activating uart during boot

Andreas Schnitzer

Intellectual 390 points

Hello,

on a beaglebone black we are using the TI -Android image: TI_Android_JB_4.2.2_DevKit_4.1.1_beagleboneblack

Activating uart1 is possible using the adb-shell with the commands:

echo 0 > /sys/kernel/debug/omap_mux/uart1_txd
echo 20 > /sys/kernel/debug/omap_mux/uart1_rxd
chmod 666 /dev/ttyO1

This is working for using e.g. the android-serialport-api

Now will execute this command on boot

We tried to add this commands to init.am335xevm.rc, only the chmod cmd was executed.

How to modify the init-scrpits accordingly?

Thanks

Andreas

over 11 years ago

0 Arun Joseph over 11 years ago

TI__Expert 7220 points

Hello,

Can you use "write <file> <value>" command instead of "echo" ?

Regards,

Arun

0 SANGILI KUMAR over 11 years ago

Genius 3920 points

HI Andreas,

I dono why you are mounting debug file system and enabling UART1 by changing the mux mode using echo command.

Better you can enable the UART1 in board file below the beaglebone_black_dev_cfg[]={

{ uart1_wl12xx_init. DEV_ON_BASEBOARD, PROFILE_NONE}.

in uart_wl12xx_pinmux command the RTS and CTS mux if you fail to command RTS&CTSyour i2c2 will not work.

There is punch of chown & chmod lines at your init.rc try to give chmod 666 /dev/ttyO1 below that.

Cheers,

Sangly.

0 Andreas Schnitzer over 11 years ago in reply to Arun Joseph

Intellectual 390 points

Hi Arun,

this works, uart now availble from boot

thank you!

0 Andreas Schnitzer over 11 years ago in reply to SANGILI KUMAR

Intellectual 390 points

Hi Sangili,

i am just new to the bbb system and installed the image provided from ti.

what else you can suggest instead of 'mounting debug file system'

where can i find beaglebone_black_dev_cfg?

Thanks

Andreas

0 SANGILI KUMAR over 11 years ago in reply to Andreas Schnitzer

Genius 3920 points

If you have the TI's Android source you can find the beaglebone_black_dev_cfg in

/kerne/arch/arm/mach-omap2/board-am335xevm.c this one is the main board file.

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activating uart during boot