Each firmware component has its own versioning scheme, and op-build brings all of these components together in one image with one global version number.
Firmware versions are exposed to the user through both the device tree (:ref:`skiboot:device-tree/ibm,firmware-versions`) and the VERSION firmware partition. As such, firmware versioning numbers MUST follow the requirements in order for some functionality to be correct.
- skiboot
- :ref:`skiboot:versioning`
- Hostboot
- Currently just uses the git SHA1 of the commit
- OCC
- Currently just uses the git SHA1 of the commit
- Petitboot
- Uses a X.Y.Z versioning scheme.
- Linux
- We use the upstream Linux kernel version, and always append
-openpowerNwhere N is a number starting at 1 that increases for each change we make to any additional patches carried in op-build for that specific kernel version. We follow the stable tree and have an "upstream first" policy in place.