summaryrefslogtreecommitdiff
path: root/lib/tiny-printf.c
blob: d743a364e944497bd827af50e56625c0655cfcc4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * Tiny printf version for SPL
 *
 * Copied from:
 * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
 *
 * Copyright (C) 2004,2008  Kustaa Nyholm
 *
 * SPDX-License-Identifier:	LGPL-2.1+
 */

#include <common.h>
#include <stdarg.h>
#include <serial.h>

static char *bf;
static char buf[12];
static unsigned int num;
static char uc;
static char zs;

static void out(char c)
{
	*bf++ = c;
}

static void out_dgt(char dgt)
{
	out(dgt + (dgt < 10 ? '0' : (uc ? 'A' : 'a') - 10));
	zs = 1;
}

static void div_out(unsigned int div)
{
	unsigned char dgt = 0;

	num &= 0xffff; /* just for testing the code with 32 bit ints */
	while (num >= div) {
		num -= div;
		dgt++;
	}

	if (zs || dgt > 0)
		out_dgt(dgt);
}

int printf(const char *fmt, ...)
{
	va_list va;
	char ch;
	char *p;

	va_start(va, fmt);

	while ((ch = *(fmt++))) {
		if (ch != '%') {
			putc(ch);
		} else {
			char lz = 0;
			char w = 0;

			ch = *(fmt++);
			if (ch == '0') {
				ch = *(fmt++);
				lz = 1;
			}

			if (ch >= '0' && ch <= '9') {
				w = 0;
				while (ch >= '0' && ch <= '9') {
					w = (((w << 2) + w) << 1) + ch - '0';
					ch = *fmt++;
				}
			}
			bf = buf;
			p = bf;
			zs = 0;

			switch (ch) {
			case 0:
				goto abort;
			case 'u':
			case 'd':
				num = va_arg(va, unsigned int);
				if (ch == 'd' && (int)num < 0) {
					num = -(int)num;
					out('-');
				}
				div_out(10000);
				div_out(1000);
				div_out(100);
				div_out(10);
				out_dgt(num);
				break;
			case 'x':
			case 'X':
				uc = ch == 'X';
				num = va_arg(va, unsigned int);
				div_out(0x1000);
				div_out(0x100);
				div_out(0x10);
				out_dgt(num);
				break;
			case 'c':
				out((char)(va_arg(va, int)));
				break;
			case 's':
				p = va_arg(va, char*);
				break;
			case '%':
				out('%');
			default:
				break;
			}

			*bf = 0;
			bf = p;
			while (*bf++ && w > 0)
				w--;
			while (w-- > 0)
				putc(lz ? '0' : ' ');
			while ((ch = *p++))
				putc(ch);
		}
	}

abort:
	va_end(va);
	return 0;
}