seti $printhelp = $printhelp
seti $help = $help
if $help = 1
  echo 'Western Digital ROYL process SA.'
  if $printhelp = 1
    exit 0
  endif
  echo 'Hit ENTER to continue...'
  userinput $choicestring
  previousscript
endif

include good_subroutines

# set a blank string variable to compare with user input
# make sure not to set this anyplace else
sets $null = ""

# set this to itself for use with the menu system
# make sure not to set this anyplace else
# if it was not previously set it will = 0
seti $using_menu = $using_menu

# set the file name to be read
while 1 = 1
  variablecheck $file
  if $error_level < 16
    seti $ask = 1
  elseif $using_menu = 1
    seti $ask = 1
  endif
  if $ask = 1
    echo "Enter file name:"
    userinput $choicestring
    if $choicestring != $null
      sets $file = $choicestring
      break
    else
      echo "Choice cannot be blank!"
    endif
  else
    break
  endif
done

getfilesize $file
seti $file_size = $error_level
if $file_size < 0
  echo "ERROR! File " $file " not found!"
  previousscript
endif
echo "Reading the file"
seti $scratchpad_size = $file_size
scratchpadsize $scratchpad_size
clearscratchpad
readscratchpad $file 0 0 $scratchpad_size

# show it on the screen
#printscratchpad 0 $scratchpad_size

seti $mod01_location = -1
gosub find_mod01
if $mod01_location > -1
  echo "mod01 found at position " $mod01_location
  gosub process_mod01
else
  echo "mod01 not found"
endif




previousscript
end



subroutine find_mod01
  # search for the directory module 01
  echo "Searching for module 01."
  sets $header_check = "ROYL"
  seti $position = 0
  seti $search_end = $scratchpad_size - 4
  while $position < $search_end
    sets $header = scratchpad $position 4
    if $header = $header_check
      # process the module
      seti $working_offset = $position
      seti $working_offset = $position + 8
      seti $mod_id = scratchpad $working_offset w
      if $mod_id = 1
        seti $mod01_location = $position
        returnsub
      endif
    endif
    seti $position = $position + 512
  done
endsubroutine






subroutine process_mod01
  # process the module
  seti $working_offset = $mod01_location
  #echo "Header:"
  #printscratchpad $working_offset 4
  seti $working_offset = $mod01_location + 8
  seti $mod_id = scratchpad $working_offset w
  hex
  #echo "Module ID = 0x" $mod_id

  # find how many sectors the module contains
  seti $working_offset = $mod01_location + 0xa
  seti $mod_length_sectors = scratchpad $working_offset
  seti $working_offset = $mod01_location + 0xb
  seti $tempnum = scratchpad $working_offset
  seti $tempnum = $tempnum > 8
  seti $mod_length_sectors = $mod_length_sectors + $tempnum

  #echo "Size in sectors = 0x" $mod_length_sectors
  seti $working_offset = $mod01_location + 0xc
  seti $checksum = scratchpad $working_offset dw
  #echo "32 bit checksum = 0x" $checksum
  seti $working_offset = $mod01_location + 0x10
  #echo "Mod version:"
  #printscratchpad $working_offset 8
  decimal

  seti $module_size = $mod_length_sectors * 512
  seti $calculated_checksum = 0
  seti $count = 0
  while $count < $module_size
    seti $working_offset = $mod01_location + $count
    if $working_offset > $search_end
      echo "end of module is past end of rom"
      break
    endif
    seti $dword = scratchpad $working_offset dw
    seti $calculated_checksum = $calculated_checksum + $dword
    seti $count = $count + 4
    # skip the actual checksum bytes
    if $count = 0xc
      seti $count = $count + 4
    endif
  done
  seti $calculated_checksum = $calculated_checksum & 0xffffffff
  seti $calculated_checksum = 0xffffffff - $calculated_checksum
  seti $calculated_checksum = $calculated_checksum + 1

  hex
  if $checksum = $calculated_checksum
    sets $checkstring = " calulated=0x" $calculated_checksum " (good)"
  else
    sets $checkstring = " calulated=0x" $calculated_checksum " (bad)"
  endif
  echo "pos=0x" $position " ModID=0x" $mod_id " size=0x" $module_size $checkstring
  decimal

  seti $working_offset = $mod01_location + 0x30
  seti $total_records = scratchpad $working_offset w
  hex
  echo "Total records = 0x" $total_records
  decimal

  # process the data records
  seti $record_count = 0
  seti $offset = 0x32 + $mod01_location
  echo ""
  while $record_count < $total_records
    seti $record_count = $record_count + 1
    seti $record_length = scratchpad $offset b
    #printscratchpad $offset $record_length
    seti $working_offset = $offset + 1
    seti $module_copies = scratchpad $working_offset b
    seti $working_offset = $offset + 2
    seti $module_id = scratchpad $working_offset w
    seti $working_offset = $offset + 4
    seti $module_size = scratchpad $working_offset w
    seti $working_offset = $offset + 0xa
    seti $module_location1 = scratchpad $working_offset dw
    seti $working_offset = $offset + 0xe
    seti $module_location2 = scratchpad $working_offset dw
    sets $found1 = "not-found"
    sets $found2 = "not-found"
    gosub check_module

    hex
    echo "ID=0x" $module_id " sectors=0x" $module_size " copies=0x" $module_copies " copy1=0x" $module_location1 " copy2=0x" $module_location2 " " $found1 " " $found2
    decimal
    seti $offset = $offset + $record_length

  done
endsubroutine





subroutine check_module
  seti $module_offset = $module_location1 * 512
  sets $header_check = "ROYL"
  sets $header = scratchpad $module_offset 4
  if $header = $header_check
    seti $working_offset = $module_offset + 8
    seti $mod_id = scratchpad $working_offset w
    if $mod_id = $module_id
      sets $found1 = "found"
    endif
  endif
  seti $module_offset = $module_location2 * 512
  sets $header_check = "ROYL"
  sets $header = scratchpad $module_offset 4
  if $header = $header_check
    seti $working_offset = $module_offset + 8
    seti $mod_id = scratchpad $working_offset w
    if $mod_id = $module_id
      sets $found2 = "found"
    endif
  endif
endsubroutine