freebsd-skq/usr.bin/mkimg/ebr.c
emaste c4e448c582 mkimg: support fat16b partitions (MBR type 06h)
Reviewed by:	marcel
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D3894
2015-10-15 01:09:14 +00:00

137 lines
3.7 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/types.h>
#include <sys/diskmbr.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "image.h"
#include "mkimg.h"
#include "scheme.h"
#ifndef DOSPTYP_FAT16B
#define DOSPTYP_FAT16B 0x06
#endif
#ifndef DOSPTYP_FAT32
#define DOSPTYP_FAT32 0x0b
#endif
static struct mkimg_alias ebr_aliases[] = {
{ ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16B) },
{ ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
{ ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
{ ALIAS_NONE, 0 }
};
static lba_t
ebr_metadata(u_int where, lba_t blk)
{
blk += (where == SCHEME_META_PART_BEFORE) ? 1 : 0;
return (round_track(blk));
}
static void
ebr_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
ebr_write(lba_t imgsz __unused, void *bootcode __unused)
{
u_char *ebr;
struct dos_partition *dp;
struct part *part, *next;
lba_t block, size;
int error;
ebr = malloc(secsz);
if (ebr == NULL)
return (ENOMEM);
memset(ebr, 0, secsz);
le16enc(ebr + DOSMAGICOFFSET, DOSMAGIC);
error = 0;
STAILQ_FOREACH_SAFE(part, &partlist, link, next) {
block = part->block - nsecs;
size = round_track(part->size);
dp = (void *)(ebr + DOSPARTOFF);
ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, nsecs);
dp->dp_typ = ALIAS_TYPE2INT(part->type);
ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
part->block + size - 1);
le32enc(&dp->dp_start, nsecs);
le32enc(&dp->dp_size, size);
/* Add link entry */
if (next != NULL) {
size = round_track(next->size);
dp++;
ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
next->block - nsecs);
dp->dp_typ = DOSPTYP_EXT;
ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
next->block + size - 1);
le32enc(&dp->dp_start, next->block - nsecs);
le32enc(&dp->dp_size, size + nsecs);
}
error = image_write(block, ebr, 1);
if (error)
break;
memset(ebr + DOSPARTOFF, 0, 2 * DOSPARTSIZE);
}
free(ebr);
return (error);
}
static struct mkimg_scheme ebr_scheme = {
.name = "ebr",
.description = "Extended Boot Record",
.aliases = ebr_aliases,
.metadata = ebr_metadata,
.write = ebr_write,
.nparts = 4096,
.maxsecsz = 4096
};
SCHEME_DEFINE(ebr_scheme);