[Info-vax] VAX VMS going forward

[VAXman- at SendSpamHere.ORG]

In article <rfeknc$al6$2 at dont-email.me>, Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>On 2020-07-23, Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
>> On 2020-07-23 17:38:33 +0000, Simon Clubley said:
>>> P1 space would also be right in the way of a flat 64-bit addressing 
>>> mode so all the code which uses P1 space would have to be rewritten to 
>>> support flat 64-bit addresses because P1 space would have to be moved 
>>> well out of the way.
>>
>> P0 and P1 space and S0 and S1 space are for VAX compatibility within 
>> apps and app source code.
>>
>
>P1 space is a little more than that. :-)
>
>It's where DCL and the associated data structures live.
>
>How much work would be involved in moving what is currently in P1 space to
>somewhere up the 64-bit memory map to just below where the kernel is mapped ?
>
>For one example, how much of the P1 code and data structures are still
>32-bit only ?
>
>That would mean as well that you would have P1 data cells with different
>locations on the system depending on whether you are running in 32-bit
>or 64-bit mode.
>
>There's also the question of whether flat 64-bit addresses are a process
>level attribute or an image level attribute. Think about what that means
>for P1 space as well as for mixing 32-bit and 64-bit applications in the
>same process space.

Read the I&DS instead of allowing it to merely occupy bookshelf space.

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VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

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