[coreboot] Enquries on how to map the bios chip into address space

[mtech se13b]

Dear all,

I'm currently actually trying to access the content of the bios chip while
the bios is doing its execution. I'm working on Intel Q35 chipset. And i
understand that while the bios is executing, i can actually access the TOP
2MB of the 4 GB address space to access the bios chip  raw data content.

However, my bios chip is actually 4MB in size, can someone advice how do i
go about accessing the other 2MB of the bios chip while the bios is
executing? Because not much documentation on this and i hope someone in the
coreboot community could help me on this.

Thank you very much.

Rgds.
Stanne.