The cornerstone of the extensible SDK is a command-line tool
called devtool
.
This tool provides a number of features that help
you build, test and package software within the extensible SDK, and
optionally integrate it into an image built by the OpenEmbedded build
system.
The devtool
command line is organized similarly
to
Git in that it has a
number of sub-commands for each function.
You can run devtool --help
to see all the
commands.
Two devtool
subcommands that provide
entry-points into development are:
devtool add
:
Assists in adding new software to be built.
devtool modify
:
Sets up an environment to enable you to modify the source of
an existing component.
As with the OpenEmbedded build system, "recipes" represent software
packages within devtool
.
When you use devtool add
, a recipe is
automatically created.
When you use devtool modify
, the specified
existing recipe is used in order to determine where to get the source
code and how to patch it.
In both cases, an environment is set up so that when you build the
recipe a source tree that is under your control is used in order to
allow you to make changes to the source as desired.
By default, both new recipes and the source go into a "workspace"
directory under the SDK.
The remainder of this section presents the
devtool add
and
devtool modify
workflows.