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diskio.c revision 1.1 
      1 /*	$NetBSD: diskio.c,v 1.1 1996/02/29 11:36:12 leo Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Waldi Ravens.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *        This product includes software developed by Waldi Ravens.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include "stand.h"
     34 #include <sys/disklabel.h>
     35 
     36 typedef int (*rdsec_f)__P((void *buffer, u_int offset, u_int count));
     37 typedef	struct { rdsec_f rds; u_int rst; u_int rend; } bdevd_t;
     38 
     39 static int rootstrategy __P((void *, int, daddr_t, size_t, void *, size_t *));
     40 static int rootopen __P((struct open_file *, ...));
     41 static int rootclose __P((struct open_file *));
     42 static int rootioctl __P((struct open_file *, u_long, void *));
     43 
     44 static struct devsw devsw[] = {
     45 	{ "root", rootstrategy, rootopen, rootclose, rootioctl }
     46 };
     47 static bdevd_t	bootdev;
     48 
     49 /*
     50  * Initialise boot device info.
     51  */
     52 int
     53 init_dskio (func, label, root)
     54 	void	*func, *label;
     55 	int	root;
     56 {
     57 	struct disklabel *dl = label;
     58 	struct partition *pd = &dl->d_partitions[root];
     59 
     60 	if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC
     61 	    || dl->d_npartitions > MAXPARTITIONS || dkcksum(dl) != 0) {
     62 		printf("Invalid disk label.\n");
     63 		return(-1);
     64 	}
     65 	if (root >= 0) {
     66 		if (root >= dl->d_npartitions
     67 		    || pd->p_fstype != FS_BSDFFS || pd->p_size == 0) {
     68 			printf("No suitable root.\n");
     69 			return(-1);
     70 		}
     71 		bootdev.rds  = func;
     72 		bootdev.rst  = pd->p_offset;
     73 		bootdev.rend = pd->p_offset + pd->p_size - 1;
     74 	}
     75 	return(0);
     76 }
     77 
     78 /*
     79  * No choice, the kernel is loaded from the
     80  * same device as the bootstrap.
     81  */
     82 int
     83 devopen (f, fname, file)
     84 	struct open_file *f;
     85 	const char *fname;
     86 	char **file;
     87 {
     88 	f->f_devdata = &bootdev;
     89 	f->f_dev = &devsw[0];
     90 	*file = (char *)fname;
     91 	return(0);
     92 }
     93 
     94 static int
     95 rootstrategy (devd, flag, dblk, size, buf, rsize)
     96 	void	*devd;
     97 	int	flag;
     98 	daddr_t	dblk;
     99 	size_t	size;
    100 	void	*buf;
    101 	size_t	*rsize;
    102 {
    103 	bdevd_t	*dd = devd;
    104 	daddr_t stb = dd->rst + dblk;
    105 	size_t	nb  = size >> 9;
    106 
    107 	if ((flag == F_READ) && !(size & 511) && (stb + nb <= dd->rend)) {
    108 		if (!dd->rds(buf, stb, nb)) {
    109 			*rsize = size;
    110 			return(0);
    111 		}
    112 	}
    113 	*rsize = 0;
    114 	return(EIO);
    115 }
    116 
    117 static int
    118 rootopen (f)
    119 	struct open_file *f;
    120 {
    121 	return(0);
    122 }
    123 
    124 static int
    125 rootclose (f)
    126 	struct open_file *f;
    127 {
    128 	return(EIO);
    129 }
    130 
    131 static int
    132 rootioctl (f, cmd, data)
    133 	struct open_file *f;
    134 	u_long	cmd;
    135 	void	*data;
    136 {
    137 	return(EIO);
    138 }
    139