Hi,

Yes, the processor is running in the real mode, both HDT(AMD debug tool) and 
machine code can verify it. The prefix of 0x66 indicates a 32bit instruction to 
the processor which is running in the real mode, however, the processor still 
executes the instructions in the 16bit way. I will check how to support 32bit 
instruction set in the real mode. And the code of wakeup.S is put here by Linux 
for resuming. When system resumes, the processor must be in the real mode, but 
you can see there are some 32bit instruction from either the assembly code or 
the machine code.


Best Regards

??? Feng Libo @ AMD  Ext: 20906
Mobile Phone: 13683249071
Office Phone: 0086-010-62801406

-----Original Message-----
From: ron minnich [mailto:[EMAIL PROTECTED] 
Sent: Tuesday, November 25, 2008 1:10 AM
To: Feng, Libo
Cc: [email protected]; Huang, FrankR; Li, Maggie; Bao, Zheng; Wang, 
Qingpei; Xie, Michael
Subject: Re: [coreboot] ACPI S3

On Sun, Nov 23, 2008 at 11:02 PM, Feng, Libo <[EMAIL PROTECTED]> wrote:
>
> Hi, All,
>
> I am still trying to implement the S3 state in dbm690t. Now I can jump into 
> the waking vector code running under the real mode. However, the code 
> contains some 32bit instructions, when these instructions are executed, the 
> system always hangs, for the processor thought they were of 16bit. Please see 
> the code in the below link.
>
> http://lxr.linux.no/linux+v2.6.18/arch/x86_64/kernel/acpi/wakeup.S
>
> In 37 and 38 line, there are two 32bit instructions,
>
> 66 6a 00   pushl   $0  # Kill any dangerous flags
> 66 9d        popfl
>
> You can see the machine codes starting with 0x66 indicating these 32bit 
> instructions. However, processor always thought these were of 16bit, so, 
> instructions are changed into:
>
> 66 6a         push byte 00h
> 00 66 9d     add [bp-63h], ah
>

what could explain this is that you are not in 16-bit mode, you are actually in 
32-bit mode for some reason. The 66 will then run these instructions in 16 bit. 
That is just a guess.

Are you certain you are in 16 bit mode?

ron



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