devtool is a helper program for adding and modifying recipes in yocto. It is available as part of the yocto build environment either through setting up a full yocto build environment or through the extensible SDK .

Upon invoking devtool, it creates a workspace layer inside the build directory to store any and all new recipes and modifications to existing ones. The workspace also includes the sources for all recipes touched by devtool, so that they can easily be modified and persist through cleaning actions such as bitbake -c cleanall.

Furthermore, devtool allows for easy creation of patches, at least when used with sources from a git repository.