/*      $NetBSD: biosdisk.c,v 1.4 2021/05/17 19:31:38 mrg Exp $ */

/*
 * Copyright (c) 1996, 1998
 *      Matthias Drochner.  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 AUTHOR ``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 AUTHOR 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.
 *
 */

/*
 * raw BIOS disk device for libsa.
 * needs lowlevel parts from bios_disk.S and biosdisk_ll.c
 * partly from netbsd:sys/arch/i386/boot/disk.c
 * no bad144 handling!
 *
 * A lot of this must match sys/kern/subr_disk_mbr.c
 */

/*
 * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
 *
 * Mach Operating System
 * Copyright (c) 1992, 1991 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

#include <sys/types.h>
#include <sys/disklabel.h>

#include <lib/libkern/libkern.h>
#include <lib/libsa/stand.h>
#include <lib/libsa/saerrno.h>
#include <lib/libsa/loadfile.h>

#include <machine/disklabel.h>

#include "biosdisk.h"
#include "biosdisk_ll.h"

#include "bootinfo.h"

#define BUFSIZE (1 * BIOSDISK_SECSIZE)

struct biosdisk {
        int     dev;
        int     boff;
        char    buf[BUFSIZE];
};

static struct btinfo_bootdisk bi_disk;

#define RF_PROTECTED_SECTORS    64      /* XXX refer to <.../rf_optnames.h> */

static struct biosdisk *
alloc_biosdisk(int dev)
{
        struct biosdisk *d;

        d = (struct biosdisk *)ALLOC(sizeof(*d));
        if (d == NULL)
                return (NULL);

        memset(d, 0, sizeof(*d));
        d->dev = dev;

        return (d);
}

static int
check_label(struct biosdisk *d, int sector)
{
        struct disklabel *lp;

        /* find partition in NetBSD disklabel */
        if (readsects(d->dev, sector + LABELSECTOR, d->buf, 1)) {
#ifdef DISK_DEBUG
                printf("Error reading disklabel\n");
#endif
                return (EIO);
        }

        lp = (struct disklabel *)(d->buf + LABELOFFSET);
        if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
#ifdef DISK_DEBUG
                printf("warning: no disklabel\n");
#endif
                return (-1);
        }

        d->boff = sector;
        return (0);
}

static int
read_label(struct biosdisk *d)
{
        struct mbr_sector *mbr_sect;
        struct disklabel dflt_lbl;
        struct mbr_partition mbr[MBR_PART_COUNT];
        struct partition *p;
        int sector, i;
        int error;
        int typ;
        int ext_base, this_ext, next_ext;
#ifdef COMPAT_386BSD_MBRPART
        int sector_386bsd = -1;
#endif

        memset(&dflt_lbl, 0, sizeof dflt_lbl);
        dflt_lbl.d_npartitions = 8;

        d->boff = 0;

        /*
         * find NetBSD Partition in DOS partition table
         * XXX check magic???
         */
        ext_base = 0;
        next_ext = 0;
        for (;;) {
                this_ext = ext_base + next_ext;
                next_ext = 0;
                mbr_sect = (struct mbr_sector *)d->buf;
                memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
                if (readsects(d->dev, this_ext, d->buf, 1)) {
#ifdef DISK_DEBUG
                        printf("error reading MBR sector %d\n", this_ext);
#endif
                        return (EIO);
                }
                memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
                /* Look for NetBSD partition ID */
                for (i = 0; i < MBR_PART_COUNT; i++) {
                        typ = mbr[i].mbrp_type;
                        if (typ == 0)
                                continue;
                        sector = this_ext + mbr[i].mbrp_start;
                        if (typ == MBR_PTYPE_NETBSD) {
                                error = check_label(d, sector);
                                if (error >= 0)
                                        return error;
                        }
                        if (MBR_IS_EXTENDED(typ)) {
                                next_ext = mbr[i].mbrp_start;
                                continue;
                        }
#ifdef COMPAT_386BSD_MBRPART
                        if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
                                sector_386bsd = sector;
#endif
                        if (this_ext != 0) {
                                if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
                                        continue;
                                p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
                        } else
                                p = &dflt_lbl.d_partitions[i];
                        p->p_offset = sector;
                        p->p_size = mbr[i].mbrp_size;
                        p->p_fstype = xlat_mbr_fstype(typ);
                }
                if (next_ext == 0)
                        break;
                if (ext_base == 0) {
                        ext_base = next_ext;
                        next_ext = 0;
                }
        }

        sector = 0;
#ifdef COMPAT_386BSD_MBRPART
        if (sector_386bsd != -1) {
                printf("old BSD partition ID!\n");
                sector = sector_386bsd;
        }
#endif

        /*
         * One of two things:
         *      1. no MBR
         *      2. no NetBSD partition in MBR
         *
         * We simply default to "start of disk" in this case and
         * press on.
         */
        error = check_label(d, sector);
        if (error >= 0)
                return (error);

        /*
         * Nothing at start of disk, return info from mbr partitions.
         */
        /* XXX fill it to make checksum match kernel one */
        dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
        memcpy(d->buf, &dflt_lbl, sizeof(dflt_lbl));
        return (-1);
}


/*
 * Determine likely partition for possible sector number of dos
 * partition.
 */
u_int
biosdisk_findptn(int biosdev, u_int sector)
{
        struct biosdisk *d;
        u_int partition = 0;
        struct disklabel *lp;

        /* Look for netbsd partition that is the dos boot one */
        d = alloc_biosdisk(biosdev);
        if (d == NULL)
                return (0);

        if (read_label(d) == 0) {
                lp = (struct disklabel *)(d->buf + LABELOFFSET);
                for (partition = lp->d_npartitions; --partition;){
                        if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
                                continue;
                        if (lp->d_partitions[partition].p_offset == sector)
                                break;
                }
        }

        DEALLOC(d, sizeof(*d));
        return (partition);
}

int
biosdisk_open(struct open_file *f, ...)
{
        va_list ap;
        struct biosdisk *d;
        struct disklabel *lp;
        int dev;
        int partition;
        int error = 0;

        va_start(ap, f);
        dev = va_arg(ap, int);
        d = alloc_biosdisk(dev);
        if (d == NULL) {
                error = ENXIO;
                goto out;
        }

        partition = va_arg(ap, int);
        bi_disk.biosdev = d->dev;
        bi_disk.partition = partition;
        bi_disk.labelsector = -1;

        if (partition == RAW_PART)
                goto nolabel;
        error = read_label(d);
        if (error == -1) {
                error = 0;
                goto nolabel;
        }
        if (error)
                goto out;

        lp = (struct disklabel *)(d->buf + LABELOFFSET);
        if (partition >= lp->d_npartitions ||
           lp->d_partitions[partition].p_fstype == FS_UNUSED) {
#ifdef DISK_DEBUG
                printf("illegal partition\n");
#endif
                error = EPART;
                goto out;
        }
        bi_disk.labelsector = d->boff + LABELSECTOR;
        bi_disk.label.type = lp->d_type;
        memcpy(bi_disk.label.packname, lp->d_packname, 16);
        bi_disk.label.checksum = lp->d_checksum;

        d->boff = lp->d_partitions[partition].p_offset;
        if (lp->d_partitions[partition].p_fstype == FS_RAID) {
                d->boff += RF_PROTECTED_SECTORS;
        }
nolabel:

#ifdef DISK_DEBUG
        printf("partition @%d\n", d->boff);
#endif

        BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));

        f->f_devdata = d;
out:
        va_end(ap);
        if (error)
                DEALLOC(d, sizeof(struct biosdisk));
        return (error);
}

int
biosdisk_close(struct open_file *f)
{
        struct biosdisk *d = f->f_devdata;

        DEALLOC(d, sizeof(struct biosdisk));
        f->f_devdata = NULL;

        return (0);
}

int 
biosdisk_ioctl(struct open_file *f, u_long cmd, void *arg)
{

        return (EIO);
}

int
biosdisk_strategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
{
        struct biosdisk *d;
        int blks;
        int frag;

        if (flag != F_READ)
                return EROFS;

        d = (struct biosdisk *)devdata;

        dblk += d->boff;

        blks = size / BIOSDISK_SECSIZE;
        if (blks && readsects(d->dev, dblk, buf, blks)) {
                if (rsize)
                        *rsize = 0;
                return (EIO);
        }

        /* do we really need this? */
        frag = size % BIOSDISK_SECSIZE;
        if (frag) {
                if (readsects(d->dev, dblk + blks, d->buf, 1)) {
                        if (rsize)
                                *rsize = blks * BIOSDISK_SECSIZE;
                        return (EIO);
                }
                memcpy(buf + blks * BIOSDISK_SECSIZE, d->buf, frag);
        }

        if (rsize)
                *rsize = size;
        return (0);
}