arch/x86/boot/tty.c

/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007 rPath, Inc. - All Rights Reserved
 *   Copyright 2009 Intel Corporation; author H. Peter Anvin
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

/**
 * @file
 * @brief Very simple screen I/O for the initialization stage
 *
 * @todo Probably should add very simple serial I/O?
 * @attention This is real mode code!
 */

#include <asm/segment.h>
#include "boot.h"

/* be aware of: */
THIS_IS_REALMODE_CODE

static void __bootcode putchar(int ch)
{
	struct biosregs ireg;

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

	initregs(&ireg);
	ireg.bx = 0x0007;
	ireg.cx = 0x0001;
	ireg.ah = 0x0e;
	ireg.al = ch;
	intcall(0x10, &ireg, NULL);
}

void __bootcode boot_puts(char *str)
{
	while (*str)
		putchar(*str++);
}