Yocto Source Location to be customized?

Question

i am trying to learn BSP Customization in Yocto. Sources which explain the files to be configured, always gives path after "arch", for example; arch/arm/boot/dts

but on the Build directory there are more than one dts with same path;

1- ./tmp/work/cortexa8hf-neon-poky-linux-gnueabi/linux-libc-headers/4.18-r0/linux-4.18/arch/arm/boot/dts

2- ./tmp/worklinux-yocto/4.18.9+gitAUTOINC+bf98e195a4_0cdc8564c6-r0/linux-beaglebone_yocto-standard-build/arch/arm/boot/dts

3- ./tmp/work/cortexa8hf-neon-poky-linux-gnueabi/linux-libc-headers/4.18-r0/linux-4.18/arch/arm/boot/dts

4- ./tmp/work-shared/beaglebone-yocto/kernel-source/arch/arm/boot/dts

Does anyone know which one of path should i use to be able to add custom u-boot and kernel( for u-boot and kernel porting )?

Thanks a lot. Best regards

Answer 1

One should not change the files in the build output path. There are two ways. Either you use a kernel or u-boot source tree which has your changes applied or apply generated patches from the changes made. In both cases you need to write a bitbake recipe for the same. Please refer the Yocto manuals for details. I recently wrote about developing a board support package here. However, you need to understand how to use and write existing/custom layers and bitbake recipes and that information you will find in Yocto manuals.