memdisk/conio.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2001-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Boston MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 /*
  14  * conio.c
  15  *
  16  * Output to the screen
  17  */
  18
  19 #include <stdint.h>
  20 #include "memdisk.h"
  21 #include "conio.h"
  22
  23 int putchar(int ch)
  24 {
  25   com32sys_t regs;
  26
  27   if ( ch == '\n' ) {
  28     /* \n -> \r\n */
  29     putchar('\r');
  30   }
  31
  32   regs.eax.w[0] = 0x0e00|(ch&0xff);
  33   syscall(0x10, &regs, NULL);
  34
  35   return ch;
  36 }
  37
  38 int puts(const char *s)
  39 {
  40   int count = 0;
  41
  42   while ( *s ) {
  43     putchar(*s);
  44     count++;
  45     s++;
  46   }
  47
  48   return count;
  49 }
  50
  51 /*
  52  * Oh, it's a waste of space, but oh-so-yummy for debugging.  It's just
  53  * initialization code anyway, so it doesn't take up space when we're
  54  * actually running.  This version of printf() does not include 64-bit
  55  * support.  "Live with it."
  56  *
  57  * Most of this code was shamelessly snarfed from the Linux kernel, then
  58  * modified.
  59  */
  60
  61 static inline int
  62 isdigit(int ch)
  63 {
  64   return (ch >= '0') && (ch <= '9');
  65 }
  66
  67 static int skip_atoi(const char **s)
  68 {
  69   int i=0;
  70
  71   while (isdigit(**s))
  72     i = i*10 + *((*s)++) - '0';
  73   return i;
  74 }
  75
  76 unsigned int atou(const char *s)
  77 {
  78   unsigned int i = 0;
  79   while (isdigit(*s))
  80     i = i*10 + (*s++ - '0');
  81   return i;
  82 }
  83
  84 static int strnlen(const char *s, int maxlen)
  85 {
  86   const char *es = s;
  87   while ( *es && maxlen ) {
  88     es++; maxlen--;
  89   }
  90
  91   return (es-s);
  92 }
  93
  94 #define ZEROPAD 1               /* pad with zero */
  95 #define SIGN    2               /* unsigned/signed long */
  96 #define PLUS    4               /* show plus */
  97 #define SPACE   8               /* space if plus */
  98 #define LEFT    16              /* left justified */
  99 #define SPECIAL 32              /* 0x */
 100 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
 101
 102 #define do_div(n,base) ({ \
 103 int __res; \
 104 __res = ((unsigned long) n) % (unsigned) base; \
 105 n = ((unsigned long) n) / (unsigned) base; \
 106 __res; })
 107
 108 static char * number(char * str, long num, int base, int size, int precision
 109         ,int type)
 110 {
 111   char c,sign,tmp[66];
 112   const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
 113   int i;
 114
 115   if (type & LARGE)
 116     digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 117   if (type & LEFT)
 118     type &= ~ZEROPAD;
 119   if (base < 2 || base > 36)
 120     return 0;
 121   c = (type & ZEROPAD) ? '0' : ' ';
 122   sign = 0;
 123   if (type & SIGN) {
 124     if (num < 0) {
 125       sign = '-';
 126       num = -num;
 127       size--;
 128     } else if (type & PLUS) {
 129       sign = '+';
 130       size--;
 131     } else if (type & SPACE) {
 132       sign = ' ';
 133       size--;
 134     }
 135   }
 136   if (type & SPECIAL) {
 137     if (base == 16)
 138       size -= 2;
 139     else if (base == 8)
 140       size--;
 141   }
 142   i = 0;
 143   if (num == 0)
 144     tmp[i++]='0';
 145   else while (num != 0)
 146     tmp[i++] = digits[do_div(num,base)];
 147   if (i > precision)
 148     precision = i;
 149   size -= precision;
 150   if (!(type&(ZEROPAD+LEFT)))
 151     while(size-->0)
 152       *str++ = ' ';
 153   if (sign)
 154     *str++ = sign;
 155   if (type & SPECIAL) {
 156     if (base==8)
 157       *str++ = '0';
 158     else if (base==16) {
 159       *str++ = '0';
 160       *str++ = digits[33];
 161     }
 162   }
 163   if (!(type & LEFT))
 164     while (size-- > 0)
 165       *str++ = c;
 166   while (i < precision--)
 167     *str++ = '0';
 168   while (i-- > 0)
 169     *str++ = tmp[i];
 170   while (size-- > 0)
 171     *str++ = ' ';
 172   return str;
 173 }
 174
 175 /* Forward decl. needed for IP address printing stuff... */
 176 int sprintf(char * buf, const char *fmt, ...);
 177
 178 int vsprintf(char *buf, const char *fmt, va_list args)
 179 {
 180   int len;
 181   unsigned long num;
 182   int i, base;
 183   char * str;
 184   const char *s;
 185
 186   int flags;            /* flags to number() */
 187
 188   int field_width;      /* width of output field */
 189   int precision;                /* min. # of digits for integers; max
 190                                    number of chars for from string */
 191   int qualifier;                /* 'h', 'l', or 'L' for integer fields */
 192
 193   for (str=buf ; *fmt ; ++fmt) {
 194     if (*fmt != '%') {
 195       *str++ = *fmt;
 196       continue;
 197     }
 198
 199     /* process flags */
 200     flags = 0;
 201   repeat:
 202     ++fmt;              /* this also skips first '%' */
 203     switch (*fmt) {
 204     case '-': flags |= LEFT; goto repeat;
 205     case '+': flags |= PLUS; goto repeat;
 206     case ' ': flags |= SPACE; goto repeat;
 207     case '#': flags |= SPECIAL; goto repeat;
 208     case '0': flags |= ZEROPAD; goto repeat;
 209     }
 210
 211     /* get field width */
 212     field_width = -1;
 213     if (isdigit(*fmt))
 214       field_width = skip_atoi(&fmt);
 215     else if (*fmt == '*') {
 216       ++fmt;
 217       /* it's the next argument */
 218       field_width = va_arg(args, int);
 219       if (field_width < 0) {
 220         field_width = -field_width;
 221         flags |= LEFT;
 222       }
 223     }
 224
 225     /* get the precision */
 226     precision = -1;
 227     if (*fmt == '.') {
 228       ++fmt;
 229       if (isdigit(*fmt))
 230         precision = skip_atoi(&fmt);
 231       else if (*fmt == '*') {
 232         ++fmt;
 233         /* it's the next argument */
 234         precision = va_arg(args, int);
 235       }
 236       if (precision < 0)
 237         precision = 0;
 238     }
 239
 240     /* get the conversion qualifier */
 241     qualifier = -1;
 242     if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
 243       qualifier = *fmt;
 244       ++fmt;
 245     }
 246
 247     /* default base */
 248     base = 10;
 249
 250     switch (*fmt) {
 251     case 'c':
 252       if (!(flags & LEFT))
 253         while (--field_width > 0)
 254           *str++ = ' ';
 255       *str++ = (unsigned char) va_arg(args, int);
 256       while (--field_width > 0)
 257         *str++ = ' ';
 258       continue;
 259
 260     case 's':
 261       s = va_arg(args, char *);
 262       len = strnlen(s, precision);
 263
 264       if (!(flags & LEFT))
 265         while (len < field_width--)
 266           *str++ = ' ';
 267       for (i = 0; i < len; ++i)
 268         *str++ = *s++;
 269       while (len < field_width--)
 270         *str++ = ' ';
 271       continue;
 272
 273     case 'p':
 274       if (field_width == -1) {
 275         field_width = 2*sizeof(void *);
 276         flags |= ZEROPAD;
 277       }
 278       str = number(str,
 279                    (unsigned long) va_arg(args, void *), 16,
 280                    field_width, precision, flags);
 281       continue;
 282
 283
 284     case 'n':
 285       if (qualifier == 'l') {
 286         long * ip = va_arg(args, long *);
 287         *ip = (str - buf);
 288       } else {
 289         int * ip = va_arg(args, int *);
 290         *ip = (str - buf);
 291       }
 292       continue;
 293
 294     case '%':
 295       *str++ = '%';
 296       continue;
 297
 298       /* integer number formats - set up the flags and "break" */
 299     case 'o':
 300       base = 8;
 301       break;
 302
 303     case 'X':
 304       flags |= LARGE;
 305     case 'x':
 306       base = 16;
 307       break;
 308
 309     case 'd':
 310     case 'i':
 311       flags |= SIGN;
 312     case 'u':
 313       break;
 314
 315     default:
 316       *str++ = '%';
 317       if (*fmt)
 318         *str++ = *fmt;
 319       else
 320         --fmt;
 321       continue;
 322     }
 323     if (qualifier == 'l')
 324       num = va_arg(args, unsigned long);
 325     else if (qualifier == 'h') {
 326       num = (unsigned short) va_arg(args, int);
 327       if (flags & SIGN)
 328         num = (short) num;
 329     } else if (flags & SIGN)
 330       num = va_arg(args, int);
 331     else
 332       num = va_arg(args, unsigned int);
 333     str = number(str, num, base, field_width, precision, flags);
 334   }
 335   *str = '\0';
 336   return str-buf;
 337 }
 338
 339 int sprintf(char * buf, const char *fmt, ...)
 340 {
 341   va_list args;
 342   int i;
 343
 344   va_start(args, fmt);
 345   i=vsprintf(buf,fmt,args);
 346   va_end(args);
 347   return i;
 348 }
 349
 350 int printf(const char *fmt, ...)
 351 {
 352   char printf_buf[1024];
 353   va_list args;
 354   int printed;
 355
 356   va_start(args, fmt);
 357   printed = vsprintf(printf_buf, fmt, args);
 358   va_end(args);
 359
 360   puts(printf_buf);
 361
 362   return printed;
 363 }