#!/bin/sh

/sbin/mount -uw /
rm -f temp.nvm
rm -f tempnvrm.txt

fname=$2
loc="/AppleInternal/Diags/WiFiFirmware/"$1"/"

filename=$(echo $fname | cut -d'.' -f1)
exts=$(echo $fname | cut -d'.' -f2)
newfname=$filename"-orig."$exts

if [ -f "$loc$newfname" ]; then
  echo "Backup nvram file exists!"
else
  cp $loc$fname $loc$newfname
fi
cat $loc$fname | tr -c "[:print:]^\n" "\n" > temp.nvm

if [ `cat temp.nvm | grep "btc_mode=4" | wc -l` -eq 0 ]; then
  len=$(cat temp.nvm | wc -l)
  i=1
  while [ `head -$i temp.nvm | tail -1 | grep "boardflags2" | wc -l` -eq 0 ]; do i=$(($i+1)); done
  head -$(($i-1)) temp.nvm > tempnvrm.txt

  echo "boardflags2=0x800000" >> tempnvrm.txt
  echo "btc_mode=4" >> tempnvrm.txt

  tail -n +$(($i+1)) temp.nvm >> tempnvrm.txt
  mv tempnvrm.txt $loc$fname
fi