#!/bin/ksh -p

#
# Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
# Use is subject to license terms.
#
#ident  "@(#)mkusb.ksh  1.1     08/05/14 SMI"

#
# mkusb
#
# Given an AK ISO image (output by mkak -I), generate a bootable USB stick
# by mounting the ISO, formatting the USB stick with a Solaris partition,
# copying the ISO content there, and then installing bootable GRUB.
#

if [[ $# -ne 2 ]]; then
        echo "Usage: $0 file.iso /dev/rdsk/<usb>p0" >& 2
        exit 2
fi

function fail
{
        cd /

        if [[ -n "$lofidev" ]]; then
                umount $rmnt >/dev/null 2>&1
                lofiadm -d $lofidev >/dev/null 2>&1
        fi

        umount $wmnt >/dev/null 2>&1
        rmdir $rmnt $wmnt >/dev/null 2>&1

        echo "$0: $*" >&2
        exit 1
}

iso=$1
pdsk=$2
rdsk=${pdsk%p0}
dsk=$(echo $rdsk | sed 's:/rdsk:/dsk:')

rmnt=/tmp/mkusb-r.$$
wmnt=/tmp/mkusb-w.$$

rm -rf $rmnt $wmnt >/dev/null 2>&1
mkdir -m 0700 $rmnt || fail "failed to mkdir: $rmnt"
mkdir -m 0700 $wmnt || fail "failed to mkdir: $wmnt"

[[ -r $iso ]] || fail "ISO is missing or not readable: $iso"
lofidev=$(lofiadm -a $iso)
[[ -n "$lofidev" ]] || fail "failed to mount ISO: $iso"

mount -F hsfs -o ro $lofidev $rmnt
rlofidev=$(echo $lofidev | sed s/lofi/rlofi/)

rmformat -l $pdsk 2>/dev/null | grep 'Bus: USB' >/dev/null 2>&1 ||
    fail "USB device path does not appear to be valid: $pdsk"

echo "Formatting USB device ... \c"
fdisk -B $pdsk || fail "failed to create USB partition"

set -- $(rmformat -l $pdsk 2>/dev/null | \
    egrep '(Device|Size):' | cut -d: -f2-)

eval $(prtvtoc $pdsk | grep '^\*' | awk '
    $3 == "bytes/sector" { printf("bytes_per_sec=%s\n", $2); }
    $3 == "sectors/cylinder" { printf("secs_per_cyl=%s\n", $2); }
    $3 == "accessible" { printf("cylinders=%s\n", $2); }')

[[ -z "$bytes_per_sec" || -z "$secs_per_cyl" || -z "$cylinders" ]] && \
    fail "failed to read vtoc attributes for $pdsk"

let sectors="$cylinders * $secs_per_cyl"

grub_sec0=0
grub_secs=$secs_per_cyl
grub_part=s8

let root_sec0="$grub_sec0 + $grub_secs"
let root_secs="$sectors - $root_sec0"
root_part=s0

dump_sec0=0
dump_secs=$sectors
dump_part=s2

[[ $root_sec0 -lt $sectors ]] || fail "root disk too small"

fmthard -s - $pdsk >/dev/null <<-EOF
${root_part#s} 2  0x00 $root_sec0 $root_secs
${dump_part#s} 5  0x00 $dump_sec0 $dump_secs
${grub_part#s} 1  0x01 $grub_sec0 $grub_secs
EOF

[[ $? -eq 0 ]] && echo "$*" || fail "failed to format USB stick"

newfs -m 0 $rdsk$root_part </dev/null 2>/dev/null || "failed to newfs USB stick"
mount -F ufs $dsk$root_part $wmnt || fail "failed to mount USB stick"

echo "Copying ISO contents to USB ... "
cd $rmnt && find . -depth -print | cpio -pdVmu $wmnt || fail "cpio failed"

echo "Editing USB boot menu ... \c"
mv -f $wmnt/boot/grub/menu.lst $wmnt/boot/grub/menu.lst.iso

sed 's/ak_media=cd/ak_media=usb/g' $wmnt/boot/grub/menu.lst.iso \
    >$wmnt/boot/grub/menu.lst  || fail "failed to edit menu file"

chmod 0444 $wmnt/boot/grub/menu.lst
echo "done."

echo "Installing USB boot ... \c"
installgrub -f -m $wmnt/boot/grub/stage1 $wmnt/boot/grub/stage2 \
    $rdsk$root_part >/dev/null || fail "installgrub to $rdsk$root_part failed"

cd /
echo "done."

umount $wmnt
umount $rmnt
lofiadm -d $lofidev

echo "done."
exit 0