text: #ifndef _IMPORTS_H_
  #define _IMPORTS_H_
  
  #define NULL 0
  
  typedef int bool;
  #define true 1
  #define false 0
  
  #define WASM_IMPORT(function, signature) \
      __attribute__((import_module("env"), import_name(function))) signature
  
  WASM_IMPORT("gpio_read", int gpio_read(unsigned int port, unsigned int pin,
                                         unsigned int* ptr));
  WASM_IMPORT("gpio_write", int gpio_write(unsigned int port, unsigned int pin,
                                           unsigned int value));
  WASM_IMPORT("gpio_deinit",
              int gpio_deinit(unsigned int port, unsigned int pin));
  WASM_IMPORT("gpio_init",
              int gpio_init(unsigned int port, unsigned int pin, int is_input));
  WASM_IMPORT("delay_ms", void delay_ms(unsigned int ms));
  WASM_IMPORT("print", void print(char const* offset, int len));
  WASM_IMPORT("uart_init",
              int uart_init(unsigned char* handle, unsigned int tx_port,
                            unsigned int tx_pin, unsigned int rx_port,
                            unsigned int rx_pin, unsigned int* cts_port,
                            unsigned int* cts_pin, unsigned int* rts_port,
                            unsigned int* rts_pin));
  WASM_IMPORT("uart_write", int uart_write(unsigned int handle, unsigned char word));
  WASM_IMPORT("uart_read", int uart_read(unsigned int handle, unsigned char* word));
  
  #endif
  