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Dual Processor Boot Procedure for LAN Services

IP.com Disclosure Number: IPCOM000109353D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24

Publishing Venue

IBM

Related People

Dobbelstein, SL: AUTHOR [+2]

Abstract

The Dual-Processor Server is the main function in the coprocessor package of LAN Services. The Dual-Processor Server makes use of an additional CPU installed in the machine to increase performance. The additional CPU is provided by an Aox MicroMASTER 486(TM) adapter card installed in the machine. Several pieces of the LAN Server are off-loaded to the Aox processor, including the File System, the Ring 0 File Server and the Protocol Stacks. This is shown in Fig. 1. Notice that this is not a full multiprocessor operating system. Rather, select pieces of the operating system are off-loaded to another processor. Off-loading these pieces improves performance in two ways.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 13% of the total text.

Dual Processor Boot Procedure for LAN Services

       The Dual-Processor Server is the main function in the
coprocessor package of LAN Services.  The Dual-Processor Server makes
use of an additional CPU installed in the machine to increase
performance.  The additional CPU is provided by an Aox MicroMASTER
486(TM) adapter card installed in the machine.  Several pieces of the
LAN Server are off-loaded to the Aox processor, including the File
System, the Ring 0 File Server and the Protocol Stacks.  This is
shown in Fig. 1. Notice that this is not a full multiprocessor
operating system.   Rather, select pieces of the operating system are
off-loaded to another processor.  Off-loading these pieces improves
performance in two ways.  First, loading these pieces on the Aox
processor allows them to run in parallel with the remainder of the
operating system that is loaded on the planar processor.  This means
that disk requests or network activity can be handled at the same
time as applications that are running on the planar processor.
Second, off-loading these components frees up CPU cycles on the
planar so that it can do other work, such as run the Data Base.

      Whenever an Aox card is installed in a system, the Aox
processor boots first.  It does this by inserting its code into the
boot procedure when its ROM is called during POST time.  This is so
that the customer can install an Aox card to replace the current
processor in the system.  In the dual-processor system, the Aox
processor boots first and OS/2* is  loaded, including the Aox half of
the Dual-Processor Server code.  The Dual-Processor Server has
special code to load and run OS/2 on the  planar processor, including
the planar half of the Dual-Processor Server code.  In this way both
processors are running in the system.   The Aox processor boots first
followed by the planar processor.

      In the Dual-Processor Server each processor is booted with
OS/2.  There is only a single version of OS/2 used for both
processors.  OS/2 requires a CONFIG.SYS file to tell it about the
configuration.  Naturally, the CONFIG.SYS for the Aox processor is
different from the CONFIG.SYS for the planar processor since
different work is done on each processor.  The problem is that each
version of OS/2 expects to find the CONFIG.SYS file in the root
directory of the C: drive.

      One possible solution is to have two files.  Since two files in
the same directory cannot have the same name, one of the CONFIG.SYS
file would either have to be renamed or located in a different
directory.  The open and read of this CONFIG.SYS would have to be
intercepted and redirected to the new file name or directory.  The
CONFIG.SYS for the Aox processor seems the likely candidate for being
renamed or relocated since it has a pretty limited set of modules
that it loads.

      A problem arises when the CONFIG.SYS files need to be changed.
In some cases, changes to system configurat...