dev.c

早期freebsd实现

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 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.
 *
 *	@(#)dev.c	8.1 (Berkeley) 6/11/93
 */

#include <sys/param.h>
#include <setjmp.h>
#include <stand.att/saio.h>

/*
 * NB: the value "io->i_dev", used to offset the devsw[] array in the
 * routines below, is munged by the machine specific stand Makefiles
 * to work for certain boots.
 */

jmp_buf exception;

devread(io)
	register struct iob *io;
{
	int cc;

	io->i_flgs |= F_RDDATA;
	io->i_error = 0;
	cc = (*devsw[io->i_dev].dv_strategy)(io, F_READ);
	io->i_flgs &= ~F_TYPEMASK;
#ifndef SMALL
	if (scankbd())
		_longjmp(exception, 1);
#endif
	return (cc);
}

devwrite(io)
	register struct iob *io;
{
	int cc;

	io->i_flgs |= F_WRDATA;
	io->i_error = 0;
	cc = (*devsw[io->i_dev].dv_strategy)(io, F_WRITE);
	io->i_flgs &= ~F_TYPEMASK;
#ifndef SMALL
	if (scankbd())
		_longjmp(exception, 1);
#endif
	return (cc);
}

devopen(io)
	register struct iob *io;
{
	int ret;

	if (!(ret = (*devsw[io->i_dev].dv_open)(io)))
		return (0);
#ifdef SMALL
	printf("open error\n");
#else
	printf("%s(%d,%d,%d,%d): ", devsw[io->i_dev].dv_name,
		io->i_adapt, io->i_ctlr, io->i_unit, io->i_part);
	switch(ret) {
	case EIO:
		break;		/* already reported */
	case EADAPT:
		printf("bad adaptor number\n");
		break;
	case ECTLR:
		printf("bad controller number\n");
		break;
	case EUNIT:
		printf("bad drive number\n");
		break;
	case EPART:
		printf("bad partition\n");
		break;
	case ERDLAB:
		printf("can't read disk label\n");
		break;
	case EUNLAB:
		printf("unlabeled\n");
		break;
	case ENXIO:
		printf("bad device specification\n");
		break;
	default:
		printf("unknown open error\n");
		break;
	}
#endif
	return (ret);
}

devclose(io)
	register struct iob *io;
{
	(*devsw[io->i_dev].dv_close)(io);
}

devioctl(io, cmd, arg)
	register struct iob *io;
	int cmd;
	caddr_t arg;
{
	return ((*devsw[io->i_dev].dv_ioctl)(io, cmd, arg));
}

/* ARGSUSED */
nullsys(io)
	struct iob *io;
{}

/* ARGSUSED */
nodev(io)
	struct iob *io;
{
	errno = EBADF;
	return(-1);
}

/* ARGSUSED */
noioctl(io, cmd, arg)
	struct iob *io;
	int cmd;
	caddr_t arg;
{
	return (ECMD);
}