Compiling/Linking Conventions

When compiling and linking System Manager applications, the following conventions must be followed:

• Applications must be compiled with the /Gs option to eliminate stack checking. The stack checking provided by the Microsoft compiler uses far pointers that cannot be fixed if memory moves.
• There must be at least 256 bytes of application stack space available for System Manager use whenever a System Manager service is called. Some of the database engine services require a larger stack, and LHAPI calls can nest back to the application many times. The suggested minimum stack size is 4K.
• Applications must link with the System Manager services interface module, SCSVC_HP.LIB. This module contains the c_service function that performs the software interrupt to transfer control to the System Manager services jump table.

• Keyboard input must be obtained only by the use of the System Manager m_action function, or task swapping will not work.
• Dynamic memory allocations should use m_get_far_block instead of m_alloc. If the m_alloc or m_alloc_large calls (HP95LX compliant) must be used, don't mix them with m_get_far_block calls. Standard C library Memory Management functions should not be used.
• Elementary C library routines such as strlen and atoi can be used.
• System Manager file I/O uses a FILE structure that is not compatible with the FILE structure defined in Microsoft C STDIO.H. Use care with including STDIO.H and, in particular, don't include both FILEIO.H and STDIO.H in the same module.
• The standard C library startup code is not used with System Manager compliant applications. This may affect the use of some types of C library functions. Particularly, there is no startup code for floating point math. It is possible, however, to build startup code that uses an alternate math library.