Update FreeBSD Sources and Rebuild World

To update your source tree and rebuild your kernel to ensure it matches the sources follow these steps.

Copy the sample supfile to /root;

# cp /usr/share/examples/cvsup/standard-supfile ~

Edit the supfile and change the line that says;

*default host=CHANGE_THIS.FreeBSD.org
So that it points to a server that is local to you. On mine I use the au mirror;
*default host=cvsup.au.freebsd.org
If you already have a working supfile, ensure it contains a line;

# src-all

Execute csup to download the kernel sources;

# csup ~/standard-supfile

Compile everything;

# cd /usr/src
# make buildworld
# make buildkernel

Install the new kernel;

# make installkernel

Reboot into single user mode;

# init 6

In single user mode execute these commands;

# adjkerntz -i
# mount -a -t ufs
# mergemaster -p
# cd /usr/src
# make installworld
# mergemaster

Reboot;
# init 6

This was lifted from the FreeBSD documentation;

http://www.freebsd.org/doc/handbook/makeworld.html