DESCRIPTION
The 
bcopy() interface is obsolete. Do not add new code using it. It will soon be purged. Use 
memcpy(9) instead. (The 
bcopy() function is now a macro for 
memcpy(9).)
 
The bcopy() function copies len bytes from string src to string dst.
Unlike 
bcopy(3) the two strings must not overlap!
In the traditional 
BSD kernel, overlapping copies were handled by the now-purged 
ovbcopy() function. If you need to copy overlapping data, see 
memmove(9).
If len is zero, no bytes are copied.