On Thu, 28 May 2015 09:13:35 +0200 Gerd Hoffmann email@example.com wrote:
- OperationRegion (RCRB, SystemMemory, 0xfed1c000, 0x4000)
Where does this address come from?
This address is reserved in an ACPI DSDT table for Intel Haswell in Coreboot project, Vlv2DeviceRefCodePkg package in EDK II as well as my Haswell laptop on which I can see it through `dmesg` :-)
Is this a standard location suggested by intel specs?
I haven't found any Intel spec or any other document that suggests such address, but from "9.4 Memory Map" section in ICH9 spec, it seems safe to use that MMIO region for the 16KiB of chipset configuration registers.
Or is the firmware free to choose it?
Given that, I would say so.