AnsweredAssumed Answered

Best practices for customizing Yocto BSP

Question asked by Stian Søvik on Nov 11, 2016
Latest reply on Nov 11, 2016 by gusarambula

I'm new to Yocto, and would appreciate some pointers to best practices, as well as corrections of possible misconceptions.


I have a custom carrier board, which uses the Variscite VAR-SOM-MX6 module which contains an iMX6, DDR, NAND, eMMC, WiFi, BT, touch screen interfaces and so on. Variscite provides a BSP which supports these units together with a carrier board.


However, we need to change at least the following aspects:
- Base the distribution on a minimal image, with added packages as necessary (e.g. shell and standard Linux utilities, but no graphical software, web server etc)
- No screen/keyboard
- Custom device tree (GPIO mux setup etc)
- Custom kernel configuration (enable drivers for devices on the carrier board)
- Custom script configuration (e.g. network setup)


The goal is to be able to efficiently maintain and update these changes, as well as get updates from Variscite when necessary, and finally being able to create images for distribution.


I imagine there are several ways to achieve this, and would like opinions on which ones are more feasible (or even possible), and of course other ways if I have missed some.


1. Use Variscite's BSP, make all changes in local build directory (local.conf)
2. Copy Varisiscite's BSP and modify to our needs. This one seems to be the most straight-forward, but seems less elegant, and makes it hard to track updates from Variscite
3. Create a new BSP which refers to Variscite's. I am not sure if a BSP layer can be "on top of" another BSP layer?
4. Use Variscite's BSP and perform manual modifications (e.g. build kernel out of tree, or modify config settings on deployed image). During my few days of experiments, I have done this, which has been fine for prototyping. However, this is no good solution with regards to efficiency, version control and distribution.