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autoconf.c revision 1.2 
      1 /*	$NetBSD: autoconf.c,v 1.2 1996/04/04 06:25:00 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994, 1995 Carnegie-Mellon University.
      5  * All rights reserved.
      6  *
      7  * Authors: Keith Bostic, Chris G. Demetriou
      8  *
      9  * Permission to use, copy, modify and distribute this software and
     10  * its documentation is hereby granted, provided that both the copyright
     11  * notice and this permission notice appear in all copies of the
     12  * software, derivative works or modified versions, and any portions
     13  * thereof, and that both notices appear in supporting documentation.
     14  *
     15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     17  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     18  *
     19  * Carnegie Mellon requests users of this software to return to
     20  *
     21  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     22  *  School of Computer Science
     23  *  Carnegie Mellon University
     24  *  Pittsburgh PA 15213-3890
     25  *
     26  * any improvements or extensions that they make and grant Carnegie the
     27  * rights to redistribute these changes.
     28  */
     29 
     30 #include <sys/param.h>
     31 #include <sys/systm.h>
     32 #include <sys/buf.h>
     33 #include <sys/disklabel.h>
     34 #include <sys/conf.h>
     35 #include <sys/reboot.h>
     36 #include <sys/device.h>
     37 
     38 #include <machine/autoconf.h>
     39 
     40 /*
     41  * configure:
     42  * called at boot time, configure all devices on system
     43  */
     44 void
     45 configure()
     46 {
     47 	extern int cold;
     48 
     49 	(void)splhigh();
     50 	if (config_rootfound("mainbus", "mainbus") == NULL)
     51 		panic("no mainbus found");
     52 	(void)spl0();
     53 
     54 #ifdef GENERIC
     55 	if ((boothowto & RB_ASKNAME) == 0)
     56 		setroot();
     57 	setconf();
     58 #else
     59 	setroot();
     60 #endif
     61 	swapconf();
     62 	cold = 0;
     63 }
     64 
     65 /*
     66  * Configure swap space and related parameters.
     67  */
     68 swapconf()
     69 {
     70 	register struct swdevt *swp;
     71 	register int nblks;
     72 
     73 	for (swp = swdevt; swp->sw_dev != NODEV; swp++) {
     74 		int maj = major(swp->sw_dev);
     75 
     76 		if (maj > nblkdev)
     77 			break;
     78 		if (bdevsw[maj].d_psize) {
     79 			nblks = (*bdevsw[maj].d_psize)(swp->sw_dev);
     80 			if (nblks != -1 &&
     81 			    (swp->sw_nblks == 0 || swp->sw_nblks > nblks))
     82 				swp->sw_nblks = nblks;
     83 			swp->sw_nblks = ctod(dtoc(swp->sw_nblks));
     84 		}
     85 	}
     86 }
     87 
     88 #define	DOSWAP			/* change swdevt and dumpdev */
     89 dev_t	bootdev = 0;		/* should be dev_t, but not until 32 bits */
     90 
     91 static	char devname[][2] = {
     92 	'x','x',	/* 0 = XX */
     93 	'x','x',	/* 1 = XX */
     94 	'x','x',	/* 2 = XX */
     95 	'x','x',	/* 3 = XX */
     96 	'x','x',	/* 4 = XX */
     97 	'x','x',	/* 5 = XX */
     98 	'x','x',	/* 6 = XX */
     99 	'x','x',	/* 7 = XX */
    100 	's','d',	/* 8 = sd */
    101 };
    102 
    103 /*
    104  * Attempt to find the device from which we were booted.
    105  * If we can do so, and not instructed not to do so,
    106  * change rootdev to correspond to the load device.
    107  */
    108 setroot()
    109 {
    110 	int  majdev, mindev, unit, part, adaptor;
    111 	dev_t temp, orootdev;
    112 	struct swdevt *swp;
    113 
    114 /*printf("howto %x bootdev %x ", boothowto, bootdev);*/
    115 	if (boothowto & RB_DFLTROOT ||
    116 	    (bootdev & B_MAGICMASK) != (u_long)B_DEVMAGIC)
    117 		return;
    118 	majdev = (bootdev >> B_TYPESHIFT) & B_TYPEMASK;
    119 	if (majdev > sizeof(devname) / sizeof(devname[0]))
    120 		return;
    121 	adaptor = (bootdev >> B_ADAPTORSHIFT) & B_ADAPTORMASK;
    122 	part = (bootdev >> B_PARTITIONSHIFT) & B_PARTITIONMASK;
    123 	unit = (bootdev >> B_UNITSHIFT) & B_UNITMASK;
    124 	mindev = (unit * MAXPARTITIONS) + part;
    125 	orootdev = rootdev;
    126 	rootdev = makedev(majdev, mindev);
    127 	/*
    128 	 * If the original rootdev is the same as the one
    129 	 * just calculated, don't need to adjust the swap configuration.
    130 	 */
    131 	if (rootdev == orootdev)
    132 		return;
    133 	printf("changing root device to %c%c%d%c\n",
    134 		devname[majdev][0], devname[majdev][1],
    135 		unit, part + 'a');
    136 
    137 #ifdef DOSWAP
    138 	for (swp = swdevt; swp->sw_dev != NODEV; swp++) {
    139 		if (majdev == major(swp->sw_dev) &&
    140 		    (mindev / MAXPARTITIONS)
    141 		    == (minor(swp->sw_dev) / MAXPARTITIONS)) {
    142 			temp = swdevt[0].sw_dev;
    143 			swdevt[0].sw_dev = swp->sw_dev;
    144 			swp->sw_dev = temp;
    145 			break;
    146 		}
    147 	}
    148 	if (swp->sw_dev == NODEV)
    149 		return;
    150 
    151 	/*
    152 	 * If dumpdev was the same as the old primary swap device, move
    153 	 * it to the new primary swap device.
    154 	 */
    155 	if (temp == dumpdev)
    156 		dumpdev = swdevt[0].sw_dev;
    157 #endif
    158 }
    159