seti $printhelp = $printhelp
seti $help = $help
if $help = 1
  echo 'Western Digital ROYL patch module 32 to file using vendor specific commands.'
  echo 'This patch is meant for drives that suffer from the "slow" issue.'
  echo 'It should be used along with the module 02 patch.'
  echo 'This patch is based on data from the following forum thread:'
  echo '  WD - Fixing the "Slow Issue" manually :'
  echo '  http://www.hddoracle.com/viewtopic.php?f=86&t=848'
  echo 'This will dump the sectors to the file "<serial>_mod32orig.bin".'
  echo 'And it will create the file "<serial>_mod32patched.bin".'
  echo 'It will also create a folder using the model and serial as the folder name,'
  echo ' and create a backup dump file with the date and time as part of the name.'
  echo 'It will create a backup dump every time a read or write is attempted.'
  echo 'The drive must be power cycled for the changes to take effect.'
  echo 'You have three options:'
  echo '1) Read the module to a file and create the patch.'
  echo '2) Write the patched data back to the disk.'
  echo '3) Restore the original dump.'
  if $printhelp = 1
    exit 0
  endif
  echo 'Hit ENTER to continue...'
  userinput $choicestring
  previousscript
endif

include good_subroutines

# set the module number
seti $module_number = 0x32

# set the filenames to be written to
sets $basefilename = "mod32original.bin"
sets $basepatchname = "mod32patched.bin"

while 1 = 1
  echo " "
  echo "WD ROYL Patch Mod32"
  echo "This modifies data in the service area of the drive!"
  echo "Use at your own risk!"
  echo "These commands can take several minutes and appear to be hung."
  echo "Please be patient and let it finish on its own."
  echo "q) Quit"
  echo "p) Previous menu"
  echo '1) Read the module to a file and create the patch.'
  echo '2) Write the patched data back to the disk.'
  echo '3) Restore the original dump.'

  echo "Enter your choice:
  userinput $choicestring

  if $choicestring = q
    exit 0

  elseif $choicestring = p
    previousscript

  elseif $choicestring = 1
    gosub read_and_create

  elseif $choicestring = 2
    gosub write_patch

  elseif $choicestring = 3
    gosub restore_original

  else
    echo "bad choice= " $choicestring
  endif

done

previousscript
end






subroutine read_module
  # get model and serial using identify device command
  echo "Performing identify device command"
  buffersize 512
  setreadpio
  ata28cmd 0 0 0 0 0 0xa0 0xec
  # check if command failed
  gosub status_check
  # extract model and serial and trim leading and trailing spaces
  sets $model = "null"
  sets $serial = "null"
  wordflipbuffer 0 512
  seti $count = 0
  seti $start_offset = 54
  while $count < 40
    seti $byte = buffer $start_offset
    if $byte > 0x20
      break
    endif
    seti $start_offset = $start_offset + 1
    seti $count = $count + 1
  done
  seti $count = 0
  seti $end_offset = 93
  while $count < 40
    seti $byte = buffer $end_offset
    if $byte > 0x20
      break
    endif
    seti $end_offset = $end_offset - 1
    seti $count = $count + 1
  done
  seti $end_offset = $end_offset + 1
  seti $size = $end_offset - $start_offset
  if $size > 0
    sets $model = buffer $start_offset $size
  endif
  # find out if it is a WD drive
  sets $wdcheck = buffer $start_offset 3
  sets $compare = "WDC"
  if $wdcheck != $compare
    echo "Model: " $model
    echo "Drive is not WD, exiting
    previousscript
  endif

  seti $count = 0
  seti $start_offset = 20
  while $count < 20
    seti $byte = buffer $start_offset
    if $byte > 0x20
      break
    endif
    seti $start_offset = $start_offset + 1
    seti $count = $count + 1
  done
  seti $count = 0
  seti $end_offset = 39
  while $count < 20
    seti $byte = buffer $end_offset
    if $byte > 0x20
      break
    endif
    seti $end_offset = $end_offset - 1
    seti $count = $count + 1
  done
  seti $end_offset = $end_offset + 1
  seti $size = $end_offset - $start_offset
  if $size > 0
    sets $serial = buffer $start_offset $size
  endif

  clearbuffer

  echo "Model: " $model
  echo "Serial: " $serial

  # create a directory named with model and serial
  sets $directory = $model "__" $serial
  sets $command = 'mkdir -p "' $directory '"'
  callcommand $command

  # set filename for backup dump file
  gettime
  sets $backup_filename = $directory "/" $time "__" $basefilename
  sets $backup_patchname = $directory "/" $time "__" $basepatchname

  # set filenames to start with serial
  sets $filename = $serial "_" $basefilename
  sets $patchname = $serial "_" $basepatchname

  echo "Reading the module"

  gosub enable_vsc

  gosub prepare_read_vsc

  # vsc to get a sector of the module
  setreadpio
  buffersize 0x200
  clearbuffer
  ata28cmd 0xd5 0x01 0xbf 0x4f 0xc2 0xa0 0xb0
  # check if command failed
  gosub status_check

  # find how many sectors the module contains
  seti $mod_length_sectors = buffer 0xa
  seti $tempnum = buffer 0xb
  seti $tempnum = $tempnum > 8
  seti $mod_length_sectors = $mod_length_sectors + $tempnum
  seti $remaining_sectors = $mod_length_sectors - 1

  # copy the sector to the scratchpad
  seti $scratchpad_size = $mod_length_sectors * 512
  scratchpadsize $scratchpad_size
  copybuffertoscratchpad 0 0 0x200

  # vsc to get the remaining sectors
  # this gets them one at a time
  # there is a way to get them all at once,
  # but there was a case where that did not work
  seti $count = 1
  while $count < $mod_length_sectors
    setreadpio
    buffersize 0x200
    clearbuffer
    ata28cmd 0xd5 0x01 0xbf 0x4f 0xc2 0xa0 0xb0
    # check if command failed
    gosub status_check
    # copy the sectors to the scratchpad
    seti $offset = $count * 0x200
    copybuffertoscratchpad 0 $offset 0x200
    seti $count = $count + 1
  done

  gosub disable_vsc

  # write the sectors to the backup file
  writescratchpad $backup_filename 0 0 $scratchpad_size

  # process the module
  echo "Header:"
  printscratchpad 0 4
  seti $mod_id = scratchpad 8 w
  hex
  echo "Module ID = 0x" $mod_id
  echo "Size in sectors = 0x" $mod_length_sectors
  seti $checksum = scratchpad 0xc dw
  echo "32 bit checksum = 0x" $checksum
  seti $table_offset = scratchpad 0x30 w
  echo "Table offset = 0x" $table_offset
  decimal
  sets $header = scratchpad 0 4
  sets $header_check = "ROYL"
  if $header != $header_check
    echo "Header is not 'ROYL', exiting"
    previousscript
  endif

  # calculate checksum
  seti $calculated_checksum = 0
  gosub calculate_checksum_scratchpad
  hex
  if $checksum = $calculated_checksum
    echo "Calculated Checksum = 0x" $calculated_checksum " (good)"
  else
    echo "Calculated Checksum = 0x" $calculated_checksum " (BAD)"
    echo "Checksum of read module is not valid, exiting"
    previousscript
  endif
  decimal

endsubroutine





subroutine make_patch
  # this patch zeros out all the data past the module header
  # the table offset previously extracted is the starting point
  # the easiest way to do this is to clear the buffer,
  # and then copy only the needed part back from the scratchpad
  #copy the scratchpad to the buffer for writing
  seti $buffer_size = $scratchpad_size
  buffersize $buffer_size
  clearbuffer
  copyscratchpadtobuffer 0 0 $table_offset

  # calculate new checksum and insert it
  seti $calculated_checksum = 0
  gosub calculate_checksum_buffer
  hex
  echo "Calculated Checksum = 0x" $calculated_checksum
  decimal
  seti $b1 = $calculated_checksum & 0xff
  seti $calculated_checksum = $calculated_checksum > 8
  seti $b2 = $calculated_checksum & 0xff
  seti $calculated_checksum = $calculated_checksum > 8
  seti $b3 = $calculated_checksum & 0xff
  seti $calculated_checksum = $calculated_checksum > 8
  seti $b4 = $calculated_checksum & 0xff
  setbuffer 0x0c
    $b1 $b2 $b3 $b4
  endbuffer

  # write the patch to the backup file
  writebuffer $backup_patchname 0 0 $scratchpad_size

  getfilesize $patchname
  if $error_level > 0
    echo ""
    echo "WARNING! The file " $patchname " already exists!"
    echo "The patched file was NOT created!"
    echo "Please rename or delete the original files to be able to run this option again."
    returnsub
  endif
  echo "Writing patched mod to file " $patchname
  writebuffer $patchname 0 0 $scratchpad_size

endsubroutine






subroutine status_check
  seti $command_failed = 0
  gosub check_command_status
  if $command_failed = 1
    echo "Command failed!"
    gosub show_sense_data
    gosub show_ata_return_status
    previousscript
  endif
endsubroutine





subroutine enable_vsc
  # enable vendor specific commands
  buffersize 0
  setreadpio
  ata28cmd 0x45 0x0b 0x00 0x44 0x57 0xa0 0x80
  # check if command failed
  gosub status_check
endsubroutine






subroutine disable_vsc
  # disable vendor specific commands
  buffersize 0
  setreadpio
  ata28cmd 0x44 0x0b 0x00 0x44 0x57 0xa0 0x80
  # check if command failed
  gosub status_check
endsubroutine





subroutine read_and_create
  gosub read_module
  # write the sectors to the file, this will overwrite any existing file
  getfilesize $filename
  if $error_level > 0
    echo ""
    echo "WARNING! The file " $filename " already exists!"
    echo "The module was NOT read to a file!"
    echo "The patched file was NOT created!"
    echo "Please rename or delete the original files to be able to run this option again."
    returnsub
  endif
  echo ""
  echo "Writing origial dump to file " $filename
  writescratchpad $filename 0 0 $scratchpad_size
  gosub make_patch
endsubroutine





subroutine write_patch
  gosub read_module
  getfilesize $patchname
  seti $patch_size = $error_level
  if $patch_size < 0
    echo "ERROR! File " $patchname " not found!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif
  seti $divide_check = $patch_size % 512
  if $divide_check != 0
    echo "ERROR! Filesize of " $patchname " is not evenly dividable by sector size!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif
  seti $size_check = $patch_size / 512
  if $size_check != $mod_length_sectors
    echo "ERROR! The size of " $patchname " does not match the value read from the module!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif
  echo "Reading the patch file"
  readscratchpad $patchname 0 0 $scratchpad_size

  # check for proper header
  sets $header = scratchpad 0 4
  sets $header_check = "ROYL"
  if $header != $header_check
    echo "Found header = " $header
    echo "ERROR! Header is not 'ROYL'!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif

  # verify checksum
  seti $checksum = scratchpad 0xc dw
  seti $calculated_checksum = 0
  gosub calculate_checksum_scratchpad
  hex
  if $checksum != $calculated_checksum
    echo "Checksum in patch file = 0x" $checksum
    echo "Calculated Checksum = 0x" $calculated_checksum
    echo "ERROR! Checksum of patch file is not valid!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif
  decimal

  echo ""
  echo "Writing the patched module to the drive"

  gosub enable_vsc

  gosub prepare_write_vsc

  # vsc to write the sectors to the disk
  # this writes them one at a time
  # there is a way to get them all at once,
  # but there was a case where that did not work
  seti $count = 0
  while $count < $mod_length_sectors
    setwritepio
    buffersize 0x200
    # copy the sector to the buffer
    seti $offset = $count * 0x200
    copyscratchpadtobuffer $offset 0 0x200
    ata28cmd 0xd6 0x01 0xbf 0x4f 0xc2 0xa0 0xb0
    # check if command failed
    gosub status_check
    seti $count = $count + 1
  done

  gosub disable_vsc

  # read the module again and compare it to what we wrote
  echo "Verifying data"

  gosub enable_vsc

  gosub prepare_read_vsc

  seti $verify_check = 0
  gosub read_and_verify

  if $verify_check = 0
    echo "Data verified!"
  else
    echo "WARNING! The data failed verification!"
    echo "It appears the data write was unsuccessful!"
  endif

  # write the sectors to the backup file
  writescratchpad $backup_filename 0 0 $scratchpad_size

  gosub disable_vsc

endsubroutine





subroutine restore_original
  gosub read_module
  getfilesize $filename
  seti $file_size = $error_level
  if $file_size < 0
    echo "ERROR! File " $filename " not found!"
    echo "The original has not been written back to the drive!"
    returnsub
  endif
  seti $divide_check = $file_size % 512
  if $divide_check != 0
    echo "ERROR! Filesize of " $filename " is not evenly dividable by sector size!"
    echo "The original has not been written back to the drive!"
    returnsub
  endif
  seti $size_check = $file_size / 512
  if $size_check != $mod_length_sectors
    echo "ERROR! The size of " $filename " does not match the value read from the module!"
    echo "The original has not been written back to the drive!"
    returnsub
  endif
  echo "Reading the original file"
  readscratchpad $filename 0 0 $scratchpad_size

  # check for proper header
  sets $header = scratchpad 0 4
  sets $header_check = "ROYL"
  if $header != $header_check
    echo "Found header = " $header
    echo "ERROR! Header is not 'ROYL'!"
    echo "The patch has not been written to the drive!"
    returnsub
  endif

  # verify checksum
  seti $checksum = scratchpad 0xc dw
  seti $calculated_checksum = 0
  gosub calculate_checksum_scratchpad
  hex
  if $checksum != $calculated_checksum
    echo "Checksum in patch file = 0x" $checksum
    echo "Calculated Checksum = 0x" $calculated_checksum
    echo "ERROR! Checksum of origial file is not valid!"
    echo "The origial has not been written to the drive!"
    returnsub
  endif
  decimal

  echo ""
  echo "Writing the origial module to the drive"

  gosub enable_vsc

  gosub prepare_write_vsc

  # vsc to write the sectors to the disk
  # this writes them one at a time
  # there is a way to get them all at once,
  # but there was a case where that did not work
  seti $count = 0
  while $count < $mod_length_sectors
    setwritepio
    buffersize 0x200
    # copy the sector to the buffer
    seti $offset = $count * 0x200
    copyscratchpadtobuffer $offset 0 0x200
    ata28cmd 0xd6 0x01 0xbf 0x4f 0xc2 0xa0 0xb0
    # check if command failed
    gosub status_check
    seti $count = $count + 1
  done

  gosub disable_vsc

  # read the module again and compare it to what we wrote
  echo "Verifying data"

  gosub enable_vsc

  gosub prepare_read_vsc

  seti $verify_check = 0
  gosub read_and_verify

  if $verify_check = 0
    echo "Data verified!"
  else
    echo "WARNING! The data failed verification!"
    echo "It appears the data write was unsuccessful!"
  endif

  # write the sectors to the backup file
  writescratchpad $backup_filename 0 0 $scratchpad_size

  gosub disable_vsc

endsubroutine





subroutine prepare_read_vsc
  # vsc to prepare (command to set for module read)
  buffersize 0x200
  clearbuffer
  setbuffer 0
    08 00 01 00 $module_number
  endbuffer
  setwritepio
  ata28cmd 0xd6 0x01 0xbe 0x4f 0xc2 0xa0 0xb0
  # check if command failed
  gosub status_check
endsubroutine




subroutine prepare_write_vsc
  # vsc to prepare (command to set for module write)
  buffersize 0x200
  clearbuffer
  setbuffer 0
    08 00 02 00 $module_number
  endbuffer
  setwritepio
  ata28cmd 0xd6 0x01 0xbe 0x4f 0xc2 0xa0 0xb0
  # check if command failed
  gosub status_check
endsubroutine




subroutine read_and_verify
  # vsc to get read the sectors
  # this gets them and verifies one at a time
  seti $count = 0
  while $count < $mod_length_sectors
    buffersize 0x200
    clearbuffer
    setreadpio
    ata28cmd 0xd5 0x01 0xbf 0x4f 0xc2 0xa0 0xb0
    # check if command failed
    gosub status_check
    # compare the data
    seti $offset = $count * 0x200
    seti $byte_count = 0
    while $byte_count < 256
      seti $b = buffer $byte_count
      seti $s = scratchpad $offset
      if $b != $s
        seti $verify_check = 1
        break
      endif
      seti $offset = $offset + 1
      seti $byte_count = $byte_count + 1
    done
    if $verify_check != 0
      break
    endif
    seti $count = $count + 1
  done
endsubroutine




subroutine calculate_checksum_scratchpad
seti $calculated_checksum = 0
  seti $count = 0
  while $count < $scratchpad_size
    seti $dword = scratchpad $count 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
endsubroutine





subroutine calculate_checksum_buffer
seti $calculated_checksum = 0
  seti $count = 0
  while $count < $buffer_size
    seti $dword = buffer $count 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
endsubroutine