Enable locked Atom functionality?

Only for programmers and BIOS gurus with technical questions.
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Shadow7789
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I am considering getting an Atom-powered netbook (Lenovo S12) in the nearish future, and I would be interested in knowing what it would take to get 64-bit functionality enabled on an Atom N270. I know the hardware is there, but Intel disables it (Along with VT for that matter).

So, I guess, I have two questions to to this end.

1) How does Intel actually go about disabling the functionality?
2) What would need to be done to reenable the functionality? Is it microcode or bios related? Both? Is it even possible? Are the tools needed out there?
3) Has anyone ever attempted anything like this before?
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

I know the hardware is there, but Intel disables it (Along with VT for that matter).
how do you know? are you working at Intel? if so you could just ask you workmates.
since i'm not with Intel, i can just guess.

1st guess: it is not disabled. it is just not there on the die. this can easily be done by altering the etching masks.
2nd guess: it is there but it is defective and thus hardware-disabled. this, too, can easily be done after production and before packaging.
3rd guess: it is there but it is hardware-disabled due to marketing reasons. done after production and before packaging.
4th guess: (this is what you've been waiting for ;)) it is there but it is software disabled via cpu registers. you'd need Intel-internal documents which require an NDA to be signed and (probably) a small amout of money.

if one of the first three guesses match there's no way to enable anything. if it is guess four you have to get hold of a complete ATOM register description (there isn't even one for the Pentium II cores, i had to refer to several sources and there's still a lot of information missing), check the BIOS code for register writes and alter the BIOS or write an OS-application which sets the appropriate bits.

good luck.
If you email me include [WIMSBIOS] in the subject.
Shadow7789
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Based on what I gathered from a lot of googling, Intel disables the functionality for market segmentation. Would this kind of strategic disabling be something that would normally be done in hardware or software?

Also, if it is something that is done with the CPU registers, how is that information held over? Is there some type of persistent storage on the CPU? I assume there has to be, since the CPUID has to be stored somewhere, but I would be interested in hearing more.
cp
BIOS Guru
Posts: 1914
Joined: Mon Oct 21, 2002 9:07 pm
Location: Germany

normally be done in hardware or software
both is possible. hardware is safer because it can't be undone. it can be done right after diffusing (by burning fuses) and before packaging or even while packaging (by burning fuses that are not available from outside the package). if done in software the bios programmers would have to take care of disabling the stuff which would quickly lead to hacked bioses or OS application software reenabling functions.

writeable cpu registers are volatile. they have to be set (by the bios) after powering on the cpu. if they are not set they'll contain default values defined by the manufacturer. there are a lot of read-only registers, too. they can not be altered in any way. they are some kind of window allowing the (bios-)programmer to look into the cpu and gather information about it, like does it support MMX, SSE or does it have a FPU or even how much cache does the CPU have.

the cpuid is stored in a non-volatile memory and is the return value of a special cpu instruction command (CPUID).
If you email me include [WIMSBIOS] in the subject.
Clown
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I have an ASUS EEE PC 1101HA, the processor (Z520) does have the VT technology on board. But it is disabled by the bios. The Everst Toll still reports the VT bit and for somehow the Windows 7 XP Mode test tool to...

So is there a way to enable it?
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