N4000 and rp7400 Server Functionality

Legacy system users will see minimal impact in their applications or system administration tools due to the changes in the platform infrastructure.

Although the configuration files on 64-bit systems (for example, /stand/system and master.d/core-hpux) and SAM will refer to CB-CDIO, PSMs and new CDIOs now included in the system, these components may coexist in the configuration files and be loaded into the kernel at the same time, even if they are inactive on a particular platform. Run-time checks evaluate which components are activated.

For legacy systems, end users might see new entries (sapic, lba, and sba) in the /stand/system file. In addition, some new lines have been added to CDIO and DRIVER_DEPENDENCY tables of the /usr/conf/master.d/core-hpux file to include the new central bus (cb) and the various new PSMs (for example, pa_psm or pa_generic_psm).

N4000 and rp7400 users must have the following modules in the kernel (via the master file entries) for the PAT, SBA, and Lower Bus Adapter (LBA) components to be detected and properly configured—and for the HP-UX kernel to boot. Without these modules, the HP-UX kernel will be unable to detect the hardware CEC components on a N4000 pr rp7400 system and the kernel will not boot.

The master file, /usr/conf/master.d/core-hpux, contains the following entries for all systems.

$CDIO Table:

cb 1
lba 0
PCItoPCI 0
pa_generic_psm 0
pa_psm 0
pat_psm
sapic 0
sba 0

$DRIVER_DEPENDENCY table:

core  pa_psm  pa_generic_psm  asp lasi
sio   pa_psm  pa_generic_psm
wsio  pat_psm core DlkmDrv
lba   pci sapic PCItoPCI
GSCtoPCI pci PCItoPCI

The /stand/system file contains the following entries:

************************************************
* Bus-Dependent subsystems
*****************************************************
* lba
*****************************************************
* PSMs
*****************************************************
* sapic
* sba

This software module interacts with N-Class and rp7400 firmware to discover and keep track of the CEC components configured on the N4000 and rp7400. The PAT PSM also provides access to platform-specific hardware components at runtime.

Although it may be included and linked into all 64-bit kernels, the PAT PSM is useful only to N4000 and rp7500 systems. As of HP-UX 11.0 Extension Pack, May 1999, a run-time test determines whether the linked-in PAT PSM is installed on the system.

Since PAT functionality is only supported on 64-bit systems, 32-bit kernels do not have the PAT PSM built into them.

The SBA PSM detects and configures the system bus adapter hardware and translates addresses between the Merced bus and the underlying LBA.

The SBA PSM supports system bus adapters on all N4000 and rp7400 systems, and is active and visible to N4000 and rp7400 users.

The SAPIC PSM manages line-based interrupts. This configurable software module handles interrupts routed through the I/O SAPICs.

The SAPIC PSM conforms to the Central Bus CDIO platform infrastructure. It maintains the SAPIC redirection table.

The CB CDIO contains interfaces that isolate platform-specific code from the rest of the kernel. These interfaces allow generic access to the platforms, regardless of which platform-specific PSMs are active in the kernel. The Central Bus framework interconnects the different PSMs that control the hardware.

For backward compatibility, the PA-CDIO has been restructured into a PA-generic PSM and PA-legacy PSM.

The LBA CDIO provides bus translation for all activity between the System Bus Adapter and the PCI bus. The LBA CDIO is the hardware-enabling HP-UX kernel module that controls the lower bus adapter and, therefore, all the intricacies of the dependent hardware. This CDIO also resolves any overlapping configuration issues with LBA, and interacts directly with the PCI CDIO.

The PCI subsystem has been redesigned to support PCI Card Online Addition and Replacement (OLAR) and to support a new interrupt line routing architecture.

On legacy systems (B-, C-, and V-Class), platform firmware had complete responsibility for configuring all devices. In contrast, the PCI CDIO detects unconfigured PCI devices and programs the base address registers in order to support PCI Card OLAR.

On N4000 and rp7400 systems, the firmware programs only the boot and console devices. The PCI CDIO programs the remaining devices, using information provided by firmware to the operating system (PAT PSM gets this for PCI).

The N4000 and rp7400 disassociates interrupt routing/handling from the platform-specific bus adapter. On legacy PCI systems, the interrupt lines are routed to the PCI host bus-adapter chip and handled by the same driver (for example, GSCtoPCI and EPIC CDIOs). On N4000 and rp7400 systems, though the interrupt lines are routed to the LBA (PCI bus interface chip), SAPIC PSM handles the interrupt support instead of the LBA CDIO.

LBA CDIO provides N4000 and rp7400 specific services to support PCI drivers and access to the PCI bus. Legacy PCI bus adapter drivers have been modified to be compatible with the new PCI CDIO.

The restructuring of the PCI subsystem permits PCItoPCI configuration of devices to more than two bridges deep. There is no new functionality for this release.