Abstract: A method and apparatus for non-interrupt-driven handshake with acknowledgment are provided. A first software resource in a data processing system communicates a data value to a second software resource by writing the data value to a first register field, where it may be read by the second software resource. On writing the data, the first resource sets a write signal in a second register field. If the second software resource attempts to read the data value before it is written by the first resource, a reset value in the second field informs the second resource that any data in the first field is invalid. The second resource then sets a first predetermined value in a third field which informs the first resource that the second has attempted a read. If the data is valid when the second resource attempts the read, the data is retrieved, and the second resource echos the value in a fourth field.

Abstract: A method, system and computer program are described for isolating bus errors detected during system start-up by utilizing a technique in which a shared mailbox associated with a service processor is provided for holding the address of an adapter in an I/O drawer. If an error is detected the server processor is notified. The server processor then retrieves the address from the mailbox, uses it to derive a location code which is then passed along with the error code to an appropriate error analysis routine. The start-up procedure is then shut down.

Abstract: A data processing system includes a plurality of components, a power control network, processing resources, and a memory that contains initialization firmware. At system startup, the power control network initiates supply of power to the plurality of components and collects information regarding which components are supplied power. In addition, the initialization firmware initializes the plurality of components to establish a configuration. If an ambiguity in the configuration arises, the initialization firmware resolves the ambiguity utilizing the information collected by the power control network.

Abstract: An apparatus and method of dynamic resource mapping for isolating interrupt sources is implemented. Each interrupt source is provided with a unique identifier. The identifier is mapped to an interrupt number which is sent to an operating system when the interrupt source corresponding to the identifier generates an interrupt. Each device is associated with a data structure that includes a data value which is operable for accessing an interrupt register. The data value may be a pointer that points to a pointer to the interrupt register for the device generating the interrupt. When an interrupt is generated, the mapping may be used to access the pointers which thereby provide direct access to the interrupt register, whereby the contents of the interrupt register are processed by an interrupt service routine.

Abstract: A command string is sent from an operating system to a microcontroller coupled to one or more I2C buses. Such a command string may instruct the microcontroller to perform a read or write operation with respect to a bus device designated within the command string. The presence of the bus device may be new and the microcontroller unaware of such a presence. Data may be read from the main system to the particular bus device through the microcontroller, or data may be read from the bus device through the microcontroller back to the main system.

Abstract: A data processing system and method for sharing a component of the data processing system between multiple resources are disclosed. According to the method, at least one query is transmitted from a first resource to a second resource. In response to receipt of the query by the second resource, a reply is transmitted from the second resource to the first resource. The reply indicates that the second resource has an active communication session through a particular communication port controlled by the shared component. In response to receipt of the reply by the first resource, a transfer command is transmitted from the first resource to the second resource. In response to receipt of the transfer command by the second resource, control of the component is transferred from the second resource to the first resource while maintaining the active communication session.