Compaq AlphaServer ES45 1B Owner's Manual page 47

When the system powers up, the SROM code is loaded into the I-cache (in-
struction cache) on the first available CPU, which becomes the primary CPU.
The order of precedence is CPU0, CPU1, and so on. The primary CPU at-
tempts to access the PCI bus. If it cannot, either a hang or a failure occurs,
and this is the only message displayed.
2
The primary CPU interrogates the I C EEROM on the system board and CPU
modules through shared RAM. The primary CPU determines the CPU and
system configuration to jump to.
The primary CPU next checks the SROM checksum to determine the validity
of the flash SROM sectors.
If flash SROM is invalid, the primary CPU reports the error and continues the
execution of the SROM code. Invalid flash SROM must be reprogrammed.
If flash SROM is good, the primary CPU programs appropriate registers with
the values from the flash data and selects itself as the target CPU to be
loaded.
The primary CPU (usually CPU0) initializes and tests the B-cache and mem-
ory, then loads the flash SROM code to the next CPU. That CPU then initial-
izes the EV68 chip) and marks itself as the secondary CPU. Once the primary
CPU sees the secondary, it loads the flash SROM code to the next CPU until
all remaining CPUs are loaded.
The flash SROM performs B-cache tests. For example, the ECC data test veri-
fies the detection logic for single- and double-bit errors.
The primary CPU initiates all memory tests. The memory is tested for ad-
dress and data errors for the first 32 MB of memory in each array. It also ini-
tializes all the "sized" memory in the system.
If a memory failure occurs, an error is reported. An untested memory array is
assigned to address 0 and the failed memory array is de-assigned. The mem-
ory tests are rerun on the first 32 MB of memory in each of the remaining ar-
rays. If all memory fails, the "No Memory Available" message is reported and
the system halts.
If all memory passes, the primary CPU loads the console and transfers control
to it.
Operation 2-5