1// SPDX-License-Identifier: GPL-2.0-only
2/* -*- linux-c -*- ------------------------------------------------------- *
3 *
4 *   Copyright (C) 1991, 1992 Linus Torvalds
5 *   Copyright 2007 rPath, Inc. - All Rights Reserved
6 *
7 * ----------------------------------------------------------------------- */
8
9/*
10 * Oh, it's a waste of space, but oh-so-yummy for debugging.  This
11 * version of printf() does not include 64-bit support.  "Live with
12 * it."
13 *
14 */
15
16#include "boot.h"
17
18static int skip_atoi(const char **s)
19{
20	int i = 0;
21
22	while (isdigit(**s))
23		i = i * 10 + *((*s)++) - '0';
24	return i;
25}
26
27#define ZEROPAD	1		/* pad with zero */
28#define SIGN	2		/* unsigned/signed long */
29#define PLUS	4		/* show plus */
30#define SPACE	8		/* space if plus */
31#define LEFT	16		/* left justified */
32#define SMALL	32		/* Must be 32 == 0x20 */
33#define SPECIAL	64		/* 0x */
34
35#define __do_div(n, base) ({ \
36int __res; \
37__res = ((unsigned long) n) % (unsigned) base; \
38n = ((unsigned long) n) / (unsigned) base; \
39__res; })
40
41static char *number(char *str, long num, int base, int size, int precision,
42		    int type)
43{
44	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
45	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
46
47	char tmp[66];
48	char c, sign, locase;
49	int i;
50
51	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
52	 * produces same digits or (maybe lowercased) letters */
53	locase = (type & SMALL);
54	if (type & LEFT)
55		type &= ~ZEROPAD;
56	if (base < 2 || base > 16)
57		return NULL;
58	c = (type & ZEROPAD) ? '0' : ' ';
59	sign = 0;
60	if (type & SIGN) {
61		if (num < 0) {
62			sign = '-';
63			num = -num;
64			size--;
65		} else if (type & PLUS) {
66			sign = '+';
67			size--;
68		} else if (type & SPACE) {
69			sign = ' ';
70			size--;
71		}
72	}
73	if (type & SPECIAL) {
74		if (base == 16)
75			size -= 2;
76		else if (base == 8)
77			size--;
78	}
79	i = 0;
80	if (num == 0)
81		tmp[i++] = '0';
82	else
83		while (num != 0)
84			tmp[i++] = (digits[__do_div(num, base)] | locase);
85	if (i > precision)
86		precision = i;
87	size -= precision;
88	if (!(type & (ZEROPAD + LEFT)))
89		while (size-- > 0)
90			*str++ = ' ';
91	if (sign)
92		*str++ = sign;
93	if (type & SPECIAL) {
94		if (base == 8)
95			*str++ = '0';
96		else if (base == 16) {
97			*str++ = '0';
98			*str++ = ('X' | locase);
99		}
100	}
101	if (!(type & LEFT))
102		while (size-- > 0)
103			*str++ = c;
104	while (i < precision--)
105		*str++ = '0';
106	while (i-- > 0)
107		*str++ = tmp[i];
108	while (size-- > 0)
109		*str++ = ' ';
110	return str;
111}
112
113int vsprintf(char *buf, const char *fmt, va_list args)
114{
115	int len;
116	unsigned long num;
117	int i, base;
118	char *str;
119	const char *s;
120
121	int flags;		/* flags to number() */
122
123	int field_width;	/* width of output field */
124	int precision;		/* min. # of digits for integers; max
125				   number of chars for from string */
126	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
127
128	for (str = buf; *fmt; ++fmt) {
129		if (*fmt != '%') {
130			*str++ = *fmt;
131			continue;
132		}
133
134		/* process flags */
135		flags = 0;
136	      repeat:
137		++fmt;		/* this also skips first '%' */
138		switch (*fmt) {
139		case '-':
140			flags |= LEFT;
141			goto repeat;
142		case '+':
143			flags |= PLUS;
144			goto repeat;
145		case ' ':
146			flags |= SPACE;
147			goto repeat;
148		case '#':
149			flags |= SPECIAL;
150			goto repeat;
151		case '0':
152			flags |= ZEROPAD;
153			goto repeat;
154		}
155
156		/* get field width */
157		field_width = -1;
158		if (isdigit(*fmt))
159			field_width = skip_atoi(&fmt);
160		else if (*fmt == '*') {
161			++fmt;
162			/* it's the next argument */
163			field_width = va_arg(args, int);
164			if (field_width < 0) {
165				field_width = -field_width;
166				flags |= LEFT;
167			}
168		}
169
170		/* get the precision */
171		precision = -1;
172		if (*fmt == '.') {
173			++fmt;
174			if (isdigit(*fmt))
175				precision = skip_atoi(&fmt);
176			else if (*fmt == '*') {
177				++fmt;
178				/* it's the next argument */
179				precision = va_arg(args, int);
180			}
181			if (precision < 0)
182				precision = 0;
183		}
184
185		/* get the conversion qualifier */
186		qualifier = -1;
187		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
188			qualifier = *fmt;
189			++fmt;
190		}
191
192		/* default base */
193		base = 10;
194
195		switch (*fmt) {
196		case 'c':
197			if (!(flags & LEFT))
198				while (--field_width > 0)
199					*str++ = ' ';
200			*str++ = (unsigned char)va_arg(args, int);
201			while (--field_width > 0)
202				*str++ = ' ';
203			continue;
204
205		case 's':
206			s = va_arg(args, char *);
207			len = strnlen(s, precision);
208
209			if (!(flags & LEFT))
210				while (len < field_width--)
211					*str++ = ' ';
212			for (i = 0; i < len; ++i)
213				*str++ = *s++;
214			while (len < field_width--)
215				*str++ = ' ';
216			continue;
217
218		case 'p':
219			if (field_width == -1) {
220				field_width = 2 * sizeof(void *);
221				flags |= ZEROPAD;
222			}
223			str = number(str,
224				     (unsigned long)va_arg(args, void *), 16,
225				     field_width, precision, flags);
226			continue;
227
228		case 'n':
229			if (qualifier == 'l') {
230				long *ip = va_arg(args, long *);
231				*ip = (str - buf);
232			} else {
233				int *ip = va_arg(args, int *);
234				*ip = (str - buf);
235			}
236			continue;
237
238		case '%':
239			*str++ = '%';
240			continue;
241
242			/* integer number formats - set up the flags and "break" */
243		case 'o':
244			base = 8;
245			break;
246
247		case 'x':
248			flags |= SMALL;
249		case 'X':
250			base = 16;
251			break;
252
253		case 'd':
254		case 'i':
255			flags |= SIGN;
256		case 'u':
257			break;
258
259		default:
260			*str++ = '%';
261			if (*fmt)
262				*str++ = *fmt;
263			else
264				--fmt;
265			continue;
266		}
267		if (qualifier == 'l')
268			num = va_arg(args, unsigned long);
269		else if (qualifier == 'h') {
270			num = (unsigned short)va_arg(args, int);
271			if (flags & SIGN)
272				num = (short)num;
273		} else if (flags & SIGN)
274			num = va_arg(args, int);
275		else
276			num = va_arg(args, unsigned int);
277		str = number(str, num, base, field_width, precision, flags);
278	}
279	*str = '\0';
280	return str - buf;
281}
282
283int sprintf(char *buf, const char *fmt, ...)
284{
285	va_list args;
286	int i;
287
288	va_start(args, fmt);
289	i = vsprintf(buf, fmt, args);
290	va_end(args);
291	return i;
292}
293
294int printf(const char *fmt, ...)
295{
296	char printf_buf[1024];
297	va_list args;
298	int printed;
299
300	va_start(args, fmt);
301	printed = vsprintf(printf_buf, fmt, args);
302	va_end(args);
303
304	puts(printf_buf);
305
306	return printed;
307}
308