#define SERIAL_BASE 0x16000000
#define SERIAL_FLAG_REGISTER 0x18
#define SERIAL_BUFFER_FULL (1 << 5)
 
void putc (char c)
{
    /* Wait until the serial buffer is empty */
    while (*(volatile unsigned long*)(SERIAL_BASE + SERIAL_FLAG_REGISTER) 
                                       & (SERIAL_BUFFER_FULL));
    /* Put our character, c, into the serial buffer */
    *(volatile unsigned long*)SERIAL_BASE = c;
}
 
void puts (const char * str)
{
    while (*str) putc (*str++);
}
 
int main (void)
{
    puts ("hello, world!\n");
    return 0;
}