lib/tiny-printf.c

   1 /*
   2  * Tiny printf version for SPL
   3  *
   4  * Copied from:
   5  * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
   6  *
   7  * Copyright (C) 2004,2008  Kustaa Nyholm
   8  *
   9  * SPDX-License-Identifier:     LGPL-2.1+
  10  */
  11
  12 #include <common.h>
  13 #include <stdarg.h>
  14 #include <serial.h>
  15
  16 static char *bf;
  17 static char zs;
  18
  19 /* Current position in sprintf() output string */
  20 static char *outstr;
  21
  22 static void out(char c)
  23 {
  24         *bf++ = c;
  25 }
  26
  27 static void out_dgt(char dgt)
  28 {
  29         out(dgt + (dgt < 10 ? '0' : 'a' - 10));
  30         zs = 1;
  31 }
  32
  33 static void div_out(unsigned int *num, unsigned int div)
  34 {
  35         unsigned char dgt = 0;
  36
  37         while (*num >= div) {
  38                 *num -= div;
  39                 dgt++;
  40         }
  41
  42         if (zs || dgt > 0)
  43                 out_dgt(dgt);
  44 }
  45
  46 int _vprintf(const char *fmt, va_list va, void (*putc)(const char ch))
  47 {
  48         char ch;
  49         char *p;
  50         unsigned int num;
  51         char buf[12];
  52         unsigned int div;
  53
  54         while ((ch = *(fmt++))) {
  55                 if (ch != '%') {
  56                         putc(ch);
  57                 } else {
  58                         bool lz = false;
  59                         int width = 0;
  60
  61                         ch = *(fmt++);
  62                         if (ch == '0') {
  63                                 ch = *(fmt++);
  64                                 lz = 1;
  65                         }
  66
  67                         if (ch >= '0' && ch <= '9') {
  68                                 width = 0;
  69                                 while (ch >= '0' && ch <= '9') {
  70                                         width = (width * 10) + ch - '0';
  71                                         ch = *fmt++;
  72                                 }
  73                         }
  74                         bf = buf;
  75                         p = bf;
  76                         zs = 0;
  77
  78                         switch (ch) {
  79                         case '\0':
  80                                 goto abort;
  81                         case 'u':
  82                         case 'd':
  83                                 num = va_arg(va, unsigned int);
  84                                 if (ch == 'd' && (int)num < 0) {
  85                                         num = -(int)num;
  86                                         out('-');
  87                                 }
  88                                 if (!num) {
  89                                         out_dgt(0);
  90                                 } else {
  91                                         for (div = 1000000000; div; div /= 10)
  92                                                 div_out(&num, div);
  93                                 }
  94                                 break;
  95                         case 'x':
  96                                 num = va_arg(va, unsigned int);
  97                                 if (!num) {
  98                                         out_dgt(0);
  99                                 } else {
 100                                         for (div = 0x10000000; div; div /= 0x10)
 101                                                 div_out(&num, div);
 102                                 }
 103                                 break;
 104                         case 'c':
 105                                 out((char)(va_arg(va, int)));
 106                                 break;
 107                         case 's':
 108                                 p = va_arg(va, char*);
 109                                 break;
 110                         case '%':
 111                                 out('%');
 112                         default:
 113                                 break;
 114                         }
 115
 116                         *bf = 0;
 117                         bf = p;
 118                         while (*bf++ && width > 0)
 119                                 width--;
 120                         while (width-- > 0)
 121                                 putc(lz ? '0' : ' ');
 122                         if (p) {
 123                                 while ((ch = *p++))
 124                                         putc(ch);
 125                         }
 126                 }
 127         }
 128
 129 abort:
 130         return 0;
 131 }
 132
 133 int printf(const char *fmt, ...)
 134 {
 135         va_list va;
 136         int ret;
 137
 138         va_start(va, fmt);
 139         ret = _vprintf(fmt, va, putc);
 140         va_end(va);
 141
 142         return ret;
 143 }
 144
 145 static void putc_outstr(char ch)
 146 {
 147         *outstr++ = ch;
 148 }
 149
 150 int sprintf(char *buf, const char *fmt, ...)
 151 {
 152         va_list va;
 153         int ret;
 154
 155         va_start(va, fmt);
 156         outstr = buf;
 157         ret = _vprintf(fmt, va, putc_outstr);
 158         va_end(va);
 159         *outstr = '\0';
 160
 161         return ret;
 162 }
 163
 164 /* Note that size is ignored */
 165 int snprintf(char *buf, size_t size, const char *fmt, ...)
 166 {
 167         va_list va;
 168         int ret;
 169
 170         va_start(va, fmt);
 171         outstr = buf;
 172         ret = _vprintf(fmt, va, putc_outstr);
 173         va_end(va);
 174         *outstr = '\0';
 175
 176         return ret;
 177 }