Re: Searching for string problems

[Andrew Kirilenko <icedank@gmx.net>]

Hello!

> > > scan:	movw	%cs, %ax
> > > 	movw	%ax, %ds
> > > 	movw	%ax, %es
> > > 	movw	$where_in_BIOS_to_start, %bx
> > > 	cld
> > > 1:	movw	$cl_id_str, %si		# Offset of search string
> > > 	movw	$cl_id_end, %cx		# Offset of string end + 1
> > > 	subw	%si, %cx		# String length
> > > 	decw	%cx			# Don't look for the \0
> > > 	movw	%bx, %di		# ES:DI = where to look
> > > 	repz	cmpsb			# Loop while the same
> > > 	jz	found			# Found the string
> > > 	incb	%bx			# Next starting offset
> > > 	cmpb	$_BIOS_END, %bx		# Check for limit
> > > 	jb	1b			# Continue
> > > never_found_anywhere:
> > >
> > > found:
> >
> > I've written something similar to this before - and it wont' work, so
> > I've reimplemented it. The problem is, that I don't know how to set ES
> > properly. I only know, that BIOS data (and code) is located in
> > 0xe000..0xf000 (real address).
>
> Yeah. So. I set ES and DS to be exactly where CS is. This means that
> if your &!)(^$&_ 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.