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Date: Mon, 4 Oct 2010 17:57:57 -0500
From: Dan Nelson <dnelson@allantgroup.com>
To: David Brodbeck <gull@gull.us>
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Subject: Re: [fbsd_questions] i386 vs amd64, on intel_64
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In the last episode (Oct 04), David Brodbeck said:
> On a 64-bit system, if you build a binary with the -m32 flag, it
> should run on both i386 and x86-64 systems.  A binary built with -m64
> will only run on x86-64.  Does that help?

Actually, -m32 on amd64 won't generate usable binaries, since
/usr/include/machine/* are all amd64 headers and you end up with things like
struct FILE with wrong-size elements.  There was a thread a few weeks ago
discussing this.  If you need to generate 32-bit executables, you'll need to
do it inside an all-32-bit chroot or a virtual machine.

-- 
	Dan Nelson
	dnelson@allantgroup.com