Difference between revisions of "Literati:Serial Port"
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4 update all
4 update all
Latest revision as of 02:44, 28 October 2011
The Serial port on the White literati model #1637287 is located on the right side of the device seen in the picture on the right. this is also true on the older black models.
currently we do not know where they are on the newer models a picture of a newer model is also on the right and circled is what is believed to be the serial port.
the serial port header has the follow pinout from top to bottom:
The UART TX and RX signals are at +3.3v TTL level which requires a RS232_Level_Shifter if connecting to a standard RS-232 interface or to a standard USB-to-RS232 adapter. A wide range of USB-to-TTLUART adapters are available including the following:
Once connected this will enable access the bootloader and start up processes of the linux kernel.
Easy Serial Port Access
Use the following items to expose the serial port in a handy way that does not require reopening of the literati to access the serial port:
- a bit of ribbon cable
- male header pins
- female socket
another option includes the use of a 1/8" audio jack which can be easily mounted by drilling a hole in the back cover.
Using CA-42 Serial Cable
One of the simplest way to connect your PC to the Literati serial port is to order a Nokia CA-42 Data Cable from DealExtreme. When you receive it, you can cut it open to find 3 or 4 wires depending on the revision. If you have three wires, then you will find GND, RX, and TX. If you have four wires, then the fourth wire is +3.3V. The example CA-42 only has three. The cable can be soldered to a female pin header so it can connect to the male pins used to expose the serial port to the outside.
during the boot process there is a 3 second count down to allow a user to enter the bootloader before booting the kernel.
To get out of the bootloader right now you type "reset" and the device will reboot allowing you to get out of the bootcmd line there is a way to boot from nand but iv forgot to log the offsets.
boot zImage from sd that fat32 part boot zImage from sd that fat32 part boot zImage from sd that fat32 part boot zImage from sd that fat32 part ? - alias for 'help' base - print or set address offset bdinfo - print Board Info structure bootm - boot application image from memory branch - enable or disable branch prediction TestMemory - start application at address 'addr' cmp - memory compare cp - memory copy crc32 - checksum calculation dcache - enable or disable data cache dnw - initialize USB device and ready to receive for Windows server (specific) echo - echo args to console erase - erase FLASH memory exit - exit script flinfo - print FLASH memory information go - start application at address 'addr' help - print online help icache - enable or disable instruction cache imls - list all images found in flash itest - return true/false on integer compare loadb - load binary file over serial line (kermit mode) loads - load S-Record file over serial line loady - load binary file over serial line (ymodem mode) loop - infinite loop on address range md - memory display mm - memory modify (auto-incrementing) movi - moviNAND sub-system mtest - simple RAM test mw - memory write (fill) nand - NAND sub-system nboot - boot from NAND device nm - memory modify (constant address) printenv- print environment variables protect - enable or disable FLASH write protection reset - Perform RESET of the CPU saveenv - save environment variables to persistent storage setenv - set environment variables sleep - delay execution for some time test - minimal test like /bin/sh version - print monitor version 1 update boot from sd 2 update kernel from sd 3 update resource from sd 4 update all