sys/i386/stand/boot.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.
 *
 *      from: @(#)boot.c        7.3 (Berkeley) 5/4/91
 *      $Id$
 */

#ifdef lint
char copyright[] =
"@(#) Copyright (c) 1990 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#include "param.h"
#include "reboot.h"
#include <a.out.h>
#include "saio.h"
#include "disklabel.h"
#include "dinode.h"

/*
 * Boot program, loaded by boot block from remaing 7.5K of boot area.
 * Sifts through disklabel and attempts to load an program image of
 * a standalone program off the disk. If keyboard is hit during load,
 * or if an error is encounter, try alternate files.
 */

char *files[] = { "386bsd", "386bsd.alt", "386bsd.old", "boot" , "vmunix", 0};
int     retry = 0;
extern struct disklabel disklabel;
extern  int bootdev, cyloffset;
static unsigned char *biosparams = (char *) 0x9ff00; /* XXX */

/*
 * Boot program... loads /boot out of filesystem indicated by arguements.
 * We assume an autoboot unless we detect a misconfiguration.
 */

main(dev, unit, off)
{
        register struct disklabel *lp;
        register int io;
        register char **bootfile = files;
        int howto = 0;
        extern int scsisn; /* XXX */


        /* are we a disk, if so look at disklabel and do things */
        lp = &disklabel;
        if (lp->d_type == DTYPE_SCSI)           /* XXX */
                off = htonl(scsisn);            /* XXX */

/*printf("cyl %x %x hd %x sect %x ", biosparams[0], biosparams[1], biosparams[2], biosparams[0xe]);
        printf("dev %x unit %x off %d\n", dev, unit, off);*/

        if (lp->d_magic == DISKMAGIC) {
            /*
             * Synthesize bootdev from dev, unit, type and partition
             * information from the block 0 bootstrap.
             * It's dirty work, but someone's got to do it.
             * This will be used by the filesystem primatives, and
             * drivers. Ultimately, opendev will be created corresponding
             * to which drive to pass to top level bootstrap.
             */
            for (io = 0; io < lp->d_npartitions; io++) {
                int sn;

                if (lp->d_partitions[io].p_size == 0)
                        continue;
                if (lp->d_type == DTYPE_SCSI)
                        sn = off;
                else
                        sn = off * lp->d_secpercyl;
                if (lp->d_partitions[io].p_offset == sn)
                        break;
            }

            if (io == lp->d_npartitions) goto screwed;
            cyloffset = off;
        } else {
screwed:
                /* probably a bad or non-existant disklabel */
                io = 0 ;
                howto |= RB_SINGLE|RB_ASKNAME ;
        }

        /* construct bootdev */
        /* currently, PC has no way of booting off alternate controllers */
        bootdev = MAKEBOOTDEV(/*i_dev*/ dev, /*i_adapt*/0, /*i_ctlr*/0,
            unit, /*i_part*/io);

        for (;;) {

/*printf("namei %s", *bootfile);*/
                io = namei(*bootfile);
                if (io > 2) {
                        copyunix(io, howto, off);
                } else
                        printf("File not found");

                printf(" - didn't load %s, ",*bootfile);
                if(*++bootfile == 0) bootfile = files;
                printf("will try %s\n", *bootfile);

                wait(1<<((retry++) + 10));
        }
}

/*ARGSUSED*/
copyunix(io, howto, cyloff)
        register io;
{
        struct exec x;
        int i;
        char *addr,c;
        struct dinode fil;
        int off;

        fetchi(io, &fil);
/*printf("mode %o ", fil.di_mode);*/
        i = iread(&fil, 0,  (char *)&x, sizeof x);
        off = sizeof x;
        if (i != sizeof x || x.a_magic != 0413) {
                printf("Not an executable format");
                return;
        }

        if (roundup(x.a_text, 4096) + x.a_data + x.a_bss > (unsigned)&fil) {
                printf("File too big to load");
                return;
        }

        off = 4096;
        if (iread(&fil, off, (char *)0, x.a_text) != x.a_text)
                goto shread;
        off += x.a_text;

        addr = (char *)x.a_text;
        while ((int)addr & CLOFSET)
                *addr++ = 0;

        if (iread(&fil, off, addr, x.a_data) != x.a_data)
                goto shread;

        addr += x.a_data;

        if (addr + x.a_bss > (unsigned) &fil) {
                printf("Warning: bss overlaps bootstrap");
                x.a_bss = (unsigned)addr - (unsigned)&fil;
        }
        bzero(addr, x.a_bss);

        /* mask high order bits corresponding to relocated system base */
        x.a_entry &= ~0xfff00000;

        /*if (scankbd()) {
                printf("Operator abort");
                kbdreset();
                return;
        }*/

        /* howto, bootdev, cyl */
        /*printf("entry %x [%x] ", x.a_entry, *(int *) x.a_entry);*/
        bcopy(0x9ff00, 0x300, 0x20); /* XXX */
        i = (*((int (*)()) x.a_entry))(howto, bootdev, off);

        if (i) printf("Program exits with %d", i) ;
        return;
shread:
        printf("Read of file is incomplete");
        return;
}