/*      $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;
}