diff options
Diffstat (limited to 'import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml')
| -rw-r--r-- | import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml b/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml index e51ceb1bf..541a47e55 100644 --- a/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml +++ b/import-layers/yocto-poky/documentation/ref-manual/ref-structure.xml @@ -660,9 +660,21 @@ <title><filename>build/tmp/cache/</filename></title> <para> - When BitBake parses the metadata, it creates a cache file of the result that can - be used when subsequently running commands. - BitBake stores these results here on a per-machine basis. + When BitBake parses the metadata (recipes and configuration files), + it caches the results in <filename>build/tmp/cache/</filename> + to speed up future builds. + The results are stored on a per-machine basis. + </para> + + <para> + During subsequent builds, BitBake checks each recipe (together + with, for example, any files included or appended to it) to see + if they have been modified. + Changes can be detected, for example, through file modification + time (mtime) changes and hashing of file contents. + If no changes to the file are detected, then the parsed result + stored in the cache is reused. + If the file has changed, it is reparsed. </para> </section> @@ -801,8 +813,9 @@ <title><filename>build/tmp/stamps/</filename></title> <para> - This directory holds information that BitBake uses for accounting purposes - to track what tasks have run and when they have run. + This directory holds information that BitBake uses for + accounting purposes to track what tasks have run and when they + have run. The directory is sub-divided by architecture, package name, and version. Following is an example: @@ -812,6 +825,13 @@ Although the files in the directory are empty of data, BitBake uses the filenames and timestamps for tracking purposes. </para> + + <para> + For information on how BitBake uses stamp files to determine if + a task should be rerun, see the + "<link linkend='stamp-files-and-the-rerunning-of-tasks'>Stamp Files and the Rerunning of Tasks</link>" + section. + </para> </section> <section id='structure-build-tmp-log'> |
