Why does FreeBSD not use the Linux kernel?

[Yuri Pankov]

On Wed, Jun 17, 2020, at 8:55 PM, Michael Sierchio wrote:
> On Wed, Jun 17, 2020 at 5:19 AM Polytropon <freebsd at edvax.de> wrote:
> 
> > On Wed, 17 Jun 2020 11:33:25 +0800, kindu smith wrote:
> > > Why does FreeBSD not use the Linux kernel? The structure of FreeBSD is
> > > very good, such as the startup and directory structure, and the user
> > > island program. The only shortcoming is poor hardware support. This is
> > > mainly due to the lack of drivers provided by the kernel.
> >
> > While there are certain basic drivers in the kernel, the
> > majority of drivers is provided by loadable kernel modules,
> > either developed by the FreeBSD team itself, or available
> > from the ports collection. They use interfaces provided by
> > the kernel.
> >
> >
> The chief difference from my perspective is that it is possible in FreeBSD
> to create a monolithic kernel and prohibit the loading of kernel modules,
> foiling one step in the chain of a rootkit.  It's especially convenient for
> embedded devices, security appliances, etc.
> 
> Some features cannot work as loadable kernel modules, such as kernel NAT in
> ipfw supplied by LIBALIAS.

FWIW:

$ ls /boot/kernel/ipfw_nat*
/boot/kernel/ipfw_nat.ko   /boot/kernel/ipfw_nat64.ko