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devopen.c revision 1.6 
      1 /*	$NetBSD: devopen.c,v 1.6 2008/04/28 20:23:16 martin 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 /*
     38  * Parse a device spec.
     39  *
     40  * Format:
     41  *  [device:][filename]
     42  */
     43 int
     44 devparse(const char *fname, int *dev, uint8_t *unit, uint8_t *part,
     45     const char **file)
     46 {
     47 	const char *col;
     48 
     49 	*unit = 0;	/* default to wd0a */
     50 	*part = 0;
     51 	*dev  = 0;
     52 	*file = DEFKERNELNAME;
     53 
     54 	if (fname == NULL)
     55 		return 0;
     56 
     57 	if ((col = strchr(fname, ':')) != NULL) {
     58 		int devlen;
     59 		uint8_t i, u, p;
     60 		struct devsw *dp;
     61 		char devname[MAXDEVNAME];
     62 
     63 		devlen = col - fname;
     64 		if (devlen > MAXDEVNAME)
     65 			return EINVAL;
     66 
     67 #define isnum(c)	(((c) >= '0') && ((c) <= '9'))
     68 #define isalpha(c)	(((c) >= 'a') && ((c) <= 'z'))
     69 
     70 		/* extract device name */
     71 		for (i = 0; isalpha(fname[i]) && (i < devlen); i++)
     72 			devname[i] = fname[i];
     73 		devname[i] = '\0';
     74 
     75 		if (strcmp(devname, "nfs") == 0) {
     76 			/* no unit number or partition suffix on netboot */
     77 			u = 0;
     78 			p = 0;
     79 		} else {
     80 			/* parse [disk][unit][part] (ex. wd0a) strings */
     81 			if (!isnum(fname[i]))
     82 				return EUNIT;
     83 
     84 			/* device number */
     85 			for (u = 0; isnum(fname[i]) && (i < devlen); i++)
     86 				u = u * 10 + (fname[i] - '0');
     87 
     88 			if (!isalpha(fname[i]))
     89 				return EPART;
     90 
     91 			/* partition number */
     92 			p = 0;
     93 			if (i < devlen)
     94 				p = fname[i++] - 'a';
     95 
     96 			if (i != devlen)
     97 				return ENXIO;
     98 		}
     99 
    100 		/* check device name */
    101 		for (dp = devsw, i = 0; i < ndevs; dp++, i++) {
    102 			if (dp->dv_name && !strcmp(devname, dp->dv_name))
    103 				break;
    104 		}
    105 
    106 		if (i >= ndevs)
    107 			return ENXIO;
    108 
    109 		*unit = u;
    110 		*part = p;
    111 		*dev  = i;
    112 		fname = ++col;
    113 	}
    114 
    115 	if (*fname)
    116 		*file = fname;
    117 
    118 	return 0;
    119 }
    120 
    121 int
    122 devopen(struct open_file *f, const char *fname, char **file)
    123 {
    124 	struct devsw *dp;
    125 	uint8_t unit, part;
    126 	int dev, error;
    127 
    128 	DPRINTF(("devopen(%s)\n", fname));
    129 
    130 	if ((error = devparse(fname, &dev, &unit, &part,
    131 	    (const char **)file)) != 0)
    132 		return error;
    133 
    134 	dp = &devsw[dev];
    135 	if ((void *)dp->dv_open == (void *)nodev)
    136 		return ENXIO;
    137 
    138 	f->f_dev = dp;
    139 
    140 	if ((error = (*dp->dv_open)(f, unit, part)) != 0)
    141 	printf("%s%d%c: %d = %s\n", devsw[dev].dv_name,
    142 	    unit, 'a' + part, error, strerror(error));
    143 
    144 	return error;
    145 }
    146