Multimode installation means that a product is installed in such a way that it can run on different platforms (/390 and X86) or so that programs can be generated for different platforms (e.g. for POSIX-SOCKETS). Multimode installation is only possible with IMON support.
There are two variants of multimode installation:
Installation variant A
Only one installation script is executed, irrespective of which platforms the product supports. If several platforms are supported, all installation scripts will be identical. The following conventions apply to this variant:
IMON Target | Logical Id | Name of installation script |
any | SINLIB | INSTALL.<productname>.<productversion> |
This installation variant is suitable for all products whose objects are platform-independent in POSIX, e.g. NFS and CRTE.
Note that links in POSIX to executable objects (LLMs) in PLAM libraries are platform-independent, but an LLM which has been copied into a POSIX file system is not.
Installation variant B
An installation script is executed for every platform supported by the product. The installation scripts may, for instance, differ from each other in that the LLMs are installed under different paths in POSIX. Examples include: POSIX-NSL, POSIX-SOCKETS, POSIX-SH.
For installation variant B, platform-specific installation scripts must be available in every PLAM library. The following conventions apply to this variant:
IMON Target | Logical Id | Name of installation script |
S | SINLIB | INSTALL.<productname>.<productversion>.390 |
K | SINLIB | INSTALL.<productname>.<productversion>.X86 |
For reasons of compatibility, the following exception applies to the products POSIX-NSL and POSIX-SOCKETS:
IMON Target | Logical Id |
S, K | SYSLIB |
Interaction with the POSIX installation program
When installing with the POSIX installation program, you only need to specify the product name, as for variant 1 in the section “The installation program in conjunction with IMON”. The IMON target determines which installation variant is to be executed:
If target A (ANY) is set, installation variant A is always executed, even if other targets are present. Links to executable objects (LLMs) in PLAM libraries are set up in such a way that the LLMs defined for the current platform or the LLMs of target A are always started in the current execution environment. The product can be used in any environment.
If target A (ANY) is not set, the following applies:
Installation variant A is executed if only one target is set or if no platform-specific installation scripts exist.
Installation variant B is executed if more than one target is set and if platform-specific installation scripts do exist. The PLAM library of the first set target in the sequence above determines the existence of platform-specific installation scripts.
Irrespective of the installation variant which has been executed, the product can only be used in environments which were defined in IMON. In other environments, the error number ENOEXEC is returned by POSIX if a program is called over a link to executable objects (LLMs) in PLAM libraries.