32 and 64-bit OS

[Terry Washington_1]

I am running HP-UX11i on a Visualize B1000 with 64-bit support. Can the OS be setup to allow both 64 and 32 bit support? If so how would this be done?

[A. Clay Stephenson · Accepted solution]

The B1000 is certified only for 64-bit HP-UX.
You could purchase another box on the used-equipment market. For example, the C160,C180,C200,C240, & C360 will run either. In that case, you can install two disks and use boot primary to load the 64-bit and boot alternate to load the 32-bit version.

[John Poff]

Hi,

Are you asking if 11i can be configured to run both 32-bit and 64-bit apps? It already will. Your 32-bit apps should run ok on 11i. Going the other direction is the hard part.

JP

[Stuart Abramson_2]

What is the point of your question?

Be aware that the 64-bit OS will run 32-bit applicatons. They just run in 32-bit space. That means that they have smaller maxdsiz and maxtsiz, etc, and smaller shared memory (which can be a pain). That's why you see kernel parameters with names like:

maxdsiz
maxdsiz_64bits

etc..

[Jeff Schussele]

Hi Terry,

Not sure if I clearly understand your question.
But if you are asking whether one can run BOTH 32 & 64 bit applications on a system running the OS 64 bit, then the answer is YES.
You can run 32 bit app SW, but you're still limited to 32-bit addressing however. So the same rules on the total addressable memory still apply to 32 bit SW running in a 64 bit kernel environment.

Rgds,
Jeff

[Terry Washington_1]

Thanks for all of the replies. I apologize if my question was vague. This is a development system and the developers want to be able to run/test their applications in both the 32-bit and 64-bit environment.

[Shannon Petry]

They should have no problems doing this. The 64bit OS runs 32bit apps just fine. They just need to make sure to compile 2 versions, 1x64bit and 1x32bit.

Reminds me of an old joke: NT is a 32bit patch to a 16 bit add on to a 8 bit disk operating system running on a 4 bit processor that's not worth 2 bits.



Regards,
Shannon

[Terry Washington_1]

Can 32-bit applications still be built within the 64-bit environment on the B1000?

[Pete Randall]

No, sorry.


Pete

[Patrick Wallek]

Yes, you absolutely can create programs in a 64-bit environment that will run in a 32-environment.

If you are using HP's C compiler, look at the +DAportable compiler flag.

[Olav Baadsvik]

Hello,

Yes, even if you have a 64-bit HP-UX you
can build for 32-bit.
Actually by default the hp-compilers will
make code for 32-bit. To get the compilers
to generate code for 64-bit you will have
to use the +DA2.0W option.

The +DAportable is for generating code that
can execute on the old PA-RISC 1.x processors.
By using this option you will get code that
does not use the most advanced instructions
in the newer PA-RISC processors and will
therefore execute slower.

Olav

[Terry Washington_1]

Thanks for the prompt response. Can this also be done with the gcc compiler?

[Patrick Wallek]

It probably can. I don't have gcc I can look at. You'll just need to go thru the gcc man page and look for the appropriate option to use.

[Terry Washington_1]

Thanks for the info!

[Pete Randall]

Terry,

Please accept my apologies. I'm not sure where I thought I'd heard that you couldn't generate 32 bit binaries on a 64 bit system, but I was pretty darn sure that's what I'd heard.

There's just no end to learning, I guess.

Pete

[Shannon Petry]

Pete, you may have heard what I did, that this is a gcc issue. I dont think I have ever seen a gcc option like the portable option with HP/ANSI-C. Now, this may have been when the initial release was done to support 64bits, but I have never seen notes stating that it worked.

Regards,
Shannon

[Pete Randall]

Thanks, Shannon. That makes me feel a little less stupid.

Pete