kvm/test/lib/x86/io.c

   1 #include "libcflat.h"
   2 #include "smp.h"
   3
   4 static struct spinlock lock;
   5
   6 static void print_serial(const char *buf)
   7 {
   8         unsigned long len = strlen(buf);
   9
  10         asm volatile ("rep/outsb" : "+S"(buf), "+c"(len) : "d"(0xf1));
  11 }
  12
  13 void puts(const char *s)
  14 {
  15         spin_lock(&lock);
  16         print_serial(s);
  17         spin_unlock(&lock);
  18 }
  19
  20 void exit(int code)
  21 {
  22         asm volatile("out %0, %1" : : "a"(code), "d"((short)0xf4));
  23 }