Chapter 4. Checkpoints; Ipl Flow - IBM RS/6000 Enterprise Server M80 Service Manual

Chapter 4. Checkpoints

Checkpoints display on the primary I/O drawer operator panel while the system is powering on and going
through the initial program load (IPL). This chapter explains the IPL flow of the system and provides a
table that lists checkpoints that you might see in the primary I/O drawer operator panel.

IPL Flow

The IPL process starts when ac power (dc power in a dc-powered system) is connected to the system.
The IPL process has four phases:
v Phase 1: Service Processor Initialization
Phase 1 starts when ac power (dc power in a dc-powered system) is connected to the system and ends
when OK is displayed in the primary I/O drawer operator panel. 8xxx checkpoints are displayed during
this phase. Several 9xxx codes may also be displayed. Service processor menus are available at the
end of this phase by pressing any key on the console keyboard.
v Phase 2: Hardware Initialization by the Service Processor
Phase 2 starts when system power up is initiated by pressing the power on button on the primary I/O
drawer operator panel. 9xxx checkpoints are displayed during this time. 91FF, the last checkpoint in this
phase, indicates the transition to Phase 3 is taking place.
v Phase 3: System Firmware initialization
At Phase 3, a system processor takes over control and continues initializing system resources. During
this phase, checkpoints in the form Exxx are displayed. E105, the last checkpoint in this phase,
indicates that control is being passed to the AIX boot program. Location codes may also be displayed in
the second line of the primary I/O drawer operator panel.
v Phase 4: AIX Boot
When AIX starts to boot, checkpoints in the form 0xxx are displayed. Location codes may also be
displayed in the second line of the primary I/O drawer operator panel. This phase ends when the AIX
login prompt appears on the AIX console. The primary I/O drawer operator panel should be blank.
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