[fpc-devel]Calling previous INTroutine

[Ingmar Tulva]

On Mon, 18 Dec 2000, startx wrote:

> >         {asm
> >                 mov ax, ds
> >                 mov ebx, offset dsdummy
> >                 mov cs:[ebx], ax
> >         end;} // this part traps on "mov ax, ds"
> 
> About this fragment, which uses CS as imposition: this is the first
> thing I tried some time ago. And, yes, this caused an error. This is
> strange, because in the FPC documentation it is stated that "the code
> segment is writeable by default".

Hello, I just happened to read it and... Can a code selector be writeable
at all?! I just like recall that it can be either execute-only or
read-and-execute. Or have I got something wrong (whitch is quite
possible, I've only read PM basics but never hacked in sutch a low level)?

Ingmar tulva,
ingmar at zbi.ee