[yocto] Building kernel with non standard source structure

[Ottavio Campana]

Hello,

I'm trying to port the kernel compilation of a bsp to yocto. My problem is that this kernel has a bunch of drivers that are out of the kernel sources tree and all the includes are hard coded with an uncommon structure.

To give you the idea, the source is organized in this way

kernel/linux/ # Where the kernel sources are (there are pointers to the other directories)
gpldrivers/ # Some drievrs with GPL license (there are pointers to the other directories)proprietarydrivers/ # Some drivers wit non free license (there are pointers to the other directories)

Kernel and drivers are in git repository.

I started to develop a recipe inhering from kernel, I am having doubts about setting the S and B variables

S = "${WORKDIR}/git"
B = "${WORKDIR}/git/kernel/linux"

By using this settings, if I run bitbake -c devshell I enter into a kernel-source directory that has the directories kernel, gpldrivers and proprietarydrivers correctly copied.

My problem is that at this point if I try to compile the kernel I get the error that in kernel-source there is no way to a make oldconfig.

How can I have the recipe entering into kernel/linux before copying defconfig and starting compilation?

Thank you

Ottavio