RTEMS with post-boot code.

[Dan A. Dickey]

Jacob W Janovetz wrote:

> >       The compilation manager changes the linker script to use the address of
> > this region as the start of the program sections. ( Recall we have put
> > them in order, prog-text, prog-data and prog-bss. )  We then recompile
> > and relink.  Afterwards, we extract only that program section from the
> > resulting image. ( eg. about 112 bytes for hello world ).  we send this
> > image down to the program manager, to be loaded into the given region. (
> > again via UDP )
>
>   This seems unacceptable to me.  Depending on what is wanted for
> any given situation, I agree that trade-offs must be taken.  I
> would much prefer to less segmentation than to have to recompile
> and relink for every download.  On each "host" connected to my
> "target", I want a bunch of applications.  I accept the need for
> a download manager (on the host) and a program manager (on the
> target), but I don't accept the need for cross-compilation and
> linking tools on the host.
>
>    At this point, I like Joel's recommendation of the linker option,
> but I didn't know that existed.  I have to look into that.
>
>    These are all great options!

Jake,
going by what has been written so far - it really looks like what you want
is RTEMS to be able to execute an image it gets from <insert-your-favorite-
storage-place-here>.  When the application is done, it's done.  Another
one could be run afterwards - or maybe at the same time.
It sounds like you really are looking for a "real" OS - one that can dynamically
load images (programs, executables, whatever-you-want-to-call-it) and
run them.  All without rebooting/reloading/restarting/resetting.  Like I said,
a "real" OS.  For this, correct me if I'm wrong (I'm sure you will), but wouldn't
you need an MMU and code to run it?  Not to mention the CPU to go with
it.

Is that what you were hinting at Jake?
I mean, if the above were possible - why not have one of the images be
the compiler/linker?  Then we can begin porting all sorts of public domain
code to run on RTEMS... :)  Anyways...it's already been a long day, and
I've a Solaris 2.6 upgrade to start in 2.5 hours... :(
    -Dan

--
Dan A. Dickey  http://www.transition.com/
mailto:ddickey at transition.com