[U-Boot-Users] Up-arrow and Down-arrow related Query

Wolfgang Denk wd at denx.de
Fri Jan 12 17:52:44 CET 2007

In message <1168625193.1678.23.camel at Kamesh> you wrote:
>        I'm using u-boot for our custom board.
> We are customizing the Cmd Line interface of U-Boot
> to suit our needs.

Start trying to understand what's already present...

> The Up-Arrow & Down-Arrow keys don't function the way
> they do in Bash Shell prompt. 

Umm... it seems you are somewhat  confused  about  functions  of  the
terminal  emulation  running  on  your  host  computer  and the imput
processing in U-Boot.

In the standard configuration, there is no such thing  as  "Up-Arrow"
or "Down-Arrow" keys - U-Boot is reading a character stream, and tere
is no such characters in the usedC (= ASCII) character set.

However, you can enable command completion, commandline editiong  and
history  functions  by  enabling  these  in your board configuration.
Then, and  only  then,  will  U-Boot  respond  to  certain  character

> The Up-Arrow takes the cursor up the screen thru the previous 
> prompt lines. Where is this Up-Arrow functionality defined ?

In the terminal emulation program running on your host system. U-Boot
is just echoing the characters in your input.

> I chkd the readline() function in common/main.c, but that does 
> not take care of Up & Down arrows in Switch - Case stmts.

It does not ven know that such things might exist.

> I need to know where the Up and Down arrow key press
> functionalities are defined.    

You repeat yourself.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Quote from a recent meeting:   "We are going to continue having these
meetings everyday until I find out why no work is getting done."

More information about the U-Boot mailing list