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 int
  24 printf(const char *fmt,...)
  25 {
  26         va_list ap;
  27         const char *hex = "0123456789abcdef";
  28         char buf[10];
  29         const char *fmt_orig = fmt;
  30         char *s;
  31         unsigned u;
  32         int c;
  33
  34         va_start(ap, fmt);
  35         while ((c = *fmt++)) {
  36                 if (c == '%') {
  37                         c = *fmt++;
  38                         switch (c) {
  39                         case 'c':
  40                                 xputchar(va_arg(ap, int));
  41                                 continue;
  42                         case 's':
  43                                 for (s = va_arg(ap, char *); *s; s++)
  44                                         xputchar(*s);
  45                                 continue;
  46                         case 'd':       /* A lie, always prints unsigned */
  47                         case 'u':
  48                                 u = va_arg(ap, unsigned);
  49                                 s = buf;
  50                                 do
  51                                         *s++ = '0' + u % 10U;
  52                                 while (u /= 10U);
  53                         dumpbuf:;
  54                                 while (--s >= buf)
  55                                         xputchar(*s);
  56                                 continue;
  57                         case 'x':
  58                                 u = va_arg(ap, unsigned);
  59                                 s = buf;
  60                                 do
  61                                         *s++ = hex[u & 0xfu];
  62                                 while (u >>= 4);
  63                                 goto dumpbuf;
  64                         }
  65                 }
  66                 xputchar(c);
  67         }
  68         va_end(ap);
  69
  70         return (int)(fmt - fmt_orig);
  71 }