csrss.exe and VDM ?

[Klemens Friedl]

I read on the ms homepage that the crss.exe contains:
 + creating and deleting processes and threads
 + console (text) windows
 + 16-bit virtual DOS machine (VDM)

Is in the csrss.exe (from ReactOS) the VDM process inluded?
I read in the old forum that someone spoke about an DOS/win16 subsystem.
Should the DOS (virtual maschine) be a part of the csrss.exe?


And, does the Ros graphic run in kernel mode (like as in Win 2000 - GDI)?


Klemens Friedl <frik85>

-- 
GMX ProMail mit bestem Virenschutz http://www.gmx.net/de/go/mail
+++ Empfehlung der Redaktion +++ Internet Professionell 10/04 +++

[Filip Navara]

----- PŮVODNÍ ZPRÁVA -----
Od: "Klemens Friedl" <klemens_friedl(a)gmx.net>
Komu: ros-dev(a)reactos.com
Předmět: [ros-dev] csrss.exe and VDM ?
Datum: 7.12.2004 - 22:32:45

>   I read on the ms homepage that the crss.exe contains:
>  + creating and deleting processes and threads 
It's informed about Win32 process creation and is involved in it,
but the main components are ntdll+ntoskrnl and kernel32.

>   + console (text) windows 
Correct.

>   + 16-bit virtual DOS machine (VDM) 
CSRSS is involved here, but the main VDM process is NTVDM.exe which
executes Win16/DOS programs and uses special kernel calls
(NtVdmControl or how is it called). The emulated devices are
handled by special device drivers (see DDK for details, there's
special section about VDD drivers and DDK Graphics Drivers section
has some info about VDM graphics handling)

>   Is in the csrss.exe (from ReactOS) the VDM process
> inluded? 
No.

>   I read in the old forum that someone spoke about an
> DOS/win16
>  subsystem.
>  Should the DOS (virtual maschine) be a part of the csrss.exe? 
See above.

>   And, does the Ros graphic run in kernel mode (like as
> in Win
>  2000 - GDI)? 
Yes (User32 and Gdi32 core is implemented in KM - win32k.sys,
higher level code is in UM).

Regards,
Filip

[Alex Ionescu]

Filip Navara wrote:

> >  + 16-bit
> > virtual DOS machine (VDM)
> >     
> >  
> CSRSS is involved here, but the main VDM process is NTVDM.exe which
> executes Win16/DOS programs and uses special kernel calls
> (NtVdmControl or how is it called). The emulated devices are
> handled by special device drivers (see DDK for details, there's
> special section about VDD drivers and DDK Graphics Drivers section
> has some info about VDM graphics handling)
>
>   
>
> >  Is in the csrss.exe (from ReactOS) the VDM process
> > inluded?
> >     
> >  
> No.
>
>   
>
> >  I read in the old forum that someone spoke about
> > an DOS/win16
> > subsystem.
> > Should the DOS (virtual maschine) be a part of the csrss.exe?
> >     
> >  
> See above.
>
>   
>
>   
>  
Just to add some information, CSRSS is quite more involved then Filip 
would make it seem :). Although NtVdmControl is used for hardware kernel 
calls, almost all the 1) Console and 2) VDM Emulation is passed back 
through CSRSS. CSRSS is the one who executes the loops to get the newest 
emulated commands to do, and who handles all the I/O.

Best regards,
Alex Ionescu

[Klemens Friedl]

>   Just to add some information, CSRSS is quite more
> involved then Filip 
>  would make it seem :). Although NtVdmControl is used for hardware kernel 
>  calls, almost all the 1) Console and 2) VDM Emulation is passed back 
>  through CSRSS. CSRSS is the one who executes the loops to get the newest 
>  emulated commands to do, and who handles all the I/O.
>  
>  Best regards,
>  Alex Ionescu
>   
I was confused about the implementation (NT 4/5).
Thanks for the information.

Klemens Friedl <fik85>

-- 
GMX ProMail mit bestem Virenschutz http://www.gmx.net/de/go/mail
+++ Empfehlung der Redaktion +++ Internet Professionell 10/04 +++

[Robert Köpferl]

What-o-ever.
In some way I like the cluttered way ntvdm is implemented. Looking 
forward on coming PC hardware and back to old DOSware and forward to 
processor portability, I'd vote for DOSbox* as ROS's dos-box.
CPUs get faster and faster and evolution is going away from ia32 (With 
vx86-mode). Thus a solely software implemented DOS-Box is more 
appropriate, now.
Can we fix this theme somewhere?  Steven? Jason?

*DOSbox = Freedos+bochs(win32)

Alex Ionescu wrote:
>   Filip Navara wrote:
>  
> > >   + 16-bit
> > > virtual DOS machine (VDM)
> > >     
> >
> >  CSRSS is involved here, but the main VDM process is NTVDM.exe which
> >  executes Win16/DOS programs and uses special kernel calls
> >  (NtVdmControl or how is it called). The emulated devices are
> >  handled by special device drivers (see DDK for details, there's
> >  special section about VDD drivers and DDK Graphics Drivers section
> >  has some info about VDM graphics handling)
> >
> >   
> >
> > >   Is in the csrss.exe (from ReactOS) the VDM
> > > process inluded?
> > >     
> >
> >  No.
> >
> >   
> >
> > >   I read in the old forum that someone spoke about
> > > an DOS/win16
> > >  subsystem.
> > >  Should the DOS (virtual maschine) be a part of the csrss.exe?
> > >     
> >
> >  See above.
> >
> >   
> >
> >   
> >  
>  
>  Just to add some information, CSRSS is quite more involved then Filip 
>  would make it seem :). Although NtVdmControl is used for hardware kernel 
>  calls, almost all the 1) Console and 2) VDM Emulation is passed back 
>  through CSRSS. CSRSS is the one who executes the loops to get the newest 
>  emulated commands to do, and who handles all the I/O.
>  
>  Best regards,
>  Alex Ionescu
>  
>  _______________________________________________
>  Ros-dev mailing list
>  Ros-dev(a)reactos.com
>  http://reactos.com:8080/mailman/listinfo/ros-dev
>

[Steven Edwards]

Hi,

--- Robert K�pferl <rob(a)koepferl.de> wrote:
>   What-o-ever.
>  In some way I like the cluttered way ntvdm is implemented. Looking 
>  forward on coming PC hardware and back to old DOSware and forward to 
>  processor portability, I'd vote for DOSbox* as ROS's dos-box.
>  CPUs get faster and faster and evolution is going away from ia32 (With 
>  vx86-mode). Thus a solely software implemented DOS-Box is more 
>  appropriate, now.
>  Can we fix this theme somewhere?  Steven? Jason?
>  
>  *DOSbox = Freedos+bochs(win32) 
I don't really care how its done. As far as I see it we dont have to be 100%
compatible when it
comes to dos/Win16. Some of the Wine guys have been working on making winedos.dll portable
so we
can use it if you would like. DOSbox would be cool with me as well.

Thanks
Steven



		
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