If so, how can the syscalls work?
Andreas Schamanek [ Editor ] from Wien, Österreich
Yes. For instance, you can install a 64 bit kernel on a 32 bit system. You’ll probably need ia32-libs and possibly amd64-libs.
Note that a number of issues have been reported. Just do some web research, and you’ll see.
A good article is Running 32-bit Applications on 64-bit Debian GNU/Linux (see also the comments there).
Your question about syscalls has been amply answered in c – How do 32-bit applications make system calls on 64-bit Linux? – Stack Overflow.