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      1 /*	$NetBSD: diskio.c,v 1.9 2021/05/17 19:31:38 mrg 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 #include <lib/libkern/libkern.h>
     38 
     39 typedef int (*rdsec_f)(void *buffer, u_int offset, u_int count);
     40 typedef	struct { rdsec_f rds; u_int rst; u_int rend; } bdevd_t;
     41 
     42 static int rootstrategy(void *, int, daddr_t, size_t, void *, size_t *);
     43 static int rootopen(struct open_file *, ...);
     44 static int rootclose(struct open_file *);
     45 static int rootioctl(struct open_file *, u_long, void *);
     46 
     47 struct devsw devsw[] = {
     48 	{ "root", rootstrategy, rootopen, rootclose, rootioctl }
     49 };
     50 static bdevd_t	bootdev;
     51 
     52 /*
     53  * Initialise boot device info.
     54  */
     55 int
     56 init_dskio (void *func, void *label, int root)
     57 {
     58 	struct disklabel *dl = label;
     59 	struct partition *pd = &dl->d_partitions[root];
     60 
     61 	if (dl->d_magic != DISKMAGIC || dl->d_magic2 != DISKMAGIC
     62 	    || dl->d_npartitions > MAXPARTITIONS || dkcksum(dl) != 0) {
     63 		printf("Invalid disk label.\n");
     64 		return(-1);
     65 	}
     66 	if (root >= 0) {
     67 		if (root >= dl->d_npartitions
     68 		    || pd->p_fstype != FS_BSDFFS || pd->p_size == 0) {
     69 			printf("No suitable root.\n");
     70 			return(-1);
     71 		}
     72 		bootdev.rds  = func;
     73 		bootdev.rst  = pd->p_offset;
     74 		bootdev.rend = pd->p_offset + pd->p_size - 1;
     75 	}
     76 	return(0);
     77 }
     78 
     79 /*
     80  * No choice, the kernel is loaded from the
     81  * same device as the bootstrap.
     82  */
     83 int
     84 devopen (struct open_file *f, const char *fname, char **file)
     85 {
     86 	f->f_devdata = &bootdev;
     87 	f->f_dev = &devsw[0];
     88 	*file = (char *)fname;
     89 	return(0);
     90 }
     91 
     92 static int
     93 rootstrategy (void *devd, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
     94 {
     95 	bdevd_t	*dd = devd;
     96 	daddr_t stb = dd->rst + dblk;
     97 	size_t	nb  = size >> 9;
     98 
     99 	if ((flag == F_READ) && !(size & 511) && (stb + nb <= dd->rend)) {
    100 		if (!dd->rds(buf, stb, nb)) {
    101 			*rsize = size;
    102 			return(0);
    103 		}
    104 	}
    105 	*rsize = 0;
    106 	return(EIO);
    107 }
    108 
    109 static int
    110 rootopen (struct open_file *f, ...)
    111 {
    112 	return(0);
    113 }
    114 
    115 static int
    116 rootclose (struct open_file *f)
    117 {
    118 	return(EIO);
    119 }
    120 
    121 static int
    122 rootioctl (struct open_file *f, u_long cmd, void *data)
    123 {
    124 	return(EIO);
    125 }
    126