xref: /openbmc/u-boot/lib/vsprintf.c (revision b24a8ec1)
1 /*
2  *  linux/lib/vsprintf.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6 
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
8 /*
9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
10  *
11  * from hush: simple_itoa() was lifted from boa-0.93.15
12  */
13 
14 #include <stdarg.h>
15 #include <linux/types.h>
16 #include <linux/string.h>
17 #include <linux/ctype.h>
18 
19 #include <common.h>
20 
21 #include <div64.h>
22 #define noinline __attribute__((noinline))
23 
24 /* we use this so that we can do without the ctype library */
25 #define is_digit(c)	((c) >= '0' && (c) <= '9')
26 
27 static int skip_atoi(const char **s)
28 {
29 	int i = 0;
30 
31 	while (is_digit(**s))
32 		i = i * 10 + *((*s)++) - '0';
33 
34 	return i;
35 }
36 
37 /* Decimal conversion is by far the most typical, and is used
38  * for /proc and /sys data. This directly impacts e.g. top performance
39  * with many processes running. We optimize it for speed
40  * using code from
41  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
42  * (with permission from the author, Douglas W. Jones). */
43 
44 /* Formats correctly any integer in [0,99999].
45  * Outputs from one to five digits depending on input.
46  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
47 static char *put_dec_trunc(char *buf, unsigned q)
48 {
49 	unsigned d3, d2, d1, d0;
50 	d1 = (q>>4) & 0xf;
51 	d2 = (q>>8) & 0xf;
52 	d3 = (q>>12);
53 
54 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
55 	q = (d0 * 0xcd) >> 11;
56 	d0 = d0 - 10*q;
57 	*buf++ = d0 + '0'; /* least significant digit */
58 	d1 = q + 9*d3 + 5*d2 + d1;
59 	if (d1 != 0) {
60 		q = (d1 * 0xcd) >> 11;
61 		d1 = d1 - 10*q;
62 		*buf++ = d1 + '0'; /* next digit */
63 
64 		d2 = q + 2*d2;
65 		if ((d2 != 0) || (d3 != 0)) {
66 			q = (d2 * 0xd) >> 7;
67 			d2 = d2 - 10*q;
68 			*buf++ = d2 + '0'; /* next digit */
69 
70 			d3 = q + 4*d3;
71 			if (d3 != 0) {
72 				q = (d3 * 0xcd) >> 11;
73 				d3 = d3 - 10*q;
74 				*buf++ = d3 + '0';  /* next digit */
75 				if (q != 0)
76 					*buf++ = q + '0'; /* most sign. digit */
77 			}
78 		}
79 	}
80 	return buf;
81 }
82 /* Same with if's removed. Always emits five digits */
83 static char *put_dec_full(char *buf, unsigned q)
84 {
85 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
86 	/* but anyway, gcc produces better code with full-sized ints */
87 	unsigned d3, d2, d1, d0;
88 	d1 = (q>>4) & 0xf;
89 	d2 = (q>>8) & 0xf;
90 	d3 = (q>>12);
91 
92 	/*
93 	 * Possible ways to approx. divide by 10
94 	 * gcc -O2 replaces multiply with shifts and adds
95 	 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
96 	 * (x * 0x67) >> 10:  1100111
97 	 * (x * 0x34) >> 9:    110100 - same
98 	 * (x * 0x1a) >> 8:     11010 - same
99 	 * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
100 	 */
101 
102 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
103 	q = (d0 * 0xcd) >> 11;
104 	d0 = d0 - 10*q;
105 	*buf++ = d0 + '0';
106 	d1 = q + 9*d3 + 5*d2 + d1;
107 		q = (d1 * 0xcd) >> 11;
108 		d1 = d1 - 10*q;
109 		*buf++ = d1 + '0';
110 
111 		d2 = q + 2*d2;
112 			q = (d2 * 0xd) >> 7;
113 			d2 = d2 - 10*q;
114 			*buf++ = d2 + '0';
115 
116 			d3 = q + 4*d3;
117 				q = (d3 * 0xcd) >> 11; /* - shorter code */
118 				/* q = (d3 * 0x67) >> 10; - would also work */
119 				d3 = d3 - 10*q;
120 				*buf++ = d3 + '0';
121 					*buf++ = q + '0';
122 	return buf;
123 }
124 /* No inlining helps gcc to use registers better */
125 static noinline char *put_dec(char *buf, uint64_t num)
126 {
127 	while (1) {
128 		unsigned rem;
129 		if (num < 100000)
130 			return put_dec_trunc(buf, num);
131 		rem = do_div(num, 100000);
132 		buf = put_dec_full(buf, rem);
133 	}
134 }
135 
136 #define ZEROPAD	1		/* pad with zero */
137 #define SIGN	2		/* unsigned/signed long */
138 #define PLUS	4		/* show plus */
139 #define SPACE	8		/* space if plus */
140 #define LEFT	16		/* left justified */
141 #define SMALL	32		/* Must be 32 == 0x20 */
142 #define SPECIAL	64		/* 0x */
143 
144 /*
145  * Macro to add a new character to our output string, but only if it will
146  * fit. The macro moves to the next character position in the output string.
147  */
148 #define ADDCH(str, ch) do { \
149 	if ((str) < end) \
150 		*(str) = (ch); \
151 	++str; \
152 	} while (0)
153 
154 static char *number(char *buf, char *end, u64 num,
155 		int base, int size, int precision, int type)
156 {
157 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
158 	static const char digits[16] = "0123456789ABCDEF";
159 
160 	char tmp[66];
161 	char sign;
162 	char locase;
163 	int need_pfx = ((type & SPECIAL) && base != 10);
164 	int i;
165 
166 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
167 	 * produces same digits or (maybe lowercased) letters */
168 	locase = (type & SMALL);
169 	if (type & LEFT)
170 		type &= ~ZEROPAD;
171 	sign = 0;
172 	if (type & SIGN) {
173 		if ((s64) num < 0) {
174 			sign = '-';
175 			num = -(s64) num;
176 			size--;
177 		} else if (type & PLUS) {
178 			sign = '+';
179 			size--;
180 		} else if (type & SPACE) {
181 			sign = ' ';
182 			size--;
183 		}
184 	}
185 	if (need_pfx) {
186 		size--;
187 		if (base == 16)
188 			size--;
189 	}
190 
191 	/* generate full string in tmp[], in reverse order */
192 	i = 0;
193 	if (num == 0)
194 		tmp[i++] = '0';
195 	/* Generic code, for any base:
196 	else do {
197 		tmp[i++] = (digits[do_div(num,base)] | locase);
198 	} while (num != 0);
199 	*/
200 	else if (base != 10) { /* 8 or 16 */
201 		int mask = base - 1;
202 		int shift = 3;
203 
204 		if (base == 16)
205 			shift = 4;
206 
207 		do {
208 			tmp[i++] = (digits[((unsigned char)num) & mask]
209 					| locase);
210 			num >>= shift;
211 		} while (num);
212 	} else { /* base 10 */
213 		i = put_dec(tmp, num) - tmp;
214 	}
215 
216 	/* printing 100 using %2d gives "100", not "00" */
217 	if (i > precision)
218 		precision = i;
219 	/* leading space padding */
220 	size -= precision;
221 	if (!(type & (ZEROPAD + LEFT))) {
222 		while (--size >= 0)
223 			ADDCH(buf, ' ');
224 	}
225 	/* sign */
226 	if (sign)
227 		ADDCH(buf, sign);
228 	/* "0x" / "0" prefix */
229 	if (need_pfx) {
230 		ADDCH(buf, '0');
231 		if (base == 16)
232 			ADDCH(buf, 'X' | locase);
233 	}
234 	/* zero or space padding */
235 	if (!(type & LEFT)) {
236 		char c = (type & ZEROPAD) ? '0' : ' ';
237 
238 		while (--size >= 0)
239 			ADDCH(buf, c);
240 	}
241 	/* hmm even more zero padding? */
242 	while (i <= --precision)
243 		ADDCH(buf, '0');
244 	/* actual digits of result */
245 	while (--i >= 0)
246 		ADDCH(buf, tmp[i]);
247 	/* trailing space padding */
248 	while (--size >= 0)
249 		ADDCH(buf, ' ');
250 	return buf;
251 }
252 
253 static char *string(char *buf, char *end, char *s, int field_width,
254 		int precision, int flags)
255 {
256 	int len, i;
257 
258 	if (s == NULL)
259 		s = "<NULL>";
260 
261 	len = strnlen(s, precision);
262 
263 	if (!(flags & LEFT))
264 		while (len < field_width--)
265 			ADDCH(buf, ' ');
266 	for (i = 0; i < len; ++i)
267 		ADDCH(buf, *s++);
268 	while (len < field_width--)
269 		ADDCH(buf, ' ');
270 	return buf;
271 }
272 
273 #ifdef CONFIG_CMD_NET
274 static const char hex_asc[] = "0123456789abcdef";
275 #define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
276 #define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
277 
278 static inline char *pack_hex_byte(char *buf, u8 byte)
279 {
280 	*buf++ = hex_asc_hi(byte);
281 	*buf++ = hex_asc_lo(byte);
282 	return buf;
283 }
284 
285 static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width,
286 				int precision, int flags)
287 {
288 	/* (6 * 2 hex digits), 5 colons and trailing zero */
289 	char mac_addr[6 * 3];
290 	char *p = mac_addr;
291 	int i;
292 
293 	for (i = 0; i < 6; i++) {
294 		p = pack_hex_byte(p, addr[i]);
295 		if (!(flags & SPECIAL) && i != 5)
296 			*p++ = ':';
297 	}
298 	*p = '\0';
299 
300 	return string(buf, end, mac_addr, field_width, precision,
301 		      flags & ~SPECIAL);
302 }
303 
304 static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width,
305 			 int precision, int flags)
306 {
307 	/* (8 * 4 hex digits), 7 colons and trailing zero */
308 	char ip6_addr[8 * 5];
309 	char *p = ip6_addr;
310 	int i;
311 
312 	for (i = 0; i < 8; i++) {
313 		p = pack_hex_byte(p, addr[2 * i]);
314 		p = pack_hex_byte(p, addr[2 * i + 1]);
315 		if (!(flags & SPECIAL) && i != 7)
316 			*p++ = ':';
317 	}
318 	*p = '\0';
319 
320 	return string(buf, end, ip6_addr, field_width, precision,
321 		      flags & ~SPECIAL);
322 }
323 
324 static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width,
325 			 int precision, int flags)
326 {
327 	/* (4 * 3 decimal digits), 3 dots and trailing zero */
328 	char ip4_addr[4 * 4];
329 	char temp[3];	/* hold each IP quad in reverse order */
330 	char *p = ip4_addr;
331 	int i, digits;
332 
333 	for (i = 0; i < 4; i++) {
334 		digits = put_dec_trunc(temp, addr[i]) - temp;
335 		/* reverse the digits in the quad */
336 		while (digits--)
337 			*p++ = temp[digits];
338 		if (i != 3)
339 			*p++ = '.';
340 	}
341 	*p = '\0';
342 
343 	return string(buf, end, ip4_addr, field_width, precision,
344 		      flags & ~SPECIAL);
345 }
346 #endif
347 
348 /*
349  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
350  * by an extra set of alphanumeric characters that are extended format
351  * specifiers.
352  *
353  * Right now we handle:
354  *
355  * - 'M' For a 6-byte MAC address, it prints the address in the
356  *       usual colon-separated hex notation
357  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
358  *       decimal for v4 and colon separated network-order 16 bit hex for v6)
359  * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
360  *       currently the same
361  *
362  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
363  * function pointers are really function descriptors, which contain a
364  * pointer to the real address.
365  */
366 static char *pointer(const char *fmt, char *buf, char *end, void *ptr,
367 		int field_width, int precision, int flags)
368 {
369 	u64 num = (uintptr_t)ptr;
370 
371 	/*
372 	 * Being a boot loader, we explicitly allow pointers to
373 	 * (physical) address null.
374 	 */
375 #if 0
376 	if (!ptr)
377 		return string(buf, end, "(null)", field_width, precision,
378 			      flags);
379 #endif
380 
381 #ifdef CONFIG_CMD_NET
382 	switch (*fmt) {
383 	case 'a':
384 		flags |= SPECIAL | ZEROPAD;
385 
386 		switch (fmt[1]) {
387 		case 'p':
388 		default:
389 			field_width = sizeof(phys_addr_t) * 2 + 2;
390 			num = *(phys_addr_t *)ptr;
391 			break;
392 		}
393 		break;
394 	case 'm':
395 		flags |= SPECIAL;
396 		/* Fallthrough */
397 	case 'M':
398 		return mac_address_string(buf, end, ptr, field_width,
399 					  precision, flags);
400 	case 'i':
401 		flags |= SPECIAL;
402 		/* Fallthrough */
403 	case 'I':
404 		if (fmt[1] == '6')
405 			return ip6_addr_string(buf, end, ptr, field_width,
406 					       precision, flags);
407 		if (fmt[1] == '4')
408 			return ip4_addr_string(buf, end, ptr, field_width,
409 					       precision, flags);
410 		flags &= ~SPECIAL;
411 		break;
412 	}
413 #endif
414 	flags |= SMALL;
415 	if (field_width == -1) {
416 		field_width = 2*sizeof(void *);
417 		flags |= ZEROPAD;
418 	}
419 	return number(buf, end, num, 16, field_width, precision, flags);
420 }
421 
422 static int vsnprintf_internal(char *buf, size_t size, const char *fmt,
423 			      va_list args)
424 {
425 	u64 num;
426 	int base;
427 	char *str;
428 
429 	int flags;		/* flags to number() */
430 
431 	int field_width;	/* width of output field */
432 	int precision;		/* min. # of digits for integers; max
433 				   number of chars for from string */
434 	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
435 				/* 'z' support added 23/7/1999 S.H.    */
436 				/* 'z' changed to 'Z' --davidm 1/25/99 */
437 				/* 't' added for ptrdiff_t */
438 	char *end = buf + size;
439 
440 	/* Make sure end is always >= buf - do we want this in U-Boot? */
441 	if (end < buf) {
442 		end = ((void *)-1);
443 		size = end - buf;
444 	}
445 	str = buf;
446 
447 	for (; *fmt ; ++fmt) {
448 		if (*fmt != '%') {
449 			ADDCH(str, *fmt);
450 			continue;
451 		}
452 
453 		/* process flags */
454 		flags = 0;
455 repeat:
456 			++fmt;		/* this also skips first '%' */
457 			switch (*fmt) {
458 			case '-':
459 				flags |= LEFT;
460 				goto repeat;
461 			case '+':
462 				flags |= PLUS;
463 				goto repeat;
464 			case ' ':
465 				flags |= SPACE;
466 				goto repeat;
467 			case '#':
468 				flags |= SPECIAL;
469 				goto repeat;
470 			case '0':
471 				flags |= ZEROPAD;
472 				goto repeat;
473 			}
474 
475 		/* get field width */
476 		field_width = -1;
477 		if (is_digit(*fmt))
478 			field_width = skip_atoi(&fmt);
479 		else if (*fmt == '*') {
480 			++fmt;
481 			/* it's the next argument */
482 			field_width = va_arg(args, int);
483 			if (field_width < 0) {
484 				field_width = -field_width;
485 				flags |= LEFT;
486 			}
487 		}
488 
489 		/* get the precision */
490 		precision = -1;
491 		if (*fmt == '.') {
492 			++fmt;
493 			if (is_digit(*fmt))
494 				precision = skip_atoi(&fmt);
495 			else if (*fmt == '*') {
496 				++fmt;
497 				/* it's the next argument */
498 				precision = va_arg(args, int);
499 			}
500 			if (precision < 0)
501 				precision = 0;
502 		}
503 
504 		/* get the conversion qualifier */
505 		qualifier = -1;
506 		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
507 		    *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
508 			qualifier = *fmt;
509 			++fmt;
510 			if (qualifier == 'l' && *fmt == 'l') {
511 				qualifier = 'L';
512 				++fmt;
513 			}
514 		}
515 
516 		/* default base */
517 		base = 10;
518 
519 		switch (*fmt) {
520 		case 'c':
521 			if (!(flags & LEFT)) {
522 				while (--field_width > 0)
523 					ADDCH(str, ' ');
524 			}
525 			ADDCH(str, (unsigned char) va_arg(args, int));
526 			while (--field_width > 0)
527 				ADDCH(str, ' ');
528 			continue;
529 
530 		case 's':
531 			str = string(str, end, va_arg(args, char *),
532 				     field_width, precision, flags);
533 			continue;
534 
535 		case 'p':
536 			str = pointer(fmt + 1, str, end,
537 					va_arg(args, void *),
538 					field_width, precision, flags);
539 			/* Skip all alphanumeric pointer suffixes */
540 			while (isalnum(fmt[1]))
541 				fmt++;
542 			continue;
543 
544 		case 'n':
545 			if (qualifier == 'l') {
546 				long *ip = va_arg(args, long *);
547 				*ip = (str - buf);
548 			} else {
549 				int *ip = va_arg(args, int *);
550 				*ip = (str - buf);
551 			}
552 			continue;
553 
554 		case '%':
555 			ADDCH(str, '%');
556 			continue;
557 
558 		/* integer number formats - set up the flags and "break" */
559 		case 'o':
560 			base = 8;
561 			break;
562 
563 		case 'x':
564 			flags |= SMALL;
565 		case 'X':
566 			base = 16;
567 			break;
568 
569 		case 'd':
570 		case 'i':
571 			flags |= SIGN;
572 		case 'u':
573 			break;
574 
575 		default:
576 			ADDCH(str, '%');
577 			if (*fmt)
578 				ADDCH(str, *fmt);
579 			else
580 				--fmt;
581 			continue;
582 		}
583 		if (qualifier == 'L')  /* "quad" for 64 bit variables */
584 			num = va_arg(args, unsigned long long);
585 		else if (qualifier == 'l') {
586 			num = va_arg(args, unsigned long);
587 			if (flags & SIGN)
588 				num = (signed long) num;
589 		} else if (qualifier == 'Z' || qualifier == 'z') {
590 			num = va_arg(args, size_t);
591 		} else if (qualifier == 't') {
592 			num = va_arg(args, ptrdiff_t);
593 		} else if (qualifier == 'h') {
594 			num = (unsigned short) va_arg(args, int);
595 			if (flags & SIGN)
596 				num = (signed short) num;
597 		} else {
598 			num = va_arg(args, unsigned int);
599 			if (flags & SIGN)
600 				num = (signed int) num;
601 		}
602 		str = number(str, end, num, base, field_width, precision,
603 			     flags);
604 	}
605 
606 	if (size > 0) {
607 		ADDCH(str, '\0');
608 		if (str > end)
609 			end[-1] = '\0';
610 		--str;
611 	}
612 	/* the trailing null byte doesn't count towards the total */
613 	return str - buf;
614 }
615 
616 int vsnprintf(char *buf, size_t size, const char *fmt,
617 			      va_list args)
618 {
619 	return vsnprintf_internal(buf, size, fmt, args);
620 }
621 
622 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
623 {
624 	int i;
625 
626 	i = vsnprintf(buf, size, fmt, args);
627 
628 	if (likely(i < size))
629 		return i;
630 	if (size != 0)
631 		return size - 1;
632 	return 0;
633 }
634 
635 int snprintf(char *buf, size_t size, const char *fmt, ...)
636 {
637 	va_list args;
638 	int i;
639 
640 	va_start(args, fmt);
641 	i = vsnprintf(buf, size, fmt, args);
642 	va_end(args);
643 
644 	return i;
645 }
646 
647 int scnprintf(char *buf, size_t size, const char *fmt, ...)
648 {
649 	va_list args;
650 	int i;
651 
652 	va_start(args, fmt);
653 	i = vscnprintf(buf, size, fmt, args);
654 	va_end(args);
655 
656 	return i;
657 }
658 
659 /**
660  * Format a string and place it in a buffer (va_list version)
661  *
662  * @param buf	The buffer to place the result into
663  * @param fmt	The format string to use
664  * @param args	Arguments for the format string
665  *
666  * The function returns the number of characters written
667  * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
668  * buffer overflows.
669  *
670  * If you're not already dealing with a va_list consider using sprintf().
671  */
672 int vsprintf(char *buf, const char *fmt, va_list args)
673 {
674 	return vsnprintf_internal(buf, INT_MAX, fmt, args);
675 }
676 
677 int sprintf(char *buf, const char *fmt, ...)
678 {
679 	va_list args;
680 	int i;
681 
682 	va_start(args, fmt);
683 	i = vsprintf(buf, fmt, args);
684 	va_end(args);
685 	return i;
686 }
687 
688 int printf(const char *fmt, ...)
689 {
690 	va_list args;
691 	uint i;
692 	char printbuffer[CONFIG_SYS_PBSIZE];
693 
694 	va_start(args, fmt);
695 
696 	/*
697 	 * For this to work, printbuffer must be larger than
698 	 * anything we ever want to print.
699 	 */
700 	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
701 	va_end(args);
702 
703 	/* Print the string */
704 	puts(printbuffer);
705 	return i;
706 }
707 
708 int vprintf(const char *fmt, va_list args)
709 {
710 	uint i;
711 	char printbuffer[CONFIG_SYS_PBSIZE];
712 
713 	/*
714 	 * For this to work, printbuffer must be larger than
715 	 * anything we ever want to print.
716 	 */
717 	i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args);
718 
719 	/* Print the string */
720 	puts(printbuffer);
721 	return i;
722 }
723 
724 
725 void __assert_fail(const char *assertion, const char *file, unsigned line,
726 		   const char *function)
727 {
728 	/* This will not return */
729 	panic("%s:%u: %s: Assertion `%s' failed.", file, line, function,
730 	      assertion);
731 }
732 
733 char *simple_itoa(ulong i)
734 {
735 	/* 21 digits plus null terminator, good for 64-bit or smaller ints */
736 	static char local[22];
737 	char *p = &local[21];
738 
739 	*p-- = '\0';
740 	do {
741 		*p-- = '0' + i % 10;
742 		i /= 10;
743 	} while (i > 0);
744 	return p + 1;
745 }
746 
747 /* We don't seem to have %'d in U-Boot */
748 void print_grouped_ull(unsigned long long int_val, int digits)
749 {
750 	char str[21], *s;
751 	int grab = 3;
752 
753 	digits = (digits + 2) / 3;
754 	sprintf(str, "%*llu", digits * 3, int_val);
755 	for (s = str; *s; s += grab) {
756 		if (s != str)
757 			putc(s[-1] != ' ' ? ',' : ' ');
758 		printf("%.*s", grab, s);
759 		grab = 3;
760 	}
761 }
762 
763 bool str2off(const char *p, loff_t *num)
764 {
765 	char *endptr;
766 
767 	*num = simple_strtoull(p, &endptr, 16);
768 	return *p != '\0' && *endptr == '\0';
769 }
770 
771 bool str2long(const char *p, ulong *num)
772 {
773 	char *endptr;
774 
775 	*num = simple_strtoul(p, &endptr, 16);
776 	return *p != '\0' && *endptr == '\0';
777 }
778