Apply the 'subsystems' :

The subsystems:

- Provide the capacity to run apps written for various operating systems.

- Intercept the calls that apps make to a specific API

- Convert the API calls into a format understood by wServers.

The converted API calls are passed to the OS parts needing to deal with the requests. 

The return codes (information) that these apps depend on are converted back to a format understood by the app.

The Win-32 based apps handle the I/O and GUI functions plus the Terminal Service.

Software has no direct access to hardware.

If an app requests hard-disk space, the software cannot access hardware to get the information.  Instead, the app accesses user mode objects that talk to kernel mode objects.
And the kernel mode objects talk down the OS stack to the Hardware Abstraction Layer (HAL).

The information is then passed all the way up the stack into the interface.
This processing is known as hand off processing.

 

The Win32 code gets a return value and developers do not need to talk to the hardware.

This is useful for developers and the operating system.

APIs that check the validity of the call protect the OS.

And, developers get a simple call-level interface, (one line of code and not 10,000 lines).

Software has no direct access to device drivers.

The philosophy outlined previously applies to device drivers as well. Hardware manufacturers build the drivers for the OS that accesses the hardware.

The drivers are prevented from going directly to the hardware.

Instead the drivers interface with abstraction objects provided by the device-driver APIs.

Software is limited to an assigned address space in memory.
The limits protect the operating system from rogue apps. 

Rogue apps might attempt to access whatever memory they can.

Rogue apps are impossible in wServer.

So, a rogue app can only destroy the one assigned address space.

 

wServer uses hard-disk space as quasi-RAM.

Apps are oblivious to the source or type of memory;

Memory is transparent to the apps.

Virtual memory is a combination of all memory in the system, and combines both physical memory in the machine and a swap file that is used to store information that cannot reside in hardware RAM.

 

This means that the apps do not get preference for access to the CPU over kernel mode processes.