os2/doc/index.html

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   8 <h1><b>OS/2 subsystem for ReactOS (ROS/2)</b></h1>
   9 <h2><font color="#009966">Introduction</font></h2>
  10 <p>The OS/2 subsystem is being developed to enable NT-like systems (like WinNT
  11   and ReactOS) to run 32-Bit OS/2 applications natively. With this it shall provide
  12   binary compatiblility on x86-Based systems. It is intended to port the ROS/2
  13   also to other platforms supported by ReactOS / NT. It is planned to provide
  14   source code compatibility on these platforms. Yeeahh, OS/2 for PowerPC is in
  15   sight.</p>
  16 <h2><font color="#009966">Components</font></h2>
  17 <p>ROS/2 consists of the following components:</p>
  18 <ul>
  19   <li>OS2SS.EXE - A native application that implements the personality of the
  20     OS/2 kernel.</li>
  21   <li>OS2.EXE - A win32 application that does the interaction of the OS/2 apps
  22     with the desktop.</li>
  23   <li>Core DLLs - These DLLs that make OS/2 programs interface with the kernel/sub
  24     system (i.E. DOSCALLS.DLL). </li>
  25   <li>Additional DLLs - DLLs that provide additional APIs for OS/2 apps. This
  26     includes Presentation Manager.</li>
  27 </ul>
  28 <h2><font color="#009966">Current state</font></h2>
  29 <p>Up to now just a fragment of DOSCALLS.DLL exists. The biggest problem are the
  30   os2 API headers which are (C) by IBM. So help is still welcome.</p>
  31 <h2><font color="#009966">16-Bit issues</font></h2>
  32 <p>It is not intended to support 16-bit OS/2 applications. This would make the
  33   system inconsistent and produce much more work that use. But there is still
  34   one issue: Current textmode applications are either 16-bit or use thunking to
  35   call the 16-bit APIs. These 32-Bit thunking applications have to be supported.
  36   We are still thinking how to accomplish that. </p>
  37 <h2><font color="#009966">32-Bit issues</font></h2>
  38 <p>It is planned to replace the current MOU- KBD- MSG- and VIO- subsystems with
  39   the <a href="http://homepages.tesco.net/%7EJ.deBoynePollard/Softwares/conapi.html">Unicode
  40   Console API</a>. This is also the foundation for other platforms we want to
  41   provide source code compatibility with. So nearly every 32-Bit processor can
  42   be supported. It sould even be possible to implement a 64-bit OS/2 API.</p>
  43 <h2><font color="#009966">Architecture</font></h2>
  44 <p>To understand the architecture of ReactOS or WinNT read a book from the &quot;Inside
  45   Windows NT&quot;-series. The architecture of ROS/2 is like every normal subsystem.
  46   When OS2SS.EXE starts, it creates an object directory named os2 and therein
  47   it creates a port object with the name Os2API. A port is something like a socket.
  48   Two programs can comunicate with each other via a port. The port Os2API provides
  49   the LPC API of the OS2SS.EXE - the actual subsystem. <br>
  50   Every OS/2 program that is loaded, is linked with DOSCALLS.DLL and NTDLL.DLL
  51   - the interface to the NT-kernel. Since DOSCALLS is implemented using NTDLL.DLL,
  52   every OS/2 app has it in its adress space. Many functions in DOSCALLS.DLL are
  53   implemented by just wrapping NTDLL.DLL functions. Some functions however need
  54   assistance by the subsystem. For this reason the app makes an LPC to OS2SS.EXE.
  55   LPC means local procedure call and it is a very fast version of RPC. Together
  56   with the first application also OS2.EXE starts up. OS2.EXE runs in the win32
  57   subsystem with the security of the current user. OS2.EXE is used to gather keyboard
  58   and mouse input and to show console windows and PM-windows of all OS/2 programms
  59   of the current user. In order to accomplish this OS2.EXE creates a port object
  60   in the os2 object directory named Os2Interact. OS/2 applications have a connection
  61   to OS2.EXE, too. OS2SS.EXE and OS2.EXE also talk to each other. An OS/2 application
  62   then makes LPCs either to OS2.EXE directly or if required via OS2SS.EXE.</p>
  63 <p>Details</p>
  64 <p>&nbsp;</p>
  65 <p>LPC Documentation</p>
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