lib/tiny-printf.c

   1 // SPDX-License-Identifier: LGPL-2.1+
   2 /*
   3  * Tiny printf version for SPL
   4  *
   5  * Copied from:
   6  * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
   7  *
   8  * Copyright (C) 2004,2008  Kustaa Nyholm
   9  */
  10
  11 #include <log.h>
  12 #include <serial.h>
  13 #include <stdarg.h>
  14 #include <linux/ctype.h>
  15
  16 struct printf_info {
  17         char *bf;       /* Digit buffer */
  18         char zs;        /* non-zero if a digit has been written */
  19         char *outstr;   /* Next output position for sprintf() */
  20
  21         /* Output a character */
  22         void (*putc)(struct printf_info *info, char ch);
  23 };
  24
  25 static void out(struct printf_info *info, char c)
  26 {
  27         *info->bf++ = c;
  28 }
  29
  30 static void out_dgt(struct printf_info *info, char dgt)
  31 {
  32         out(info, dgt + (dgt < 10 ? '0' : 'a' - 10));
  33         info->zs = 1;
  34 }
  35
  36 static void div_out(struct printf_info *info, unsigned long *num,
  37                     unsigned long div)
  38 {
  39         unsigned char dgt = 0;
  40
  41         while (*num >= div) {
  42                 *num -= div;
  43                 dgt++;
  44         }
  45
  46         if (info->zs || dgt > 0)
  47                 out_dgt(info, dgt);
  48 }
  49
  50 #ifdef CONFIG_SPL_NET
  51 static void string(struct printf_info *info, char *s)
  52 {
  53         char ch;
  54
  55         while ((ch = *s++))
  56                 out(info, ch);
  57 }
  58
  59 static const char hex_asc[] = "0123456789abcdef";
  60 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
  61 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
  62
  63 static inline char *pack_hex_byte(char *buf, u8 byte)
  64 {
  65         *buf++ = hex_asc_hi(byte);
  66         *buf++ = hex_asc_lo(byte);
  67         return buf;
  68 }
  69
  70 static void mac_address_string(struct printf_info *info, u8 *addr,
  71                                 bool separator)
  72 {
  73         /* (6 * 2 hex digits), 5 colons and trailing zero */
  74         char mac_addr[6 * 3];
  75         char *p = mac_addr;
  76         int i;
  77
  78         for (i = 0; i < 6; i++) {
  79                 p = pack_hex_byte(p, addr[i]);
  80                 if (separator && i != 5)
  81                         *p++ = ':';
  82         }
  83         *p = '\0';
  84
  85         string(info, mac_addr);
  86 }
  87
  88 static char *put_dec_trunc(char *buf, unsigned int q)
  89 {
  90         unsigned int d3, d2, d1, d0;
  91         d1 = (q >> 4) & 0xf;
  92         d2 = (q >> 8) & 0xf;
  93         d3 = (q >> 12);
  94
  95         d0 = 6 * (d3 + d2 + d1) + (q & 0xf);
  96         q = (d0 * 0xcd) >> 11;
  97         d0 = d0 - 10 * q;
  98         *buf++ = d0 + '0'; /* least significant digit */
  99         d1 = q + 9 * d3 + 5 * d2 + d1;
 100         if (d1 != 0) {
 101                 q = (d1 * 0xcd) >> 11;
 102                 d1 = d1 - 10 * q;
 103                 *buf++ = d1 + '0'; /* next digit */
 104
 105                 d2 = q + 2 * d2;
 106                 if ((d2 != 0) || (d3 != 0)) {
 107                         q = (d2 * 0xd) >> 7;
 108                         d2 = d2 - 10 * q;
 109                         *buf++ = d2 + '0'; /* next digit */
 110
 111                         d3 = q + 4 * d3;
 112                         if (d3 != 0) {
 113                                 q = (d3 * 0xcd) >> 11;
 114                                 d3 = d3 - 10 * q;
 115                                 *buf++ = d3 + '0';  /* next digit */
 116                                 if (q != 0)
 117                                         *buf++ = q + '0'; /* most sign. digit */
 118                         }
 119                 }
 120         }
 121         return buf;
 122 }
 123
 124 static void ip4_addr_string(struct printf_info *info, u8 *addr)
 125 {
 126         /* (4 * 3 decimal digits), 3 dots and trailing zero */
 127         char ip4_addr[4 * 4];
 128         char temp[3];   /* hold each IP quad in reverse order */
 129         char *p = ip4_addr;
 130         int i, digits;
 131
 132         for (i = 0; i < 4; i++) {
 133                 digits = put_dec_trunc(temp, addr[i]) - temp;
 134                 /* reverse the digits in the quad */
 135                 while (digits--)
 136                         *p++ = temp[digits];
 137                 if (i != 3)
 138                         *p++ = '.';
 139         }
 140         *p = '\0';
 141
 142         string(info, ip4_addr);
 143 }
 144 #endif
 145
 146 /*
 147  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
 148  * by an extra set of characters that are extended format
 149  * specifiers.
 150  *
 151  * Right now we handle:
 152  *
 153  * - 'M' For a 6-byte MAC address, it prints the address in the
 154  *       usual colon-separated hex notation.
 155  * - 'm' Same as above except there is no colon-separator.
 156  * - 'I4'for IPv4 addresses printed in the usual way (dot-separated
 157  *       decimal).
 158  */
 159
 160 static void __maybe_unused pointer(struct printf_info *info, const char *fmt,
 161                                    void *ptr)
 162 {
 163 #ifdef DEBUG
 164         unsigned long num = (uintptr_t)ptr;
 165         unsigned long div;
 166 #endif
 167
 168         switch (*fmt) {
 169 #ifdef DEBUG
 170         case 'a':
 171
 172                 switch (fmt[1]) {
 173                 case 'p':
 174                 default:
 175                         num = *(phys_addr_t *)ptr;
 176                         break;
 177                 }
 178                 break;
 179 #endif
 180 #ifdef CONFIG_SPL_NET
 181         case 'm':
 182                 return mac_address_string(info, ptr, false);
 183         case 'M':
 184                 return mac_address_string(info, ptr, true);
 185         case 'I':
 186                 if (fmt[1] == '4')
 187                         return ip4_addr_string(info, ptr);
 188 #endif
 189         default:
 190                 break;
 191         }
 192 #ifdef DEBUG
 193         div = 1UL << (sizeof(long) * 8 - 4);
 194         for (; div; div /= 0x10)
 195                 div_out(info, &num, div);
 196 #endif
 197 }
 198
 199 static int _vprintf(struct printf_info *info, const char *fmt, va_list va)
 200 {
 201         char ch;
 202         char *p;
 203         unsigned long num;
 204         char buf[12];
 205         unsigned long div;
 206
 207         while ((ch = *(fmt++))) {
 208                 if (ch != '%') {
 209                         info->putc(info, ch);
 210                 } else {
 211                         bool lz = false;
 212                         int width = 0;
 213                         bool islong = false;
 214
 215                         ch = *(fmt++);
 216                         if (ch == '-')
 217                                 ch = *(fmt++);
 218
 219                         if (ch == '0') {
 220                                 ch = *(fmt++);
 221                                 lz = 1;
 222                         }
 223
 224                         if (ch >= '0' && ch <= '9') {
 225                                 width = 0;
 226                                 while (ch >= '0' && ch <= '9') {
 227                                         width = (width * 10) + ch - '0';
 228                                         ch = *fmt++;
 229                                 }
 230                         }
 231                         if (ch == 'l') {
 232                                 ch = *(fmt++);
 233                                 islong = true;
 234                         }
 235
 236                         info->bf = buf;
 237                         p = info->bf;
 238                         info->zs = 0;
 239
 240                         switch (ch) {
 241                         case '\0':
 242                                 goto abort;
 243                         case 'u':
 244                         case 'd':
 245                         case 'i':
 246                                 div = 1000000000;
 247                                 if (islong) {
 248                                         num = va_arg(va, unsigned long);
 249                                         if (sizeof(long) > 4)
 250                                                 div *= div * 10;
 251                                 } else {
 252                                         num = va_arg(va, unsigned int);
 253                                 }
 254
 255                                 if (ch != 'u') {
 256                                         if (islong && (long)num < 0) {
 257                                                 num = -(long)num;
 258                                                 out(info, '-');
 259                                         } else if (!islong && (int)num < 0) {
 260                                                 num = -(int)num;
 261                                                 out(info, '-');
 262                                         }
 263                                 }
 264                                 if (!num) {
 265                                         out_dgt(info, 0);
 266                                 } else {
 267                                         for (; div; div /= 10)
 268                                                 div_out(info, &num, div);
 269                                 }
 270                                 break;
 271                         case 'p':
 272                                 if (CONFIG_IS_ENABLED(NET) || _DEBUG) {
 273                                         pointer(info, fmt, va_arg(va, void *));
 274                                         /*
 275                                          * Skip this because it pulls in _ctype which is
 276                                          * 256 bytes, and we don't generally implement
 277                                          * pointer anyway
 278                                          */
 279                                         while (isalnum(fmt[0]))
 280                                                 fmt++;
 281                                         break;
 282                                 }
 283                                 islong = true;
 284                                 /* no break */
 285                         case 'x':
 286                                 if (islong) {
 287                                         num = va_arg(va, unsigned long);
 288                                         div = 1UL << (sizeof(long) * 8 - 4);
 289                                 } else {
 290                                         num = va_arg(va, unsigned int);
 291                                         div = 0x10000000;
 292                                 }
 293                                 if (!num) {
 294                                         out_dgt(info, 0);
 295                                 } else {
 296                                         for (; div; div /= 0x10)
 297                                                 div_out(info, &num, div);
 298                                 }
 299                                 break;
 300                         case 'c':
 301                                 out(info, (char)(va_arg(va, int)));
 302                                 break;
 303                         case 's':
 304                                 p = va_arg(va, char*);
 305                                 break;
 306                         case '%':
 307                                 out(info, '%');
 308                         default:
 309                                 break;
 310                         }
 311
 312                         *info->bf = 0;
 313                         info->bf = p;
 314                         while (*info->bf++ && width > 0)
 315                                 width--;
 316                         while (width-- > 0)
 317                                 info->putc(info, lz ? '0' : ' ');
 318                         if (p) {
 319                                 while ((ch = *p++))
 320                                         info->putc(info, ch);
 321                         }
 322                 }
 323         }
 324
 325 abort:
 326         return 0;
 327 }
 328
 329 #if CONFIG_IS_ENABLED(PRINTF)
 330 static void putc_normal(struct printf_info *info, char ch)
 331 {
 332         putc(ch);
 333 }
 334
 335 int vprintf(const char *fmt, va_list va)
 336 {
 337         struct printf_info info;
 338
 339         info.putc = putc_normal;
 340         return _vprintf(&info, fmt, va);
 341 }
 342
 343 int printf(const char *fmt, ...)
 344 {
 345         struct printf_info info;
 346
 347         va_list va;
 348         int ret;
 349
 350         info.putc = putc_normal;
 351         va_start(va, fmt);
 352         ret = _vprintf(&info, fmt, va);
 353         va_end(va);
 354
 355         return ret;
 356 }
 357 #endif
 358
 359 static void putc_outstr(struct printf_info *info, char ch)
 360 {
 361         *info->outstr++ = ch;
 362 }
 363
 364 int sprintf(char *buf, const char *fmt, ...)
 365 {
 366         struct printf_info info;
 367         va_list va;
 368         int ret;
 369
 370         va_start(va, fmt);
 371         info.outstr = buf;
 372         info.putc = putc_outstr;
 373         ret = _vprintf(&info, fmt, va);
 374         va_end(va);
 375         *info.outstr = '\0';
 376
 377         return ret;
 378 }
 379
 380 #if CONFIG_IS_ENABLED(LOG)
 381 /* Note that size is ignored */
 382 int vsnprintf(char *buf, size_t size, const char *fmt, va_list va)
 383 {
 384         struct printf_info info;
 385         int ret;
 386
 387         info.outstr = buf;
 388         info.putc = putc_outstr;
 389         ret = _vprintf(&info, fmt, va);
 390         *info.outstr = '\0';
 391
 392         return ret;
 393 }
 394 #endif
 395
 396 /* Note that size is ignored */
 397 int snprintf(char *buf, size_t size, const char *fmt, ...)
 398 {
 399         struct printf_info info;
 400         va_list va;
 401         int ret;
 402
 403         va_start(va, fmt);
 404         info.outstr = buf;
 405         info.putc = putc_outstr;
 406         ret = _vprintf(&info, fmt, va);
 407         va_end(va);
 408         *info.outstr = '\0';
 409
 410         return ret;
 411 }
 412
 413 void print_grouped_ull(unsigned long long int_val, int digits)
 414 {
 415         /* Don't try to print the upper 32-bits */
 416         printf("%ld ", (ulong)int_val);
 417 }