BitBake also contains a set of "fetcher" modules that allow
retrieval of source code from various types of sources.
For example, BitBake can get source code from a disk with the metadata, from websites,
from remote shell accounts or from Source Code Management (SCM) systems
like cvs/subversion/git
.
Fetchers are usually triggered by entries in
SRC_URI
.
You can find information about the options and formats of entries for specific
fetchers in the BitBake manual located in the
bitbake/doc/manual
directory of the
Source Directory.
One useful feature for certain Source Code Manager (SCM) fetchers is the ability to
"auto-update" when the upstream SCM changes version.
Since this ability requires certain functionality from the SCM, not all
systems support it.
Currently Subversion, Bazaar and to a limited extent, Git support the ability to "auto-update".
This feature works using the SRCREV
variable.
See the
"Using an External SCM" section
in the Yocto Project Development Manual for more information.