This page is a work in process.
Softbank Phones by NEC
Check the dumping hardware overview for a list of known preservation hardware.
If you need help, please come chat with us on the VGPC or No-Intro discord servers.
Introduction
Softbank NEC phones fall into two categories. The later, higher end devices are very similar to Docomo NEC phones, and are compatible with the same tools. These phones run on a customized form of Linux, and they use M2 CPUs.
The earlier models have U100/U250 CPUs. Very little is known about them.
There are a few exceptions to these two categories
- The 840N is not understood - it should work with current exploits, but it just doesn't
- The 740N/741N are simplified phone models meant for children. They are not compatible with applications.
| Phone Model | Extractable? | File System/FTL | Tools |
|---|---|---|---|
| V-N701 | Unknown | Unknown | Unknown |
| 802N | Unknown | Unknown | Unknown |
| 703N | Unknown | Unknown | Unknown |
| 804N | Unknown | Unknown | Unknown |
| 705N | Unknown | Unknown | Unknown |
| 706N | Unknown | Unknown | Unknown |
| 820N | Yes | JFFS2 | Jefferson |
| 821N | Yes | JFFS2 | Jefferson |
| 821N GLA | Unknown, might be same as 821N | Unknown | Unknown |
| 930N | Yes | JFFS2 | Jefferson |
| 830N | Yes | JFFS2 | Jefferson |
| 931N | Yes | JFFS2 | Jefferson |
| 831N | Yes | JFFS2 | Jefferson |
| 940N | Yes | JFFS2 | Jefferson |
| 840N | No | Unknown (but probably JFFS2) | Unknown |
| 740N | No | Unknown | Unknown |
| 841N | Yes | JFFS2 | Jefferson |
| 741N | No | Unknown | Unknown |
| 001N | Yes | JFFS2 | Jefferson |
Methods
Ktdumper
Ktdumper is a tool for extracting data from feature phones that are compatible with the Foma debug adapter, which includes all Docomo phones and select SoftBank phones. Please note that ktdumper will not work unless you have the Foma debug adapter.
Ktdumper is compatible with Linux and WSL (Windows System on Linux). It can be used as a command line tool or as a live Linux iso with a GUI.
Ktdumper Command Line
- Make sure your phone is connected to the PC (if using WSL, you will need to bind your USB device)
- Download the ktdumper repository from Github
- Navigate to the main ktdumper folder, where the code will be executed.
- You can execute the following commands
- NAND (contains user data, downloads, etc.)
sudo ./ktdumper.sh [insert phone model] dump_nand
- NOR
sudo ./ktdumper.sh [insert phone model] dump_nor
- JAVA Folder (only works on select Mitsubishi/Fujitsu phones)
sudo ./ktdumper.sh [insert phone model] dump_java
Sample For D904i
sudo ./ktdumper.sh d904i dump_nand
Ktdumper Live Iso
WIP
Reading Data
Jefferson
The JFFS2 file system can be extracted with Jefferson, which runs on Python. You can install Jefferson in a pre-existing Python using pip:
sudo apt-get install python3-pip sudo pip3 install jefferson
The following command creates a folder called “jffs2_extracted” to contain the data extracted from nand.bin.
sudo jefferson -d jffs2_extracted nand.bin
Note: You may see the error
data_crc does not match!
The dump may still be working. Let it continue until the process is complete before trying other steps.
Troubleshooting
If the jffs2_extracted folder contains no data, the offset will need to be removed from the .bin file.
You can determine the offset two ways:
- Using binwalk, look for the address where the JFFS2 file system begins.
binwalk nand.bin
- Using a hex editor such as HxD, look for the following four bytes:
85 20 19 E0
Or
85 19 02 E0
Delete all data before those four bytes and try again to extract with Jefferson.
Note: It is not possible to undelete files from a JFFS2 file system.
Gathering and Submitting Dump Info
Once you've dumped your games, it's time to generate and submit metadata to a preservation project for validating and cataloging. See the dump submission instructions for more information.