tests/tcg/minilib/printf.c

   1 /*
   2  * Copyright (C) 2015 Virtual Open Systems SAS
   3  * Author: Alexander Spyridakis <a.spyridakis@virtualopensystems.com>
   4  *
   5  * printf based on implementation by Kevin Wolf <kwolf@redhat.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-only
  12  */
  13
  14 #include "minilib.h"
  15
  16 typedef __builtin_va_list   va_list;
  17 #define va_start(ap, X)     __builtin_va_start(ap, X)
  18 #define va_arg(ap, type)    __builtin_va_arg(ap, type)
  19 #define va_end(ap)          __builtin_va_end(ap)
  20
  21 static void print_str(char *s)
  22 {
  23     while (*s) {
  24         __sys_outc(*s++);
  25     }
  26 }
  27
  28 static void print_num(unsigned long long value, int base)
  29 {
  30     char digits[] = "0123456789abcdef";
  31     char buf[32];
  32     int i = sizeof(buf) - 2, j;
  33
  34     /* Set the buffer to 0. See problem of before. */
  35     for (j = 0; j < 32; j++) {
  36         buf[j] = 0;
  37     }
  38
  39     do {
  40         buf[i--] = digits[value % base];
  41         value /= base;
  42     } while (value);
  43
  44     print_str(&buf[i + 1]);
  45 }
  46
  47 void ml_printf(const char *fmt, ...)
  48 {
  49     va_list ap;
  50     char *str;
  51     int base;
  52     int has_long;
  53     int alt_form;
  54     unsigned long long val;
  55
  56     va_start(ap, fmt);
  57
  58     for (; *fmt; fmt++) {
  59         if (*fmt != '%') {
  60             __sys_outc(*fmt);
  61             continue;
  62         }
  63         fmt++;
  64
  65         if (*fmt == '#') {
  66             fmt++;
  67             alt_form = 1;
  68         } else {
  69             alt_form = 0;
  70         }
  71
  72         if (*fmt == 'l') {
  73             fmt++;
  74             if (*fmt == 'l') {
  75                 fmt++;
  76                 has_long = 2;
  77             } else {
  78                 has_long = 1;
  79             }
  80         } else {
  81             has_long = 0;
  82         }
  83
  84         switch (*fmt) {
  85         case 'x':
  86         case 'p':
  87             base = 16;
  88             goto convert_number;
  89         case 'd':
  90         case 'i':
  91         case 'u':
  92             base = 10;
  93             goto convert_number;
  94         case 'o':
  95             base = 8;
  96             goto convert_number;
  97
  98         convert_number:
  99             switch (has_long) {
 100             case 0:
 101                 val = va_arg(ap, unsigned int);
 102                 break;
 103             case 1:
 104                 val = va_arg(ap, unsigned long);
 105                 break;
 106             case 2:
 107                 val = va_arg(ap, unsigned long long);
 108                 break;
 109             }
 110
 111             if (alt_form && base == 16) {
 112                 print_str("0x");
 113             }
 114
 115             print_num(val, base);
 116             break;
 117
 118         case 's':
 119             str = va_arg(ap, char*);
 120             print_str(str);
 121             break;
 122         case '%':
 123             __sys_outc(*fmt);
 124             break;
 125         default:
 126             __sys_outc('%');
 127             __sys_outc(*fmt);
 128             break;
 129         }
 130     }
 131
 132     va_end(ap);
 133 }