#! /bin/sh
#
# Replicate boot files in separate file system e.g. a flash memory drive.
#
# Use: Assume a system where 2 disks form a gmirror RAID that lacks BIOS
#      boot support, and a device daN is a flash memory device that is to
#      hold the /boot files (and get us the BIOS booting).
#
#      Run this script as command "sh.make_boot_FlashMemoryFS" to copy
#      the boot files over.  Before the copy, the root file system device
#      is set as vfs.root.mountfrom="ufs:/dev/mirror/XXXXs1a" in the file
#      loader.conf in the /boot directory in both the current root file
#      system and the removable disk's s1a.
#
#
# Note: You also need to specify which disk and slice to boot from via a
#       command such as
#         boot0cfg -s 1 -v -B -o noupdate da0  # specify slice 1 of boot disk
#

# extract the last removable device listed in dmesg
x=`dmesg|egrep "^da" | grep "Direct Access" | grep -v "Fixed Direct Access" | tail -1 | cut -d':' -f1`

if [ -n "$x" ] ; then
  echo "OK to use this device?"
  dmesg|grep "Direct Access" | egrep "^$x"
  echo
  echo "Press Enter for this device or enter spec such as da0"
  read TheDevice
  if [ x"$TheDevice" = x ] ; then
    TheDevice=$x
  fi
else
  echo "Enter target device spec such as da0"
  read TheDevice 
  echo
fi

WORKDIR=`pwd`

TheFS=${TheDevice}s1a
if [ -e /dev/$TheFS ] ; then
  echo "Target file system will be $TheFS"
else
  echo '?'" didn't see ${TheFS} (e.g. da2s1a, or da0s1a etc.)"
  exit 1
fi

#
#1 ensure the file /boot/loader.conf contains vfs.root.mountfrom setting
#

cd /boot

( echo '# set vfs.root.mountfrom to switch to gmirror after load'       ;
  echo 'vfs.root.mountfrom="ufs:'$(set `df /|egrep "^/dev"`;echo $1)'"' ;
  cp -p loader.conf loader.conf.orig                                    ;
  cat loader.conf.orig | grep -v "vfs.root.mountfrom" ) > loader.conf__new__
mv loader.conf__new__ loader.conf
pwd ; ls -al loader.conf*

cd $WORKDIR

#
# 2 copy boot files into flash memory
#

mkdir -p /mnt2
fsck /dev/${TheFS}
mount /dev/${TheFS} /mnt2
df /mnt2
mkdir -p /mnt2/dev ; mkdir -p /mnt2/boot
(cd /boot ; tar -c --exclude kernel.old -f - *)|(cd /mnt2/boot; tar xvpf -)
df /mnt2
umount /mnt2