def replace_in_binary_file(file_path, replacements):
    """
    Replaces all instances of a pattern in a binary file with the specified replacement.
    'replacements' is a list of tuples in the form (pattern, repl) where 'pattern'
    is a pattern and 'repl' is its replacement. Regex is not supported.
    """
    file = open(file_path, 'rb')
    file_content = file.read()
    file.close()
    for replacement in replacements:
        pattern, repl = replacement
        file_content = file_content.replace(pattern, repl)
    file = open(file_path, 'wb')
    file.write(file_content)
    file.close()
