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Finish implementing "setdrv" option. This is intended to be used

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(with care) in those instances where boot0 is not passed the
correct drive number by the PC BIOS.  (The symptoms are a
"F5   Drive 0" line, even though the current drive is drive 0.)
This commit is contained in:
Robert Nordier 1999-02-26 14:57:17 +00:00
parent 5052aa25a1
commit ee6fb785cd
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=44297
2 changed files with 10 additions and 7 deletions
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10
usr.sbin/boot0cfg/boot0cfg.8
View File

@ -22,7 +22,7 @@
.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $Id: boot0cfg.8,v 1.1.1.1 1999/02/21 21:23:42 rnordier Exp $
.\" $Id: boot0cfg.8,v 1.2 1999/02/22 09:36:54 rnordier Exp $
.\"
.Dd February 21, 1999
.Dt BOOT0CFG 8
@ -101,7 +101,7 @@ the conventional (CHS) interface, when accessing disk-related BIOS
services. The default is
.Sq nopacket .
.It setdrv
Causes the drive containing the disk to be referenced using drive
Forces the drive containing the disk to be referenced using drive
number definable by means of the -d option. The default is
.Sq nosetdrv .
.It update
@ -131,7 +131,7 @@ option may cause
.Sq boot0
to fail, depending on the nature of BIOS support.
.Pp
The
Use of the
.Sq setdrv
option is presently implemented
.Dq syntactically but not semantically .
option with an incorrect -d operand may cause the MBR to be written
to the wrong disk. Be careful!

7
usr.sbin/boot0cfg/boot0cfg.c
View File

@ -26,7 +26,7 @@
#ifndef lint
static const char rcsid[] =
"$Id: boot0cfg.c,v 1.1.1.1 1999/02/21 21:23:42 rnordier Exp $";
"$Id: boot0cfg.c,v 1.2 1999/02/22 09:36:54 rnordier Exp $";
#endif /* not lint */
#include <sys/param.h>
@ -44,6 +44,7 @@ static const char rcsid[] =
#define MBRSIZE 512 /* master boot record size */
#define OFF_DRIVE 0x1ba /* offset: setdrv drive */
#define OFF_FLAGS 0x1bb /* offset: option flags */
#define OFF_TICKS 0x1bc /* offset: clock ticks */
#define OFF_PTBL 0x1be /* offset: partition table */
@ -154,6 +155,8 @@ main(int argc, char *argv[])
errx(1, "%s: bad magic", bpath);
memcpy(buf + OFF_PTBL, part, sizeof(part));
}
if (d_arg != -1)
buf[OFF_DRIVE] = d_arg;
if (o_flag) {
buf[OFF_FLAGS] &= o_and;
buf[OFF_FLAGS] |= o_or;
@ -185,7 +188,7 @@ main(int argc, char *argv[])
part[i].dp_size);
}
printf("\n");
printf("drive=0x0 options=");
printf("drive=0x%x options=", buf[OFF_DRIVE]);
for (i = 0; i < nopt; i++) {
if (i)
printf(",");