tests/multiboot/libc.c

   1 /*
   2  * Copyright (c) 2013 Kevin Wolf <kwolf@redhat.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20  * THE SOFTWARE.
  21  */
  22
  23 #include "libc.h"
  24
  25 static void print_char(char c)
  26 {
  27     outb(0xe9, c);
  28 }
  29
  30 static void print_str(char *s)
  31 {
  32     while (*s) {
  33         print_char(*s++);
  34     }
  35 }
  36
  37 static void print_num(uint64_t value, int base)
  38 {
  39     char digits[] = "0123456789abcdef";
  40     char buf[32] = { 0 };
  41     int i = sizeof(buf) - 2;
  42
  43     do {
  44         buf[i--] = digits[value % base];
  45         value /= base;
  46     } while (value);
  47
  48     print_str(&buf[i + 1]);
  49 }
  50
  51 void printf(const char *fmt, ...)
  52 {
  53     va_list ap;
  54     uint64_t val;
  55     char *str;
  56     int base;
  57     int has_long;
  58     int alt_form;
  59
  60     va_start(ap, fmt);
  61
  62     for (; *fmt; fmt++) {
  63         if (*fmt != '%') {
  64             print_char(*fmt);
  65             continue;
  66         }
  67         fmt++;
  68
  69         if (*fmt == '#') {
  70             fmt++;
  71             alt_form = 1;
  72         } else {
  73             alt_form = 0;
  74         }
  75
  76         if (*fmt == 'l') {
  77             fmt++;
  78             if (*fmt == 'l') {
  79                 fmt++;
  80                 has_long = 2;
  81             } else {
  82                 has_long = 1;
  83             }
  84         } else {
  85             has_long = 0;
  86         }
  87
  88         switch (*fmt) {
  89         case 'x':
  90         case 'p':
  91             base = 16;
  92             goto convert_number;
  93         case 'd':
  94         case 'i':
  95         case 'u':
  96             base = 10;
  97             goto convert_number;
  98         case 'o':
  99             base = 8;
 100             goto convert_number;
 101
 102         convert_number:
 103             switch (has_long) {
 104             case 0:
 105                 val = va_arg(ap, unsigned int);
 106                 break;
 107             case 1:
 108                 val = va_arg(ap, unsigned long);
 109                 break;
 110             case 2:
 111                 val = va_arg(ap, unsigned long long);
 112                 break;
 113             }
 114
 115             if (alt_form && base == 16) {
 116                 print_str("0x");
 117             }
 118
 119             print_num(val, base);
 120             break;
 121
 122         case 's':
 123             str = va_arg(ap, char*);
 124             print_str(str);
 125             break;
 126         case '%':
 127             print_char(*fmt);
 128             break;
 129         default:
 130             print_char('%');
 131             print_char(*fmt);
 132             break;
 133         }
 134     }
 135
 136     va_end(ap);
 137 }
 138
 139