SlackBuildsOrg/system/virtualbox-kernel

This is the supplementary kernel driver for the VirtualBox
virtualisation environment.

To build the package for a kernel different from the running one,
start the script setting the KERNEL variable as in
  KERNEL=2.6.38.8 ./virtualbox-kernel.SlackBuild

If you want to build a kernel module for an other virtualbox version
you can use the included "virtualbox-kernel-mksrctarball.sh" which will
generate the needed source package for you. You will need to have
the coresponding virtualbox-ose version already installed.

Note to 32-bit users: VirtualBox no longer supports 32-bit x86, as of
version 6.0.