#!/usr/bin/python
# mkefiboot - a tool to make EFI boot images
# Copyright (C) 2011  Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Red Hat Author(s):  Will Woods <wwoods@redhat.com>

import os, tempfile, optparse
from subprocess import check_call, PIPE
from pylorax.imgutils import mkdosimg, round_to_blocks, LoopDev, DMDev, dm_detach

def mkefiboot(bootdir, outfile, label):
    '''Make an EFI boot image with the contents of bootdir in EFI/BOOT'''
    mkdosimg(None, outfile, label=label, graft={'EFI/BOOT':bootdir})

def mkefidisk(efiboot, outfile):
    '''Make a bootable EFI disk image out of the given EFI boot image.'''
    partsize = os.path.getsize(efiboot) + 17408
    disksize = round_to_blocks(17408 + partsize, 512)
    with LoopDev(outfile, disksize) as loopdev:
        with DMDev(loopdev, disksize) as dmdev:
            check_call(["parted", "--script", "/dev/mapper/%s" % dmdev,
            "mklabel", "gpt",
            "unit", "b",
            "mkpart", "'EFI System Partition'", "fat32", "17408", str(partsize),
            "set", "1", "boot", "on"], stdout=PIPE, stderr=PIPE)
            partdev = "/dev/mapper/{0}p1".format(dmdev)
            with open(efiboot, "rb") as infile:
                with open(partdev, "wb") as outfile:
                    outfile.write(infile.read())
            dm_detach(dmdev+"p1")

if __name__ == '__main__':
    parser = optparse.OptionParser(usage="%prog EFIBOOTDIR IMGFILE")
    parser.add_option("-d", "--disk", action="store_true", default=False,
                      help="make a full EFI disk image")
    parser.add_option("-l", "--label", action="store", default="ANACONDA",
                      help="filesystem label to use")
    # get args
    (opt, args) = parser.parse_args()
    if len(args) != 2:
        parser.error("need exactly two arguments")
    (bootdir, outfile) = args
    # sanity checks
    if not os.path.isdir(bootdir):
        parser.error("%s is not a directory" % bootdir)
    if os.getuid() > 0:
        parser.error("need root permissions")
    # do the thing!
    if opt.disk:
        efiboot = tempfile.NamedTemporaryFile(prefix="mkefiboot.").name
        mkefiboot(bootdir, efiboot, opt.label)
        mkefidisk(efiboot, outfile)
    else:
        mkefiboot(bootdir, outfile, opt.label)