freebsd-dev/usr.bin/mkimg/mbr.c
Marcel Moolenaar 789a10b106 Add mkimg_write() which combines lseek(2) and write(2) and uses
sector granularity for both offset and length. Have all schemes
use mkimg_write() instead of mkimg_seek() followed by write(2).

Now that schemes don't use lseek(2) nor write(2) directly, it's
easier to support output formats other than raw disks.
2014-05-06 21:54:05 +00:00

116 lines
3.3 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 "mkimg.h"
#include "scheme.h"
#ifndef DOSPTYP_FAT32
#define DOSPTYP_FAT32 0x0b
#endif
static struct mkimg_alias mbr_aliases[] = {
{ ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) },
{ ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
{ ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
{ ALIAS_NONE, 0 } /* Keep last! */
};
static u_int
mbr_metadata(u_int where)
{
u_int secs;
secs = (where == SCHEME_META_IMG_START) ? nsecs : 0;
return (secs);
}
static void
mbr_chs(u_char *cyl, u_char *hd, u_char *sec, uint32_t lba __unused)
{
*cyl = 0xff; /* XXX */
*hd = 0xff; /* XXX */
*sec = 0xff; /* XXX */
}
static int
mbr_write(int fd, lba_t imgsz __unused, void *bootcode)
{
u_char *mbr;
struct dos_partition *dpbase, *dp;
struct part *part;
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);
STAILQ_FOREACH(part, &partlist, link) {
dp = dpbase + part->index;
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 + part->size - 1);
le32enc(&dp->dp_start, part->block);
le32enc(&dp->dp_size, part->size);
}
error = mkimg_write(fd, 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);