text: #ifndef	_DAC_INTERFACE_H_
  #define _DAC_INTERFACE_H_
  
  #include "typedef.h"
  
  
  struct dac_driver {
      void (*init)();
  
      void (*handler_register)(void (*)(void));
  
      void (*ioctrl)(u8, ...);
  };
  
  #define REGISTER_DAC_DRIVER(drv) \
  	const struct dac_driver *__dac_drv \
  			sec(.text) = &drv
  
  extern const struct dac_driver *__dac_drv;
  
  #endif
  