, |
1874 | and | 1874 | and |
1875 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-populate_sysroot'><filename>do_populate_sysroot</filename></ulink>. | 1875 | <ulink url='&YOCTO_DOCS_REF_URL;#ref-tasks-populate_sysroot'><filename>do_populate_sysroot</filename></ulink>. |
1876 | Notice that these are most of the tasks whose output is an | 1876 | Notice that these tasks represent most of the tasks whose |
1877 | end result. | 1877 | output is an end result. |
1878 | </para> | 1878 | </para> |
1879 | 1879 | ||
1880 | <para> | 1880 | <para> |
1881 | The OpenEmbedded build system has knowledge of the | 1881 | The build system has knowledge of the relationship between |
1882 | relationship between these tasks and other tasks that | 1882 | these tasks and other preceding tasks. |
1883 | precede them. | ||
1884 | For example, if BitBake runs | 1883 | For example, if BitBake runs |
1885 | <filename>do_populate_sysroot_setscene</filename> for | 1884 | <filename>do_populate_sysroot_setscene</filename> for |
1886 | something, there is little point in running any of the | 1885 | something, it does not make sense to run any of the |
1887 | <filename>do_fetch</filename>, | 1886 | <filename>do_fetch</filename>, |
1888 | <filename>do_unpack</filename>, | 1887 | <filename>do_unpack</filename>, |
1889 | <filename>do_patch</filename>, | 1888 | <filename>do_patch</filename>, |
@@ -1891,7 +1890,7 @@ | |||
1891 | <filename>do_compile</filename>, and | 1890 | <filename>do_compile</filename>, and |
1892 | <filename>do_install</filename> tasks. | 1891 | <filename>do_install</filename> tasks. |
1893 | However, if <filename>do_package</filename> needs to be | 1892 | However, if <filename>do_package</filename> needs to be |
1894 | run, BitBake would need to run those other tasks. | 1893 | run, BitBake needs to run those other tasks. |
1895 | </para> | 1894 | </para> |
1896 | 1895 | ||
1897 | <para> | 1896 | <para> |
@@ -1899,7 +1898,7 @@ | |||
1899 | from an sstate cache because some objects are simply | 1898 | from an sstate cache because some objects are simply |
1900 | not required at all. | 1899 | not required at all. |
1901 | For example, you do not need a compiler or native tools, | 1900 | For example, you do not need a compiler or native tools, |
1902 | such as quilt, if there is nothing to compile or patch. | 1901 | such as quilt, if nothing exists to compile or patch. |
1903 | If the <filename>do_package_write_*</filename> packages | 1902 | If the <filename>do_package_write_*</filename> packages |
1904 | are available from sstate, BitBake does not need the | 1903 | are available from sstate, BitBake does not need the |
1905 | <filename>do_package</filename> task data. | 1904 | <filename>do_package</filename> task data. |
@@ -1918,26 +1917,24 @@ | |||
1918 | </para> | 1917 | </para> |
1919 | 1918 | ||
1920 | <para> | 1919 | <para> |
1921 | If objects are found in the sstate cache, the OpenEmbedded | 1920 | If objects are found in the sstate cache, the build system |
1922 | build system works backwards from the end targets specified | 1921 | works backwards from the end targets specified by the user. |
1923 | by the user. | 1922 | For example, if an image is being built, the build system |
1924 | For example, if an image is being built, the OpenEmbedded | 1923 | first looks for the packages needed for that image and the |
1925 | build system first looks for the packages needed for | 1924 | tools needed to construct an image. |
1926 | that image and the tools needed to construct an image. | ||
1927 | If those are available, the compiler is not needed. | 1925 | If those are available, the compiler is not needed. |
1928 | Thus, the compiler is not even downloaded. | 1926 | Thus, the compiler is not even downloaded. |
1929 | If something was found to be unavailable, or the | 1927 | If something was found to be unavailable, or the |
1930 | download or setscene task fails, the OpenEmbedded build | 1928 | download or setscene task fails, the build system then |
1931 | system then tries to install dependencies, such as the | 1929 | tries to install dependencies, such as the compiler, from |
1932 | compiler, from the cache. | 1930 | the cache. |
1933 | </para> | 1931 | </para> |
1934 | 1932 | ||
1935 | <para> | 1933 | <para> |
1936 | The availability of objects in the sstate cache is | 1934 | The availability of objects in the sstate cache is |
1937 | handled by the function specified by the | 1935 | handled by the function specified by the |
1938 | <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_HASHCHECK_FUNCTION'><filename>BB_HASHCHECK_FUNCTION</filename></ulink> | 1936 | <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_HASHCHECK_FUNCTION'><filename>BB_HASHCHECK_FUNCTION</filename></ulink> |
1939 | variable and returns a list of the objects that are | 1937 | variable and returns a list of available objects. |
1940 | available. | ||
1941 | The function specified by the | 1938 | The function specified by the |
1942 | <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_SETSCENE_DEPVALID'><filename>BB_SETSCENE_DEPVALID</filename></ulink> | 1939 | <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_SETSCENE_DEPVALID'><filename>BB_SETSCENE_DEPVALID</filename></ulink> |
1943 | variable is the function that determines whether a given | 1940 | variable is the function that determines whether a given |