Didj UART Boot

Hardware Needed
To perform UART boot, you must:

Make a serial connection to the UART pins on the Didj. To do this you can use a breakout board, or you can solder wires directly to the cartridge connector pins. Pull cartridge pin D5 to ground, via a pulldown resistor. (470Ω, 2200Ω, and 3300Ω are known to work).

Software Needed
Lightning-boot 1.4+

u-boot

Terminal program(s) - (ex: cutecom) that can send plain binary, xmodem and kermit

zImage kernel file for Didj Linux

Step 1 - Lightning Boot

 * 1) Connect your Didj UART Console cable, and connect D5 to ground via the resistor mentioned above.  Do not power up your Didj yet.
 * 2) Run cutecom, select the connection to your device (ex: /dev/ttyUSB0), and set the connection params to 19200 8N1.
 * 3) Select a download type of Plain.
 * 4) Click Send File- and in the next dialog select your lightning-boot.bin but do not send it yet.
 * 5) Pull the power switch on the didj down and hold it down.
 * 6) While doing this, send the lightning-boot file from Cutecom, while continuing to hold the Didj power switch down as it loads.
 * 7) Upon completion, the lightning boot screen will display on your Didj; at which time you may let go of the power button (and massage your finger). With lightning-boot 1.4+ you can use the menu to load zImage or u-boot.bin off an SD card, if you don't have those or would like to continue booting over UART, continue.
 * 8) Disconnect the connection (but dont leave cutecom)

Step 2 - U-Boot
When U-Boot is loaded you will see
 * 1) Change the baud rate to 115200 and then reopen the connection to the device.
 * 2) Select a download type of XModem, click Send File and select/open the U-Boot.bin file. (This will queue up the file for transmission.)
 * 3) Trigger the transmission of this file by pressing any button on the device.
 * 4. Quit cutecom.

Step 3 - Kernel

 * 1. From the command line, run Kermit:


 * 2. Paste the following at the  prompt once Kermit launches: (TODO - Command Line Params)


 * This takes you to the u-boot  prompt.


 * 3. Enter the following:


 * Followed by:


 * 4. Type ctrl-backslash and type letter c. This returns you to the   prompt.
 * Enter the following to send your image:

The file is sent. When done, kermit returns you to the   prompt.


 * 5. Reconnect to u-boot and boot the image you just sent:

If you see boot messages filling your console display, you have successfully performed a UART boot.