From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264178AbTDWSNZ (ORCPT ); Wed, 23 Apr 2003 14:13:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264166AbTDWSNZ (ORCPT ); Wed, 23 Apr 2003 14:13:25 -0400 Received: from mail.gmx.de ([213.165.64.20]:37981 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S264178AbTDWSNW convert rfc822-to-8bit (ORCPT ); Wed, 23 Apr 2003 14:13:22 -0400 Content-Type: text/plain; charset=US-ASCII From: Andrew Kirilenko To: linux-kernel@vger.kernel.org Subject: Re: Searching for string problems Date: Wed, 23 Apr 2003 21:25:22 +0300 User-Agent: KMail/1.4.3 References: <200304231958.43235.icedank@gmx.net> <200304232105.38722.icedank@gmx.net> In-Reply-To: MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: <200304232125.22270.icedank@gmx.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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.