usr/src/sys/i386/i386/autoconf.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)autoconf.c  7.1 (Berkeley) 5/9/91
 */

/*
 * Setup the system to run on the current machine.
 *
 * Configure() is called at boot time and initializes the vba
 * device tables and the memory controller monitoring.  Available
 * devices are determined (from possibilities mentioned in ioconf.c),
 * and the drivers are initialized.
 */
#include "param.h"
#include "systm.h"
#include "map.h"
#include "buf.h"
#include "dkstat.h"
#include "conf.h"
#include "dmap.h"
#include "reboot.h"

#include "machine/pte.h"

/*
 * The following several variables are related to
 * the configuration process, and are used in initializing
 * the machine.
 */
int     dkn;            /* number of iostat dk numbers assigned so far */
extern int      cold;           /* cold start flag initialized in locore.s */

/*
 * Determine i/o configuration for a machine.
 */
configure()
{

#include "isa.h"
#if NISA > 0
        isa_configure();
#endif

#if GENERICxxx
        if ((boothowto & RB_ASKNAME) == 0)
                setroot();
        setconf();
#else
        setroot();
#endif
        /*
         * Configure swap area and related system
         * parameter based on device(s) used.
         */
        swapconf();
        cold = 0;
}

/*
 * Configure swap space and related parameters.
 */
swapconf()
{
        register struct swdevt *swp;
        register int nblks;
extern int Maxmem;

        for (swp = swdevt; swp->sw_dev > 0; swp++)
        {
                if ( swp->sw_dev < 0 || swp->sw_dev > nblkdev ) break;
                if (bdevsw[major(swp->sw_dev)].d_psize) {
                        nblks =
                          (*bdevsw[major(swp->sw_dev)].d_psize)(swp->sw_dev);
                        if (nblks != -1 &&
                            (swp->sw_nblks == 0 || swp->sw_nblks > nblks))
                                swp->sw_nblks = nblks;
                }
        }
        if (dumplo == 0 && bdevsw[major(dumpdev)].d_psize)
        /*dumplo = (*bdevsw[major(dumpdev)].d_psize)(dumpdev) - physmem;*/
                dumplo = (*bdevsw[major(dumpdev)].d_psize)(dumpdev) -
                        Maxmem*NBPG/512;
        if (dumplo < 0)
                dumplo = 0;
}

#define DOSWAP                  /* change swdevt and dumpdev */
u_long  bootdev = 0;            /* should be dev_t, but not until 32 bits */

static  char devname[][2] = {
        'w','d',        /* 0 = wd */
        's','w',        /* 1 = sw */
        'f','d',        /* 2 = fd */
        'w','t',        /* 3 = wt */
        'x','d',        /* 4 = xd */
};

#define PARTITIONMASK   0x7
#define PARTITIONSHIFT  3

/*
 * Attempt to find the device from which we were booted.
 * If we can do so, and not instructed not to do so,
 * change rootdev to correspond to the load device.
 */
setroot()
{
        int  majdev, mindev, unit, part, adaptor;
        dev_t temp, orootdev;
        struct swdevt *swp;

        if (boothowto & RB_DFLTROOT ||
            (bootdev & B_MAGICMASK) != (u_long)B_DEVMAGIC)
                return;
        majdev = (bootdev >> B_TYPESHIFT) & B_TYPEMASK;
        if (majdev > sizeof(devname) / sizeof(devname[0]))
                return;
        adaptor = (bootdev >> B_ADAPTORSHIFT) & B_ADAPTORMASK;
        part = (bootdev >> B_PARTITIONSHIFT) & B_PARTITIONMASK;
        unit = (bootdev >> B_UNITSHIFT) & B_UNITMASK;
        mindev = (unit << PARTITIONSHIFT) + part;
        orootdev = rootdev;
        rootdev = makedev(majdev, mindev);
        /*
         * If the original rootdev is the same as the one
         * just calculated, don't need to adjust the swap configuration.
         */
        if (rootdev == orootdev)
                return;
        printf("changing root device to %c%c%d%c\n",
                devname[majdev][0], devname[majdev][1],
                mindev >> PARTITIONSHIFT, part + 'a');
#ifdef DOSWAP
        mindev &= ~PARTITIONMASK;
        for (swp = swdevt; swp->sw_dev; swp++) {
                if (majdev == major(swp->sw_dev) &&
                    mindev == (minor(swp->sw_dev) & ~PARTITIONMASK)) {
                        temp = swdevt[0].sw_dev;
                        swdevt[0].sw_dev = swp->sw_dev;
                        swp->sw_dev = temp;
                        break;
                }
        }
        if (swp->sw_dev == 0)
                return;
        /*
         * If dumpdev was the same as the old primary swap
         * device, move it to the new primary swap device.
         */
        if (temp == dumpdev)
                dumpdev = swdevt[0].sw_dev;
#endif
}