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/arch/x86/boot/printf.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 309 lines | 248 code | 34 blank | 27 comment | 79 complexity | 64d21728509791e4f58619565edf65b8 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/* -*- linux-c -*- ------------------------------------------------------- *
  2 *
  3 *   Copyright (C) 1991, 1992 Linus Torvalds
  4 *   Copyright 2007 rPath, Inc. - All Rights Reserved
  5 *
  6 *   This file is part of the Linux kernel, and is made available under
  7 *   the terms of the GNU General Public License version 2.
  8 *
  9 * ----------------------------------------------------------------------- */
 10
 11/*
 12 * Oh, it's a waste of space, but oh-so-yummy for debugging.  This
 13 * version of printf() does not include 64-bit support.  "Live with
 14 * it."
 15 *
 16 */
 17
 18#include "boot.h"
 19
 20static int skip_atoi(const char **s)
 21{
 22	int i = 0;
 23
 24	while (isdigit(**s))
 25		i = i * 10 + *((*s)++) - '0';
 26	return i;
 27}
 28
 29#define ZEROPAD	1		/* pad with zero */
 30#define SIGN	2		/* unsigned/signed long */
 31#define PLUS	4		/* show plus */
 32#define SPACE	8		/* space if plus */
 33#define LEFT	16		/* left justified */
 34#define SMALL	32		/* Must be 32 == 0x20 */
 35#define SPECIAL	64		/* 0x */
 36
 37#define do_div(n,base) ({ \
 38int __res; \
 39__res = ((unsigned long) n) % (unsigned) base; \
 40n = ((unsigned long) n) / (unsigned) base; \
 41__res; })
 42
 43static char *number(char *str, long num, int base, int size, int precision,
 44		    int type)
 45{
 46	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
 47	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
 48
 49	char tmp[66];
 50	char c, sign, locase;
 51	int i;
 52
 53	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
 54	 * produces same digits or (maybe lowercased) letters */
 55	locase = (type & SMALL);
 56	if (type & LEFT)
 57		type &= ~ZEROPAD;
 58	if (base < 2 || base > 36)
 59		return NULL;
 60	c = (type & ZEROPAD) ? '0' : ' ';
 61	sign = 0;
 62	if (type & SIGN) {
 63		if (num < 0) {
 64			sign = '-';
 65			num = -num;
 66			size--;
 67		} else if (type & PLUS) {
 68			sign = '+';
 69			size--;
 70		} else if (type & SPACE) {
 71			sign = ' ';
 72			size--;
 73		}
 74	}
 75	if (type & SPECIAL) {
 76		if (base == 16)
 77			size -= 2;
 78		else if (base == 8)
 79			size--;
 80	}
 81	i = 0;
 82	if (num == 0)
 83		tmp[i++] = '0';
 84	else
 85		while (num != 0)
 86			tmp[i++] = (digits[do_div(num, base)] | locase);
 87	if (i > precision)
 88		precision = i;
 89	size -= precision;
 90	if (!(type & (ZEROPAD + LEFT)))
 91		while (size-- > 0)
 92			*str++ = ' ';
 93	if (sign)
 94		*str++ = sign;
 95	if (type & SPECIAL) {
 96		if (base == 8)
 97			*str++ = '0';
 98		else if (base == 16) {
 99			*str++ = '0';
100			*str++ = ('X' | locase);
101		}
102	}
103	if (!(type & LEFT))
104		while (size-- > 0)
105			*str++ = c;
106	while (i < precision--)
107		*str++ = '0';
108	while (i-- > 0)
109		*str++ = tmp[i];
110	while (size-- > 0)
111		*str++ = ' ';
112	return str;
113}
114
115int vsprintf(char *buf, const char *fmt, va_list args)
116{
117	int len;
118	unsigned long num;
119	int i, base;
120	char *str;
121	const char *s;
122
123	int flags;		/* flags to number() */
124
125	int field_width;	/* width of output field */
126	int precision;		/* min. # of digits for integers; max
127				   number of chars for from string */
128	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
129
130	for (str = buf; *fmt; ++fmt) {
131		if (*fmt != '%') {
132			*str++ = *fmt;
133			continue;
134		}
135
136		/* process flags */
137		flags = 0;
138	      repeat:
139		++fmt;		/* this also skips first '%' */
140		switch (*fmt) {
141		case '-':
142			flags |= LEFT;
143			goto repeat;
144		case '+':
145			flags |= PLUS;
146			goto repeat;
147		case ' ':
148			flags |= SPACE;
149			goto repeat;
150		case '#':
151			flags |= SPECIAL;
152			goto repeat;
153		case '0':
154			flags |= ZEROPAD;
155			goto repeat;
156		}
157
158		/* get field width */
159		field_width = -1;
160		if (isdigit(*fmt))
161			field_width = skip_atoi(&fmt);
162		else if (*fmt == '*') {
163			++fmt;
164			/* it's the next argument */
165			field_width = va_arg(args, int);
166			if (field_width < 0) {
167				field_width = -field_width;
168				flags |= LEFT;
169			}
170		}
171
172		/* get the precision */
173		precision = -1;
174		if (*fmt == '.') {
175			++fmt;
176			if (isdigit(*fmt))
177				precision = skip_atoi(&fmt);
178			else if (*fmt == '*') {
179				++fmt;
180				/* it's the next argument */
181				precision = va_arg(args, int);
182			}
183			if (precision < 0)
184				precision = 0;
185		}
186
187		/* get the conversion qualifier */
188		qualifier = -1;
189		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
190			qualifier = *fmt;
191			++fmt;
192		}
193
194		/* default base */
195		base = 10;
196
197		switch (*fmt) {
198		case 'c':
199			if (!(flags & LEFT))
200				while (--field_width > 0)
201					*str++ = ' ';
202			*str++ = (unsigned char)va_arg(args, int);
203			while (--field_width > 0)
204				*str++ = ' ';
205			continue;
206
207		case 's':
208			s = va_arg(args, char *);
209			len = strnlen(s, precision);
210
211			if (!(flags & LEFT))
212				while (len < field_width--)
213					*str++ = ' ';
214			for (i = 0; i < len; ++i)
215				*str++ = *s++;
216			while (len < field_width--)
217				*str++ = ' ';
218			continue;
219
220		case 'p':
221			if (field_width == -1) {
222				field_width = 2 * sizeof(void *);
223				flags |= ZEROPAD;
224			}
225			str = number(str,
226				     (unsigned long)va_arg(args, void *), 16,
227				     field_width, precision, flags);
228			continue;
229
230		case 'n':
231			if (qualifier == 'l') {
232				long *ip = va_arg(args, long *);
233				*ip = (str - buf);
234			} else {
235				int *ip = va_arg(args, int *);
236				*ip = (str - buf);
237			}
238			continue;
239
240		case '%':
241			*str++ = '%';
242			continue;
243
244			/* integer number formats - set up the flags and "break" */
245		case 'o':
246			base = 8;
247			break;
248
249		case 'x':
250			flags |= SMALL;
251		case 'X':
252			base = 16;
253			break;
254
255		case 'd':
256		case 'i':
257			flags |= SIGN;
258		case 'u':
259			break;
260
261		default:
262			*str++ = '%';
263			if (*fmt)
264				*str++ = *fmt;
265			else
266				--fmt;
267			continue;
268		}
269		if (qualifier == 'l')
270			num = va_arg(args, unsigned long);
271		else if (qualifier == 'h') {
272			num = (unsigned short)va_arg(args, int);
273			if (flags & SIGN)
274				num = (short)num;
275		} else if (flags & SIGN)
276			num = va_arg(args, int);
277		else
278			num = va_arg(args, unsigned int);
279		str = number(str, num, base, field_width, precision, flags);
280	}
281	*str = '\0';
282	return str - buf;
283}
284
285int sprintf(char *buf, const char *fmt, ...)
286{
287	va_list args;
288	int i;
289
290	va_start(args, fmt);
291	i = vsprintf(buf, fmt, args);
292	va_end(args);
293	return i;
294}
295
296int printf(const char *fmt, ...)
297{
298	char printf_buf[1024];
299	va_list args;
300	int printed;
301
302	va_start(args, fmt);
303	printed = vsprintf(printf_buf, fmt, args);
304	va_end(args);
305
306	puts(printf_buf);
307
308	return printed;
309}