serial_console.c   [plain text]


/*
 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <i386/mp.h>
#include <i386/machine_routines.h>

void
cnputc(char c)
{
	boolean_t	nolock = mp_kdp_trap || !ml_get_interrupts_enabled();

	/*
	 * Note: this lock prevents other cpus interferring with the
	 * output is this one character to the console (screen). It
	 * does not prevent multiple printfs being interleaved - that's
	 * the responsibility of the caller.  Without this lock,
	 * an unreadable black-on-black or white-on-white display may result.
	 * We avoid taking this lock, however, if we're in the debugger or
	 * at interrupt level.
	 */
	if (!nolock)
		simple_lock(&mp_putc_lock);
	vcputc(0, 0, c);
	if (c == '\n')
		vcputc(0, 0,'\r');
	if (!nolock)
		simple_unlock(&mp_putc_lock);
}