rebuilding from latest and kernel versions

Polytropon freebsd at
Mon Sep 16 12:39:36 UTC 2019

On Mon, 16 Sep 2019 02:25:18 -0700, vm finance wrote:
> Hello,
> I downloaded pre-built VM image of FreeBSD 12.0 STABLE from and
> using that vmdk, I was able to get FreeBSD running under VMPlayer.
> Kernel version (uname -a):
> FreeBSD osboxes 12.0-RELEASE FreeBSD 12.0-RELEASE r341666 GENERIC amd64
> I wanted to try latest TCP code so downloaded latest codebase on this VM:
> *svn co svn:// /usr/src*
> built a new kernel:
> cd /usr/src;
> make buildworld buildkernel
> make installkernel
> reboot


Have a look at the comment header of /usr/src/Makefile where you
will find the correct order of commands to do a successful source-based

> After reboot, kernel version is still the same, except its has
> FreeBSD 12.0-RELEASE FreeBSD 12.0-RELEASE r341666 GENERIC amd64.
> Questions:
> 1. kernel version (r341666) hasn't changed after building
> that expected?

That is at least possible. The kernel version returned of "uname -a"
will only change when the _kernel_ changed, not when something in the
OS has been patched. Use "freebsd-version" to find out more. The
information in "uname -a" should contain the version timestamp and
your kernel configuration filename if you did build yourself.

> 2. Is it possible to label it differently and allow bootloader to pick
> latest vs 12.0 published kernel?

Yes, you can specify a custom kernel in /boot/loader.conf:

	kernel="kernel.prev"	# where you saved your previous kernel
	bootfile="kernel"	# should work -> /boot/kernel.prev/kernel
	kernel_options=""	# if needed

See "man 5 loader.conf" and /boot/defaults/loader.conf for details.

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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