It is necessary to rewrite a piece of erlang-code php. How?

Question

PHP

Actually, this line:

PasswordHash = util_hex:from_binary(crypto:hash(sha512, <<Salt/binary, Password/binary>>))

Answer 1

Let's write in Russian:
$a = $salt + $password;
$hash = hash sha512 from $a
and what is util_hex:from_binary I xs
suppose that the translation from binary to hexadecimal