Hello,

One of the things I find interesting in D is it's capability to support both higher level programming stuff (such as GC, OO, etc), and at the same time allow low level stuff (such as inline assembler). (and keep it elegant :)

Currently I'm experimenting with D's low level capabilities, and I've ran into a problem:
How can I do a far jump in D, using the inline assembler?
In NASM I would have something like this (I got this from a tutorial in kernel programming at osdever.net):

<code>
jmp 0x08:flush2   ; 0x08 is the offset to our code segment: Far jump!
flush2: ret       ; Returns back to the C (D actually :) code!
</code>

I can find some references to far pointers and segmentation in D's inline assembler section, but it's unclear to me how to use this, or even if this is possible at all?

thanks,
Kevin

These far jumps are only for real mode. http://www.answers.com/main/ntquery?method=4&dsid=2222&dekey=X86-jmp&gwp=8&curtab=2222_1

D assumes it is running always in protected / flat mode I guess.

Andrew.


"Kevin VR" <azra@pandora.be> wrote in message news:d68mje$k40$1@digitaldaemon.com...
> Hello,
>
> One of the things I find interesting in D is it's capability to support both higher level programming stuff (such as GC, OO, etc), and at the same time allow low level stuff (such as inline assembler). (and keep it elegant :)
>
> Currently I'm experimenting with D's low level capabilities, and I've ran
> into a problem:
> How can I do a far jump in D, using the inline assembler?
> In NASM I would have something like this (I got this from a tutorial in
> kernel programming at osdever.net):
>
> <code>
> jmp 0x08:flush2   ; 0x08 is the offset to our code segment: Far jump!
> flush2: ret       ; Returns back to the C (D actually :) code!
> </code>
>
> I can find some references to far pointers and segmentation in D's inline assembler section, but it's unclear to me how to use this, or even if this is possible at all?
>
> thanks,
> Kevin

Well, you could just push the full address on the stack and then do a retf.

:push <segment>
:push <address>
:retf

That would be the same thing as a far jump if I'm not mistaken.

Or you could just assemble it by hand,

:db 0xea
:dd <address>
:dw <segment>

However, it would be nice if you could just do the jump, but I'm not sure if that's possible in D, since it's built for 32-bit protected mode only.

In article <d68mje$k40$1@digitaldaemon.com>, Kevin VR says...
>
>Hello,
>
>One of the things I find interesting in D is it's capability to support both higher level programming stuff (such as GC, OO, etc), and at the same time allow low level stuff (such as inline assembler). (and keep it elegant :)
>
>Currently I'm experimenting with D's low level capabilities, and I've
>ran into a problem:
>How can I do a far jump in D, using the inline assembler?
>In NASM I would have something like this (I got this from a tutorial in
>kernel programming at osdever.net):
>
><code>
>jmp 0x08:flush2   ; 0x08 is the offset to our code segment: Far jump!
>flush2: ret       ; Returns back to the C (D actually :) code!
></code>
>
>I can find some references to far pointers and segmentation in D's inline assembler section, but it's unclear to me how to use this, or even if this is possible at all?
>
>thanks,
>Kevin