Didj Boot From UART
How to boot the Didj from a UART Connection.
a working kernel image
Terminal program, Hyperterminal, or equivalent, must be able to send via Plain Text, Xmodem, and Kermit.
Latching the power button
Pull D6 pin of NAND Flash low, boot as normal, watching in Terminal, after boot, pull both D5 and D6 low, type command "reboot". Didj will reboot and you won't have to hold down the power button during this process.
Starting the UART Boot
Keeping the D5 and D6 of NAND Flash pins low (note: Screen will be blank)
1) Configure hyperterminal to 19200 8/n/1
2) Make sure UART is connected, and hold down power button and any other button on the Didj.
3) Using Send Text method, switch file type to "all" and load lightning-boot.bin, nothing will be displayed, but usb/rs232 adapter will show activity, if its got an LED to do so.
4) Once loaded, let up on other button. Switch hyperterminal to 115200 8/n/1 and use Xmodem method to send uboot.bin. Press send, then press a button on the Didj to initiate transfer.
5) Once uboot has been sent there'll be a terminal prompt, enter.
LF1000# setenv bootargs mem=18M init=/sbin/init console=ttyS0,115200 root=31:06 ro rootflags=noatime rootfstype=jffs2 ubi.mtd=Brio ubi.mtd=prg_Brio ubi.mtd=Cartridge ubi.mtd=EXT
LF1000# setenv loadaddr 1800000
6) Then send zImage file using Kermit method once finished there will be another terminal prompt, enter.
LF1000# go 1800000
7) Should now see linux kernel uncompressing then booting.
Custom Boot Loaders
Refer to the proper sequence provided by the custom bootloader, as some or all of these steps may be different or unnecessary.