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From: DrPi <314@drpi.fr>
Subject: Re: is there a version of unix written in Ada
Date: Sun, 27 Sep 2020 22:59:38 +0200
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Le 27/09/2020 à 17:01, Dmitry A. Kazakov a écrit :
> On 27/09/2020 16:25, Shark8 wrote:
> 
>> ... POSIX is a terrible idea, it mandates many things that [IMO] 
>> severely constrain the architecture, to include directory layout IIRC, 
>> and making another *nix is something that holds zero appeal to me; 
>> instead, I would advise having a very solid foundational framework and 
>> some "native" constructs that you're not going to find elsewhere.
> 
> Sure. There is no reason to develop anything resembling UNIX.
Good option but...
> 
> An OS worth designing should be based on persistent objects and have no 
> files and filesystem whatsoever.
...one problem with this concept is you can't compile/run the huge 
amount of existing software. You have to recreate everything. Unless you 
have a comptibility layer for legacy software.
> 
> On the programming language side, Ada requires a type system with 
> visibility and privacy potentially done per hardware.
> 
> Presently it is not possible to map private parts of a package and types 
> declared there onto physically different memory pages protected from 
> reading/writing in public view context. Calls to primitive operations 
> cannot be routed through the kernel. Tasks and protected objects are not 
> extensible. Without these OS API would rapidly degrade to low-level 
> C-esque stuff.
> 
This will make memory management very very complex.