Managing Superdome Complexes: A Guide for HP-UX System Administrators

Planning Superdome Conﬁgurations

Building Blocks and Deﬁnitions

Appendix A 311

What Happens when a Cell Boots

This section explains how a cell becomes active as its partition boots. The

sequence is as follows:

1. The system administrator enables power to the cell.

(This can be done by means of the HP-UX frupower command, or

from SAM or the GSP.)

2. The cell is held in the reset state until power stabilizes.

3. The cell is released from reset and boot is blocked (that is, the cell

is on but is not allowed to boot).

4. The cell’s monarch processor’s PDC (Processor-Dependent Code)

sets a ﬂag that signals the GSP that it can post a new complex

proﬁle (the complex proﬁle is replicated in every cell’s memory; see

“The Complex Proﬁle” on page 292).

5. The cell’s monarch processor’s PDC performs selftests, identiﬁes the

cell's hardware, checks for I/O (is the cell connected to an I/O chassis,

and if so what devices are connected?) and identiﬁes everything the

cell is connected to via its crossbar link (XBC).

6. The cell reports its hardware conﬁguration to the GSP.

7. The GSP ensures that the cell’s copy of the complex proﬁle has

current information, reﬂecting both the cell’s partition and the

complex as a whole.

8. The GSP clears the “boot is blocked” ﬂag, allowing the cell to boot.

9. The cell's monarch processor’s PDC checks that the cell is compatible

with the other cells in the partition (see “Cell Compatibility” on page

308).

10.If the cell is compatible, its monarch processor’s PDC reads the

complex proﬁle and the cell boots as part of its partition.

If this is the core cell, its monarch CPU performs the system boot

and executes IPL (Initial Program Load) for the partition.