5 replies to this topic

[rcork]

So i just got a new motherboard (GA-Z77X-UP5 TH) and i'm going to undertake an effort to create a minimal DSDT. I'm reading the ACPI spec and learning a lot. However, in order to understand how my current DSDT is working, i need to find out what the values are for the fields specified in system memory in this instruction:

OperationRegion (GNVS, SystemMemory, 0x7E2EFE18, 0x01CD)
	Field (GNVS, AnyAcc, Lock, Preserve)
	{
		OSYS,   16,
		SMIF,   8,
		PRM0,   8,
		PRM1,   8,
		SCIF,   8,
		PRM2,   8,
		PRM3,   8,
		......

From what i understand, this area of system memory holds data from the CMOS that has been loaded into system memory. These fields allow read and/or write access to those values by the ACPI code in the DSDT.  

Does anyone know of any tools that will let me dump the system memory or inspect this memory region directly so that i can start to document all these fields?

[XLR]

Perhaps this is what you looking for: http://www.projectos...?showtopic=2447

[Gringo Vermelho]

OperationRegion/SystemMemory values change depending on how much RAM you have installed. Different BIOS versions for the same motherboard may also use different values. Two reasons why you should not use someone else's DSDT. (Not telling you, just adding what I know to the topic!)

[rcork]

@XLR - DarwinDumper doesn't provide any data around the values that are copied from CMOS to SystemMemory at boot.

@Gringo Vermelho - Correct. Any the addresses of SystemMemory changes based on memory, whether onboard graphics is utilized, how much onboard memory is dedicated to GPU, etc. That's why i'm trying to create my own minimal DSDT.

BTW....i think i found what i'm going to use to inspect the GVNS operation region. i found some useful info on debugging ACPI code and can use the Store method to write to the debug object, which will output to the console if i boot with acpi debugging enabled.

[Gringo Vermelho]

That's a cool trick, please demonstrate for us visual minded people if you can.

Have you seen this, it's pretty cool too, ACPI debugging with morse code!
http://www.projectos...p?showtopic=456

[rcork]

Gringo Vermelho, on 24 August 2012 - 07:15 PM, said:

That's a cool trick, please demonstrate for us visual minded people if you can.

Have you seen this, it's pretty cool too, ACPI debugging with morse code!
http://www.projectos...p?showtopic=456

That's exactly what i found as well, except i'm more interested in the following function than the morse code

Store ("Method _WAK begin...", Debug)

I'm going to add a bunch of these statements to the _INI method of \_SB to output the values of each field from GVNS.