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devopen.c revision 1.2.2.2 
      1 /*	$NetBSD: devopen.c,v 1.2.2.2 2007/10/31 23:13:57 joerg 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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <lib/libsa/stand.h>
     40 #include <lib/libkern/libkern.h>
     41 
     42 #include "boot.h"
     43 
     44 /*
     45  * Parse a device spec.
     46  *
     47  * Format:
     48  *  [device:][filename]
     49  */
     50 int
     51 devparse(const char *fname, int *dev, uint8_t *unit, uint8_t *part,
     52     const char **file)
     53 {
     54 	const char *col;
     55 
     56 	*unit = 0;	/* default to wd0a */
     57 	*part = 0;
     58 	*dev  = 0;
     59 	*file = DEFKERNELNAME;
     60 
     61 	if (fname == NULL)
     62 		return 0;
     63 
     64 	if ((col = strchr(fname, ':')) != NULL) {
     65 		int devlen;
     66 		uint8_t i, u, p;
     67 		struct devsw *dp;
     68 		char devname[MAXDEVNAME];
     69 
     70 		devlen = col - fname;
     71 		if (devlen > MAXDEVNAME)
     72 			return EINVAL;
     73 
     74 #define isnum(c)	(((c) >= '0') && ((c) <= '9'))
     75 #define isalpha(c)	(((c) >= 'a') && ((c) <= 'z'))
     76 
     77 		/* extract device name */
     78 		for (i = 0; isalpha(fname[i]) && (i < devlen); i++)
     79 			devname[i] = fname[i];
     80 		devname[i] = '\0';
     81 
     82 		if (strcmp(devname, "nfs") == 0) {
     83 			/* no unit number or partition suffix on netboot */
     84 			u = 0;
     85 			p = 0;
     86 		} else {
     87 			/* parse [disk][unit][part] (ex. wd0a) strings */
     88 			if (!isnum(fname[i]))
     89 				return EUNIT;
     90 
     91 			/* device number */
     92 			for (u = 0; isnum(fname[i]) && (i < devlen); i++)
     93 				u = u * 10 + (fname[i] - '0');
     94 
     95 			if (!isalpha(fname[i]))
     96 				return EPART;
     97 
     98 			/* partition number */
     99 			if (i < devlen)
    100 				p = fname[i++] - 'a';
    101 
    102 			if (i != devlen)
    103 				return ENXIO;
    104 		}
    105 
    106 		/* check device name */
    107 		for (dp = devsw, i = 0; i < ndevs; dp++, i++) {
    108 			if (dp->dv_name && !strcmp(devname, dp->dv_name))
    109 				break;
    110 		}
    111 
    112 		if (i >= ndevs)
    113 			return ENXIO;
    114 
    115 		*unit = u;
    116 		*part = p;
    117 		*dev  = i;
    118 		fname = ++col;
    119 	}
    120 
    121 	if (*fname)
    122 		*file = fname;
    123 
    124 	return 0;
    125 }
    126 
    127 int
    128 devopen(struct open_file *f, const char *fname, char **file)
    129 {
    130 	struct devsw *dp;
    131 	uint8_t unit, part;
    132 	int dev, error;
    133 
    134 	DPRINTF(("devopen(%s)\n", fname));
    135 
    136 	if ((error = devparse(fname, &dev, &unit, &part,
    137 	    (const char **)file)) != 0)
    138 		return error;
    139 
    140 	dp = &devsw[dev];
    141 	if ((void *)dp->dv_open == (void *)nodev)
    142 		return ENXIO;
    143 
    144 	f->f_dev = dp;
    145 
    146 	if ((error = (*dp->dv_open)(f, unit, part)) != 0)
    147 	printf("%s%d%c: %d = %s\n", devsw[dev].dv_name,
    148 	    unit, 'a' + part, error, strerror(error));
    149 
    150 	return error;
    151 }
    152