Re: Ada OS Kernel features

[Alfred Hilscher <Alfred.Hilscher@icn.siemens.de>]

Brian Catlin wrote:
> 
> What sort of features would be desirable/required in the kernel?
> 
> Processor architectures:
>   What sort of processor architectures should be supported?  32-bit obviously,
> but what about 64-bit, or 16-bit?  Little-endian only, or big-endian too?

32-bit open for future 64-bit.

Both, _big_ and _little_ endian.

> (personally, I view big-endian as a crime against nature, and would vote against

Why ?

> processors)  Deciding on these issues early is very important, as it will
> greatly influence the rest of the design and implementation of the kernel.  All

In which manner? Where do you think that there will be any influence?
 
> Memory management:
>   A demand-paged memory manager would seem to be required.  However, I would not
> like to see paging made a requirement - as long as there is enough physical
> memory, there should be no need.

Thats what I liked on OS/2, one was able to switch it off.

> process an I/O request is passed around between drivers.  What form should a
> driver take?  Implementing a driver as one or more tasks in the kernel seems to
> be the most natural.  The layering of device drivers (as implemented) in NT
> would also seem to be a very valuable feature.

You should be able to load/unload a driver dynamically (I hate rebooting
because of driver change). 

You should be able to "overload" a driver. What I mean ?  Lets assume
you have a simple grafic driver on bootup, then you load a "better"
(more complex, higher resolution, 3D excelerator ...) one. If this one
crashes, then it should simply be unloaded and the system should
continue work with the (simple) default driver - instead of showing a
"blue screen" ;-)