Re: Searching for string problems

[Andrew Kirilenko]

Hello!

> > > > I've written something similar to this before - and it wont' work, so
> > > > I've reimplemented it. The problem is, that I don't know how to set
> > > > ES properly. I only know, that BIOS data (and code) is located in
> > > > 0xe000..0xf000 (real address).
> > >
> > > Yeah. So. I set ES and DS to be exactly where CS is. This means that
> > > if your &!)(^$&_ code executes it will work. So, instead of trying
> > > it, you just blindly ignore it and state that it won't work.
> > >
> > > Bullshit. I do this for a living and I gave you some valuable time
> > > which you rejected out-of-hand. Have fun.
> >
> > Of course, I've tried your code as well - the same result! Sorry, if you
> > haven't understand me.
> >
> > The problem is, that I don't know where this BIOS code is relative to
> > current code segment (CS). I only know (hope), that it should be in
> > 0x0:0xe000...0x0:0xf000. I have tried to set ES to 0 (xor %ax, %ax; mov
> > %ax, %es) - no luck as well. BTW, `strings /dev/mem | grep "REQUESTED
> > STRING"` founds it perfectly...
> >
> > Best regards,
> > Andrew.
> > -
>
> The bios is in segment 0xf000. You set ES to that area. ES:DI will
> start at 0 if bx=0 in the code shown. The BIOS is only 64k.
> This means that where bx is being incremented (it should be incw, not
> incb). It would generate an assembly error with incb which is why
> I knew you didn't even try it.  -- you just jnz back to 1b, without
> any additional test.

1. How to set ES to this area? "movw $0xf000, %ax ; movw %ax, %es" will be 
enough?
2. Is the are really starts from 0xf000? Or 0xe000?
3. I'm smart enough to correct "incb %bx" to "incw %bx" ;)

Best regards,
Andrew.