Console-writing code for the new x86 setup code

/* -*- linux-c -*- ------------------------------------------------------- *

 *

 *   Copyright (C) 1991, 1992 Linus Torvalds

 *   Copyright 2007 rPath, Inc. - All Rights Reserved

 *

 *   This file is part of the Linux kernel, and is made available under

 *   the terms of the GNU General Public License version 2.

 *

 * ----------------------------------------------------------------------- */

/*

 * arch/i386/boot/printf.c

 *

 * Oh, it's a waste of space, but oh-so-yummy for debugging.  This

 * version of printf() does not include 64-bit support.  "Live with

 * it."

 *

 */

#include "boot.h"

static int skip_atoi(const char **s)

{

	int i = 0;

	while (isdigit(**s))

		i = i * 10 + *((*s)++) - '0';

	return i;

}

#define ZEROPAD	1		/* pad with zero */

#define SIGN	2		/* unsigned/signed long */

#define PLUS	4		/* show plus */

#define SPACE	8		/* space if plus */

#define LEFT	16		/* left justified */

#define SPECIAL	32		/* 0x */

#define LARGE	64		/* use 'ABCDEF' instead of 'abcdef' */

#define do_div(n,base) ({ \

int __res; \

__res = ((unsigned long) n) % (unsigned) base; \

n = ((unsigned long) n) / (unsigned) base; \

__res; })

static char *number(char *str, long num, int base, int size, int precision,

		    int type)

{

	char c, sign, tmp[66];

	const char *digits = "0123456789abcdefghijklmnopqrstuvwxyz";

	int i;

	if (type & LARGE)

		digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

	if (type & LEFT)

		type &= ~ZEROPAD;

	if (base < 2 || base > 36)

		return 0;

	c = (type & ZEROPAD) ? '0' : ' ';

	sign = 0;

	if (type & SIGN) {

		if (num < 0) {

			sign = '-';

			num = -num;

			size--;

		} else if (type & PLUS) {

			sign = '+';

			size--;

		} else if (type & SPACE) {

			sign = ' ';

			size--;

		}

	}

	if (type & SPECIAL) {

		if (base == 16)

			size -= 2;

		else if (base == 8)

			size--;

	}

	i = 0;

	if (num == 0)

		tmp[i++] = '0';

	else

		while (num != 0)

			tmp[i++] = digits[do_div(num, base)];

	if (i > precision)

		precision = i;

	size -= precision;

	if (!(type & (ZEROPAD + LEFT)))

		while (size-- > 0)

			*str++ = ' ';

	if (sign)

		*str++ = sign;

	if (type & SPECIAL) {

		if (base == 8)

			*str++ = '0';

		else if (base == 16) {

			*str++ = '0';

			*str++ = digits[33];

		}

	}

	if (!(type & LEFT))

		while (size-- > 0)

			*str++ = c;

	while (i < precision--)

		*str++ = '0';

	while (i-- > 0)

		*str++ = tmp[i];

	while (size-- > 0)

		*str++ = ' ';

	return str;

}

int vsprintf(char *buf, const char *fmt, va_list args)

{

	int len;

	unsigned long num;

	int i, base;

	char *str;

	const char *s;

	int flags;		/* flags to number() */

	int field_width;	/* width of output field */

	int precision;		/* min. # of digits for integers; max

				   number of chars for from string */

	int qualifier;		/* 'h', 'l', or 'L' for integer fields */

	for (str = buf; *fmt; ++fmt) {

		if (*fmt != '%') {

			*str++ = *fmt;

			continue;

		}

		/* process flags */

		flags = 0;

	      repeat:

		++fmt;		/* this also skips first '%' */

		switch (*fmt) {

		case '-':

			flags |= LEFT;

			goto repeat;

		case '+':

			flags |= PLUS;

			goto repeat;

		case ' ':

			flags |= SPACE;

			goto repeat;

		case '#':

			flags |= SPECIAL;

			goto repeat;

		case '0':

			flags |= ZEROPAD;

			goto repeat;

		}

		/* get field width */

		field_width = -1;

		if (isdigit(*fmt))

			field_width = skip_atoi(&fmt);

		else if (*fmt == '*') {

			++fmt;

			/* it's the next argument */

			field_width = va_arg(args, int);

			if (field_width < 0) {

				field_width = -field_width;

				flags |= LEFT;

			}

		}

		/* get the precision */

		precision = -1;

		if (*fmt == '.') {

			++fmt;

			if (isdigit(*fmt))

				precision = skip_atoi(&fmt);

			else if (*fmt == '*') {

				++fmt;

				/* it's the next argument */

				precision = va_arg(args, int);

			}

			if (precision < 0)

				precision = 0;

		}

		/* get the conversion qualifier */

		qualifier = -1;

		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {

			qualifier = *fmt;

			++fmt;

		}

		/* default base */

		base = 10;

		switch (*fmt) {

		case 'c':

			if (!(flags & LEFT))

				while (--field_width > 0)

					*str++ = ' ';

			*str++ = (unsigned char)va_arg(args, int);

			while (--field_width > 0)

				*str++ = ' ';

			continue;

		case 's':

			s = va_arg(args, char *);

			len = strnlen(s, precision);

			if (!(flags & LEFT))

				while (len < field_width--)

					*str++ = ' ';

			for (i = 0; i < len; ++i)

				*str++ = *s++;

			while (len < field_width--)

				*str++ = ' ';

			continue;

		case 'p':

			if (field_width == -1) {

				field_width = 2 * sizeof(void *);

				flags |= ZEROPAD;

			}

			str = number(str,

				     (unsigned long)va_arg(args, void *), 16,

				     field_width, precision, flags);

			continue;

		case 'n':

			if (qualifier == 'l') {

				long *ip = va_arg(args, long *);

				*ip = (str - buf);

			} else {

				int *ip = va_arg(args, int *);

				*ip = (str - buf);

			}

			continue;

		case '%':

			*str++ = '%';

			continue;

			/* integer number formats - set up the flags and "break" */

		case 'o':

			base = 8;

			break;

		case 'X':

			flags |= LARGE;

		case 'x':

			base = 16;

			break;

		case 'd':

		case 'i':

			flags |= SIGN;

		case 'u':

			break;

		default:

			*str++ = '%';

			if (*fmt)

				*str++ = *fmt;

			else

				--fmt;

			continue;

		}

		if (qualifier == 'l')

			num = va_arg(args, unsigned long);

		else if (qualifier == 'h') {

			num = (unsigned short)va_arg(args, int);

			if (flags & SIGN)

				num = (short)num;

		} else if (flags & SIGN)

			num = va_arg(args, int);

		else

			num = va_arg(args, unsigned int);

		str = number(str, num, base, field_width, precision, flags);

	}

	*str = '\0';

	return str - buf;

}

int sprintf(char *buf, const char *fmt, ...)

{

	va_list args;

	int i;

	va_start(args, fmt);

	i = vsprintf(buf, fmt, args);

	va_end(args);

	return i;

}

int printf(const char *fmt, ...)

{

	char printf_buf[1024];

	va_list args;

	int printed;

	va_start(args, fmt);

	printed = vsprintf(printf_buf, fmt, args);

	va_end(args);

	puts(printf_buf);

	return printed;

}

/* -*- linux-c -*- ------------------------------------------------------- *

 *

 *   Copyright (C) 1991, 1992 Linus Torvalds

 *   Copyright 2007 rPath, Inc. - All Rights Reserved

 *

 *   This file is part of the Linux kernel, and is made available under

 *   the terms of the GNU General Public License version 2.

 *

 * ----------------------------------------------------------------------- */

/*

 * arch/i386/boot/tty.c

 *

 * Very simple screen I/O

 * XXX: Probably should add very simple serial I/O?

 */

#include "boot.h"

/*

 * These functions are in .inittext so they can be used to signal

 * error during initialization.

 */

void __attribute__((section(".inittext"))) putchar(int ch)

{

	unsigned char c = ch;

	if (c == '\n')

		putchar('\r');	/* \n -> \r\n */

	/* int $0x10 is known to have bugs involving touching registers

	   it shouldn't.  Be extra conservative... */

	asm volatile("pushal; int $0x10; popal"

		     : : "b" (0x0007), "c" (0x0001), "a" (0x0e00|ch));

}

void __attribute__((section(".inittext"))) puts(const char *str)

{

	int n = 0;

	while (*str) {

		putchar(*str++);

		n++;

	}

}

/*

 * Read the CMOS clock through the BIOS, and return the

 * seconds in BCD.

 */

static u8 gettime(void)

{

	u16 ax = 0x0200;

	u16 cx, dx;

	asm("int $0x1a"

	    : "+a" (ax), "=c" (cx), "=d" (dx)

	    : : "ebx", "esi", "edi");

	return dx >> 8;

}

/*

 * Read from the keyboard

 */

int getchar(void)

{

	u16 ax = 0;

	asm("int $0x16" : "+a" (ax));

	return ax & 0xff;

}

static int kbd_pending(void)

{

	u8 pending;

	asm("int $0x16; setnz %0"

	    : "=rm" (pending)

	    : "a" (0x0100));

	return pending;

}

void kbd_flush(void)

{

	for (;;) {

		if (!kbd_pending())

			break;

		getchar();

	}

}

int getchar_timeout(void)

{

	int cnt = 30;

	int t0, t1;

	t0 = gettime();

	while (cnt) {

		if (kbd_pending())

			return getchar();

		t1 = gettime();

		if (t0 != t1) {

			cnt--;

			t0 = t1;

		}

	}

	return 0;		/* Timeout! */

}