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diskio.c revision 1.7 
      1 /*	$NetBSD: diskio.c,v 1.7 2009/03/14 21:04:07 dsl 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 <lib/libsa/stand.h>
     34 #include "atari_stand.h"
     35 #include <sys/disklabel.h>
     36 
     37 typedef int (*rdsec_f)(void *buffer, u_int offset, u_int count);
     38 typedef	struct { rdsec_f rds; u_int rst; u_int rend; } bdevd_t;
     39 
     40 static int rootstrategy(void *, int, daddr_t, size_t, void *, size_t *);
     41 static int rootopen(struct open_file *, ...);
     42 static int rootclose(struct open_file *);
     43 static int rootioctl(struct open_file *, u_long, void *);
     44 
     45 struct devsw devsw[] = {
     46 	{ "root", rootstrategy, rootopen, rootclose, rootioctl }
     47 };
     48 static bdevd_t	bootdev;
     49 
     50 /*
     51  * Initialise boot device info.
     52  */
     53 int
     54 init_dskio (void *func, void *label, int root)
     55 {
     56 	struct disklabel *dl = label;
     57 	struct partition *pd = &dl->d_partitions[root];
     58 
     59 	if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC
     60 	    || dl->d_npartitions > MAXPARTITIONS || dkcksum(dl) != 0) {
     61 		printf("Invalid disk label.\n");
     62 		return(-1);
     63 	}
     64 	if (root >= 0) {
     65 		if (root >= dl->d_npartitions
     66 		    || pd->p_fstype != FS_BSDFFS || pd->p_size == 0) {
     67 			printf("No suitable root.\n");
     68 			return(-1);
     69 		}
     70 		bootdev.rds  = func;
     71 		bootdev.rst  = pd->p_offset;
     72 		bootdev.rend = pd->p_offset + pd->p_size - 1;
     73 	}
     74 	return(0);
     75 }
     76 
     77 /*
     78  * No choice, the kernel is loaded from the
     79  * same device as the bootstrap.
     80  */
     81 int
     82 devopen (struct open_file *f, const char *fname, char **file)
     83 {
     84 	f->f_devdata = &bootdev;
     85 	f->f_dev = &devsw[0];
     86 	*file = (char *)fname;
     87 	return(0);
     88 }
     89 
     90 static int
     91 rootstrategy (void *devd, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
     92 {
     93 	bdevd_t	*dd = devd;
     94 	daddr_t stb = dd->rst + dblk;
     95 	size_t	nb  = size >> 9;
     96 
     97 	if ((flag == F_READ) && !(size & 511) && (stb + nb <= dd->rend)) {
     98 		if (!dd->rds(buf, stb, nb)) {
     99 			*rsize = size;
    100 			return(0);
    101 		}
    102 	}
    103 	*rsize = 0;
    104 	return(EIO);
    105 }
    106 
    107 static int
    108 rootopen (struct open_file *f)
    109 {
    110 	return(0);
    111 }
    112 
    113 static int
    114 rootclose (struct open_file *f)
    115 {
    116 	return(EIO);
    117 }
    118 
    119 static int
    120 rootioctl (struct open_file *f, u_long cmd, void *data)
    121 {
    122 	return(EIO);
    123 }
    124