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 void* memcpy(void *dest, const void *src, int n)
  26 {
  27     char *d = dest;
  28     const char *s = src;
  29
  30     while (n--) {
  31         *d++ = *s++;
  32     }
  33
  34     return dest;
  35 }
  36
  37 static void print_char(char c)
  38 {
  39     outb(0xe9, c);
  40 }
  41
  42 static void print_str(char *s)
  43 {
  44     while (*s) {
  45         print_char(*s++);
  46     }
  47 }
  48
  49 static void print_num(uint64_t value, int base)
  50 {
  51     char digits[] = "0123456789abcdef";
  52     char buf[32] = { 0 };
  53     int i = sizeof(buf) - 2;
  54
  55     do {
  56         buf[i--] = digits[value % base];
  57         value /= base;
  58     } while (value);
  59
  60     print_str(&buf[i + 1]);
  61 }
  62
  63 void printf(const char *fmt, ...)
  64 {
  65     va_list ap;
  66     uint64_t val;
  67     char *str;
  68     int base;
  69     int has_long;
  70     int alt_form;
  71
  72     va_start(ap, fmt);
  73
  74     for (; *fmt; fmt++) {
  75         if (*fmt != '%') {
  76             print_char(*fmt);
  77             continue;
  78         }
  79         fmt++;
  80
  81         if (*fmt == '#') {
  82             fmt++;
  83             alt_form = 1;
  84         } else {
  85             alt_form = 0;
  86         }
  87
  88         if (*fmt == 'l') {
  89             fmt++;
  90             if (*fmt == 'l') {
  91                 fmt++;
  92                 has_long = 2;
  93             } else {
  94                 has_long = 1;
  95             }
  96         } else {
  97             has_long = 0;
  98         }
  99
 100         switch (*fmt) {
 101         case 'x':
 102         case 'p':
 103             base = 16;
 104             goto convert_number;
 105         case 'd':
 106         case 'i':
 107         case 'u':
 108             base = 10;
 109             goto convert_number;
 110         case 'o':
 111             base = 8;
 112             goto convert_number;
 113
 114         convert_number:
 115             switch (has_long) {
 116             case 0:
 117                 val = va_arg(ap, unsigned int);
 118                 break;
 119             case 1:
 120                 val = va_arg(ap, unsigned long);
 121                 break;
 122             case 2:
 123                 val = va_arg(ap, unsigned long long);
 124                 break;
 125             }
 126
 127             if (alt_form && base == 16) {
 128                 print_str("0x");
 129             }
 130
 131             print_num(val, base);
 132             break;
 133
 134         case 's':
 135             str = va_arg(ap, char*);
 136             print_str(str);
 137             break;
 138         case '%':
 139             print_char(*fmt);
 140             break;
 141         default:
 142             print_char('%');
 143             print_char(*fmt);
 144             break;
 145         }
 146     }
 147
 148     va_end(ap);
 149 }
 150
 151