| From: | Joseph Fenton |
| Date: | 10 Dec 99 at 21:06:48 |
| Subject: | Re: [warpup] 68K emulation |
Morten Str�rup wrote:
>
> On Tuesday, December 07 1999, 22:23:02, Sam Jordan was caught saying:
>
> >Sorry, this has nothing in common with *real* memory protection, which
> >I anyway don't expect to see in AOS, because of some fundamental
> >conceptual problems with AMIGA software programming (like passing
> >data inside messages by reference instead of by value).
>
> You mean instead of sending the message, its just sending a pointer to an
> address that contains what should be inside the message ?
>
> Why would one do that ?
Windows 9x started message by value in anticipation of
memory protection (which it has to a small degree).
Think of it this way... if no other task can access
the memory of another task, how can you access data
pointed to by the pointer in a message? You can't,
so you pass ALL the data in the message instead of
a pointer to the data. You could pass just a pointer
IF the system made special provision of mapping
the data from one task to another, but that is
complicated and decreases the memory protection
as tasks are now sharing data to some extent.
> My first idea wasn't exactly a hit, but how about this then:
>
> On the POP box I assume WarpOS has to run on something like Linux and not
> just on the raw metal. When starting a PPC task under such a setup, would it
> be possible to have WarpOS spawn the program as a task under the host OS and
> thereby using the memoryprotection facilities of the host OS ?
This means you must have a virtual machine for each
and every program you run... basically, you are
emulating the Amiga. This is the safest way, but
slower and subject to how accurate your emu is.
I still want to try my hand at an Amiga emu, maybe
late winter/spring.