User`s manual

Start-up

1-8

Under normal conditions, the startup sequence begins at 0x1100

and continues to the PPC1-Bug> prompt just after 0x11D4. RAM

initialization problems may cause the startup sequence to terminate

at the : (RawBug) prompt just after 0x11D8 instead.

The operating system boot sequence begins at 0x11E0 with the

creation of residual data and continues to 0x11EC just before

execution is passed to the boot image. The OS may have its own

LED codes which are displayed after 0x11EC.

A line feed can be inserted after each serial code is displayed to

prevent it from being overwritten by the next code. This is also

enabled by an ENV parameter:

Serial Startup Code LF Enable [Y/N]=N?

The following firmware codes are always sent to 7-segment LEDs

located at ISA I/O address 0x8C0. These codes can also be sent to

the debugger serial port if the ENV parameter ÒSerial Startup Code

Master EnableÓ is set to ÔYÕ. The list of LED/serial codes follows.

Table 1-1. LED/Serial Startup Diagnostic Codes

Code (Hex) Location in Startup

1100 Setting up MSR (startup begins)

1102 Invalidating caches

1104 Determining ROM or RAM execution mode

1106 Setting up machine state register

1108 Setting up CPUÕs address translation registers

110A Setting up CPUÕs address translation table

110C Shutting down redundant processors

110E Initializing super I/O chip (CPU initialization completed)

1110 Initializing raw I/O device

1112 Getting PHB (PCI Host Bridge) Table Pointer

1114 Initializing PCI bridge

1116 Initializing the powerup ßag indicator

1118 Calculating the speed of the processor bus

111A Waiting for hardware to initialize memory