I'm trying to understand flash descriptor and read/write permissions that can be configured using master region. I'm using MinnowBoard Turbot B and trying to change flash descriptor so it will have any effect in my Linux system, but apparently I have problem with that. I read IFD with chipsec. I was able to modify IFD in below way:
+ 0x0060 Master Section:
========================================================
+ 0x0060 FLMSTR0 : 0xFDFF0000
+ 0x0064 FLMSTR1 : 0xFFFF0000
Master Read/Write Access to Flash Regions
--------------------------------------------------------
Region | CPU | ME
--------------------------------------------------------
0 Flash Descriptor | RW | RW
1 BIOS | R | RW
2 Intel ME | RW | RW
Despite that I'm still able to use flashrom to write BIOS region. Why it is still possible ? Who enforce this access rights ?
Description in Bay Trail datasheet IMO is not clear or I miss some fundamental knowledge about IFD.