>>777
/usr/src/Makefile

# For individuals wanting to upgrade their sources (even if only a
# delta of a few days):
#
# 1. `cd /usr/src' (or to the directory containing your source tree).
# 2. `make buildworld'
# 3. `make buildkernel KERNCONF=YOUR_KERNEL_HERE' (default is GENERIC).
# 4. `make installkernel KERNCONF=YOUR_KERNEL_HERE' (default is GENERIC).
# 5. `reboot' (in single user mode: boot -s from the loader prompt).
# 6. `mergemaster -p'
# 7. `make installworld'
# 8. `mergemaster'
# 9. `reboot'