#!/usr/bin/perl -w

# Program to create a netboot image for ROM/FreeDOS/DOS/Linux
# Placed under GNU Public License by Ken Yap, December 2000

BEGIN {
	push(@INC, '/usr/lib/mknbi');
}

use strict;
use Getopt::Long;
use Socket;

use TruncFD;
use Nbi;
use Elf;

use constant;
use constant DEBUG => 0;

use vars qw($libdir $version $format $target $output $module $relocseg $relocsegstr
	$progreturns $param $append $rootdir $rootmode $ipaddrs $ramdisk $rdbase
	$simhd $dishd $squashfd $first16 $first32pm);

sub check_file
{
	my ($f, $status);

	$status = 1;
	foreach $f (@_) {
		if (!-e $f) {
			print STDERR "$f: file not found\n";
			$status = 0;
		} elsif (!-f $f) {
			print STDERR "$f: not a plain file\n";
			$status = 0;
		} elsif (!-r $f) {
			print STDERR "$f: file not readable\n";
			$status = 0;
		}
	}
	return ($status);
}

sub mknbi_rom ($)
{
	my ($format) = @_;
	my ($romdesc);

	$#ARGV >= 0 or die "Usage: progname romimage\n";
	return unless check_file($ARGV[0]);
	$format->add_header("mknbi-rom-$version", $relocseg + 0x3E0, 0x1000, 6);
	$romdesc = { file => $ARGV[0],
		segment => 0x1000,
		maxlen => 0x10000,
		id => 16,
		end => 1 };
	$format->add_segment($romdesc);
	$format->dump_segments();
	$format->copy_file($romdesc);
}

sub inet_aton_warn
{
	my ($ip);

	print STDERR "Warning: $_[0] cannot be resolved to an IP address\n" unless defined($ip = inet_aton($_[0]));
	return ($ip);
}

sub resolve_names
{
	my ($i);

	my ($client, $server, $gateway, $netmask, $hostname) = split(/:/, $_[0], 5);
	unless (defined($hostname)) {
		print STDERR "$_[0]: invalid specification\n";
		return ($_[0]);
	}
	$client = inet_ntoa($i) if defined($i = &inet_aton_warn($client));
	$server = inet_ntoa($i) if defined($i = &inet_aton_warn($server));
	$gateway = inet_ntoa($i) if defined($i = &inet_aton_warn($gateway));
	return (join(':', $client, $server, $gateway, $netmask, $hostname));
}

sub make_paramstring ($)
{
	my ($paramsize) = @_;
	my ($string, $nfsroot);

	# --param= overrides everything
	return ($param) if (defined($param));
	# String substitute various options, should do sanity checks also
	if (!defined($rootdir)) {
		$rootdir = '/dev/nfs';
	} elsif ($rootdir !~ m(^/dev/)) {
		$nfsroot = $rootdir;
		undef($nfsroot) if ($nfsroot eq 'kernel');
		$rootdir = '/dev/nfs';
	}
	if (defined($ipaddrs)) {
		if ($ipaddrs eq 'kernel') {
			undef($ipaddrs);
		} elsif ($ipaddrs !~ /^(rom|off|none|on|any|dhcp|bootp|rarp|both)$/) {
			$ipaddrs = &resolve_names($ipaddrs);
		}
	} elsif (!defined($ramdisk)) {
		print STDERR "Warning: The --ip option was not used; you may need it if you use NFSroot.\n\tPlease see the documentation.\n";
	}
	die "Ramdisk mode should be one of: top asis 0xNNNNNNNN (hex address)\n"
		if (defined($rdbase) and $rdbase !~ /^(top|asis|0x[\da-fA-F]{1,8})$/);
	# If rootmode is set, then check if it's rw or ro, and if so, use it
	if (defined($rootmode) and $rootmode !~ /^(rw|ro)$/) {
		die "-rootmode should be either rw or ro\n";
		undef($rootmode);
	}
	$string = defined($rootmode) ? $rootmode : 'rw';
	$string .= " root=$rootdir";
	$string .= " nfsroot=$nfsroot" if (defined($nfsroot));
	$string .= " ip=$ipaddrs" if (defined($ipaddrs));
	$string .= " rdbase=$rdbase" if (defined($rdbase));
	$string .= " $append" if (defined($append));
	return ($string);
}

use constant HEADER_SEG_OFFSET => 0x220;	# in units of 16 bytes
use constant START_OFFSET => 0x280;		# in units of 16 bytes
use constant START_MAX_LENGTH => 6144;
use constant PARAM_SEG_OFFSET => 0x240;		# in units of 16 bytes
use constant PARAM_MAX_LENGTH => 1024;

sub mknbi_linux ($)
{
	my ($format) = @_;
	my ($startaddr, $setupfile, $setupfile32, $libfile, $kernelfile, $setupdesc);
	my ($paramseg, $paramstring, $bootseg, $block);
	my ($setupseg, $kernelseg, $kernellen, $ramdiskseg, $rdloc);
	my ($setupsects, $flags, $syssize, $swapdev,
		$ramsize, $vidmode, $rootdev, $sig, $ver, $bigker);

	$startaddr = sprintf("%#x", ($relocseg + START_OFFSET) * 0x10);
	$libfile = ($main::format eq 'elf') ? "first32elf\@${startaddr}.linux" : "first32pm\@${startaddr}.linux";
	if (defined($first32pm)) {
		print STDERR "Warning: elf format and --first32pm require Etherboot 5.0 or later\n";
		$first16 = 0;	# implies 32 bit code
		# if empty, use default
		$setupfile32 = $first32pm eq '' ? "$libdir/$libfile" : $first32pm;
	} else {
		# otherwise use real mode version
		$setupfile32 = "$libdir/first32\@${startaddr}.linux";
	}
	# Use old 16 bit version?
	$setupfile = $first16 ? "$libdir/first16.linux" : $setupfile32;
	$#ARGV >= 0 or die "Usage: progname kernelimage [ramdisk]\n";
	$kernelfile = $ARGV[0];
	return unless check_file($setupfile, $kernelfile);
	if (defined($ramdisk = $ARGV[1])) {
		return unless check_file($ramdisk);
	}
	if (defined($first32pm)) {
		$format->add_pm_header("mknbi-linux-$version", $relocseg + HEADER_SEG_OFFSET, hex($startaddr), $progreturns);
	} else {
		$format->add_header("mknbi-linux-$version", $relocseg + HEADER_SEG_OFFSET, hex($startaddr) / 0x10, 0);
	}
	$setupdesc = { file => $setupfile,
		segment => hex($startaddr) / 0x10,
		maxlen => START_MAX_LENGTH,
		id => 16 };
	$paramstring = &make_paramstring(PARAM_MAX_LENGTH);
	$paramseg = { string => $paramstring,
		segment => $relocseg + PARAM_SEG_OFFSET,
		maxlen => 2048,
		id => 17 };
	$bootseg = { file => $kernelfile,
		segment => $relocseg + 0x0,
		len => 512,
		maxlen => 512,
		id => 18 };
	$format->peek_file($bootseg, \$block, 512) == 512
		or die "Error reading boot sector of $kernelfile\n";
	(undef, $setupsects, $flags, $syssize, $swapdev, $ramsize, $vidmode,
		$rootdev, $sig) = unpack('a497Cv7', $block);
	if ($sig != 0xAA55) {
		print STDERR "$kernelfile: not a Linux kernel image\n";
		return;
	}
	print STDERR 'setupsects flags syssize swapdev ramsize vidmode rootdev sig', "\n" if (DEBUG);
	print STDERR "$setupsects $flags $syssize $swapdev $ramsize $vidmode $rootdev $sig\n" if (DEBUG);
	$setupseg = { file => $kernelfile,
		segment => $relocseg + 0x20,
		fromoff => 512,
		len => $setupsects * 512,
		maxlen => 79 * 512,
		id => 19 };
	$format->peek_file($setupseg, \$block, 512) == 512
		or die "Error reading first setup sector of $kernelfile\n";
	(undef, $sig, $ver, undef, undef, undef, undef, undef, $flags) =
		unpack('va4v5C2', $block);
	print STDERR 'sig ver flags', "\n" if (DEBUG);
	print STDERR "$sig $ver $flags\n" if (DEBUG);
	if ($sig ne 'HdrS' or $ver < 0x201) {
		print STDERR "$kernelfile: not a Linux kernel image\n";
		return;
	}
	$bigker = ($flags & 0x1);
	$kernelseg = { file => $ARGV[0],
		segment => $bigker ? 0x10000 : 0x1000,
		maxlen => $bigker ? 15 * 1024 * 1024 : 1024 * 512, 
		fromoff => $setupsects * 512 + 512,
		id => 20,
		end => 1 };
	$ramdiskseg = { file => $ramdisk,
		segment => 0x10000,
		align => 4096,
		id => 21,
		end => 1 };
	$$kernelseg{'end'} = 0 if (defined($ramdisk));
	$format->add_segment($setupdesc);
	$format->add_segment($paramseg);
	$format->add_segment($bootseg);
	$format->add_segment($setupseg);
	$kernellen = $format->add_segment($kernelseg);
	if (!$bigker and $kernellen > (($relocseg - 0x1000) * 16)) {
		print STDERR "Warning, zImage kernel may collide with Etherboot\n";
	}
	# Put ramdisk following kernel at next 4096 byte boundary
	$$ramdiskseg{'segment'} += (($kernellen + 0xFFF) & ~0xFFF) >> 4 if ($bigker);
	# should be 0, 1 or 2 depending on rdbase
	$format->add_segment($ramdiskseg, "\x00") if (defined($ramdisk));
	$format->dump_segments();
	$format->copy_file($setupdesc);
	$format->copy_string($paramseg);
	$format->copy_file($bootseg);
	$format->copy_file($setupseg);
	$format->copy_file($kernelseg);
	$format->copy_file($ramdiskseg) if (defined($ramdisk));
}

sub get_geom ($$)
{
	my ($file, $block) = @_;
	my ($usedsize, $declsize, $firsttracksize, $geom_string, $fstype);
	my ($secttot, $secttrk, $heads, $bootid, $sig, $cyltot);

	($usedsize = $squashfd ? &TruncFD::truncfd($file) : -s $file) > 0
		or die "Error reading $file\n";
	(undef, $secttot, undef, $secttrk, $heads, undef, $bootid, undef,
		$fstype, $sig) = unpack('a19va3vva8Ca17a5@510a2', $$block);
	print STDERR "Warning, this doesn't appear to be a DOS boot sector\n"
		if ($sig ne "\x55\xAA");
	if ($simhd) {
		# change MediaDescriptor
		substr($$block, 0x15, 1) = "\xF8";
		# change HiddenSectors
		substr($$block, 0x1c, 4) = pack('V', $secttrk * $heads);
		# change the boot drive
		substr($$block, 0x24, 1) = "\x80";
	}
	$cyltot = $secttot / ($secttrk * $heads);
	$declsize = $secttot * 512;
	$firsttracksize = $secttrk * $heads * 512;
	print STDERR "Warning, used size $usedsize is greater than declared size $declsize\n"
		if ($usedsize > $declsize);
	$geom_string = pack('v3C2', $secttot, $secttrk, $cyltot, $simhd ? 0x80 : 0, $dishd);
	return ($usedsize, $declsize, $firsttracksize, $geom_string, $fstype);
}

sub mod_geom_string ($)
{
	my ($geom_string) = @_;
	my ($secttot, $secttrk, $cyltot, $simhd, $dishd) = unpack('v3C2', $geom_string);
	$cyltot++;	# for partition table
	return (pack('v3C2', $secttot, $secttrk, $cyltot, $simhd, $dishd));
}

sub encode_chs ($$$)
{
	my ($c, $h, $s) = @_;

	$s = ($s & 0x3F) | (($c & 0x300) >> 2);
	$c &= 0xFF;
	return ($h, $s, $c);
}

sub make_mbr ($$)
{
	my ($geom_string, $fstype) = @_;
	my ($heads, $bootsect);
	my ($secttot, $secttrk, $cyltot, $simhd, $x) = unpack('v3C2', $geom_string);

	$cyltot--;
	# $cyltot was incremented in mod_geom_string
	$heads = $secttot / ($secttrk * $cyltot);
	# bootsect is first sector of track 1
	$bootsect = $secttrk * $heads;
	# CHS stupidity:
	# cylinders is 0 based, heads is 0 based, but sectors is 1 based
	# 0x01 for FAT12, 0x04 for FAT16
	return (pack('@446C8V2@510v', 0x80, &encode_chs(1, 0, 1),
		$fstype eq 'FAT12' ? 0x01 : 0x04, &encode_chs($cyltot, $heads - 1, $secttrk),
		$bootsect, $secttot, 0xAA55));
}

sub mknbi_fdos ($)
{
	my ($format) = @_;
	my ($setupfile, $bootblock);
	my ($usedsize, $declsize, $firsttracksize, $geom_string, $fstype);
	my ($setupdesc, $kerneldesc, $firsttrackdesc, $bootdesc, $floppydesc);

	$setupfile = "$libdir/first.fdos";
	$#ARGV >= 1 or die "Usage: progname kernel.sys floppyimage\n";
	return unless check_file($setupfile, $ARGV[0], $ARGV[1]);
	$format->add_header("mknbi-fdos-$version", $relocseg + 0x200, $relocseg + 0x300, 0);
	$setupdesc = { file => $setupfile,
		segment => $relocseg + 0x300,
		maxlen => 4096,
		id => 16 };
	$kerneldesc = { file => $ARGV[0],
		segment => 0x60,
		maxlen => 0x40000,
		id => 17 };
	die "Ramdisk base should be of the form 0xNNNNNNNN (linear hex address)\n"
		if (defined($rdbase) and $rdbase !~ /^0x[\da-fA-F]{1,8}$/);
	$floppydesc = { file => $ARGV[1],
		segment => (defined($rdbase) ? (hex($rdbase) >> 4) : 0x11000),
		id => 18,
		end => 1 };
	$format->add_segment($setupdesc);
	$format->add_segment($kerneldesc);
	$format->peek_file($floppydesc, \$bootblock, 512) == 512
		or die "Error reading boot sector of $ARGV[1]\n";
	($usedsize, $declsize, $firsttracksize, $geom_string, $fstype)
		= &get_geom($ARGV[1], \$bootblock);
	$firsttrackdesc = { align => $firsttracksize };
	$$floppydesc{'fromoff'} = 512;
	$$floppydesc{'len'} = $usedsize;
	$$floppydesc{'len'} += $firsttracksize if $simhd;
	$$floppydesc{'maxlen'} = $declsize;
	$geom_string = &mod_geom_string($geom_string) if $simhd;
	$format->add_segment($floppydesc, $geom_string);
	$format->dump_segments();
	$format->copy_file($setupdesc);
	$format->copy_file($kerneldesc);
	if ($simhd) {
		$$firsttrackdesc{'string'} = &make_mbr($geom_string, $fstype);
		$format->copy_string($firsttrackdesc);
	}
	# write out modified bootblock, not the one in the file
	$bootdesc = { string => $bootblock };
	$format->copy_string($bootdesc);
	# Restore correct value of len and account for bootblock skipped
	$$floppydesc{'len'} = $usedsize - 512;
	$format->copy_file($floppydesc);
}

sub mknbi_dos ($)
{
	my ($format) = @_;
	my ($setupfile, $bootblock);
	my ($usedsize, $declsize, $firsttracksize, $geom_string, $fstype);
	my ($setupdesc, $firsttrackdesc, $bootdesc, $floppydesc);

	$setupfile = "$libdir/first.dos";
	$#ARGV >= 0 or die "Usage: progname floppyimage\n";
	return unless check_file($setupfile, $ARGV[0]);
	$format->add_header("mknbi-dos-$version", 0x1000, 0x1040, 0);
	$setupdesc = { file => $setupfile,
		segment => 0x1040,
		maxlen => 64512,
		id => 16 };
	die "Ramdisk base should be of the form 0xNNNNNNNN (linear hex address)\n"
		if (defined($rdbase) and $rdbase !~ /^0x[\da-fA-F]{1,8}$/);
	$floppydesc = { file => $ARGV[0],
		segment => (defined($rdbase) ? (hex($rdbase) >> 4) : 0x11000),
		id => 17,
		end => 1 };
	$format->add_segment($setupdesc);
	$format->peek_file($floppydesc, \$bootblock, 512) == 512
		or die "Error reading boot sector of $ARGV[0]\n";
	($usedsize, $declsize, $firsttracksize, $geom_string, $fstype)
		= &get_geom($ARGV[0], \$bootblock);
	$firsttrackdesc = { align => $firsttracksize };
	$$floppydesc{'fromoff'} = 512;
	$$floppydesc{'len'} = $usedsize;
	$$floppydesc{'len'} += $firsttracksize if $simhd;
	$$floppydesc{'maxlen'} = $declsize;
	$geom_string = &mod_geom_string($geom_string) if $simhd;
	$format->add_segment($floppydesc, $geom_string);
	$format->dump_segments();
	$format->copy_file($setupdesc);
	if ($simhd) {
		$$firsttrackdesc{'string'} = &make_mbr($geom_string, $fstype);
		$format->copy_string($firsttrackdesc);
	}
	# write out modified bootblock, not the one in the file
	$bootdesc = { string => $bootblock };
	$format->copy_string($bootdesc);
	# Restore correct value of len and account for bootblock skipped
	$$floppydesc{'len'} = $usedsize - 512;
	$format->copy_file($floppydesc);
}

sub mknbi_menu ($)
{
	my ($module) = @_;
	my ($menudesc, $datadesc);

	$#ARGV >= -1 or die "Usage: mk$format-menu [menudata]\n";
	print STDERR "Warning: mk$format-menu requires Etherboot 5.0 or later\n";
	return unless check_file("$libdir/menu");
	# $progreturns == 1
	$module->add_pm_header("mknbi-menu-$version", $relocseg + 0x0, 0x10000, 1);
	$menudesc = { file => "$libdir/menu",
		segment => 0x1000,
		maxlen => 0x10000,
		id => 16 };
	$module->add_segment($menudesc);
	if ($#ARGV >= 0) {
		return unless check_file($ARGV[0]);
		$datadesc = { file => $ARGV[0],
			segment => 0x2000,
			maxlen => 0x10000,
			id => 17,
			end => 1 };
		$module->add_segment($datadesc);
	} else {
		$$menudesc{'end'} = 1;
	}
	$module->dump_segments();
	$module->copy_file($menudesc);
	$module->copy_file($datadesc) if ($#ARGV >= 0);
}

$libdir = '/usr/lib/mknbi';		# where config and auxiliary files are stored

$version = '1.2-8';
$simhd = 0;
$dishd = 0;
$squashfd = 1;
$first16 = 0;
$relocsegstr = '0x9000';
$progreturns = 0;
GetOptions('format=s' => \$format,
	'target=s' => \$target,
	'output=s' => \$output,
	'param=s' => \$param,
	'append=s' => \$append,
	'rootdir=s' => \$rootdir,
	'rootmode=s' => \$rootmode,
	'ip=s' => \$ipaddrs,
	'ipaddrs=s' => \$ipaddrs,
	'rdbase=s' => \$rdbase,
	'harddisk!' => \$simhd,
	'disableharddisk!' => \$dishd,
	'squash!' => \$squashfd,
	'first16!' => \$first16,
	'first32pm:s' => \$first32pm,
	'progreturns!' => \$progreturns,
	'relocseg=s' => \$relocsegstr);

$0 =~ /mk([a-z]*)-([a-z]+)$/ and ($format = $1, $target = $2);
if (!defined($format)) {
	print STDERR "No format specified with program name or --format=\n";
	exit 1;
}
if (!defined($target)) {
	print STDERR "No target specified with program name or --target=\n";
	exit 1;
}
if (defined($output)) {
	die "$output: $!\n" unless open(STDOUT, ">$output");
}
binmode(STDOUT);

if ($format eq 'nbi') {
	$module = Nbi->new($libdir);
} elsif ($format eq 'elf') {
	# ELF implies 32-bit and PM interface
	$first16 = 0;
	$first32pm = '' if !defined($first32pm);
	$module = Elf->new($libdir);
} else {
	print STDERR "Format $format not supported\n";
}
if ($relocsegstr eq '0x9000' or $relocsegstr eq '0x8000') {
	$relocseg = hex($relocsegstr);
} else {
	print STDERR "relocseg must be 0x9000 or 0x8000 only, setting to 0x9000\n";
	$relocseg = 0x9000;
}
if ($target eq 'rom') {
	&mknbi_rom($module);
} elsif ($target eq 'linux') {
	&mknbi_linux($module);
} elsif ($target eq 'fdos') {
	if ($simhd and $dishd) {
		print STDERR "Warning: --harddisk and --disableharddisk are incompatible\n";
	}
	&mknbi_fdos($module);
} elsif ($target eq 'dos') {
	if ($simhd and $dishd) {
		print STDERR "Warning: --harddisk and --disableharddisk are incompatible\n";
	}
	&mknbi_dos($module);
} elsif ($target eq 'menu') {
	&mknbi_menu($module);
} else {
	print STDERR "Target $target not supported\n";
}

close(STDOUT);
exit 0;

__END__

=head1 NAME

mknbi - make network bootable image

=head1 SYNOPSIS

B<mknbi> --format=I<format> --target=I<target> [--output=I<outputfile>] I<target-specific-arguments>

B<mknbi-linux> [--output=I<outputfile>] I<kernelimage> [I<ramdisk>]

B<mkelf-linux> [--output=I<outputfile>] I<kernelimage> [I<ramdisk>]

B<mknbi-rom> [--output=I<outputfile>] I<ROM-image>

B<mknbi-menu> [--output=I<outputfile>] [I<dataimage>]

B<mkelf-menu> [--output=I<outputfile>] [I<dataimage>]

B<mknbi-fdos> [--output=I<outputfile>] I<kernel.sys floppyimage>

B<mknbi-dos> [--output=I<outputfile>] I<floppyimage>

=head1 DESCRIPTION

B<mknbi> is a program that makes network bootable images for various
operating systems suitable for network loading by Etherboot or Netboot,
which are ROM boot loaders.  If you are looking to boot using PXE, look
no further, mknbi is not what you want. You probably want something like
PXELINUX which is part of the SYSLINUX package.

B<mknbi> can be invoked with the B<--format> and B<--target> options or
links can be made to it under format and target specific names. E.g.
mkelf-linux is the same as mknbi --format=elf --target=linux.

B<--format>=I<format> Specify the format of the output. Currently
available are nbi and elf.  ELF format only works with linux and menu.
Otherwise the invocation is the same as for mknbi. In discussions below,
the mknbi form is used.

B<--target>=I<target> Specify the target binary. Currently available are
linux, menu, rom, fdos and dos. B<mknbi> is not needed for booting
FreeBSD.

B<--output=>I<outputfile> Specify the output file, can be used with
all variants.  Stdout is the default.

The package must be installed in the destination location before the
executables can be run, because it looks for library files.

Each of the variants will be described separately.

=head1 MKNBI-LINUX

B<mknbi-linux> makes a tagged image from a Linux kernel image, either
a zImage or a bzImage.

=head1 MKNBI-LINUX OPTIONS

B<--param=>I<string> Replace the default parameter string with the
specified one. This option overrides all the following options so you
should know what you are doing.

B<--append>=I<string> Appends the specified string to the existing
parameter string. This option operates after the other parameter options
have been evaluated.

B<--rootdir>=I<rootdir> Define name of directory to mount via NFS from
the boot server.

In the absence of this option, the default is to use the directory
C</tftpboot/>I<%s>, with the I<%s> representing the hostname or
IP-address of the booting system, depending on whether the hostname
attribute is present in the BOOTP/DHCP reply.

If C<rom> is given, and if the BOOTP/DHCP server is able to handle the RFC 1497
extensions, the value of the rootpath option is used as the root directory.

If the name given to the option starts with C</dev/>, the corresponding
device is used as the root device, and no NFS directory will be mounted.

B<--rootmode>=C<ro|rw> Defines whether the root device will be mounted
read-only or read-write respectively. Without this parameter, the
default is C<rw>.

B<--ip=>I<string> Define client and server IP addresses.
B<--ipaddrs=>I<string> is a synonym for the same thing (deprecated, will
disappear in some future version).

In the absence of this option no IP addresses are defined, and the
kernel will determine the IP addresses by itself, usually by using DHCP,
BOOTP or RARP.  Note that the kernel's query is I<in addition to> the
query made by the bootrom, and requires the IP: kernel level
autoconfiguration (CONFIG_IP_PNP) feature to be included in the kernel.

Important note: In Linux kernels 2.2.x where x >= 18, and 2.4.x where x
>= 5, it is B<necessary> to specify one of the enabling options in the
next paragraph to cause the IP autoconfiguration to be activated.
Unlike in previous kernels, IP autoconfiguration does not happen by
default.

If one of the following: C<off, none, on, any, dhcp, bootp, rarp, both>,
is given, then the option will be passed unmodified to the kernel and
cause that autoconfig option to be chosen.

If C<rom> is given as the argument to this option, all necessary IP
addresses for NFS root mounting will be inherited from the BOOTP/DHCP
answer the bootrom got from the server.

It's also possible to define the addresses during compilation of the boot
image. Then, all addresses must be separated by a colon, and ordered in
the following way:

C<--ip=>I<client:server:gateway:netmask:hostname[:dev[:proto]]>

Using this option B<mknbi-linux> will automatically convert system names
into decimal IP addresses for the first three entries in this string.
The B<hostname> entry will be used by the kernel to set the host name of
the booted Linux diskless client.  When more than one network interface
is installed in the diskless client, it is possible to specify the name
of the interface to use for mounting the root directory via NFS by
giving the optional value C<dev>.  This entry has to start with the
string C<eth> followed by a number from 0 to 9. However, if only one
interface is installed in the client, this I<dev> entry including the
preceding semicolon can be left out. The I<proto> argument is one of the
IP autoconfiguration enabling options listed above.  (Author: it's not
clear to me what the IP autoconfiguration does when the parameters are
already specified.  Perhaps it's to obtain parameters not specified,
e.g. NIS domain.)

B<--rdbase=>I<top|asis|0xNNNNNNNN> Set the ramdisk load address.  C<top>
moves the ramdisk to the top of memory before jumping to the kernel.
This is the default if rdbase is not specified.  This option requires
that first-linux's kernel sizing work correctly.  C<asis> loads it at
0x100000 (1MB) if the kernel is loaded low; or leaves it just after the
kernel in memory, if the kernel is loaded high. For this option to work,
the kernel must be able to handle ramdisks at these addresses.  I'm told
2.4 kernels can do this, but I have not been able to confirm it.
I<0xNNNNNNNN> moves the ramdisk to the hex address specified. The onus
is on the user to specify a suitable address that is acceptable to the
kernel and doesn't overlap with any other segments. It will have to be
aligned to a 4k byte boundary so you should ensure that this is so. (The
last three hex digits must be 0.)

B<--first16> Use old first stage setup program (first-linux.S). By
default the new first stage setup program (first32.c) is used. The new
setup program has some advantages, including being able to detect memory
> 64 MB and in general being more maintainable. --first16 is only valid
for tagged images, not ELF. It will be ignored if specified with ELF.

B<--first32pm=>I<[program]> Use a more efficient protected mode call
protocol for the first stage setup program. This requires Etherboot ROMs
version 5.0 and above and so is not enabled by default. It can also be
used to call extensions to the Etherboot code, which paves the way for
additional useful functionality without enlarging the size of the
Etherboot footprint. When a I<program> is not specified, the default is
to use the standard first stage setup program suitable for booting a
Linux kernel. --first32pm is implied by the ELF format and does not have
to be specified in this case. Note that you still need the = if you
don't specify a I<program> to prevent this option from swallowing up the
next argument as = and space are equivalent in the Getopt routine
provided by Perl.

B<--progreturns> This option is used in conjunction with and only valid
with the --first32pm option to indicate to the Etherboot loader that the
called program will return to loader and hence Etherboot should not
disable the network device as is the case when the program will never
return to Etherboot.

B<--relocseg=>I<segaddr> This option is used to specify a relocation of
the Linux first, boot, setup, and parameter segments to another 64k
band.  Currently the only valid values are 0x9000 and 0x8000,
corresponding to linear addresses of 0x90000 and 0x80000 upwards. The
default is 0x9000.  You also need to relocate Etherboot to 0x84000 if
you use the 0x8000 band and your Linux kernel must support relocation
which implies a 2.4 kernel at least.

B<mem=>I<memsize> This is not a command line option but a kernel
parameter that is intercepted by the first32 stage and used as the top
of memory, to match Linux's interpretation. I<memsize> can be suffixed
by C<G> to indicate gibibytes (times 2^30), C<M> to indicate mebibytes
(times 2^20) or C<K> to indicate kibibytes (times 2^10). Note that the
suffixes are uppercase. This kernel parameter can be specified in
--append= or option-129 of the DHCP/BOOTP record.

Run the program thus:

C<mknbi-linux> I<kernel-image> [I<ramdisk-image>] > C<linux.nb>

Then move F<linux.nb> to where the network booting process expects to
find it.

=head1 MKNBI-LINUX BOOTP/DHCP VENDOR TAGS

B<mknbi-linux> includes a startup code at the beginning of the Linux
kernel which is able to detect certain BOOTP vendor defined tags. These
can be used to modify the kernel loading process at runtime. To use
these tags with bootpd, a publicly available BOOTP server daemon, you
can use the following syntax in the F</etc/bootptab> file:

C<T>I<number>C<=">I<string>C<">

For example, to specify a different root NFS device, you can use:

C<T130="eth1">

The following tags are presently supported by B<mknbi-linux>:

B<129> The I<string> value given with this tag is appended verbatim to
the end of the kernel command line.  It can be used to specify arguments
like I/O addresses or DMA channels required for special hardware
like SCSI adapters, network cards etc. Please consult the Linux kernel
documentation about the syntax required by those options. It is the same
as the B<--append> command line option to B<mknbi-linux>, but works at
boot time instead of image build time.

B<130> With this tag it is possible to the select the network adapter
used for mounting root via NFS on a multihomed diskless client. The
syntax for the I<string> value is the same as for the C<dev> entry used
with the B<--ip=> option as described above. However note that the
B<mknbi-linux> runtime setup routine does not check the syntax of the
string.

The same tags will work in DHCP with the appropriate syntax for your
DHCP server configuration file.

Remember that you need to specify tag 128 in the correct format in order
for the previous tags to be valid. See the documentation file
vendortags.

=head1 MKNBI-ROM

B<mknbi-rom> makes a tagged image from an Etherboot C<.rom> or C<.lzrom>
boot ROM image.  This allows it to be netbooted using an existing
ROM. This is useful for developing Etherboot drivers.

Run mknbi like this:

C<mknbi-rom nic.lzrom> > C<nic.nb>

Move F<nic.nb> to where the network booting process expects to find it.
The boot ROM will load this as the I<operating system> and execute the
ROM image.

=head1 MKNBI-MENU

B<mknbi-menu> and B<mkelf-menu> make a tagged or ELF image from an
auxiliary menu program. Etherboot has the ability to load an auxiliary
program which can interact with the user, modify the DHCP structure, and
return a status.  Based on the status, Etherboot can load another
binary, restart or exit.  This makes it possible to have elaborate user
interface programs without having to modify Etherboot. The specification
for auxiliary program is documented in the Etherboot Developer's Manual.

B<mknbi-menu> and B<mkelf-menu> take a binary named C<menu> from the
library directory, which is assumed to have an entry point of 0x10000.
An optional argument is accepted, and this is loaded at 0x20000. This
can be a data file used by the menu program.

Currently, the menu binary provided duplicates the builtin menu facility
of Etherboot with the exception of a couple of small differences: no
server or gateway specifications are used and nested TFTP loads don't
work. You should not have MOTD or IMAGE_MENU defined in your Etherboot
build to be able to use this external menu binary. The specifications of
the DHCP tags required is in the vendortags document in the Etherboot
documentation.

Typical usage is like this:

C<mkelf-menu> > C<menu.nb>

Then put menu.nb in the TFTP boot directory and edit your DHCP tags
according to the documentation.

Alternate user interface programs are highly encouraged.

=head1 MKNBI-FDOS

B<mknbi-fdos> makes a tagged image from a FreeDOS kernel file and a
floppy image.  Note that the kernel image is not read from the floppy
section of the tagged image, but is a separate section in the tagged
image. The bootloader has been adjusted to jump to it directly. This
means the space that would be taken up on the I<floppy> by the kernel
image file can now be used for applications and data.

Obtain a distribution of FreeDOS with a recent kernel, probably at least
2006. It has been tested with 2012 but nothing older. You can get the
FreeDOS kernel here:

C<http://freedos.sourceforge.net/>

Follow the instructions to make a bootable floppy. Then get an image
of the floppy with:

C<dd if=/dev/fd0 of=/tmp/floppyimage>

Also extract F<kernel.sys> from the floppy. You can do this from the
image using the mtools package, by specifying a file as a I<drive>
with a declaration like this in F<~/.mtoolsrc>:

C<drive x: file="/tmp/floppyimage">

Then run:

C<mcopy x:kernel.sys .>

Then run mknbi by:

C<mknbi-fdos kernel.sys /tmp/floppyimage> > C<freedos.nb>

where F<kernel.sys> and F</tmp/floppyimage> are the files extracted above.
Then move F<freedos.nb> to where the network booting process expects to
find it.

If you have got it to netboot successfully, then you can go back and
add your files to the floppy image. You can delete F<kernel.sys> in
the floppy image to save space, that is not needed. Note that you can
create a floppy image of any size you desire with the mformat program
from mtools, you are not restricted to the actual size of the boot floppy.

=head1 MKNBI-FDOS OPTIONS

B<--harddisk> Make the boot ramdisk the first hard disk, i.e. C:. One
reason you might want to do this is because you want to use the real
floppy. The limit on "disk size" in the boot image is not raised by this
option so that is not a reason to use this option. This option is
incompatible with --disableharddisk.

B<--disableharddisk> When the ramdisk is simulating a floppy disk drive,
this switch will disable hard disk accesses.  This is necessary if the
client should use a network file system as drive C:, which is only
possible if there are no hard disks found by DOS. This option is
incompatible with --harddisk.

B<--nosquash> Do not try to chop unused sectors from the end of the
floppy image. This increases the tagged image size and hence loading
time if the FAT filesystem on the floppy is mostly empty but you may
wish to use this option if you have doubts as to whether the squashing
algorithm is working correctly.

B<--rdbase=>I<0xNNNNNNNN> Set the ramdisk load address. The default
load address for the ramdisk is 0x110000. It can be moved higher
(lower will not work) if for some reason you need to load other stuff
at the address it currently occupies. As this is a linear address and
not a segment address, the last 4 bits are not used and should be 0.

=head1 MKNBI-DOS

B<mknbi-dos> makes a tagged image from a floppy image containing a
bootable DOS filesystem.  It is not necessary to build the filesystem
on a physical floppy if you have the mtools package, but you need a
bootable floppy of any size to start with. First extract the boot block
from the floppy, this boot block must match the DOS kernel files you
will copy in the next step:

C<dd if=/dev/fd0 of=bootblock bs=512 count=1>

Then get the DOS kernel files (this is correct for DR-DOS, the names
are different in MS-DOS, IO.SYS and MSDOS.SYS):

C<mcopy a:IBMBIO.COM a:IBMDOS.COM a:COMMAND.COM .>

Next make an entry in F<~/.mtoolsrc> to declare a floppy to be mapped
to a file:

C<drive x: file="/tmp/floppyimage">

Now format a floppy of the desired size, in this example a 2.88 MB floppy,
at the same time writing the bootblock onto it:

C<mformat -C -t 80 -s 36 -h 2 -B bootblock x:>

The size of the "floppy" is only limited by the limits on the number of
cylinders, sectors and heads, which are 1023, 63 and 255 respectively,
and the amount of RAM you are willing to allocate to the "floppy" in
memory. As RAM is precious, choose a size slightly bigger than what is
needed to hold your "floppy" files.

Finally, copy all your desired files onto the floppy:

C<mcopy IBMBIO.COM x:>

C<mcopy IBMDOS.COM x:>

C<mcopy COMMAND.COM x:>

C<mcopy CONFIG.SYS AUTOEXEC.BAT APP.EXE APP.DAT ... x:>

For MS-DOS substitute IO.SYS for IBMIO.COM, and MSDOS.SYS for
IBMDOS.COM.  The case of the files must be preserved, it may not work if
VFAT lower case names are generated in the floppy image.  Pay attention
to the order of copying as the boot block may expect the first two
entries on a newly formatted disk to be IO.SYS, MSDOS.SYS.  Possibly too
COMMAND.COM has to be the third entry so we play safe.  Thanks to Phil
Davey and Phillip Roa for these tips.

I have reports that the bootblock of MS-DOS 6.22 sometimes fails to boot
the ramdisk.  You could try using the boot block from Netboot instead of
getting the boot block off the floppy. I have provided this boot block
in the distribution as altboot.bin, and in source form as altboot.S and
boot.inc. One essential thing is to make IO.SYS the first file on the
disk, or this bootblock will not work.

If you happen to have a media of the same size you could test if the
image is bootable by copying it onto the media, and then booting it:

C<dd if=/tmp/floppyimage of=/dev/fd0>

Then run mknbi-dos over the image F</tmp/floppyimage> to create a
tagged image:

C<mknbi-dos /tmp/floppyimage> > C<dos.nb>

Move F<dos.nb> to where the network booting process expects to find it.

=head1 MKNBI-DOS OPTIONS

B<--harddisk> Make the boot ramdisk the first hard disk, i.e. C:. One
reason you might want to do this is because you want to use the real
floppy. The limit on "disk size" in the boot image is not raised by this
option so that is not a reason to use this option. This option is
incompatible with --disableharddisk.

B<--disableharddisk> When the ramdisk is simulating a floppy disk drive,
this switch will disable hard disk accesses.  This is necessary if the
client should use a network file system as drive C:, which is only
possible if there are no hard disks found by DOS. This option is
incompatible with --harddisk.

B<--nosquash> Do not try to chop unused sectors from the end of the
floppy image. This increases the tagged image size and hence loading
time if the FAT filesystem on the floppy is mostly empty but you may
wish to use this option if you have doubts as to whether the squashing
algorithm is working correctly.

B<--rdbase=>I<0xNNNNNNNN> Set the ramdisk load address. The default
load address for the ramdisk is 0x110000. It can be moved higher
(lower will not work) if for some reason you need to load other stuff
at the address it currently occupies. As this is a linear address and
not a segment address, the last 4 bits are not used and should be 0.

=head1 BUGS

Please report all bugs to the author.

=head1 SEE ALSO

Etherboot tutorial at C<http://etherboot.sourceforge.net/> Mtools package
is at C<http://wauug.erols.com/pub/knaff/mtools/> Make sure you have a
recent version, the ability to map a drive to a file is not present in
old versions.

=head1 COPYRIGHT

B<mknbi> is under the GNU Public License

=head1 AUTHOR

Ken Yap (C<ken_yap@users.sourceforge.net>)

=head1 DATE

See man page footer for date and version. Sorry, not available in the
HTML version.
