.\"	$NetBSD: dosboot.8,v 1.11 2000/09/24 17:03:28 jdolecek Exp $
.Dd May 13, 2000
.Os
.Dt DOSBOOT 8 i386
.Sh NAME
.Nm dosboot
.Nd boot NetBSD/i386 from DOS
.Sh SYNOPSIS
.Nm
.Op Fl u
.Op Fl c Ar command
.Op Fl i
.Op Ar path Op Fl adqsv
.Sh DESCRIPTION
.Nm
is an 
.Tn MS-DOS
program.  It is a boot loader for
.Nx Ns Tn /i386
designed to permit
.Nx
to be booted directly from 
.Tn MS-DOS .
By default, it boots a file with
name
.Pa NETBSD
in the current 
.Tn MS-DOS
directory.
.Nm
shares common code with the standard boot loader,
.Xr boot 8 .
.Pp
The recognized options are:
.Bl -tag -width -ads -offset 04n
.It Fl u
Boot from a UFS filesystem instead of an 
.Tn MS-DOS
filesystem.
.It Fl c
Execute
.Ar command
(see below).
.It Fl i
Enter interactive mode.
.Nm
will present a prompt, allowing input of commands (see below).
.Pp
.It Pa path
Specifies the kernel file. In 
.Tn MS-DOS
mode (default) a normal 
.Tn MS-DOS
filename (with or without drive specification) is accepted.
In UFS mode (after
.Fl u
or after a 
.Ic mode ufs
command), a path in a
.Nx
filesystem
is expected. By default, the file is looked up in partition 'a' of
the first harddisk. Another device or partition can be specified
by prepending a block device name in terms of
.Nx ,
followed
by a colon (see 
.Xr boot 8
and examples).
.It Fl adqsv
Flags passed to the kernel, see
.Xr boot 8 .
.El
.Pp
The commands accepted after the
.Fl c
flag or in interactive mode are:
.\" NOTE: much of this text is duplicated in boot.8; please try to
.\" keep both files synchronized.
.Bl -tag -width 04n -offset 04n
.It Xo Ic boot
.Op Va device : Ns
.Op Va filename
.Op Fl adqsv
.Xc
Boot
.Nx . See
.Cm boot
in
.Xr boot 8
for full details.
.It Ic dev Op device
Set the default device and partition for subsequent filesystem operations.
Without an operand, print the current setting.
This setting doesn't apply to 
.Tn MS-DOS
mode.
.It Ic help
Print an overview about commands and arguments.
.It Ic ls Op Pa path
Print a directory listing of
.Pa path ,
containing inode number, filename and file type. This command works in
UFS mode only. path can contain a device specification.
.It Ic mode Va fstype
Switch filesystem type;
.Va fstype
should be one of
.Ar dos
or
.Ar ufs .
.It Ic quit
Leave the
.Nm
program and exit to 
.Tn MS-DOS .
.El
.Pp
.Nm
is also installed in the
.Xr release 7
hierarchy, under
.Pa installation/misc/dosboot.com .
.Sh EXAMPLES
To boot a
.Nx
kernel located on 
.Tn MS-DOS
drive D, one would issue:
.Bd -literal -offset indent
dosboot D:\\NODOS\\NETBSD
.Ed
.Pp
To boot from a
.Nx
floppy into single user mode, type eg:
.Bd -literal -offset indent
dosboot -u fd0a:netbsd -s
.Ed
.Sh FILES
.Pa /usr/mdec/dosboot.com
.Sh BUGS
.Nm
assumes that the processor is in real mode at startup. It does not work
well in the presence of 
.Tn MS-DOS
extenders and memory managers.
.Pp
.Nm
does not run directly under 
.Tn Windows 95 .
See
.Xr w95boot 8
for a method of starting
.Nx
from
.Tn Windows 95
using dosboot.
.Pp
In UFS mode, files can only be loaded from devices known to the BIOS.
The device names do not necessarily comply with the names later
used by the booted
.Nx
kernel.
.Pp
In 
.Tn MS-DOS
mode, no useful boot device specification is passed to
.Nx .
It is necessary to have the root device hardwired into the kernel
configuration or to enter it manually.
.Sh SEE ALSO
.Xr release 7 ,
.Xr boot 8 ,
.Xr w95boot 8
.Sh HISTORY
The
.Nx Ns Tn /i386
.Nm
command first appeared in
.Nx 1.3 .