beginning-of-buffer is an interactive compiled Lisp function in `simple.el'.

It is bound to <begin>, <C-home>, M-<, <menu-bar> <edit> <goto> <beg-of-buf>.

(beginning-of-buffer &optional ARG)

This function is for interactive use only;
in Lisp code use `(goto-char (point-min))' instead.

Move point to the beginning of the buffer.
With numeric arg N, put point N/10 of the way from the beginning.
If the buffer is narrowed, this command uses the beginning of the
accessible part of the buffer.

If Transient Mark mode is disabled, leave mark at previous
position, unless a C-u prefix is supplied.