From: Paul Guyot (pguyot_at_kallisys.net)
Date: Tue Oct 07 2003 - 10:52:42 PDT
Aux environs du 7/10/03 à 11:39 -0600, sous le titre "Re: [NTLK]
protected memory", Andrei Chichak prit sa plus belle plume pour
écrire les mots suivants:
>The object system allows finding pointers to other objects in the system
>(like other programs) de-referencing them and allowing you do munge the
>results. This is used in the various soup debugging programs.
I don't understand this or what you refer to here.
>The memory space does not use protection between processes.
It does and it can, but not as much as between processes in a Unix environment.
Basically, to save time in process-switching, all you can do is to
play with domains and the ARM MMU has a limited number of domains.
>You can also place your version of system routines into the object lookup
>hierarchy and mask system routines in ROM. So the operating system is not
>protected from you either. This is how patches are able to override stuff
>in ROM.
Er.
You cannot patch most system calls. What you can do is to interact at
the NewtonScript level.
NewtonScript is a task on its own (well, since 2.0 it can be splitted
in several tasks, but it's heavy and not very useful).
NewtonOS actually includes many other tasks.
What is true is that there is virtually no protection in the
NewtonScript world except the fact that packages are read-only. This
means a program can interact and change another one. It could be a
weakness, but it's also a great strength. There is nothing to protect
your data as well. A program can get all the e-mail addresses stored
on your Newton. Likewise, it could be a weakness, in a world full of
viruses, but on the Newton it's a great strength because basically
any program can link data to persons in your address book, let you
e-mail stuff and so on.
This is a good balance for a PDA, but it wouldn't be suitable for a
desktop environment.
Paul
-- Philosophie de baignoire - consultations sur rendez-vous. NPDS/NewtonOS: http://newton.kallisys.net:8080/ Apache/FreeBSD: http://www.kallisys.com/ -- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/
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