Function util_sha512h 

pub unsafe extern "C" fn util_sha512h(
    write_ptr: u32,
    write_len: u32,
    read_ptr: u32,
    read_len: u32,
) -> i64

Compute the first half of a SHA512 checksum. @param write_ptr The buffer to write the checksum into. Must be at least 32 bytes. @param write_len The length of the buffer. @param read_ptr The buffer to read data for digest from. @param read_len The amount of data to read from the buffer. @return The number of bytes written to write_ptr or a negative integer on error.