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 static void out(char c)
  20 {
  21         *bf++ = c;
  22 }
  23
  24 static void out_dgt(char dgt)
  25 {
  26         out(dgt + (dgt < 10 ? '0' : 'a' - 10));
  27         zs = 1;
  28 }
  29
  30 static void div_out(unsigned int *num, unsigned int div)
  31 {
  32         unsigned char dgt = 0;
  33
  34         while (*num >= div) {
  35                 *num -= div;
  36                 dgt++;
  37         }
  38
  39         if (zs || dgt > 0)
  40                 out_dgt(dgt);
  41 }
  42
  43 int vprintf(const char *fmt, va_list va)
  44 {
  45         char ch;
  46         char *p;
  47         unsigned int num;
  48         char buf[12];
  49         unsigned int div;
  50
  51         while ((ch = *(fmt++))) {
  52                 if (ch != '%') {
  53                         putc(ch);
  54                 } else {
  55                         char lz = 0;
  56                         char w = 0;
  57
  58                         ch = *(fmt++);
  59                         if (ch == '0') {
  60                                 ch = *(fmt++);
  61                                 lz = 1;
  62                         }
  63
  64                         if (ch >= '0' && ch <= '9') {
  65                                 w = 0;
  66                                 while (ch >= '0' && ch <= '9') {
  67                                         w = (w * 10) + ch - '0';
  68                                         ch = *fmt++;
  69                                 }
  70                         }
  71                         bf = buf;
  72                         p = bf;
  73                         zs = 0;
  74
  75                         switch (ch) {
  76                         case 0:
  77                                 goto abort;
  78                         case 'u':
  79                         case 'd':
  80                                 num = va_arg(va, unsigned int);
  81                                 if (ch == 'd' && (int)num < 0) {
  82                                         num = -(int)num;
  83                                         out('-');
  84                                 }
  85                                 for (div = 1000000000; div; div /= 10)
  86                                         div_out(&num, div);
  87                                 break;
  88                         case 'x':
  89                                 num = va_arg(va, unsigned int);
  90                                 for (div = 0x10000000; div; div /= 0x10)
  91                                         div_out(&num, div);
  92                                 break;
  93                         case 'c':
  94                                 out((char)(va_arg(va, int)));
  95                                 break;
  96                         case 's':
  97                                 p = va_arg(va, char*);
  98                                 break;
  99                         case '%':
 100                                 out('%');
 101                         default:
 102                                 break;
 103                         }
 104
 105                         *bf = 0;
 106                         bf = p;
 107                         while (*bf++ && w > 0)
 108                                 w--;
 109                         while (w-- > 0)
 110                                 putc(lz ? '0' : ' ');
 111                         while ((ch = *p++))
 112                                 putc(ch);
 113                 }
 114         }
 115
 116 abort:
 117         return 0;
 118 }
 119
 120 int printf(const char *fmt, ...)
 121 {
 122         va_list va;
 123         int ret;
 124
 125         va_start(va, fmt);
 126         ret = vprintf(fmt, va);
 127         va_end(va);
 128
 129         return ret;
 130 }