/*      $NetBSD: amiga.c,v 1.10 2019/05/07 04:35:31 thorpej Exp $       */

/*-
 * Copyright (c) 1999, 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Michael Hitch.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Luke Mewburn of Wasabi Systems.
 *
 * 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.
 */

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if !defined(__lint)
__RCSID("$NetBSD: amiga.c,v 1.10 2019/05/07 04:35:31 thorpej Exp $");
#endif  /* !__lint */

#include <sys/param.h>
#include <sys/stat.h>

#include <assert.h>
#include <err.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#include "installboot.h"

/* XXX Must be kept in sync with bbstart.s! */
#define CMDLN_LOC 0x10
#define CMDLN_LEN 0x20

#define CHKSUMOFFS 1

u_int32_t chksum(u_int32_t *, int);

static int amiga_setboot(ib_params *);

struct ib_mach ib_mach_amiga = {
        .name           =       "amiga",
        .setboot        =       amiga_setboot,
        .clearboot      =       no_clearboot,
        .editboot       =       no_editboot,
        .valid_flags    =       IB_STAGE1START | IB_STAGE2START | IB_COMMAND,
};

static int
amiga_setboot(ib_params *params)
{
        int retval;
        ssize_t                 rv;
        char *dline;
        int sumlen;
        u_int32_t sum2, sum16;

        struct stat             bootstrapsb;

        u_int32_t block[128*16];

        retval = 0;
        if (fstat(params->s1fd, &bootstrapsb) == -1) {
                warn("Examining `%s'", params->stage1);
                goto done;
        }
        if (!S_ISREG(bootstrapsb.st_mode)) {
                warnx("`%s' must be a regular file", params->stage1);
                goto done;
        }

        rv = pread(params->s1fd, &block, sizeof(block), 0);
        if (rv == -1) {
                warn("Reading `%s'", params->stage1);
                goto done;
        } else if (rv != sizeof(block)) {
                warnx("Reading `%s': short read", params->stage1);
                goto done;
        }

        /* XXX the choices should not be hardcoded */

        sum2  = chksum(block, 1024/4);
        sum16 = chksum(block, 8192/4);

        if (sum16 == 0xffffffff) {
                sumlen = 8192/4;
        } else if (sum2 == 0xffffffff) {
                sumlen = 1024/4;
        } else {
                errx(1, "%s: wrong checksum", params->stage1);
                /* NOTREACHED */
        }

        if (sum2 == sum16) {
                warnx("eek - both sums are the same");
        }

        if (params->flags & IB_COMMAND) {
                dline = (char *)&(block[CMDLN_LOC/4]);
                /* XXX keep the default default line in sync with bbstart.s */
                if (strcmp(dline, "netbsd -ASn2") != 0) {
                        errx(1, "Old bootblock version? Can't change command line.");
                }
                (void)strncpy(dline, params->command, CMDLN_LEN-1);

                block[1] = htobe32(0);
                block[1] = htobe32(0xffffffff - chksum(block, sumlen));
        }

        if (params->flags & IB_NOWRITE) {
                retval = 1;
                goto done;
        }

        if (params->flags & IB_VERBOSE)
                printf("Writing boot block\n");
        rv = pwrite(params->fsfd, &block, sizeof(block), 0);
        if (rv == -1) {
                warn("Writing `%s'", params->filesystem);
                goto done;
        } else if (rv != sizeof(block)) {
                warnx("Writing `%s': short write", params->filesystem);
                goto done;
        } else {
                retval = 1;
        }

 done:
        return (retval);
}

u_int32_t
chksum(block, size)
        u_int32_t *block;
        int size;
{
        u_int32_t sum, lastsum;
        int i;

        sum = 0;

        for (i=0; i<size; i++) {
                lastsum = sum;
                sum += be32toh(block[i]);
                if (sum < lastsum)
                        ++sum;
        }

        return sum;
}