kvm/user/test/x86/lib/printf.c

   1 #include "printf.h"
   2 #include "smp.h"
   3 #include <stdarg.h>
   4 #include "string.h"
   5
   6 static struct spinlock lock;
   7
   8 void print(const char *s);
   9
  10 typedef struct pstream {
  11     char *buffer;
  12     int remain;
  13     int added;
  14 } pstream_t;
  15
  16 static void addchar(pstream_t *p, char c)
  17 {
  18     if (p->remain) {
  19         *p->buffer++ = c;
  20         --p->remain;
  21     }
  22     ++p->added;
  23 }
  24
  25 void print_str(pstream_t *p, const char *s)
  26 {
  27     while (*s)
  28         addchar(p, *s++);
  29 }
  30
  31 static char digits[16] = "0123456789abcdef";
  32
  33 void print_int(pstream_t *ps, long long n, int base)
  34 {
  35     char buf[sizeof(long) * 3 + 2], *p = buf;
  36     int s = 0, i;
  37
  38     if (n < 0) {
  39         n = -n;
  40         s = 1;
  41     }
  42
  43     while (n) {
  44         *p++ = digits[n % base];
  45         n /= base;
  46     }
  47
  48     if (s)
  49         *p++ = '-';
  50
  51     if (p == buf)
  52         *p++ = '0';
  53
  54     for (i = 0; i < (p - buf) / 2; ++i) {
  55         char tmp;
  56
  57         tmp = buf[i];
  58         buf[i] = p[-1-i];
  59         p[-1-i] = tmp;
  60     }
  61
  62     *p = 0;
  63
  64     print_str(ps, buf);
  65 }
  66
  67 void print_unsigned(pstream_t *ps, unsigned long long n, int base)
  68 {
  69     char buf[sizeof(long) * 3 + 1], *p = buf;
  70     int i;
  71
  72     while (n) {
  73         *p++ = digits[n % base];
  74         n /= base;
  75     }
  76
  77     if (p == buf)
  78         *p++ = '0';
  79
  80     for (i = 0; i < (p - buf) / 2; ++i) {
  81         char tmp;
  82
  83         tmp = buf[i];
  84         buf[i] = p[-1-i];
  85         p[-1-i] = tmp;
  86     }
  87
  88     *p = 0;
  89
  90     print_str(ps, buf);
  91 }
  92
  93 int vsnprintf(char *buf, int size, const char *fmt, va_list va)
  94 {
  95     pstream_t s;
  96
  97     s.buffer = buf;
  98     s.remain = size - 1;
  99     s.added = 0;
 100     while (*fmt) {
 101         char f = *fmt++;
 102         int nlong = 0;
 103
 104         if (f != '%') {
 105             addchar(&s, f);
 106             continue;
 107         }
 108     morefmt:
 109         f = *fmt++;
 110         switch (f) {
 111         case '%':
 112             addchar(&s, '%');
 113             break;
 114         case '\0':
 115             --fmt;
 116             break;
 117         case 'l':
 118             ++nlong;
 119             goto morefmt;
 120         case 'd':
 121             switch (nlong) {
 122             case 0:
 123                 print_int(&s, va_arg(va, int), 10);
 124                 break;
 125             case 1:
 126                 print_int(&s, va_arg(va, long), 10);
 127                 break;
 128             default:
 129                 print_int(&s, va_arg(va, long long), 10);
 130                 break;
 131             }
 132             break;
 133         case 'x':
 134             switch (nlong) {
 135             case 0:
 136                 print_unsigned(&s, va_arg(va, unsigned), 16);
 137                 break;
 138             case 1:
 139                 print_unsigned(&s, va_arg(va, unsigned long), 16);
 140                 break;
 141             default:
 142                 print_unsigned(&s, va_arg(va, unsigned long long), 16);
 143                 break;
 144             }
 145             break;
 146         case 'p':
 147             print_str(&s, "0x");
 148             print_unsigned(&s, (unsigned long)va_arg(va, void *), 16);
 149             break;
 150         case 's':
 151             print_str(&s, va_arg(va, const char *));
 152             break;
 153         default:
 154             addchar(&s, f);
 155             break;
 156         }
 157     }
 158     *s.buffer = 0;
 159     ++s.added;
 160     return s.added;
 161 }
 162
 163
 164 int snprintf(char *buf, int size, const char *fmt, ...)
 165 {
 166     va_list va;
 167     int r;
 168
 169     va_start(va, fmt);
 170     r = vsnprintf(buf, size, fmt, va);
 171     va_end(va);
 172     return r;
 173 }
 174
 175 void print_serial(const char *buf)
 176 {
 177     unsigned long len = strlen(buf);
 178
 179     asm volatile ("rep/outsb" : "+S"(buf), "+c"(len) : "d"(0xf1));
 180 }
 181
 182 int printf(const char *fmt, ...)
 183 {
 184     va_list va;
 185     char buf[2000];
 186     int r;
 187
 188     va_start(va, fmt);
 189     r = vsnprintf(buf, sizeof buf, fmt, va);
 190     va_end(va);
 191     spin_lock(&lock);
 192     print_serial(buf);
 193     spin_unlock(&lock);
 194     return r;
 195 }