static struct segoff __text16 ( int20_vector );
  #define int20_vector __use_text16 ( int20_vector )
  extern void int20_wrapper ( void );
  static __cdecl void int20 ( struct i386_all_regs *ix86 ) {
     // INT 20 handler goes here
  }
  
  static void hook_int20 ( void ) {
          __asm__  __volatile__ (
                TEXT16_CODE ( "\nint20_wrapper:\n\t"
                               "pushl %0\n\t"
                               "pushw %%cs\n\t"
                               "call prot_call\n\t"
                               "addw $4, %%sp\n\t"
                               "iret\n\t" )
                 : : "i" ( int20 ) );
  
          hook_bios_interrupt ( 0x20, ( unsigned int ) int20_wrapper,
                                &int20_vector );
  }