/*      $NetBSD: autoconf.c,v 1.11 2023/12/20 15:00:08 thorpej Exp $    */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: autoconf.c,v 1.11 2023/12/20 15:00:08 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/disklabel.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/disk.h>
#include <sys/proc.h>
#include <sys/kauth.h>

#include <machine/bootinfo.h>
#include <machine/intr.h>

void
cpu_configure(void)
{

        /* Start configuration */
        splhigh();
        intr_init();

        if (config_rootfound("mainbus", NULL) == NULL)
                panic("no mainbus found");

        /* Configuration is finished, turn on interrupts. */
        spl0();
}

static int
is_valid_disk(device_t dv)
{
        const char *name;

        if (device_class(dv) != DV_DISK)
                return (0);
        
        name = device_cfdata(dv)->cf_name;

        return (strcmp(name, "sd") == 0 || strcmp(name, "wd") == 0 ||
                strcmp(name, "ld") == 0);
}

/*
 * Helper function for findroot():
 * Return non-zero if disk device matches bootinfo.
 */
static int
match_bootdisk(device_t dv, struct btinfo_bootdisk *bid)
{
        struct vnode *tmpvn;
        int error;
        struct disklabel label;
        int found = 0;
        int bmajor;

        /*
         * A disklabel is required here.  The boot loader doesn't refuse
         * to boot from a disk without a label, but this is normally not
         * wanted.
         */
        if (bid->labelsector == -1)
                return (0);
        
        /*
         * Lookup major number for disk block device.
         */
        bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
        if (bmajor == -1)
                return (0);     /* XXX panic ??? */

        /*
         * Fake a temporary vnode for the disk, open it, and read
         * the disklabel for comparison.
         */
        if (bdevvp(MAKEDISKDEV(bmajor, device_unit(dv), RAW_PART), &tmpvn))
                panic("match_bootdisk: can't alloc vnode");
        vn_lock(tmpvn, LK_EXCLUSIVE | LK_RETRY);
        error = VOP_OPEN(tmpvn, FREAD, NOCRED);
        if (error) {
#ifndef DEBUG
                /*
                 * Ignore errors caused by missing device, partition,
                 * or medium.
                 */
                if (error != ENXIO && error != ENODEV)
#endif
                        aprint_error("match_bootdisk: can't open dev %s (%d)\n",
                            device_xname(dv), error);
                vput(tmpvn);
                return (0);
        }
        VOP_UNLOCK(tmpvn);
        error = VOP_IOCTL(tmpvn, DIOCGDINFO, &label, FREAD, NOCRED);
        if (error) {
                /*
                 * XXX Can't happen -- open() would have errored out
                 * or faked one up.
                 */
                aprint_error("match_bootdisk: can't get label for dev %s (%d)\n",
                    device_xname(dv), error);
                goto closeout;
        }

        /* Compare with our data. */
        if (label.d_type == bid->label.type &&
            label.d_checksum == bid->label.checksum &&
            strncmp(label.d_packname, bid->label.packname, 16) == 0)
                found = 1;

closeout:
        vn_lock(tmpvn, LK_EXCLUSIVE | LK_RETRY);
        VOP_CLOSE(tmpvn, FREAD, NOCRED);
        vput(tmpvn);
        return (found);
}

/*
 * 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.
 */
static void
findroot(void)
{
        struct btinfo_bootdisk *bid;
        device_t dv;
        deviter_t di;

        if (booted_device)
                return;

        if ((bid = lookup_bootinfo(BTINFO_BOOTDISK)) != NULL) {
                /*
                 * Scan all disk devices for ones that match the passed data.
                 * Don't break if one is found, to get possible multiple
                 * matches - for problem tracking.  Use the first match anyway
                 * because lower device numbers are more likely to be the
                 * boot device.
                 */
                for (dv = deviter_first(&di, DEVITER_F_ROOT_FIRST);
                     dv != NULL;
                     dv = deviter_next(&di)) {
                        if (device_class(dv) != DV_DISK)
                                continue;

                        if (is_valid_disk(dv)) {
                                if (match_bootdisk(dv, bid) == 0)
                                        continue;
                                goto bootdisk_found;
                        }
                        continue;

bootdisk_found:
                        if (booted_device) {
                                aprint_error("WARNING: double match for boot "
                                    "device (%s, %s)\n",
                                    device_xname(booted_device), device_xname(dv));
                                continue;
                        }
                        booted_device = dv;
                        booted_partition = bid->partition;
                }
                deviter_release(&di);

                if (booted_device)
                        return;
        }
}

void
cpu_rootconf(void)
{

        findroot();

        aprint_normal("boot device: %s\n",
            booted_device ? device_xname(booted_device) : "<unknown>");
        rootconf();
}