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devopen.c revision 1.1.4.2 
      1 /*	$NetBSD: devopen.c,v 1.1.4.2 2011/03/05 20:51:16 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Rolf Grossmann.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <lib/libsa/stand.h>
     33 #include <lib/libkern/libkern.h>
     34 
     35 #include "boot.h"
     36 
     37 extern const struct fs_ops file_system_nfs;
     38 
     39 /*
     40  * Parse a device spec.
     41  *
     42  * Format:
     43  *  [device:][filename]
     44  */
     45 int
     46 devparse(const char *fname, int *dev, uint8_t *unit, uint8_t *part,
     47     const char **file)
     48 {
     49 	const char *col;
     50 
     51 	*unit = 0;	/* default to wd0a */
     52 	*part = 0;
     53 	*dev  = 0;
     54 	*file = DEFKERNELNAME;
     55 
     56 	if (fname == NULL)
     57 		return 0;
     58 
     59 	if ((col = strchr(fname, ':')) != NULL) {
     60 		int devlen;
     61 		uint8_t i, u, p;
     62 		struct devsw *dp;
     63 		char devname[MAXDEVNAME];
     64 
     65 		devlen = col - fname;
     66 		if (devlen > MAXDEVNAME)
     67 			return EINVAL;
     68 
     69 #define isnum(c)	(((c) >= '0') && ((c) <= '9'))
     70 #define isalpha(c)	(((c) >= 'a') && ((c) <= 'z'))
     71 
     72 		/* extract device name */
     73 		for (i = 0; isalpha(fname[i]) && (i < devlen); i++)
     74 			devname[i] = fname[i];
     75 		devname[i] = '\0';
     76 
     77 		/* parse [disk][unit][part] (ex. wd0a) strings */
     78 		if (!isnum(fname[i]))
     79 			return EUNIT;
     80 
     81 		/* device number */
     82 		for (u = 0; isnum(fname[i]) && (i < devlen); i++)
     83 			u = u * 10 + (fname[i] - '0');
     84 
     85 		if (!isalpha(fname[i]))
     86 			return EPART;
     87 
     88 		/* partition number */
     89 		p = 0;
     90 		if (i < devlen)
     91 			p = fname[i++] - 'a';
     92 
     93 		if (i != devlen)
     94 			return ENXIO;
     95 
     96 		/* check device name */
     97 		for (dp = devsw, i = 0; i < ndevs; dp++, i++) {
     98 			if (dp->dv_name && !strcmp(devname, dp->dv_name))
     99 				break;
    100 		}
    101 
    102 		if (i >= ndevs)
    103 			return ENXIO;
    104 
    105 		*unit = u;
    106 		*part = p;
    107 		*dev  = i;
    108 		fname = ++col;
    109 	}
    110 
    111 	if (*fname)
    112 		*file = fname;
    113 
    114 	return 0;
    115 }
    116 
    117 int
    118 devopen(struct open_file *f, const char *fname, char **file)
    119 {
    120 	struct devsw *dp;
    121 	uint8_t unit, part;
    122 	int dev, error;
    123 
    124 	DPRINTF(("devopen(%s)\n", fname));
    125 
    126 	if ((error = devparse(fname, &dev, &unit, &part,
    127 	    (const char **)file)) != 0)
    128 		return error;
    129 
    130 	dp = &devsw[dev];
    131 	if ((void *)dp->dv_open == (void *)nodev)
    132 		return ENXIO;
    133 
    134 	f->f_dev = dp;
    135 
    136 	if ((error = (*dp->dv_open)(f, unit, part)) != 0)
    137 	printf("%s%d%c: %d = %s\n", devsw[dev].dv_name,
    138 	    unit, 'a' + part, error, strerror(error));
    139 
    140 	return error;
    141 }
    142