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AVM Fritz!Box Fon WLAN 7112

The Fritz!Box Fon WLAN 7112 is a small DSL router that is also sold with DSL contracts from DSL provider 1&1 in Germany.

Supported Versions

Unsupported at the moment (February 2015)

Hardware Highlights

SoC Ram Flash Network USB Serial JTag
AR7 32 MiB 8 MiB 1x maybe 2x unknown

Manufacturer's site:

Forum: (No forum topics)


There is no OpenWRT support for this device at the moment.

Flash Layout

This is the MTD layout of the vendor firmware from /proc/mtd

dev size erasesize name
mtd0 0x800000 0x10000 "phys_mapped_flash"
mtd1 0x6d3000 0x10000 "filesystem"
mtd2 0x770000 0x10000 "kernel"
mtd3 0x10000 0x10000 "bootloader"
mtd4 0x40000 0x10000 "tffs (1)"
mtd5 0x40000 0x10000 "tffs (2)"
mtd6 0x200000 0x10000 "jffs2"
mtd7 0x570000 0x10000 "Kernel without jffs2"

MTD partitions as seen in /var/env

mtd0 0x90000000 0x90000000
mtd1 0x90010000 0x90780000
mtd2 0x90000000 0x90010000
mtd3 0x90780000 0x907C0000
mtd4 0x907C0000 0x90800000

Failsafe mode


The Fritz!Box Fon WLAN 7112 has one button.

WLAN WLAN on/off

Vendor firmware

These are the default settings for the vendor firmware:

  • IP address: (with DHCP server, served IPs start at
  • WLAN SSID: Fritz!Box Fon WLAN 7112
  • password: no password
  • Telnet: disabled

Enable/disable telnet

Telnet access can be enabled by connecting a telephone to one of the telephone ports and dialing the number #96*7*. The Fritz!Box will answer with one dial tone. Disabling telnet can be done with dialing #96*8*.



Instruction set: MIPS
Bootloader: EVA (Version 1.607)
System-On-Chip: AR7 OHIO (Infineon PSB7200ZDW)
CPU @Frq MIPS 4KEc V4.8 @ 125 MHz
Flash size: 8192 KiB
Flash Chip:
RAM size: 32 MiB
RAM Chip:
Wireless: ?
Switch: ?
Modem: (DSL Annex-B)
USB: No USB port, may be possible
Serial: 2x
JTAG: unknown



  • 1: System timer (OHIO System)
  • 6: OHIO primary (OHIO System)
  • 15: serial (OHIO primary)
  • 23: SAR (OHIO primary)
  • 27: Cpmac driver (OHIO primary)
  • 28: ubki2_swirq (OHIO primary)
  • 31: DSL (OHIO primary)


Driver: avm_cpmac


There are several clocks installed as part of the OHIO system. The list below shows their frequencies when using the vendor firmware (found in /proc/clocks)

  • CPU: 125000 kHz
  • System: 125000 kHz
  • USB: 100000 kHz
  • DSP: 211968 kHz
  • VLYNQ: 0 kHz






Opening the case

Note: This will void your warranty!

To open the case you need a small flat screwdriver. However there are no screws you need to unscrew.

  • First you have to remove the reflecting plastic cover. You need to place the small screwdriver between the cover and the case. Then you need to lever the cover with the screwdriver.

avm_fb7112_open_3.jpg avm_fb7112_open_4.jpg

  • The case is splitted into an upper and lower part. On all sides there is a slit where both parts of the case are put together. You need to place the small screwdriver in one edge at the slit and lever the upper part of the case.


  • To unmount the PCB you have to use the small screwdriver and lever the pcb on one of the frond edges.


Photo of PCB

Top: avm_fb7112_pcb_2.jpg

Bottom: avm_fb7112_pcb_3.jpg


port.serial general information about the serial port, serial port cable, etc.

There are two serial ports available: tty0 and tty1. tty0 is for booting. The serial mode for both ports is: 38400,n,8,1,hw

How to connect to the Serial Port of this specific device: TODO

Photo of PCB with markings


port.jtag general information about the JTAG port, JTAG cable, etc.

How to connect to the JTAG Port of this specific device: TODO

Photo of PCB with markings


Bootloader Mods

  1. you could read about bootloader in general

Hardware mods

  1. as a beginner, you really should inform yourself about soldering in general and then obtain some practical experience!


OEM bootlog


OpenWrt bootlog

Not available!


This device is not supported anymore by AVM.



For some Help with the Tags, please have a look here: tags

toh/avm/ · Last modified: 2015/02/22 00:33 by Pizzamann