'Send SPI attach command to enable the SPI flash pins
ESP8266 ROM does this when you send flash_begin, ESP32 ROM
has it as a SPI command.'

def flash_spi_attach(self, hspi_arg):

    arg = struct.pack('<I', hspi_arg)
    if (not self.IS_STUB):
        is_legacy = 0
        arg += struct.pack('BBBB', is_legacy, 0, 0, 0)
    self.check_command('configure    SPI    flash    pins', ESP32ROM.ESP_SPI_ATTACH, arg)
