qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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libc.c (3491B)

      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