sdk/lib/stdio/printf.c - 3p/cheriot-rtos - Git at Google

 /*-
  * Copyright (c) 1986, 1988, 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
  * (c) UNIX System Laboratories, Inc.
  * All or some portions of this file are derived from material licensed
  * to the University of California by American Telephone and Telegraph
  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  * the permission of UNIX System Laboratories, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
  */

 /* __FBSDID("$FreeBSD: stable/8/sys/kern/subr_prf.c 210305 2010-07-20 18:55:13Z
  * jkim $"); */

 #include <cdefs.h>
 #include <cheri-builtins.h>
 #include <compartment.h>
 #include <inttypes.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>

 /*
  * Definitions snarfed from various parts of the FreeBSD headers:
  */
 #define toupper(c) ((c)-0x20 * (((c) >= 'a') && ((c) <= 'z')))

 static char hex2ascii(uintmax_t in)
 {
 	return (in < 10) ? '0' + in : 'a' + in - 10;
 }

 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
 #define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1)

 struct snprintf_arg
 {
 	char * str;
 	size_t remain;
 };

 static void snprintf_func(int ch, void *arg)
 {
 	struct snprintf_arg *const info = arg;

 	if (info->remain >= 2)
 	{
 		*info->str++ = ch;
 		info->remain--;
 	}
 }

 /*
  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
  * order; return an optional length and a pointer to the last character
  * written in the buffer (i.e., the first character of the string).
  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
  */
 // FIXME: Using `unsigned` for `num` instead of `uintmax_t` means that we are
 // going to truncate large numbers, but it avoids needing a library routine to
 // handle division.
 static char *ksprintn(char *nbuf, unsigned num, int base, int *lenp, int upper)
 {
 	char *p, c;

 	p  = nbuf;
 	*p = '\0';
 	do
 	{
 		c    = hex2ascii(num % base);
 		*++p = upper ? toupper(c) : c;
 	} while (num /= base);
 	if (lenp)
 		*lenp = p - nbuf;
 	return (p);
 }

 /*
  * Scaled down version of printf(3).
  *
  * Two additional formats:
  *
  * The format %b is supported to decode error registers.
  * Its usage is:
  *
  *	printf("reg=%b\n", regval, "<base><arg>*");
  *
  * where <base> is the output base expressed as a control character, e.g.
  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
  * the first of which gives the bit number to be inspected (origin 1), and
  * the next characters (up to a control character, i.e. a character <= 32),
  * give the name of the register.  Thus:
  *
  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
  *
  * would produce output:
  *
  *	reg=3<BITTWO,BITONE>
  *
  * %D  -- Hexdump, takes pointer and separator string:
  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
  *		("%*D", len, ptr, " " -> XX XX XX XX ...
  */
 static int kvprintf(char const *fmt,
                     void (*func)(int, void *),
                     void *  arg,
                     int     radix,
                     va_list ap)
 {
 #define PCHAR(c)                                                               \
 	{                                                                          \
 		int cc = (c);                                                          \
 		if (func)                                                              \
 			(*func)(cc, arg);                                                  \
 		else                                                                   \
 			*d++ = cc;                                                         \
 		retval++;                                                              \
 	}
 	char           nbuf[MAXNBUF];
 	char *         d;
 	const char *   p, *percent, *q;
 	unsigned char *up;
 	int            ch, n;
 	uintmax_t      num;
 	int  base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
 	int  cflag, hflag, jflag, tflag, zflag;
 	int  dwidth, upper;
 	char padc;
 	int  stop = 0, retval = 0;
 	char null_str[1] = {'\0'};

 	num = 0;
 	if (!func)
 		d = (char *)arg;
 	else
 		d = NULL;

 	if (fmt == NULL)
 		fmt = null_str;

 	if (radix < 2 || radix > 36)
 		radix = 10;

 	for (;;)
 	{
 		padc  = ' ';
 		width = 0;
 		while ((ch = (unsigned char)*fmt++) != '%' || stop)
 		{
 			if (ch == '\0')
 				return (retval);
 			PCHAR(ch);
 		}
 		percent   = fmt - 1;
 		qflag     = 0;
 		lflag     = 0;
 		ladjust   = 0;
 		sharpflag = 0;
 		neg       = 0;
 		sign      = 0;
 		dot       = 0;
 		dwidth    = 0;
 		upper     = 0;
 		cflag     = 0;
 		hflag     = 0;
 		jflag     = 0;
 		tflag     = 0;
 		zflag     = 0;
 	reswitch:
 		switch (ch = (unsigned char)*fmt++)
 		{
 			case '.':
 				dot = 1;
 				goto reswitch;
 			case '#':
 				sharpflag = 1;
 				goto reswitch;
 			case '+':
 				sign = 1;
 				goto reswitch;
 			case '-':
 				ladjust = 1;
 				goto reswitch;
 			case '%':
 				PCHAR(ch);
 				break;
 			case '*':
 				if (!dot)
 				{
 					width = va_arg(ap, int);
 					if (width < 0)
 					{
 						ladjust = !ladjust;
 						width   = -width;
 					}
 				}
 				else
 				{
 					dwidth = va_arg(ap, int);
 				}
 				goto reswitch;
 			case '0':
 				if (!dot)
 				{
 					padc = '0';
 					goto reswitch;
 				}
 			case '1':
 			case '2':
 			case '3':
 			case '4':
 			case '5':
 			case '6':
 			case '7':
 			case '8':
 			case '9':
 				for (n = 0;; ++fmt)
 				{
 					n  = n * 10 + ch - '0';
 					ch = *fmt;
 					if (ch < '0' || ch > '9')
 						break;
 				}
 				if (dot)
 					dwidth = n;
 				else
 					width = n;
 				goto reswitch;
 			case 'b':
 				num = (unsigned int)va_arg(ap, int);
 				p   = va_arg(ap, char *);
 				for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
 					PCHAR(*q--);

 				if (num == 0)
 					break;

 				for (tmp = 0; *p;)
 				{
 					n = *p++;
 					if (num & (1 << (n - 1)))
 					{
 						PCHAR(tmp ? ',' : '<');
 						for (; (n = *p) > ' '; ++p)
 							PCHAR(n);
 						tmp = 1;
 					}
 					else
 						for (; *p > ' '; ++p)
 							continue;
 				}
 				if (tmp)
 					PCHAR('>');
 				break;
 			case 'c':
 				PCHAR(va_arg(ap, int));
 				break;
 			case 'D':
 				up = va_arg(ap, unsigned char *);
 				p  = va_arg(ap, char *);
 				if (!width)
 					width = 16;
 				while (width--)
 				{
 					PCHAR(hex2ascii(*up >> 4));
 					PCHAR(hex2ascii(*up & 0x0f));
 					up++;
 					if (width)
 						for (q = p; *q; q++)
 							PCHAR(*q);
 				}
 				break;
 			case 'd':
 			case 'i':
 				base = 10;
 				sign = 1;
 				goto handle_sign;
 			case 'h':
 				if (hflag)
 				{
 					hflag = 0;
 					cflag = 1;
 				}
 				else
 					hflag = 1;
 				goto reswitch;
 			case 'j':
 				jflag = 1;
 				goto reswitch;
 			case 'l':
 				if (lflag)
 				{
 					lflag = 0;
 					qflag = 1;
 				}
 				else
 					lflag = 1;
 				goto reswitch;
 			case 'n':
 				if (jflag)
 					*(va_arg(ap, intmax_t *)) = retval;
 				else if (qflag)
 					*(va_arg(ap, long long *)) = retval;
 				else if (lflag)
 					*(va_arg(ap, long *)) = retval;
 				else if (zflag)
 					*(va_arg(ap, size_t *)) = retval;
 				else if (hflag)
 					*(va_arg(ap, short *)) = retval;
 				else if (cflag)
 					*(va_arg(ap, char *)) = retval;
 				else
 					*(va_arg(ap, int *)) = retval;
 				break;
 			case 'o':
 				base = 8;
 				goto handle_nosign;
 			case 'p':
 				base      = 16;
 				sharpflag = (width == 0);
 				sign      = 0;
 				num       = (size_t)va_arg(ap, void *);
 				goto number;
 			case 'q':
 				qflag = 1;
 				goto reswitch;
 			case 'r':
 				base = radix;
 				if (sign)
 					goto handle_sign;
 				goto handle_nosign;
 			case 's':
 				p = va_arg(ap, char *);
 				if (p == NULL)
 					p = null_str;
 				if (!dot)
 					n = strlen(p);
 				else
 					for (n = 0; n < dwidth && p[n]; n++)
 						continue;

 				width -= n;

 				if (!ladjust && width > 0)
 					while (width--)
 						PCHAR(padc);
 				while (n--)
 					PCHAR(*p++);
 				if (ladjust && width > 0)
 					while (width--)
 						PCHAR(padc);
 				break;
 			case 't':
 				tflag = 1;
 				goto reswitch;
 			case 'u':
 				base = 10;
 				goto handle_nosign;
 			case 'X':
 				upper = 1;
 			case 'x':
 				base = 16;
 				goto handle_nosign;
 			case 'y':
 				base = 16;
 				sign = 1;
 				goto handle_sign;
 			case 'z':
 				zflag = 1;
 				goto reswitch;
 			handle_nosign:
 				sign = 0;
 				if (jflag)
 					num = va_arg(ap, uintmax_t);
 				else if (qflag)
 					num = va_arg(ap, unsigned long long);
 				else if (tflag)
 					num = va_arg(ap, ptrdiff_t);
 				else if (lflag)
 					num = va_arg(ap, unsigned long);
 				else if (zflag)
 					num = va_arg(ap, size_t);
 				else if (hflag)
 					num = (unsigned short)va_arg(ap, int);
 				else if (cflag)
 					num = (unsigned char)va_arg(ap, int);
 				else
 					num = va_arg(ap, unsigned int);
 				goto number;
 			handle_sign:
 				if (jflag)
 					num = va_arg(ap, intmax_t);
 				else if (qflag)
 					num = va_arg(ap, long long);
 				else if (tflag)
 					num = va_arg(ap, ptrdiff_t);
 				else if (lflag)
 					num = va_arg(ap, long);
 				else if (zflag)
 					num = va_arg(ap, ssize_t);
 				else if (hflag)
 					num = (short)va_arg(ap, int);
 				else if (cflag)
 					num = (char)va_arg(ap, int);
 				else
 					num = va_arg(ap, int);
 			number:
 				if (sign && (intmax_t)num < 0)
 				{
 					neg = 1;
 					num = -(intmax_t)num;
 				}
 				p   = ksprintn(nbuf, num, base, &n, upper);
 				tmp = 0;
 				if (sharpflag && num != 0)
 				{
 					if (base == 8)
 						tmp++;
 					else if (base == 16)
 						tmp += 2;
 				}
 				if (neg)
 					tmp++;

 				if (!ladjust && padc == '0')
 					dwidth = width - tmp;
 				width -= tmp + (dwidth > n ? dwidth : n);
 				dwidth -= n;
 				if (!ladjust)
 					while (width-- > 0)
 						PCHAR(' ');
 				if (neg)
 					PCHAR('-');
 				if (sharpflag && num != 0)
 				{
 					if (base == 8)
 					{
 						PCHAR('0');
 					}
 					else if (base == 16)
 					{
 						PCHAR('0');
 						PCHAR('x');
 					}
 				}
 				while (dwidth-- > 0)
 					PCHAR('0');

 				while (*p)
 					PCHAR(*p--);

 				if (ladjust)
 					while (width-- > 0)
 						PCHAR(' ');

 				break;
 			default:
 				while (percent < fmt)
 					PCHAR(*percent++);
 				/*
 				 * Since we ignore an formatting argument it is no
 				 * longer safe to obey the remaining formatting
 				 * arguments as the arguments will no longer match
 				 * the format specs.
 				 */
 				stop = 1;
 				break;
 		}
 	}
 #undef PCHAR
 }

 /*
  * Scaled down version of vsnprintf(3).
  */
 int __cheri_libcall vsnprintf(char *str, size_t size, const char *format, va_list ap)
 {
 	struct snprintf_arg info;
 	int                 retval;

 	info.str    = str;
 	info.remain = size;
 	retval      = kvprintf(format, snprintf_func, &info, 10, ap);
 	if (info.remain >= 1)
 		*info.str++ = '\0';
 	return (retval);
 }

 #define UART_REG_QUEUE 0
 #define UART_REG_LINESTAT (5)
 #define UART_REG_STATUS_RX (0x01)
 #define UART_REG_STATUS_TX (0x20)


 [[cheri::interrupt_state(disabled)]]
 static void uart16550_txbuffer(const char *ptr)
 {
 	long               flags;
 	volatile uint32_t *uart16550 = MMIO_CAPABILITY(uint32_t, uart);

 	for (int i = 0; i < PRT_MAX_SIZE && ptr[i]; i++)
 	{
 		while ((uart16550[UART_REG_LINESTAT] & UART_REG_STATUS_TX) == 0) {}

 		uart16550[UART_REG_QUEUE] = ptr[i];
 	}
 }

 int __cheri_libcall printf(const char *format, ...)
 {
 	char    buf[PRT_MAX_SIZE];
 	int     rv;
 	va_list ap;

 	va_start(ap, format);
 	rv = vsnprintf(buf, PRT_MAX_SIZE, format, ap);
 	va_end(ap);
 	uart16550_txbuffer(buf);

 	return rv;
 }

 int __cheri_libcall snprintf(char *str, size_t size, const char *format, ...)
 {
 	int     rv;
 	va_list ap;

 	va_start(ap, format);
 	rv = vsnprintf(str, size, format, ap);
 	va_end(ap);

 	return rv;
 }
	/*-
	* Copyright (c) 1986, 1988, 1991, 1993
	* The Regents of the University of California. All rights reserved.
	* (c) UNIX System Laboratories, Inc.
	* All or some portions of this file are derived from material licensed
	* to the University of California by American Telephone and Telegraph
	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	* the permission of UNIX System Laboratories, Inc.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 4. Neither the name of the University nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*
	* @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
	*/

	/* __FBSDID("$FreeBSD: stable/8/sys/kern/subr_prf.c 210305 2010-07-20 18:55:13Z
	* jkim $"); */

	#include <cdefs.h>
	#include <cheri-builtins.h>
	#include <compartment.h>
	#include <inttypes.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <string.h>

	/*
	* Definitions snarfed from various parts of the FreeBSD headers:
	*/
	#define toupper(c) ((c)-0x20 * (((c) >= 'a') && ((c) <= 'z')))

	static char hex2ascii(uintmax_t in)
	{
	return (in < 10) ? '0' + in : 'a' + in - 10;
	}

	/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
	#define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1)

	struct snprintf_arg
	{
	char * str;
	size_t remain;
	};

	static void snprintf_func(int ch, void *arg)
	{
	struct snprintf_arg *const info = arg;

	if (info->remain >= 2)
	{
	*info->str++ = ch;
	info->remain--;
	}
	}

	/*
	* Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
	* order; return an optional length and a pointer to the last character
	* written in the buffer (i.e., the first character of the string).
	* The buffer pointed to by `nbuf' must have length >= MAXNBUF.
	*/
	// FIXME: Using `unsigned` for `num` instead of `uintmax_t` means that we are
	// going to truncate large numbers, but it avoids needing a library routine to
	// handle division.
	static char ksprintn(char nbuf, unsigned num, int base, int *lenp, int upper)
	{
	char *p, c;

	p = nbuf;
	*p = '\0';
	do
	{
	c = hex2ascii(num % base);
	*++p = upper ? toupper(c) : c;
	} while (num /= base);
	if (lenp)
	*lenp = p - nbuf;
	return (p);
	}

	/*
	* Scaled down version of printf(3).
	*
	* Two additional formats:
	*
	* The format %b is supported to decode error registers.
	* Its usage is:
	*
	* printf("reg=%b\n", regval, "<base><arg>*");
	*
	* where <base> is the output base expressed as a control character, e.g.
	* \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
	* the first of which gives the bit number to be inspected (origin 1), and
	* the next characters (up to a control character, i.e. a character <= 32),
	* give the name of the register. Thus:
	*
	* kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
	*
	* would produce output:
	*
	* reg=3<BITTWO,BITONE>
	*
	* %D -- Hexdump, takes pointer and separator string:
	* ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX
	* ("%*D", len, ptr, " " -> XX XX XX XX ...
	*/
	static int kvprintf(char const *fmt,
	void (func)(int, void ),
	void * arg,
	int radix,
	va_list ap)
	{
	#define PCHAR(c) \
	{ \
	int cc = (c); \
	if (func) \
	(*func)(cc, arg); \
	else \
	*d++ = cc; \
	retval++; \
	}
	char nbuf[MAXNBUF];
	char * d;
	const char * p, percent, q;
	unsigned char *up;
	int ch, n;
	uintmax_t num;
	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
	int cflag, hflag, jflag, tflag, zflag;
	int dwidth, upper;
	char padc;
	int stop = 0, retval = 0;
	char null_str[1] = {'\0'};

	num = 0;
	if (!func)
	d = (char *)arg;
	else
	d = NULL;

	if (fmt == NULL)
	fmt = null_str;

	if (radix < 2 \|\| radix > 36)
	radix = 10;

	for (;;)
	{
	padc = ' ';
	width = 0;
	while ((ch = (unsigned char)*fmt++) != '%' \|\| stop)
	{
	if (ch == '\0')
	return (retval);
	PCHAR(ch);
	}
	percent = fmt - 1;
	qflag = 0;
	lflag = 0;
	ladjust = 0;
	sharpflag = 0;
	neg = 0;
	sign = 0;
	dot = 0;
	dwidth = 0;
	upper = 0;
	cflag = 0;
	hflag = 0;
	jflag = 0;
	tflag = 0;
	zflag = 0;
	reswitch:
	switch (ch = (unsigned char)*fmt++)
	{
	case '.':
	dot = 1;
	goto reswitch;
	case '#':
	sharpflag = 1;
	goto reswitch;
	case '+':
	sign = 1;
	goto reswitch;
	case '-':
	ladjust = 1;
	goto reswitch;
	case '%':
	PCHAR(ch);
	break;
	case '*':
	if (!dot)
	{
	width = va_arg(ap, int);
	if (width < 0)
	{
	ladjust = !ladjust;
	width = -width;
	}
	}
	else
	{
	dwidth = va_arg(ap, int);
	}
	goto reswitch;
	case '0':
	if (!dot)
	{
	padc = '0';
	goto reswitch;
	}
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	for (n = 0;; ++fmt)
	{
	n = n * 10 + ch - '0';
	ch = *fmt;
	if (ch < '0' \|\| ch > '9')
	break;
	}
	if (dot)
	dwidth = n;
	else
	width = n;
	goto reswitch;
	case 'b':
	num = (unsigned int)va_arg(ap, int);
	p = va_arg(ap, char *);
	for (q = ksprintn(nbuf, num, p++, NULL, 0); q;)
	PCHAR(*q--);

	if (num == 0)
	break;

	for (tmp = 0; *p;)
	{
	n = *p++;
	if (num & (1 << (n - 1)))
	{
	PCHAR(tmp ? ',' : '<');
	for (; (n = *p) > ' '; ++p)
	PCHAR(n);
	tmp = 1;
	}
	else
	for (; *p > ' '; ++p)
	continue;
	}
	if (tmp)
	PCHAR('>');
	break;
	case 'c':
	PCHAR(va_arg(ap, int));
	break;
	case 'D':
	up = va_arg(ap, unsigned char *);
	p = va_arg(ap, char *);
	if (!width)
	width = 16;
	while (width--)
	{
	PCHAR(hex2ascii(*up >> 4));
	PCHAR(hex2ascii(*up & 0x0f));
	up++;
	if (width)
	for (q = p; *q; q++)
	PCHAR(*q);
	}
	break;
	case 'd':
	case 'i':
	base = 10;
	sign = 1;
	goto handle_sign;
	case 'h':
	if (hflag)
	{
	hflag = 0;
	cflag = 1;
	}
	else
	hflag = 1;
	goto reswitch;
	case 'j':
	jflag = 1;
	goto reswitch;
	case 'l':
	if (lflag)
	{
	lflag = 0;
	qflag = 1;
	}
	else
	lflag = 1;
	goto reswitch;
	case 'n':
	if (jflag)
	(va_arg(ap, intmax_t )) = retval;
	else if (qflag)
	(va_arg(ap, long long )) = retval;
	else if (lflag)
	(va_arg(ap, long )) = retval;
	else if (zflag)
	(va_arg(ap, size_t )) = retval;
	else if (hflag)
	(va_arg(ap, short )) = retval;
	else if (cflag)
	(va_arg(ap, char )) = retval;
	else
	(va_arg(ap, int )) = retval;
	break;
	case 'o':
	base = 8;
	goto handle_nosign;
	case 'p':
	base = 16;
	sharpflag = (width == 0);
	sign = 0;
	num = (size_t)va_arg(ap, void *);
	goto number;
	case 'q':
	qflag = 1;
	goto reswitch;
	case 'r':
	base = radix;
	if (sign)
	goto handle_sign;
	goto handle_nosign;
	case 's':
	p = va_arg(ap, char *);
	if (p == NULL)
	p = null_str;
	if (!dot)
	n = strlen(p);
	else
	for (n = 0; n < dwidth && p[n]; n++)
	continue;

	width -= n;

	if (!ladjust && width > 0)
	while (width--)
	PCHAR(padc);
	while (n--)
	PCHAR(*p++);
	if (ladjust && width > 0)
	while (width--)
	PCHAR(padc);
	break;
	case 't':
	tflag = 1;
	goto reswitch;
	case 'u':
	base = 10;
	goto handle_nosign;
	case 'X':
	upper = 1;
	case 'x':
	base = 16;
	goto handle_nosign;
	case 'y':
	base = 16;
	sign = 1;
	goto handle_sign;
	case 'z':
	zflag = 1;
	goto reswitch;
	handle_nosign:
	sign = 0;
	if (jflag)
	num = va_arg(ap, uintmax_t);
	else if (qflag)
	num = va_arg(ap, unsigned long long);
	else if (tflag)
	num = va_arg(ap, ptrdiff_t);
	else if (lflag)
	num = va_arg(ap, unsigned long);
	else if (zflag)
	num = va_arg(ap, size_t);
	else if (hflag)
	num = (unsigned short)va_arg(ap, int);
	else if (cflag)
	num = (unsigned char)va_arg(ap, int);
	else
	num = va_arg(ap, unsigned int);
	goto number;
	handle_sign:
	if (jflag)
	num = va_arg(ap, intmax_t);
	else if (qflag)
	num = va_arg(ap, long long);
	else if (tflag)
	num = va_arg(ap, ptrdiff_t);
	else if (lflag)
	num = va_arg(ap, long);
	else if (zflag)
	num = va_arg(ap, ssize_t);
	else if (hflag)
	num = (short)va_arg(ap, int);
	else if (cflag)
	num = (char)va_arg(ap, int);
	else
	num = va_arg(ap, int);
	number:
	if (sign && (intmax_t)num < 0)
	{
	neg = 1;
	num = -(intmax_t)num;
	}
	p = ksprintn(nbuf, num, base, &n, upper);
	tmp = 0;
	if (sharpflag && num != 0)
	{
	if (base == 8)
	tmp++;
	else if (base == 16)
	tmp += 2;
	}
	if (neg)
	tmp++;

	if (!ladjust && padc == '0')
	dwidth = width - tmp;
	width -= tmp + (dwidth > n ? dwidth : n);
	dwidth -= n;
	if (!ladjust)
	while (width-- > 0)
	PCHAR(' ');
	if (neg)
	PCHAR('-');
	if (sharpflag && num != 0)
	{
	if (base == 8)
	{
	PCHAR('0');
	}
	else if (base == 16)
	{
	PCHAR('0');
	PCHAR('x');
	}
	}
	while (dwidth-- > 0)
	PCHAR('0');

	while (*p)
	PCHAR(*p--);

	if (ladjust)
	while (width-- > 0)
	PCHAR(' ');

	break;
	default:
	while (percent < fmt)
	PCHAR(*percent++);
	/*
	* Since we ignore an formatting argument it is no
	* longer safe to obey the remaining formatting
	* arguments as the arguments will no longer match
	* the format specs.
	*/
	stop = 1;
	break;
	}
	}
	#undef PCHAR
	}

	/*
	* Scaled down version of vsnprintf(3).
	*/
	int __cheri_libcall vsnprintf(char str, size_t size, const char format, va_list ap)
	{
	struct snprintf_arg info;
	int retval;

	info.str = str;
	info.remain = size;
	retval = kvprintf(format, snprintf_func, &info, 10, ap);
	if (info.remain >= 1)
	*info.str++ = '\0';
	return (retval);
	}

	#define UART_REG_QUEUE 0
	#define UART_REG_LINESTAT (5)
	#define UART_REG_STATUS_RX (0x01)
	#define UART_REG_STATUS_TX (0x20)


	[[cheri::interrupt_state(disabled)]]
	static void uart16550_txbuffer(const char *ptr)
	{
	long flags;
	volatile uint32_t *uart16550 = MMIO_CAPABILITY(uint32_t, uart);

	for (int i = 0; i < PRT_MAX_SIZE && ptr[i]; i++)
	{
	while ((uart16550[UART_REG_LINESTAT] & UART_REG_STATUS_TX) == 0) {}

	uart16550[UART_REG_QUEUE] = ptr[i];
	}
	}

	int __cheri_libcall printf(const char *format, ...)
	{
	char buf[PRT_MAX_SIZE];
	int rv;
	va_list ap;

	va_start(ap, format);
	rv = vsnprintf(buf, PRT_MAX_SIZE, format, ap);
	va_end(ap);
	uart16550_txbuffer(buf);

	return rv;
	}

	int __cheri_libcall snprintf(char str, size_t size, const char format, ...)
	{
	int rv;
	va_list ap;

	va_start(ap, format);
	rv = vsnprintf(str, size, format, ap);
	va_end(ap);

	return rv;
	}