Oem Section; Region Access Control Table Options - Intel PCH-LP Programming Manual

4.2

OEM Section

Memory Address: F00h
256 Bytes are reserved at the top of the Flash Descriptor for use by the OEM. The
information stored by the OEM can only be written during the manufacturing process as
the Flash Descriptor read/write permissions must be set to Read Only when the
computer leaves the manufacturing floor. The PCH Flash controller does not read this
information. FFh is suggested to reduce programming time.
4.3 Region Access Control
Regions of the flash can be defined from read or write access by setting a protection
parameter in the Master section of the Descriptor. There are only three masters that
have the ability to access other regions: CPU/BIOS, Intel
software/driver running on CPU.
Table 4-1.

Region Access Control Table Options

Region (#)
Descriptor (0)
BIOS
ME
GbE
PDR
Notes:
1. Descriptor and PDR regions are not masters, so they will not have Master R/W access.
2. Descriptor should NOT have write access by any master in production systems.
3. PDR region should only have read and/or write access by CPU/Host. GbE and ME should NOT have access to
PDR region.
36
Master Read/Write Access
CPU and BIOS
Read / Write
CPU and BIOS can always
(1) read from and write to
BIOS region
(2) Read / Write
(3) Read / Write
(4) Read / Write
Intel Confidential
Size: 256 Bytes
®
ME Firmware, and GbE
ME/MCH
Read / Write
Read / Write
ME can always read from
and write to ME region
GbE software can always
Read / Write read from and write to
Read / Write
Descriptor Overview
GbE Controller
Read / Write
Read / Write
Read / Write
GbE region
Read / Write
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