[jggimi]

I will guess that you did not understand the use of the variable $SHA256 inside that script, and have replaced your /bsd kernel with a hash file.

To recover:

1. Boot /bsd.booted or /bsd.sp
2. # cp /bsd.booted /bsd
3. # sha256 -h /var/db/kernel.SHA256 /bsd
4. # reboot