sys/boot/arm/at91/libat91/printf.c

   1 /*-
   2  * Copyright (c) 1998 Robert Nordier
   3  * All rights reserved.
   4  * Copyright (c) 2006 M. Warner Losh
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms are freely
   8  * permitted provided that the above copyright notice and this
   9  * paragraph and the following disclaimer are duplicated in all
  10  * such forms.
  11  *
  12  * This software is provided "AS IS" and without any express or
  13  * implied warranties, including, without limitation, the implied
  14  * warranties of merchantability and fitness for a particular
  15  * purpose.
  16  *
  17  * $FreeBSD$
  18  */
  19
  20 #include <stdarg.h>
  21 #include "lib.h"
  22
  23 void
  24 printf(const char *fmt,...)
  25 {
  26         va_list ap;
  27         const char *hex = "0123456789abcdef";
  28         char buf[10];
  29         char *s;
  30         unsigned u;
  31         int c;
  32
  33         va_start(ap, fmt);
  34         while ((c = *fmt++)) {
  35                 if (c == '%') {
  36                         c = *fmt++;
  37                         switch (c) {
  38                         case 'c':
  39                                 xputchar(va_arg(ap, int));
  40                                 continue;
  41                         case 's':
  42                                 for (s = va_arg(ap, char *); *s; s++)
  43                                         xputchar(*s);
  44                                 continue;
  45                         case 'd':       /* A lie, always prints unsigned */
  46                         case 'u':
  47                                 u = va_arg(ap, unsigned);
  48                                 s = buf;
  49                                 do
  50                                         *s++ = '0' + u % 10U;
  51                                 while (u /= 10U);
  52                         dumpbuf:;
  53                                 while (--s >= buf)
  54                                         xputchar(*s);
  55                                 continue;
  56                         case 'x':
  57                                 u = va_arg(ap, unsigned);
  58                                 s = buf;
  59                                 do
  60                                         *s++ = hex[u & 0xfu];
  61                                 while (u >>= 4);
  62                                 goto dumpbuf;
  63                         }
  64                 }
  65                 xputchar(c);
  66         }
  67         va_end(ap);
  68
  69         return;
  70 }