[Info-vax] Why (conceptually) does executive mode code need unrestricted kernel mode access ?

[Simon Clubley]

Why, at a conceptual level, does executive mode code need unrestricted
kernel mode access ?

If kernel mode access is required, then why can't executive mode code go
through a normal system service to provide the additional functionality
like everyone else does ?

For example, what does RMS actually _need_ direct unrestricted kernel mode
access for and why can't this be provided for by a normal system service ?

If it's a privileges problem, the system service could check that the
previous mode was executive mode before deciding whether to allow the
specific operation in question.

No specific reason for the questions, it's just something that occurred
to me while reading some documentation.

Thanks,

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.