HOW CAN I ENABLE /dev/tts/0 for rs-232 serial comm?

[darthracing]

Hi,

After linux boots, I would like to enable the main rs-232 serial port for serial communication to my external rs-232 device.
I assume something is set to force the board in console, maybe in the boot call?

I would like to toggle between console availability and my device use to make sure I have a serial console for emergency repair
(this is why I would like to be able to take control after boot vs changing kernel startup params).

ALTERNATELY, where can I get a serial expansion board (for the QQ2440V3)?

Thanks
-Todd

[ekilab]

[quote="darthracing"]Hi,

After linux boots, I would like to enable the main rs-232 serial port for serial communication to my external rs-232 device.

2 ways to do it:
1.
in vivi enter kernel parameter that instructs system to send console messages to

an excert from friendlyarm mini2440 manual page 21 (of 78)

How to set linux command line
Linux_cmd_line is a very often used parameter for kernel startup. Here is an example for how to
change default tty terminal from serial 0 to serial 1:
View current parameters:
Linux_cmd_line: noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC0
Input “s”, and then input “linux_cmd_line”, input “return”, and then input:
“noinitrd root=/dev/mtdblock2 init=/linuxrc console=ttySAC1,115200”

2. put quiet in the command line, but that is not foolproof, it would still send stuff maybe such as kernel panic into the console

[darthracing]

I figured this out and eventually locked myself out of console because I failed to create a means to interrupt the boot process from running
my program that uses the serial port :/

I ended up initializing the code in C to get it working for my application.

I ended up learning how to reflash the device finally - now when WIFI doesn't come up or the MMC card is not found, it runs in standard console mode