Browse Prior Art Database

Intercomponent Calling Method for Environments without Operating System API Support

IP.com Disclosure Number: IPCOM000107815D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Allison, GG: AUTHOR [+3]

Abstract

In environments such as Remote-IPL, where at the time control is first passed from the hardware to the software components loaded into memory by the network adapter, operating system support is not available to enable a program to call an entry point in another program.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 68% of the total text.

Intercomponent Calling Method for Environments without Operating System API Support

       In environments such as Remote-IPL, where at the time
control is first passed from the hardware to the software components
loaded into memory by the network adapter, operating system support
is not available to enable a program to call an entry point in
another program.

      To solve this problem, three programs are involved. The program
that contains the function that needs to be called was developed as
two logical portions:  an Assembly language portion that serves as a
function dispatcher, and a C language portion that contains the
actual routines that perform the required function (Fig. 1).

      The advantage of this approach is that the C language routines
can be changed and will be dynamically resolved when the program is
linked.

      To make this program work, two other programs were modified.
First, the program that executes on the server was modified such that
it puts the offsets of the fixed entry points into a data area.  This
data area is sent along with the programs themselves to the
workstation at Initial Program Load (IPL).  The server program only
takes this action if the callable program is among the programs to
send to the workstation.  This ensures compatibility with other
implementations.

      Next, the calling program was modified to extract the offsets
of the fixed entry points from the data area if the callable program
is among t...