When enabled, it will keep a record of the changes to each package and image in the form of a Git repository in a way that can be explored and analyzed.
Note that build history will only record changes to the build. If your project is already built, you will have to modify something or remove the tmp folder in order for build history to be generated.
The build configuration and metadata revision, as printed by Bitbake, is stored in the build-id.txt file.
For a package, build history records the following information:
- Package and recipe revision
- Dependencies
- Package size
- Files
For an image, it records the following information:
- Build configuration
- Dependency graphs
- A list of files that include ownership and permissions, as well as size and symlink information
- A list of installed packages
And for an SDK, it records the following information:
- SDK configuration
- A list of both host and target files, including ownership and permissions, as well as size and symlinks information
- Package-related information is only generated for the standard SDK, not for the extensible SDK. This includes:
- Dependency graphs
- A list of installed packages
For more details about using Yocto SDKs, please refer to the Preparing an SDK and Using the extensible SDK recipes in Chapter 4, Application Development.