Build mainline driver for another Kernel Version

[Greg KH]

On Wed, May 17, 2023 at 09:16:45AM +0100, Lucas Tanure wrote:
> Hi,
> 
> Can I build a driver in the mainline kernel to a previous kernel version?

Not easily, and you really do not want to do that as the whole kernel
source, drivers included, are a snapshot in time and depend on each
other.

> Like, in the mainline kernel, I have a Z driver, and I want to use
> that driver for my current stable driver in my embedded system with
> version kernel 5.15. Is there a procedure to build a kernel driver
> against other specific kernel headers?

Update to a newer kernel version, it will be much easier and simpler
overall.

Drivers consume _everything_ from the core kernel, and are not
stand-alone at all.  They depend on everything else, trying to pick one
out and put it into a different kernel is not how Linux works at all,
sorry.

What prevents you from just using a newer kernel?

thanks,

greg k-h