@echo off
rem Boot The Loop
rem map LOOP.ISO hole CD
rem prepare: mkisofs -graft-points /LOOP.ISO=nul
rem cdrtools-2.01.01a18 expected at last - new algorithm for zero length files

set PE_ISO=%~1

rem ####################################################################################################
set PE_ISO=dest.iso
rem ####################################################################################################

if not exist "%PE_ISO%" (echo error: file %PE_ISO% not found &goto :eof)

rem grab ISO file size and convert to Hex
for %%A in ("%PE_ISO%") do (echo %PE_ISO% file size: %%~zA &call :DecimalToHex %%~zA FileSizeHex)
set FileSizeHex=0000000%FileSizeHex%
set FileSizeHex=%FileSizeHex:~-9%
echo %PE_ISO% file size: 0x%FileSizeHex%

rem ISO9660: 9.1.4 Data Length stored according 7.3.3 Both-byte orders
set FileSizeISO=:x%FileSizeHex:~6,2%:x%FileSizeHex:~4,2%:x%FileSizeHex:~2,2%:x%FileSizeHex:~0,2%
set FileSizeISO=%FileSizeISO%:x%FileSizeHex:~0,2%:x%FileSizeHex:~2,2%:x%FileSizeHex:~4,2%:x%FileSizeHex:~6,2%
rem echo %FileSizeISO%

set gsar_s=:xF0:xFF:xFF:xFF:xFF:xFF:xFF:xF0:x00:x00:x00:x00:x00:x00:x00:x00:x46:x01:x01:x04:x00:x00:x10:x00:x00:x00:x01:x00:x00:x01:x08:x4C:x4F:x4F:x50:x2E:x49:x53:x4F:x00
set gsar_r=:x00:x00:x00:x00:x00:x00:x00:x00%FileSizeISO%:x46:x01:x01:x04:x00:x00:x10:x00:x00:x00:x01:x00:x00:x01:x08:x4C:x4F:x4F:x50:x2E:x49:x53:x4F:x00

echo on
build\bin\gsar -o "-s%gsar_s%" "-r%gsar_r%" dest.iso
@goto :eof


::===============================================================
rem T.Salmi
rem http://lipas.uwasa.fi/~ts/http/http2.html#cmdscript
rem ftp://garbo.uwasa.fi/pc/link/tscmd.zip
:DecimalToHex DecimalIn HexOut
::
setlocal enableextensions
set /a dec_=%1
if %dec_% LSS 0 (endlocal & set %2=Error: negative & goto :EOF)
set hex_=
:_hexloop
  set /a dec1_=%dec_%
  set /a dec_=%dec_% / 16
  set /a hexdigit_=%dec1_% - 16*%dec_%
  set /a hexidx_=%hexdigit_%+1
  for /f "tokens=%hexidx_%" %%h in ('echo 0 1 2 3 4 5 6 7 8 9 A B C D E F') do set hexdigit_=%%h
  set hex_=%hexdigit_%%hex_%
  if %dec_% GTR 0 goto :_hexloop
endlocal & set %2=%hex_% & goto :EOF