Re: building an image

Hello,

I'm still trying to figure out, like a high level model of the VM. The
available documentation doesn't help me much here, I have to say, and
it took some time to get into this. So not sure what you mean exactly
with

> trying to sort out how the image gets built so I can track the
> entrypoint into the runtime environment and see what how the UI gets
> loaded.

, but I'll try to explain briefly what I've found out about how the VM
starts into the GUI.

- VM starts in shell.cpp, initialization (bootstrap.cpp, mainly
bootstrap::parse_file())
- in process.cpp: VMProcess::activate_system(). This is where things
get interesting (and difficult, at least for me ;). The VM process
tries to retrieve a 'Delta level Processor' (see comments there) from
the system dictionary, which was (supposedly) previously loaded from
the image by the bootstrap code. I guess that the OOPs (processOop
etc.) involved are actually C++ representations of Smalltalk classes/
objects stored in the image (if this makes sense). You can inspect the
Smalltalk code by opening Strongtalk, then Browse->All Classes-
>Processor(->ProcessorScheduler).
- then, the "initial process" is created (new DeltaProcess) to call
the "start" method of scheduler just created (a method written in
Smalltalk, see Strongtalk class browser: Class ProcessorScheduler-
>Instance side->restricted->start).
- the actual call to "start" originates in the delta process once it
is run (that is, control is transfered by the scheduler): process.cpp
DeltaProcess::launch_delta, then delta.cpp Delta::call, all the way
down to interpreter_asm.asm call_delta, where the actual call takes
place. So I assume this is the point where Smalltalk code takes over
and drives further initialization of the system and GUI.
- also, if you look at the Smalltalk classes, especially
ExternalProxy, External* and Win32, I believe that there is a lot of
platform specific code written in Smalltalk, using Windows DLL calls
to interface with the OS (hence all the dll stuff/primitives in the C+
+ code)... just speculating, though!

So, that's about my quick tour of the VM startup, hope it helps -- or
maybe I've just missed the point of your post?  I haven't even manage
to build a new image file from within the Strongtalk GUI, but it's
been a while.Some information about the image file format and its
contents would definitely be helpful; I have to look at this again
when time permits.

Oliver


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "Strongtalk-general" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [email protected]
For more options, visit this group at http://groups.google.com/group/strongtalk-general?hl=en
-~----------~----~----~----~------~----~------~--~---