Talk Details

Reverse Engineering the Motorola EZX (A768,A780,E680) series of Linux-based GSM phones

Name Harald Welte

Organisation hmw-consulting.de

Website http://gnumonks.org/users/laforge

Scope Technical

Topic Embedded Systems

Type talk

Abstract It's been two years since Motorola has released the first Linux Smartphone (A760). More recently, two new models were introduced, the A780 and the E680, the former even officially distributed in Germany and all over the EU.

What's so special about a Linux based smartphone? It's special because the Linux kernel acts as an enabler for 3rd party hacks and 3rd party software, like it can be observed with the OpenWRT, OpenTom, NSLU2-Linux, OpenEmbedded, OpenZaurus and other similar projects.

The author of this presentation has sucessfully obtained "telnet root" access to an A780 cellphone, built a matching cross-compilation toolchain and installed various applications for debugging, such as busybox, iptables, nmap, lsof, strace, etc.

While re-engineering efforts are still in a early stage, work is proceeding extremely fast, and important pieces such as the protocol between the PXA270 frontend processor and the ARM7TDMI GSM processor have already been partially re-engineered. The project is expected to progress significantly until FOSS.in/2005.

Pre-requisites A bit of knowledge on ARM/Xscale embedded systems and Linux is good, but not required.

Profile Harald Welte is the chairman of the netfilter/iptables core team.

His main interest in computing has always been networking. In the few time
left besides netfilter/iptables related work, he's writing obscure documents
like the UUCP over SSL HOWTO. Other kernel-related projects he has been
contributing are user mode linux, the international (crypto) kernel patch, device drivers and the neighbour cache.

He has been working as an independent IT Consultant working on projects for
various companies ranging from banks to manufacturers of networking gear.
During the year 2001 he was living in Curitiba (Brazil), where he got
sponsored for his Linux related work by Conectiva Inc.

Starting with February 2002, Harald has been contracted part-time by
Astaro AG, who are sponsoring him for his
current netfilter/iptables work.

Aside from the Astaro sponsoring, he continues to work as a freelancing
kernel developer and network security consultant.

He licenses his software under the terms of the GNU GPL. He is determined to bring all users, distributors, value added resellers and vendors of netfilter/iptables based products in full compliance with the GPL, even if it includes raising legal charges.