EP80579 Datasheet, PDF (177/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
6.3
6.3.1
The BIOS must first establish an environment suitable for execution of the PXE OpROM.
This environment must provide the following:
• System memory sufficient for C-code execution. This memory will be used to load/
execute OpROM code, implement a call stack and data storage. In addition system
memory must be available for loading/execution of OS.
• BIOS runtime services sufficient for OpROM execution. These services are typically
provided by system BIOS and allow the PXE OpROM to be implemented for
platform independence.
• The PCI sub-system is enumerated with allocation of system memory space, IO
space and interrupts completed. This will establish the address location of
resources accessed by the OpROM code during execution.
After OpROM initialization, the code remains in memory and waits until the BIOS
reaches the point at which the OS-boot process begins. When a GbE is selected for
boot, code in the OpROM will be used to initiate communication with a server to supply
the images required for boot. After these images are loaded execution control passes
from the BIOS to the images loaded in memory. This transition concludes the Preboot
phase and enters in to the OS-boot phase.
Power Management
Power Management States
Figure 6-9. Global System Power States and Transitions
From a user-visible level, the system can be thought of as being in one of the states
shown in Figure 6-9. In general use, computers alternate between the Working and
Sleeping states. In the Working state, the computer is used to do work. User-mode
application threads are dispatched and running. Individual devices can be in low-power
(Dx) states and processors can be in low-power (Cx) states if they are not being used.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
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