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lazer1



Joined: 24 Jan 2006
Posts: 185
lazer1
AMD vol2 p295 says that long mode iret requires a 64-bit
rex prefix,

now AMD vol 3 p16 talks about rex, it says
there are 4 flags rex.w, rex.r, rex.x, rex.b

no idea how you do this with fasm,

how do I do a 64 bit no-op interrupt handler?

fasm does not accept eg:

Code:
use64
handler:
       rex
       iret
    


anyone know the correct way to do this?

can I do it via a db value eg
"db 66h" is the "opsize" prefix
Post 24 Apr 2006, 19:15
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Madis731



Joined: 25 Sep 2003
Posts: 2141
Location: Estonia
Madis731
I think you can do iretd and iretq and the prefix added is not 66h but 48h
Post 24 Apr 2006, 20:30
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lazer1



Joined: 24 Jan 2006
Posts: 185
lazer1
Madis731 wrote:
I think you can do iretd and iretq and the prefix added is not 66h but 48h


ok, I tried it just now and it looks correct Razz

the hex of "iretq" is 48CFh which appears to be right,


with interrupt handlers where there is an error code
do I have to pop the error code before iretq or
is that done automatically? Surprised

or can I do it both ways either pop or not pop? Confused

one other thing: how many interrupt handlers are required?

vectors 0 up to 255 or less?

I want to create a full set of no-op handlers,
Post 24 Apr 2006, 21:28
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