xref: /openbmc/u-boot/lib/vsprintf.c (revision ccf7988b)
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 #include <errno.h>
19 
20 #include <common.h>
21 #if !defined (CONFIG_PANIC_HANG)
22 #include <command.h>
23 #endif
24 
25 #include <div64.h>
26 # define NUM_TYPE long long
27 #define noinline __attribute__((noinline))
28 
29 const char hex_asc[] = "0123456789abcdef";
30 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
31 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
32 
33 static inline char *pack_hex_byte(char *buf, u8 byte)
34 {
35 	*buf++ = hex_asc_hi(byte);
36 	*buf++ = hex_asc_lo(byte);
37 	return buf;
38 }
39 
40 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
41 {
42 	unsigned long result = 0,value;
43 
44 	if (*cp == '0') {
45 		cp++;
46 		if ((*cp == 'x') && isxdigit(cp[1])) {
47 			base = 16;
48 			cp++;
49 		}
50 		if (!base) {
51 			base = 8;
52 		}
53 	}
54 	if (!base) {
55 		base = 10;
56 	}
57 	while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
58 	    ? toupper(*cp) : *cp)-'A'+10) < base) {
59 		result = result*base + value;
60 		cp++;
61 	}
62 	if (endp)
63 		*endp = (char *)cp;
64 	return result;
65 }
66 
67 /**
68  * strict_strtoul - convert a string to an unsigned long strictly
69  * @cp: The string to be converted
70  * @base: The number base to use
71  * @res: The converted result value
72  *
73  * strict_strtoul converts a string to an unsigned long only if the
74  * string is really an unsigned long string, any string containing
75  * any invalid char at the tail will be rejected and -EINVAL is returned,
76  * only a newline char at the tail is acceptible because people generally
77  * change a module parameter in the following way:
78  *
79  *      echo 1024 > /sys/module/e1000/parameters/copybreak
80  *
81  * echo will append a newline to the tail.
82  *
83  * It returns 0 if conversion is successful and *res is set to the converted
84  * value, otherwise it returns -EINVAL and *res is set to 0.
85  *
86  * simple_strtoul just ignores the successive invalid characters and
87  * return the converted value of prefix part of the string.
88  *
89  * Copied this function from Linux 2.6.38 commit ID:
90  * 521cb40b0c44418a4fd36dc633f575813d59a43d
91  *
92  */
93 int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
94 {
95 	char *tail;
96 	unsigned long val;
97 	size_t len;
98 
99 	*res = 0;
100 	len = strlen(cp);
101 	if (len == 0)
102 		return -EINVAL;
103 
104 	val = simple_strtoul(cp, &tail, base);
105 	if (tail == cp)
106 		return -EINVAL;
107 
108 	if ((*tail == '\0') ||
109 		((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
110 		*res = val;
111 		return 0;
112 	}
113 
114 	return -EINVAL;
115 }
116 
117 long simple_strtol(const char *cp,char **endp,unsigned int base)
118 {
119 	if(*cp=='-')
120 		return -simple_strtoul(cp+1,endp,base);
121 	return simple_strtoul(cp,endp,base);
122 }
123 
124 int ustrtoul(const char *cp, char **endp, unsigned int base)
125 {
126 	unsigned long result = simple_strtoul(cp, endp, base);
127 	switch (**endp) {
128 	case 'G' :
129 		result *= 1024;
130 		/* fall through */
131 	case 'M':
132 		result *= 1024;
133 		/* fall through */
134 	case 'K':
135 	case 'k':
136 		result *= 1024;
137 		if ((*endp)[1] == 'i') {
138 			if ((*endp)[2] == 'B')
139 				(*endp) += 3;
140 			else
141 				(*endp) += 2;
142 		}
143 	}
144 	return result;
145 }
146 
147 unsigned long long simple_strtoull (const char *cp, char **endp, unsigned int base)
148 {
149 	unsigned long long result = 0, value;
150 
151 	if (*cp == '0') {
152 		cp++;
153 		if ((*cp == 'x') && isxdigit (cp[1])) {
154 			base = 16;
155 			cp++;
156 		}
157 		if (!base) {
158 			base = 8;
159 		}
160 	}
161 	if (!base) {
162 		base = 10;
163 	}
164 	while (isxdigit (*cp) && (value = isdigit (*cp)
165 				? *cp - '0'
166 				: (islower (*cp) ? toupper (*cp) : *cp) - 'A' + 10) < base) {
167 		result = result * base + value;
168 		cp++;
169 	}
170 	if (endp)
171 		*endp = (char *) cp;
172 	return result;
173 }
174 
175 /* we use this so that we can do without the ctype library */
176 #define is_digit(c)	((c) >= '0' && (c) <= '9')
177 
178 static int skip_atoi(const char **s)
179 {
180 	int i=0;
181 
182 	while (is_digit(**s))
183 		i = i*10 + *((*s)++) - '0';
184 	return i;
185 }
186 
187 /* Decimal conversion is by far the most typical, and is used
188  * for /proc and /sys data. This directly impacts e.g. top performance
189  * with many processes running. We optimize it for speed
190  * using code from
191  * http://www.cs.uiowa.edu/~jones/bcd/decimal.html
192  * (with permission from the author, Douglas W. Jones). */
193 
194 /* Formats correctly any integer in [0,99999].
195  * Outputs from one to five digits depending on input.
196  * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
197 static char* put_dec_trunc(char *buf, unsigned q)
198 {
199 	unsigned d3, d2, d1, d0;
200 	d1 = (q>>4) & 0xf;
201 	d2 = (q>>8) & 0xf;
202 	d3 = (q>>12);
203 
204 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
205 	q = (d0 * 0xcd) >> 11;
206 	d0 = d0 - 10*q;
207 	*buf++ = d0 + '0'; /* least significant digit */
208 	d1 = q + 9*d3 + 5*d2 + d1;
209 	if (d1 != 0) {
210 		q = (d1 * 0xcd) >> 11;
211 		d1 = d1 - 10*q;
212 		*buf++ = d1 + '0'; /* next digit */
213 
214 		d2 = q + 2*d2;
215 		if ((d2 != 0) || (d3 != 0)) {
216 			q = (d2 * 0xd) >> 7;
217 			d2 = d2 - 10*q;
218 			*buf++ = d2 + '0'; /* next digit */
219 
220 			d3 = q + 4*d3;
221 			if (d3 != 0) {
222 				q = (d3 * 0xcd) >> 11;
223 				d3 = d3 - 10*q;
224 				*buf++ = d3 + '0';  /* next digit */
225 				if (q != 0)
226 					*buf++ = q + '0';  /* most sign. digit */
227 			}
228 		}
229 	}
230 	return buf;
231 }
232 /* Same with if's removed. Always emits five digits */
233 static char* put_dec_full(char *buf, unsigned q)
234 {
235 	/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
236 	/* but anyway, gcc produces better code with full-sized ints */
237 	unsigned d3, d2, d1, d0;
238 	d1 = (q>>4) & 0xf;
239 	d2 = (q>>8) & 0xf;
240 	d3 = (q>>12);
241 
242 	/*
243 	 * Possible ways to approx. divide by 10
244 	 * gcc -O2 replaces multiply with shifts and adds
245 	 * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
246 	 * (x * 0x67) >> 10:  1100111
247 	 * (x * 0x34) >> 9:    110100 - same
248 	 * (x * 0x1a) >> 8:     11010 - same
249 	 * (x * 0x0d) >> 7:      1101 - same, shortest code (on i386)
250 	 */
251 
252 	d0 = 6*(d3 + d2 + d1) + (q & 0xf);
253 	q = (d0 * 0xcd) >> 11;
254 	d0 = d0 - 10*q;
255 	*buf++ = d0 + '0';
256 	d1 = q + 9*d3 + 5*d2 + d1;
257 		q = (d1 * 0xcd) >> 11;
258 		d1 = d1 - 10*q;
259 		*buf++ = d1 + '0';
260 
261 		d2 = q + 2*d2;
262 			q = (d2 * 0xd) >> 7;
263 			d2 = d2 - 10*q;
264 			*buf++ = d2 + '0';
265 
266 			d3 = q + 4*d3;
267 				q = (d3 * 0xcd) >> 11; /* - shorter code */
268 				/* q = (d3 * 0x67) >> 10; - would also work */
269 				d3 = d3 - 10*q;
270 				*buf++ = d3 + '0';
271 					*buf++ = q + '0';
272 	return buf;
273 }
274 /* No inlining helps gcc to use registers better */
275 static noinline char* put_dec(char *buf, unsigned NUM_TYPE num)
276 {
277 	while (1) {
278 		unsigned rem;
279 		if (num < 100000)
280 			return put_dec_trunc(buf, num);
281 		rem = do_div(num, 100000);
282 		buf = put_dec_full(buf, rem);
283 	}
284 }
285 
286 #define ZEROPAD	1		/* pad with zero */
287 #define SIGN	2		/* unsigned/signed long */
288 #define PLUS	4		/* show plus */
289 #define SPACE	8		/* space if plus */
290 #define LEFT	16		/* left justified */
291 #define SMALL	32		/* Must be 32 == 0x20 */
292 #define SPECIAL	64		/* 0x */
293 
294 static char *number(char *buf, unsigned NUM_TYPE num, int base, int size, int precision, int type)
295 {
296 	/* we are called with base 8, 10 or 16, only, thus don't need "G..."  */
297 	static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
298 
299 	char tmp[66];
300 	char sign;
301 	char locase;
302 	int need_pfx = ((type & SPECIAL) && base != 10);
303 	int i;
304 
305 	/* locase = 0 or 0x20. ORing digits or letters with 'locase'
306 	 * produces same digits or (maybe lowercased) letters */
307 	locase = (type & SMALL);
308 	if (type & LEFT)
309 		type &= ~ZEROPAD;
310 	sign = 0;
311 	if (type & SIGN) {
312 		if ((signed NUM_TYPE) num < 0) {
313 			sign = '-';
314 			num = - (signed NUM_TYPE) num;
315 			size--;
316 		} else if (type & PLUS) {
317 			sign = '+';
318 			size--;
319 		} else if (type & SPACE) {
320 			sign = ' ';
321 			size--;
322 		}
323 	}
324 	if (need_pfx) {
325 		size--;
326 		if (base == 16)
327 			size--;
328 	}
329 
330 	/* generate full string in tmp[], in reverse order */
331 	i = 0;
332 	if (num == 0)
333 		tmp[i++] = '0';
334 	/* Generic code, for any base:
335 	else do {
336 		tmp[i++] = (digits[do_div(num,base)] | locase);
337 	} while (num != 0);
338 	*/
339 	else if (base != 10) { /* 8 or 16 */
340 		int mask = base - 1;
341 		int shift = 3;
342 		if (base == 16) shift = 4;
343 		do {
344 			tmp[i++] = (digits[((unsigned char)num) & mask] | locase);
345 			num >>= shift;
346 		} while (num);
347 	} else { /* base 10 */
348 		i = put_dec(tmp, num) - tmp;
349 	}
350 
351 	/* printing 100 using %2d gives "100", not "00" */
352 	if (i > precision)
353 		precision = i;
354 	/* leading space padding */
355 	size -= precision;
356 	if (!(type & (ZEROPAD+LEFT)))
357 		while(--size >= 0)
358 			*buf++ = ' ';
359 	/* sign */
360 	if (sign)
361 		*buf++ = sign;
362 	/* "0x" / "0" prefix */
363 	if (need_pfx) {
364 		*buf++ = '0';
365 		if (base == 16)
366 			*buf++ = ('X' | locase);
367 	}
368 	/* zero or space padding */
369 	if (!(type & LEFT)) {
370 		char c = (type & ZEROPAD) ? '0' : ' ';
371 		while (--size >= 0)
372 			*buf++ = c;
373 	}
374 	/* hmm even more zero padding? */
375 	while (i <= --precision)
376 		*buf++ = '0';
377 	/* actual digits of result */
378 	while (--i >= 0)
379 		*buf++ = tmp[i];
380 	/* trailing space padding */
381 	while (--size >= 0)
382 		*buf++ = ' ';
383 	return buf;
384 }
385 
386 static char *string(char *buf, char *s, int field_width, int precision, int flags)
387 {
388 	int len, i;
389 
390 	if (s == 0)
391 		s = "<NULL>";
392 
393 	len = strnlen(s, precision);
394 
395 	if (!(flags & LEFT))
396 		while (len < field_width--)
397 			*buf++ = ' ';
398 	for (i = 0; i < len; ++i)
399 		*buf++ = *s++;
400 	while (len < field_width--)
401 		*buf++ = ' ';
402 	return buf;
403 }
404 
405 #ifdef CONFIG_CMD_NET
406 static char *mac_address_string(char *buf, u8 *addr, int field_width,
407 				int precision, int flags)
408 {
409 	char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */
410 	char *p = mac_addr;
411 	int i;
412 
413 	for (i = 0; i < 6; i++) {
414 		p = pack_hex_byte(p, addr[i]);
415 		if (!(flags & SPECIAL) && i != 5)
416 			*p++ = ':';
417 	}
418 	*p = '\0';
419 
420 	return string(buf, mac_addr, field_width, precision, flags & ~SPECIAL);
421 }
422 
423 static char *ip6_addr_string(char *buf, u8 *addr, int field_width,
424 			 int precision, int flags)
425 {
426 	char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */
427 	char *p = ip6_addr;
428 	int i;
429 
430 	for (i = 0; i < 8; i++) {
431 		p = pack_hex_byte(p, addr[2 * i]);
432 		p = pack_hex_byte(p, addr[2 * i + 1]);
433 		if (!(flags & SPECIAL) && i != 7)
434 			*p++ = ':';
435 	}
436 	*p = '\0';
437 
438 	return string(buf, ip6_addr, field_width, precision, flags & ~SPECIAL);
439 }
440 
441 static char *ip4_addr_string(char *buf, u8 *addr, int field_width,
442 			 int precision, int flags)
443 {
444 	char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */
445 	char temp[3];	/* hold each IP quad in reverse order */
446 	char *p = ip4_addr;
447 	int i, digits;
448 
449 	for (i = 0; i < 4; i++) {
450 		digits = put_dec_trunc(temp, addr[i]) - temp;
451 		/* reverse the digits in the quad */
452 		while (digits--)
453 			*p++ = temp[digits];
454 		if (i != 3)
455 			*p++ = '.';
456 	}
457 	*p = '\0';
458 
459 	return string(buf, ip4_addr, field_width, precision, flags & ~SPECIAL);
460 }
461 #endif
462 
463 /*
464  * Show a '%p' thing.  A kernel extension is that the '%p' is followed
465  * by an extra set of alphanumeric characters that are extended format
466  * specifiers.
467  *
468  * Right now we handle:
469  *
470  * - 'M' For a 6-byte MAC address, it prints the address in the
471  *       usual colon-separated hex notation
472  * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated
473  *       decimal for v4 and colon separated network-order 16 bit hex for v6)
474  * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is
475  *       currently the same
476  *
477  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
478  * function pointers are really function descriptors, which contain a
479  * pointer to the real address.
480  */
481 static char *pointer(const char *fmt, char *buf, void *ptr, int field_width, int precision, int flags)
482 {
483 	if (!ptr)
484 		return string(buf, "(null)", field_width, precision, flags);
485 
486 #ifdef CONFIG_CMD_NET
487 	switch (*fmt) {
488 	case 'm':
489 		flags |= SPECIAL;
490 		/* Fallthrough */
491 	case 'M':
492 		return mac_address_string(buf, ptr, field_width, precision, flags);
493 	case 'i':
494 		flags |= SPECIAL;
495 		/* Fallthrough */
496 	case 'I':
497 		if (fmt[1] == '6')
498 			return ip6_addr_string(buf, ptr, field_width, precision, flags);
499 		if (fmt[1] == '4')
500 			return ip4_addr_string(buf, ptr, field_width, precision, flags);
501 		flags &= ~SPECIAL;
502 		break;
503 	}
504 #endif
505 	flags |= SMALL;
506 	if (field_width == -1) {
507 		field_width = 2*sizeof(void *);
508 		flags |= ZEROPAD;
509 	}
510 	return number(buf, (unsigned long) ptr, 16, field_width, precision, flags);
511 }
512 
513 /**
514  * vsprintf - Format a string and place it in a buffer
515  * @buf: The buffer to place the result into
516  * @fmt: The format string to use
517  * @args: Arguments for the format string
518  *
519  * This function follows C99 vsprintf, but has some extensions:
520  * %pS output the name of a text symbol
521  * %pF output the name of a function pointer
522  * %pR output the address range in a struct resource
523  *
524  * The function returns the number of characters written
525  * into @buf.
526  *
527  * Call this function if you are already dealing with a va_list.
528  * You probably want sprintf() instead.
529  */
530 int vsprintf(char *buf, const char *fmt, va_list args)
531 {
532 	unsigned NUM_TYPE num;
533 	int base;
534 	char *str;
535 
536 	int flags;		/* flags to number() */
537 
538 	int field_width;	/* width of output field */
539 	int precision;		/* min. # of digits for integers; max
540 				   number of chars for from string */
541 	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
542 				/* 'z' support added 23/7/1999 S.H.    */
543 				/* 'z' changed to 'Z' --davidm 1/25/99 */
544 				/* 't' added for ptrdiff_t */
545 
546 	str = buf;
547 
548 	for (; *fmt ; ++fmt) {
549 		if (*fmt != '%') {
550 			*str++ = *fmt;
551 			continue;
552 		}
553 
554 		/* process flags */
555 		flags = 0;
556 		repeat:
557 			++fmt;		/* this also skips first '%' */
558 			switch (*fmt) {
559 				case '-': flags |= LEFT; goto repeat;
560 				case '+': flags |= PLUS; goto repeat;
561 				case ' ': flags |= SPACE; goto repeat;
562 				case '#': flags |= SPECIAL; goto repeat;
563 				case '0': flags |= ZEROPAD; goto repeat;
564 			}
565 
566 		/* get field width */
567 		field_width = -1;
568 		if (is_digit(*fmt))
569 			field_width = skip_atoi(&fmt);
570 		else if (*fmt == '*') {
571 			++fmt;
572 			/* it's the next argument */
573 			field_width = va_arg(args, int);
574 			if (field_width < 0) {
575 				field_width = -field_width;
576 				flags |= LEFT;
577 			}
578 		}
579 
580 		/* get the precision */
581 		precision = -1;
582 		if (*fmt == '.') {
583 			++fmt;
584 			if (is_digit(*fmt))
585 				precision = skip_atoi(&fmt);
586 			else if (*fmt == '*') {
587 				++fmt;
588 				/* it's the next argument */
589 				precision = va_arg(args, int);
590 			}
591 			if (precision < 0)
592 				precision = 0;
593 		}
594 
595 		/* get the conversion qualifier */
596 		qualifier = -1;
597 		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
598 		    *fmt == 'Z' || *fmt == 'z' || *fmt == 't') {
599 			qualifier = *fmt;
600 			++fmt;
601 			if (qualifier == 'l' && *fmt == 'l') {
602 				qualifier = 'L';
603 				++fmt;
604 			}
605 		}
606 
607 		/* default base */
608 		base = 10;
609 
610 		switch (*fmt) {
611 		case 'c':
612 			if (!(flags & LEFT))
613 				while (--field_width > 0)
614 					*str++ = ' ';
615 			*str++ = (unsigned char) va_arg(args, int);
616 			while (--field_width > 0)
617 				*str++ = ' ';
618 			continue;
619 
620 		case 's':
621 			str = string(str, va_arg(args, char *), field_width, precision, flags);
622 			continue;
623 
624 		case 'p':
625 			str = pointer(fmt+1, str,
626 					va_arg(args, void *),
627 					field_width, precision, flags);
628 			/* Skip all alphanumeric pointer suffixes */
629 			while (isalnum(fmt[1]))
630 				fmt++;
631 			continue;
632 
633 		case 'n':
634 			if (qualifier == 'l') {
635 				long * ip = va_arg(args, long *);
636 				*ip = (str - buf);
637 			} else {
638 				int * ip = va_arg(args, int *);
639 				*ip = (str - buf);
640 			}
641 			continue;
642 
643 		case '%':
644 			*str++ = '%';
645 			continue;
646 
647 		/* integer number formats - set up the flags and "break" */
648 		case 'o':
649 			base = 8;
650 			break;
651 
652 		case 'x':
653 			flags |= SMALL;
654 		case 'X':
655 			base = 16;
656 			break;
657 
658 		case 'd':
659 		case 'i':
660 			flags |= SIGN;
661 		case 'u':
662 			break;
663 
664 		default:
665 			*str++ = '%';
666 			if (*fmt)
667 				*str++ = *fmt;
668 			else
669 				--fmt;
670 			continue;
671 		}
672 		if (qualifier == 'L')  /* "quad" for 64 bit variables */
673 			num = va_arg(args, unsigned long long);
674 		else if (qualifier == 'l') {
675 			num = va_arg(args, unsigned long);
676 			if (flags & SIGN)
677 				num = (signed long) num;
678 		} else if (qualifier == 'Z' || qualifier == 'z') {
679 			num = va_arg(args, size_t);
680 		} else if (qualifier == 't') {
681 			num = va_arg(args, ptrdiff_t);
682 		} else if (qualifier == 'h') {
683 			num = (unsigned short) va_arg(args, int);
684 			if (flags & SIGN)
685 				num = (signed short) num;
686 		} else {
687 			num = va_arg(args, unsigned int);
688 			if (flags & SIGN)
689 				num = (signed int) num;
690 		}
691 		str = number(str, num, base, field_width, precision, flags);
692 	}
693 	*str = '\0';
694 	return str-buf;
695 }
696 
697 /**
698  * sprintf - Format a string and place it in a buffer
699  * @buf: The buffer to place the result into
700  * @fmt: The format string to use
701  * @...: Arguments for the format string
702  *
703  * The function returns the number of characters written
704  * into @buf.
705  *
706  * See the vsprintf() documentation for format string extensions over C99.
707  */
708 int sprintf(char * buf, const char *fmt, ...)
709 {
710 	va_list args;
711 	int i;
712 
713 	va_start(args, fmt);
714 	i=vsprintf(buf,fmt,args);
715 	va_end(args);
716 	return i;
717 }
718 
719 void panic(const char *fmt, ...)
720 {
721 	va_list	args;
722 	va_start(args, fmt);
723 	vprintf(fmt, args);
724 	putc('\n');
725 	va_end(args);
726 #if defined (CONFIG_PANIC_HANG)
727 	hang();
728 #else
729 	udelay (100000);	/* allow messages to go out */
730 	do_reset (NULL, 0, 0, NULL);
731 #endif
732 	while (1)
733 		;
734 }
735 
736 void __assert_fail(const char *assertion, const char *file, unsigned line,
737 		   const char *function)
738 {
739 	/* This will not return */
740 	panic("%s:%u: %s: Assertion `%s' failed.", file, line, function,
741 	      assertion);
742 }
743 
744 char *simple_itoa(ulong i)
745 {
746 	/* 21 digits plus null terminator, good for 64-bit or smaller ints */
747 	static char local[22];
748 	char *p = &local[21];
749 
750 	*p-- = '\0';
751 	do {
752 		*p-- = '0' + i % 10;
753 		i /= 10;
754 	} while (i > 0);
755 	return p + 1;
756 }
757