Linux-IA64 execution of ILP32 binaries

Has co-existance / running of 32-bit (ILP32) Linux executables been addressed such that they could run under the LP64 data model of Linux-IA64 ? If not, shouldn't the IA-64 section of the Linux Standard Base address this ? I've only seen references to the Intel ABI documents, which I don't believe cover some of the (considerable)interoperability issues that would be involved...

Thanks

Phil Smith

Phil> Has co-existance / running of 32-bit (ILP32) Linux executables Phil> been addressed such that they could run under the LP64 data Phil> model of Linux-IA64 ? If not, shouldn't the IA-64 section of Phil> the Linux Standard Base address this ? I've only seen Phil> references to the Intel ABI documents, which I don't believe Phil> cover some of the (considerable)interoperability issues that Phil> would be involved...

This comes up periodically and the answer remains the same: IA-64 Linux is LP64 _only_ and there is no effort to add ILP32 support. A primary reason for this is to avoid market fragmentation, though there are other reasons as well (see mailing list archive for earlier discussions).

Of course, if you just want to run an old binary, you can get ILP32 in the form of an x86 binary, but that won't perform at native speeds.

	--david

My primary question wasn't as much about supporting ILP32 development under Linux-IA64, but just executing binaries created under such an environment. The biggest question should surround the VM address space, which could be a subset of the Linux-IA64 map. If pointers are sign-extended, a single region in a 61-bit address area can accommodate the 32-bit range for x86. Obviously, things like big files could not be accessed without special APIs for the 32-bit developers. Commercial UNIX vendors (i.e., HP and Sun) have taken great pains to provide a migration path. It seems that not accommodating this creates GREATER market fragmentation, especially with more commercial products being available on Linux. It seems ironic that 16-bit DOS, Windows and 32-bit Windows will still run under Wine or Win64, but 32-bit Linux software on the market today won't run on Linux-IA64...

Perhaps it's a topic for another list, but does anyone know how the Linux Standard Base will handle this ?

Phil Smith

-----Original Message-----
From: David Mosberger [mailto:[email protected]]
Sent: Tuesday, March 12, 2002 2:35 PM
To: Smith, Phil
Cc: [email protected]
Subject: Re: [Linux-ia64] Linux-IA64 execution of ILP32 binaries

<[email protected]> said:

Phil> Has co-existance / running of 32-bit (ILP32) Linux executables Phil> been addressed such that they could run under the LP64 data Phil> model of Linux-IA64 ? If not, shouldn't the IA-64 section of Phil> the Linux Standard Base address this ? I've only seen Phil> references to the Intel ABI documents, which I don't believe Phil> cover some of the (considerable)interoperability issues that Phil> would be involved...

This comes up periodically and the answer remains the same: IA-64 Linux is LP64 _only_ and there is no effort to add ILP32 support. A primary reason for this is to avoid market fragmentation, though there are other reasons as well (see mailing list archive for earlier discussions).

Of course, if you just want to run an old binary, you can get ILP32 in the form of an x86 binary, but that won't perform at native speeds.

	--david

Phil> My primary question wasn't as much about supporting ILP32 Phil> development under Linux-IA64, but just executing binaries Phil> created under such an environment. The biggest question should Phil> surround the VM address space, which could be a subset of the Phil> Linux-IA64 map.

Oh, that's easy: you can set the maximum virtual address space size of a task and its map-base to any value in the Linux kernel. That's what we use to enforce VM < 4GB for IA-32 tasks.

Phil> If pointers are sign-extended, a single region Phil> in a 61-bit address area can accommodate the 32-bit range for Phil> x86. Obviously, things like big files could not be accessed Phil> without special APIs for the 32-bit developers. Commercial Phil> UNIX vendors (i.e., HP and Sun) have taken great pains to Phil> provide a migration path. It seems that not accommodating this Phil> creates GREATER market fragmentation, especially with more Phil> commercial products being available on Linux. It seems ironic Phil> that 16-bit DOS, Windows and 32-bit Windows will still run Phil> under Wine or Win64, but 32-bit Linux software on the market Phil> today won't run on Linux-IA64...

You *can* run IA-32 binaries on IA-64 Linux. Just try realplay or some other x86-only application and I think you'll find it works just fine.

	--david