[FreeVMS] x86_64 ia32 emulation

[Guido]

On 05/30/2015 03:18 PM, Roar Thronæs wrote:
> On Fri, May 29, 2015 at 11:55:08PM +0200, Guido wrote:
>> What is the reason that the FreeVMS linux kernel configuration has IA32
>> emulation support on x86_64 architecture?
> It was inherited from the imported kernel.
> It might come in handy to run 32-bit images, but I have not used it yet.
>
OK. I can not imagine what kind of 32 bit images that will be though, 
because IA32 emulation would only necessary for closed source x86 VMS 
binaries or maybe when wine (www.winehq.org) is ported to VMS.

The problem with the current FreeVMS code is that it is very unstable. 
Changing anything in one place can easily break things in a seemingly 
unrelated other parts. I experienced this both with simple code changes, 
but also with small changes in the build environment. Reasons can be 
uninitialized variables, function parameters that are properly checked 
before use, using type "long" on both i386 (where long is 32 bits wide) 
and x86_64 (long is 64 bits wide), etc.

I am trying to strip the code down to what is really needed and to add 
some automated tests to identify and fix these problems. The tests can 
also be used for regression testing. Anyway, this is quite lot of work, 
so do not expect new features any time soon.

Regards,
Guido