Почему собирается этот модуль ядра

calculate demas # emerge -a @module-rebuild

Local copy of remote index is up-to-date and will be used.

Local copy of remote index is up-to-date and will be used.

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R    ] app-emulation/virtualbox-modules-5.0.4 
[ebuild   R    ] net-wireless/broadcom-sta-6.30.223.248-r4 

Would you like to merge these packages? [Yes/No] yes
>>> Verifying ebuild manifests
>>> Emerging (1 of 2) app-emulation/virtualbox-modules-5.0.4::gentoo
>>> Emerging (2 of 2) net-wireless/broadcom-sta-6.30.223.248-r4::gentoo
>>> Installing (2 of 2) net-wireless/broadcom-sta-6.30.223.248-r4::gentoo
>>> Installing (1 of 2) app-emulation/virtualbox-modules-5.0.4::gentoo
>>> Jobs: 2 of 2 complete                           Load avg: 2.85, 1.21, 0.45

 * Messages for package net-wireless/broadcom-sta-6.30.223.248-r4:

 *   B43: If you insist on building this, you must blacklist it!
 *   BCMA: If you insist on building this, you must blacklist it!
 *   SSB: If you insist on building this, you must blacklist it!
 *   MAC80211: If you insist on building this, you must blacklist it!
 *   PREEMPT_RCU: Please do not set the Preemption Model to "Preemptible Kernel"; choose something else.
 *   CONFIG_PREEMPT:     should not be set. But it is.
 * Please check to make sure these options are set correctly.
 * Failure to do so may cause unexpected problems.

 * Messages for package app-emulation/virtualbox-modules-5.0.4:

 * If you are using sys-apps/openrc, please add "vboxdrv", "vboxnetflt"
 * and "vboxnetadp" to:
 *   /etc/conf.d/modules
>>> Auto-cleaning packages...

>>> No outdated packages were found on your system.

 * GNU info directory index is up-to-date.