IBM RS/6000 - Manual (Page 90)

If the firmware is corrupted, run the firmware recovery procedure (see
4.4.4, “Firmware Recovery” on page 69).
6. The firmware core copies a particular part of the firmware code into the small
amount of memory. This firmware code runs the memory POST and configures
3 MB of good memory.
If it fails, the hard file LED is turned on, and the system stops.
Passed Critical Phase
After 3 MB of good memory has been successfully configured, the system
will not stop. Any subsequent failures will be logged and displayed as
8-digit error numbers.
7. The compressed firmware is copied into the larger amount of good memory (3
MB) and uncompress.
8. A new C environment is set up in the larger area, along with a user stack, an
interrupt stack, a debugger stack, and a TOC (Table of Contents) pointer.
9. The individual subsystems are initialized:
The Virtual Disk is brought online
NVRAM initialization
PCI set up
Interrupts initialization
Real-Time Clock initialization
Keyboard/mouse controller initialization
Password initialization
Debugger initialization
10. The Virtual Disk (VDISK) file system is loaded and initialized.
11. All device drives from the VDISK file system are loaded.
VIDEO: initialize ASCII terminal and/or VGA adapter
– Initialize Async Console Support (ASCII terminal S1 serial port)
– Execute the VGA adapter POST. If there is an error, then one long
beep and one short beep is sounded on the speaker.
Display the “brand” logo on the graphic console or a POST indicator on an
ASCII terminal.
Keyboard icon appears; initialize the keyboard and mouse.
The window for pressing F1 (GUI SMS interface) or F4 (ASCII) keys is now
open.
The diskette icon appears; initialize the controller.
Extended memory icon appears; test the reminder of memory. Memory
modules failures are displayed with the 8-digit error code 00020000.
The SCSI icon appears; initialize the adapters: SCSI, ethernet, pci_c970,
trpci, tcpip, and initialize network when present.
The last icon is the boot disk icon.
12. One long beep is sounded on the speaker.
66 Introduction to PCI-Based RS/6000 Servers