#! /usr/bin/perl

use strict;
use warnings;
use POSIX;
use Getopt::Long qw(:config bundling);
use Fcntl 'SEEK_SET';

# Read Pintos.pm from the same directory as this program.
BEGIN { my $self = $0; $self =~ s%/+[^/]*$%%; require "$self/Pintos.pm"; }

our ($disk_fn);			# Output disk file name.
our (%parts);			# Partitions.
our ($format);			# "partitioned" (default) or "raw"
our (%geometry);		# IDE disk geometry.
our ($align);			# Align partitions on cylinders?
our ($loader_fn);		# File name of loader.
our ($include_loader);		# Include loader?
our (@kernel_args);		# Kernel arguments.

if (grep ($_ eq '--', @ARGV)) {
    @kernel_args = @ARGV;
    @ARGV = ();
    while ((my $arg = shift (@kernel_args)) ne '--') {
	push (@ARGV, $arg);
    }
}

GetOptions ("h|help" => sub { usage (0); },

	    "kernel=s" => \&set_part,
	    "filesys=s" => \&set_part,
	    "scratch=s" => \&set_part,
	    "swap=s" => \&set_part,

	    "filesys-size=s" => \&set_part,
	    "scratch-size=s" => \&set_part,
	    "swap-size=s" => \&set_part,

	    "kernel-from=s" => \&set_part,
	    "filesys-from=s" => \&set_part,
	    "scratch-from=s" => \&set_part,
	    "swap-from=s" => \&set_part,

	    "format=s" => \$format,
	    "loader:s" => \&set_loader,
	    "no-loader" => \&set_no_loader,
	    "geometry=s" => \&set_geometry,
	    "align=s" => \&set_align)
  or exit 1;
usage (1) if @ARGV != 1;

$disk_fn = $ARGV[0];
die "$disk_fn: already exists\n" if -e $disk_fn;

# Sets the loader to copy to the MBR.
sub set_loader {
    die "can't specify both --loader and --no-loader\n"
      if defined ($include_loader) && !$include_loader;
    $include_loader = 1;
    $loader_fn = $_[1] if $_[1] ne '';
}

# Disables copying a loader to the MBR.
sub set_no_loader {
    die "can't specify both --loader and --no-loader\n"
      if defined ($include_loader) && $include_loader;
    $include_loader = 0;
}

# Figure out whether to include a loader.
$include_loader = exists ($parts{KERNEL}) && $format eq 'partitioned'
  if !defined ($include_loader);
die "can't write loader to raw disk\n" if $include_loader && $format eq 'raw';
die "can't write command-line arguments without --loader or --kernel\n"
  if @kernel_args && !$include_loader;
print STDERR "warning: --loader only makes sense without --kernel "
  . "if this disk will be used to load a kernel from another disk\n"
  if $include_loader && !exists ($parts{KERNEL});

# Open disk.
my ($disk_handle);
open ($disk_handle, '>', $disk_fn) or die "$disk_fn: create: $!\n";

# Read loader.
my ($loader);
$loader = read_loader ($loader_fn) if $include_loader;

# Write disk.
my (%disk) = %parts;
$disk{DISK} = $disk_fn;
$disk{HANDLE} = $disk_handle;
$disk{ALIGN} = $align;
$disk{GEOMETRY} = %geometry;
$disk{FORMAT} = $format;
$disk{LOADER} = $loader;
$disk{ARGS} = \@kernel_args;
assemble_disk (%disk);

# Done.
exit 0;

sub usage {
    print <<'EOF';
pintos-mkdisk, a utility for creating Pintos virtual disks
Usage: pintos-mkdisk [OPTIONS] DISK [-- ARGUMENT...]
where DISK is the virtual disk to create,
      each ARGUMENT is inserted into the command line written to DISK,
  and each OPTION is one of the following options.
Partition options: (where PARTITION is one of: kernel filesys scratch swap)
  --PARTITION=FILE         Use a copy of FILE for the given PARTITION
  --PARTITION-size=SIZE    Create an empty PARTITION of the given SIZE in MB
  --PARTITION-from=DISK    Use of a copy of the given PARTITION in DISK
  (There is no --kernel-size option.)
Output disk options:
  --format=partitioned     Write partition table to output (default)
  --format=raw             Do not write partition table to output
  (Pintos can only use partitioned disks.)
Partitioned format output options:
  --loader[=FILE]          Get bootstrap loader from FILE (default: loader.bin
                           if --kernel option is specified, empty otherwise)
  --no-loader              Do not include a bootstrap loader
  --geometry=H,S           Use H head, S sector geometry (default: 16, 63)
  --geometry=zip           Use 64 head, 32 sector geometry for USB-ZIP boot
                           per http://syslinux.zytor.com/usbkey.php
  --align=bochs            Round size to cylinder for Bochs support (default)
  --align=full             Align partition boundaries to cylinder boundary to
                           let fdisk guess correct geometry and quiet warnings
  --align=none             Don't align partitions at all, to save space
Other options:
  -h, --help               Display this help message.
EOF
    exit ($_[0]);
}