Didj

Project Summary
The Didj is a toy produced by Leapfrog marketed for educational games for 5-10 year olds. Although it has a proprietary graphical front end, it runs a generic Linux distribution on an Arm based processor. Soon after the Didj's release, it was discovered that the cartridge port contained pins that allowed for serial console access with root privileges. After this discovery, work began to modify the Didj into an accessible emulation device.

Since development began, much has been accomplished, including:


 * Discovered that the Arm chip is the same as on the GP2X Wiz, only at a lower clock speed.
 * Created cartridges that support SD cards
 * Accessed the UART features in the cartridge slot

Project Goals
Here is a place to list all the the goals or wants that we have for this project.


 * GP2x / GP2x Wiz
 * Port Libraries
 * Flash Player
 * Emulation (Wiz Emulators)
 * NES
 * SNES
 * Gameboy BW/Color/Advanced
 * Gamegear
 * MAME
 * Atari 2600
 * Colecovision
 * Others
 * GUI
 * Custom or Modified
 * Customizable Themes
 * Homebrew Games
 * Overclock Processor

Project Status and Issues

 * Project Issues Tracker

Tutorials/How To's
 Booting From External Sources 
 * Boot Didj from UART Connection - Linux
 * Boot Didj from UART Connection - Windows

Build Environments
 * Creating a Kernel Build Scratchbox
 * Setting up a Cross Compiler Build Environment and Basic Usage

 Flashing the Didj
 * Updating Bootloader/Firmware over USB
 * U-Boot NAND Utilities and Bootloader Update

 Hardware Adding, Hacking
 * Adding Serial Console
 * Didj SD MMC Expansion

 LFConnect Software
 * How to Extract Files From the Firmware .exe
 * LFConnect Update Server Bypass

 Mounting Didj USB Drive 
 * Gain Access to the Didj as a Thumb Drive from Windows.
 * USB Mounting Under Windows, Linux, and OS X

Networking
 * Networking HOWTO - Enabling Networking, telnetd, and Dropbear (via the USB Gadget Ethernet Driver)
 * Bridge your Didj: Connecting your Didj to the wider Internet using bridging

 On Host 
 * Mount Didj File System (erootfs.jffs2) Under Linux
 * SCSI Commands

 On Didj 
 * Common Commands Reference
 * Didj Stop Start Up Junk How to Remove All the Kid's Game Files

Technical Information
2008 version
 * Home Brew Cartridge and Custom Bootloader
 * Initial Memory Map Dump
 * Map of Didj GPIO Pins
 * The #edev guys (#edev on irc.freenode.net) located THIS on the leapfrog site.
 * Didj Linux and root filesystem source is here
 * busybox isn't listed
 * The linux kernel source is now available from LeapFrog.

2009 version
 * Didj Source Info
 * LF1000 UART Bootstrap Utility written in Python
 * [[media:lf1000-bootstrap-utilities.tar.gz |LF1000 UART Bootstrap Utilities]] based on the OMAP boot utilities from TI

Discussion

 * Didj Project Forum
 * #Didj on Freenode IRC
 * Cozybit boasts of their involvment in integrating Linux with the Didj
 * Hacking around with the Leapfrog Didj
 * Didj Homebrew Forum (Empty?)
 * Hackaday Posts
 * Didj Hacking
 * Didj Hacking Followup

Graphics Hardware

 * Resolution: 320x240


 * Display Modes: RGBA 565


 * MLC: Multi-layer controller provides HW compositing for up to three graphics layers
 * One 24-bit 2D layers (no HW accel)
 * One 16-bit 3D layer
 * One YUV video layer (no HW accel)


 * Graphics API OpenGL ES 1.1: A reduced instruction set version of OpenGL for embedded systems. OpenGL is a 3D graphics programming interface. Proprietary interface to Multi- Layer Display controller for 2D RGB and YUV video buffer support. FreeType Font renderer. Theora video codec plays OGG-Theora files.

Chip List










Processor

 * OEM branded version of the MagicEyes Pollux VF3520F [[media:pollux-datasheet.pdf|Datasheet]]
 * Appears to be the 393MHz version of the same processor in the GP2x Wiz
 * Marked with:
 * "LF-1000" - LF-1000 Specifications
 * "ARM"
 * "N12N1D"
 * "H0815"

Memory
or
 * 1 QImonda HYB25DC25616OCE-5 - 32megabyte sdram [[media:HYB25DC25616OCE-5.pdf | Datasheet]]
 * 1 Nanya NT5DS16M16CS-5T - 32megabyte sdram (Datasheet)


 * 1 Micron MT29F2G08AAC - 256megabyte nand flash 8-bit [[media:MT29F2G08AAC.pdf | Datasheet]
 * 1 7s08f -2 input or gate connected to WP on flash

Audio

 * 1 Cirrus Logic CS43L22 - audio codec [[media:CS43L22.pdf | Datasheet]]

Display Driver

 * 1 Giantplus GPM758A0 - 320x240 TFT Pinouts and Specifications

Power

 * 1 Intersil ISL7665SACBAZ - Programmable Over/Under Voltage Detector [[media:isl7665s.pdf | Datasheet]]
 * 3 TI TPS62050 - Adjustable Step-Down Converter [[media:tps62050.pdf | Datasheet]]

Crystals

 * Oscillators
 * 12MHz Crystal
 * For usb
 * 27MHz Crystal
 * For the Processor*
 * Barrel Crystal
 * For the RTC 32.768KHz*

Test Pads

 * JTAG on pads
 * TP8 - Vcc
 * TP9
 * TP10
 * TP11
 * TP12
 * TP13
 * TP14 - Vss

Ethernet?
There is info of a CS9800 Ethernet controller used on the development board

* See the processor datasheet page 20.

= USB =

USB 2.0 Device Interface

 * Pins USB_DP and USB_DM on the Processor
 * The Usb 2.0 Device port is what is used on the Didj to connect to the PC.

USB 1.1 HOST Interface

 * Pins UP and UM on the Processor
 * The USB1.1 Host pins must be pulled down through 15Kohm resistor whether it is used or not.
 * There is no traces to the USB Host pins thus we can not use USB Host

= UART Adapter Info = A direct serial-line connection won't work with the Didj because the RS-232 spec uses 12v, while the Didj prefers about 3-5v. So you'll need an adapter to communicate to the UART on the Didj.

= Cartridges = Detailed Pin info of the Cart Connector

Original Cartridge
Manufactured by Sandisk
 * s740878-1
 * 4620329
 * 0621
 * 151-10043-07-a

DJHI
DJHI stand for "Did Ja Hack It?" Right now you can only buy them fully assembled and tested from JerTechOnline.com

Home Etched Didj Breakout Board

 * Easy to make at home (can be made with a radioshack kit and a dremel)
 * The board layout was designed in eagle.
 * The Eagle Board file [[media:dijibreakoutboard.zip|Download]]
 * The Didj Edgecard connector library file [[media:LEAPFROG_DIJI_EDGECARD.zip|Download]]
 * You can use this to make any board you want.
 * Edited Didj Cartridge library Download
 * (including outlines and keepout regions according to Awesomnesser's diagrams)
 * This cartridge locks in just like the real thing.
 * It is easy to do just superglue a small piece of FR4 in the corner and dremel a notch out. (see dimensions below)
 * You will also need a spacer on the top and bottom and those dimensions are also included.

Hack an Original Cart

 * Modify an original cart to have a uart output

Claudes Cartridge

 * Features
 * Jumpers (For custom bootloader)
 * SD Card (Enabled through the custom bootloader)
 * USB through a FTDI chip
 * Optional NAND
 * Claudes Website
 * [[media:ClaudesSchematic.pdf | Claudes Schematic]]
 * [[media:ClaudesGerberFiles.zip | Claudes Gerber Files]]

SD and USB Serial Cart

 * Features
 * Fits (mostly) within the Didj
 * Includes an FTDI FT232RL USB-Serial adaptor for Bootloader and Serial Console
 * Includes SD card slot
 * Includes solder jumpers for custom bootloader
 * Open Eagle source files (CC Attribution, Non-Commercial, Share Alike)
 * Front and Back PDF
 * Eagle files
 * BatchPCB public design
 * Comments welcome!
 * Gerbers haven't been made yet. Please post comments here, or as a message to me.
 * I think the design is correct based on Claude's schematic and Awesomenesser's diagrams, but I can't be sure.
 * Later, I'll have this produced by BatchPCB, I'll post a link to the public design on that site, if others want boards made.

= SSP / SPI Controller = Didj SPI Info

= File System Info =


 * rootfs / rootfs rw


 * /dev/root / jffs2 ro


 * none /proc proc rw


 * sysfs /sys sysfs rw


 * /dev/ram0 /tmp tmpfs rw


 * /dev/mtdblock1 /flags jffs2 rw,sync,noatime


 * /dev/mtdblock2 /mfgdata jffs2 ro,sync,noatime


 * /dev/mtdblock10 /Didj vfat rw,noatime,fmask=0022,dmask=0022,codepage=cp437,iocha rset=iso8859-1


 * /dev/mtdblock11 /Cart vfat ro,noatime,fmask=0022,dmask=0022,codepage=cp437,iocha rset=iso8859-1

Filesystem               Size       Mounted on

/dev/mtdblock6          14.0M     /

/dev/mtdblock1         896.0k    /flags

/dev/mtdblock2           1.0M    /mfgdata

/dev/mtdblock9         215.8M    /Didj

if at boot you see:

root=31:04

you are using mtd4: 00e00000 00020000 "Linux_RFS0"

root=31:06

you are using mtd6: 00e00000 00020000 "Linux_RFS1"