Compiling amd64 binary on i386 root with amd64 kernel (Debian)
I have a rather old Debian testing system that has all packages installed as i386. Usually I'm running a PAE kernel (linux-image-3.16.0-4-686-pae:i386).
I'm trying to compile a simple C++ program that needs more than 4 GB of memory. I've installed the linux-image-3.16.0-4-amd64:amd64 kernel because I think it is not possible to get more than 3GB of memory on a PAE machine.
Unfortunately, the whole toolchain/libraries are still i386. I guess I need a special flavour of GCC (multilib?) and the amd64 version of some libraries.
I've found tutorials on how to compile 32bit stuff on 64bit rootfs systems, but not the other way round. I don't want to cross-grade the whole system to amd64 just for this test, so:
Is there a way to safely compile and run 64bit code on this setup with as little changes to the system as necessary? Ideally it would be possible to cross-grade from this setup at some point in the future. Alternately, would it be possible to create a 64bit chroot environment from a Debian Live CD, chroot into it, compile the code and run it from there? Or compile it statically and run it outside the chroot?
EDIT: Installing g++multilib solves the problem compiling 64bit (using the -m64 option). Can anyone help with the chroot / cross-grade part of my question?