[Info-vax] VMS internals design, was: Re: BASIC and AST routines

[chris]

On 11/29/21 19:27, Simon Clubley wrote:

>
> This is how I design my own bare metal setups and it works robustly
> and cleanly. The information is still on the stack, but it is strictly
> outside of the bounds of the stack space that the called routine is
> allowed to touch or view. The information is considered to belong to
> the dispatcher and _not_ to the routine the dispatcher calls.
>
> Simon.
>

Lets qualify that by saying the information is not in any protected
memory space and could be accessed  using an offset add / subtract
from the current stack pointer, whatever function the code is currently
running. Seem to remember examples of that for context switching in
embedded os's.

It's quite common in some work to specify a call interface as a
structure + pointer for some subgroup of functionality. Some of
the structure elements used within the called functions and some
are call parameters, but the whole structure is visible to both
sides. I don't see a problem with that...

Chris