Christine Axnix

z990 netmessage-protocol-based processor to support element communication interface

The communication interface between support element applications and applications running on the zSeries® system processors is an essential part of the zSeries system design. For example, the interface is used to load firmware during startup, it is used for service actions such as configuring or deconfiguring I/O channels, and for many other functions. It must be fast, reliable, and failsafe. A special hardware interface in the clock chip is used to connect the service infrastructure (support element and cage controller) to the central electronic complex (CEC). Four firmware parties are involved in the communication: support element, cage controller, and two firmware layers running on the processors in the CEC: millicode and i390 code. Starting with the z900, the interface between the support element and cage controller was implemented using the NetMessage protocol, whereas the interface between the cage controller and processors still used the legacy service-word communication protocol from previous IBM S/390® models. This meant that the cage controller had to translate the NetMessage protocol from the support element side to the legacy service-word protocol toward the CEC side. In the z990, the communication interface between the support element and the CEC was generally replaced by the NetMessage protocol. The following paper describes the new design and structure of the support element to CEC communication.

Open-standard development environment for IBM System z9 host firmware

When the PL8 64-bit GNU compiler collection front end was introduced with the IBM z990 system, it laid the foundation to move toward an open-standard development environment for the i390 layer of IBM System zTM host firmware. However, when the z990 system was developed, the proprietary project development library system and the table of contents object file format for i390 code were still being used. With the IBM System z9TM, we have moved to a fully open-standard development environment. This paper describes the steps we took to get there, to improve code performance, development efficiency, and regression testing, and to develop base functionality for important System z9 features such as enhanced driver maintenance. We also discuss plans to further enhance the development environment for future systems.

Capacity on Demand advancements on the IBM system z10

Capacity on Demand (CoD), a key feature of the IBM System z® B. D. Valentine platform, allows customers to adjust their processing and memory capacity to their specific needs without having to shut down and restart the machine and with no interruption to the complete software stack running on it. The first System z CoD functions, introduced with the IBM S/390 Parallel Enterprise Server™ 9672 G5 in 1998, were concurrent upgrade on demand for permanent capacity and capacity back up for temporary capacity. Since then, the functionality has been continuously enhanced, but CoD still had a number of limitations that needed to be addressed to better meet customer requirements. The IBM System z10™ platform introduces a completely new architecture for CoD that provides more flexibility, granularity, and responsiveness. In addition, the System z10 platform provides an enhanced set of CoD application programming interfaces for use by systems management or automation software. This paper describes the new capabilities from both a business and a customer perspective as well as from a technical perspective.