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freebsd/usr.bin/mkimg/mbr.c
Warner Losh c30dcf40ba Add a new flag to mkimg (-a num) to specify the active partition for
those partitioning schemes that have this concept. Implement it as an
override for mbr's setting 0x80 in the flags for the first partition
when we have boot code.

Differential Revision: https://reviews.freebsd.org/D4403
2016-10-18 05:43:12 +00:00

126 lines
3.6 KiB
C

/*-
* Copyright (c) 2014 Juniper Networks, 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 AUTHOR 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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <sys/errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <mbr.h>
#include "endian.h"
#include "image.h"
#include "mkimg.h"
#include "scheme.h"
static struct mkimg_alias mbr_aliases[] = {
{ ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) },
{ ALIAS_EFI, ALIAS_INT2TYPE(DOSPTYP_EFI) },
{ ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) },
{ ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
{ ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
{ ALIAS_NTFS, ALIAS_INT2TYPE(DOSPTYP_NTFS) },
{ ALIAS_PPCBOOT, ALIAS_INT2TYPE(DOSPTYP_PPCBOOT) },
{ ALIAS_NONE, 0 } /* Keep last! */
};
static lba_t
mbr_metadata(u_int where, lba_t blk)
{
blk += (where == SCHEME_META_IMG_START) ? 1 : 0;
return (round_track(blk));
}
static void
mbr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
{
u_int cyl, hd, sec;
mkimg_chs(lba, 1023, &cyl, &hd, &sec);
*cylp = cyl;
*hdp = hd;
*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
}
static int
mbr_write(lba_t imgsz __unused, void *bootcode)
{
u_char *mbr;
struct dos_partition *dpbase, *dp;
struct part *part;
lba_t size;
int error;
mbr = malloc(secsz);
if (mbr == NULL)
return (ENOMEM);
if (bootcode != NULL) {
memcpy(mbr, bootcode, DOSPARTOFF);
memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF);
} else
memset(mbr, 0, secsz);
le16enc(mbr + DOSMAGICOFFSET, DOSMAGIC);
dpbase = (void *)(mbr + DOSPARTOFF);
TAILQ_FOREACH(part, &partlist, link) {
size = round_track(part->size);
dp = dpbase + part->index;
if (active_partition != 0)
dp->dp_flag =
(part->index + 1 == active_partition) ? 0x80 : 0;
else
dp->dp_flag =
(part->index == 0 && bootcode != NULL) ? 0x80 : 0;
mbr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
part->block);
dp->dp_typ = ALIAS_TYPE2INT(part->type);
mbr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
part->block + size - 1);
le32enc(&dp->dp_start, part->block);
le32enc(&dp->dp_size, size);
}
error = image_write(0, mbr, 1);
free(mbr);
return (error);
}
static struct mkimg_scheme mbr_scheme = {
.name = "mbr",
.description = "Master Boot Record",
.aliases = mbr_aliases,
.metadata = mbr_metadata,
.write = mbr_write,
.bootcode = 512,
.nparts = NDOSPART,
.maxsecsz = 4096
};
SCHEME_DEFINE(mbr_scheme);