Android UART Problem

[koray.duran]

Hello,

I got a A13 with Wi-Fi and LCD+TS. I've just plugged usb-f-cable and able to receive debug information.
But I need to use uart0 and uart1 in my applications so i just need to turn off debug mode.
I tried to access serial port via /dev/ttyS0 it says i dont have permisson to write and read this.

Can you please explain me how to close debug mode for uart and how to use them ?

Thanks a lot.

[olimex]

to disable the console on UART1 do this: enter as root, then

#vi /etc/inittab

Comment the line: "T0:23:respawn:/sbin/getty -L -a root ttyS0 115200 vt102"
Save the file and reboot.
!!!Before rebooting you should have working SSH

log via SSH and you can use UART1

[koray.duran]

there is no inittab in etc directory.
I think it's in debian version, android doesnt have it.
i found it on proc directory but after i comment, system recovers this file.

[olimex]

sorry, I'm not familiar with Android

[vinifr]

You need edit script.bin/script.fex into nanda: http://elinux.org/Hack_A10_devices

You can use ssh instead adb. 

[koray.duran]

i did it and succesfully updated the script.bin file but somehow it doesnt work.
do you have any experince about it? try to change or disable the debug port that i can use it.

modified part :

[uart_para]
uart_debug_port          = 0
uart_debug_tx            = port:PB19<2><1><default><default>
uart_debug_rx            = port:PB20<2><1><default><default>

[murerten]

It is not easy I think. Because you have to change /init.rc file in android image. There are lines that start debug on UART0. I don't know how you can change those lines without making your custom android image.

[koray.duran]

Many people has same or similiar problems about uart on the forum. I've tried so many ways. This need to be solved by Admins, i think.
murarten you are right, i've also seen these lines in init.rc and to change it you must download boot image edit and upload again. also we may need to change ueventd.rc to give write permission.

here is what i find but i'm not so familiar with linux systems.
http://droidcore.blogspot.com/2012/12/how-to-edit-initrc-in-android.html

[vinifr]

I had forgotten, you need to change the parameters of the bootloader also. Edit /sdcard/nanda/linux/params, if you want to disable the console.

Code Select Expand

root=/dev/nandb rw init=/init fbmem=32M@0x5a000000 loglevel=8;

[koray.duran]

I had forgotten, you need to change the parameters of the bootloader also. Edit /sdcard/nanda/linux/params, if you want to disable the console.

Code Select Expand

root=/dev/nandb rw init=/init fbmem=32M@0x5a000000 loglevel=8;

i couldnt find params there.

[vinifr]

Sorry, i mean, change

Code Select Expand

console=ttyS0,115200 root=/dev/nandb rw init=/init fbmem=32M@0x5a000000 loglevel=8; to

Code Select Expand

root=/dev/nandb rw init=/init fbmem=32M@0x5a000000 loglevel=8; into /mountpoint/nanda/linux/params

That is, you need to delete console=ttyS0,115200

mountpoint: directory where you mounted nanda

[koray.duran]

There is no such file "params"!!! Maybe i have some problem 
First i have mounted nandaand then check the location "/sdcard/nanda/linux/"
but htere is no params file. only three files :
linux.bmp
linux.ini
u-boot.bin

[vinifr]

You are right. There is only 3 files. But somewhere the parameters being passed.

You could pass the parameters directly to the u-boot, via command line. Just press any button before the u-boot boot the kernel.

[koray.duran]

Also tried, it doesn't work. 

[gkania]

Hi.

Look here
http://www.imajeenyus.com/computer/20130301_android_tablet/android/partitions_detailed.html

especially at description of

/dev/block/nandb - env