19.4 Kernel Specifications
The 64-bit kernels for x86_64, ppc64, and s390x
offer both a 64-bit and a 32-bit kernel ABI (application binary interface).
The latter is identical with the ABI for the corresponding 32-bit kernel.
This means that the 32-bit application can communicate with the 64-bit
kernel in the same way as with the 32-bit kernel.
The 32-bit emulation of system calls for a 64-bit kernel does not support
all the APIs used by system programs. This depends on the platform. For
this reason, a small number of applications, like lspci,
must be compiled on non-ppc64 platforms as 64-bit programs
to function properly. On IBM System z, not all ioctls are available in the
32-bit kernel ABI.
A 64-bit kernel can only load 64-bit kernel modules that have been
specially compiled for this kernel. It is not
possible to use 32-bit kernel modules.
HINT:
Some applications require separate kernel-loadable modules. If
you intend to use such a 32-bit application in a 64-bit system
environment, contact the provider of this application and Novell
to make sure that the 64-bit version of the kernel-loadable module
and the 32-bit compiled version of the kernel API are available
for this module.