[Q] Kernel serial console - Nexus 10 Q&A, Help & Troubleshooting

Hi guys,
I'm looking for a way to read the kernel output during the boot process. I've already tried recompiling the kernel with/without FIQ_DEBUGGER, KGDB_SERIAL and SERIAL_SAMSUNG (_DEBUG), as well as setting the kernel console in the cmdline to every possible /dev/tty* port without any success.
I also tried echoing in every available serial port and use a digital analyzer on a breakout-microusb board to monitor the output. But all of the tty devices seem to be disconnected from the USB port. There are a lot of hints on the internet for other devices, but the most of them use a dialer to get into the service menu (e.g. for smartphones: http://forum.xda-developers.com/showthread.php?t=1515570) or a jig-cable with a resistor between ID and GND (http://redmine.replicant.us/projects/replicant/wiki/SamsungSerial). Both approaches failed on my Nexus 10.
I got no clue what to do next, so I would be very appreciated for any hints or new ideas.

I dont know much about kernel debug code stuff, but there is this command to see kernel messages in real time:
-adb shell watch "dmesg | tail -40"
Does that display things during bootup?

EniGmA1987 said:
I dont know much about kernel debug code stuff, but there is this command to see kernel messages in real time:
-adb shell watch "dmesg | tail -40"
Does that display things during bootup?
Click to expand...
Click to collapse
Thanks for that, but as far as I know the ADB daemon is started only after the kernel initialization. I can read the dmesg after Android is booted, but it doesn't help me to debug problems if the kernel panics.
I think I need some kind of a correct serial cable to read the kernel (and bootloader) output, but I couldn't find any working method for N10.

Did you have any luck with your case?

Related

Himalaya, familiar and the serial port...

Hi there,
I'm trying to get linux working with XDA2...
At the moment, I use HARET to boot the kernel, but I encounter some problems.
1. USB Serial Connection is breaking when booting the new kernel. I wouldn't have assumed anything different. But the Xda-Developers tutiorials shows how to connect via that virtual port.
2. I can use the real serial port to redirect Kernel Output until it says: "Login:"
I'm using minicom to get the output. But I can't enter the username. I'm sure that I use correct port settings, is there anything special with the connection to the XDA2? Should I use another Application to login? What's wrong with my serial input line?
Can somebody tell me how to use the Serial port via other Terminals? (Linux shell commands are highly appreciated.)
Thanks in advance for some hints!
Edit:
I also tried to compile custom kernel, but after haret switches to the dark screen (after showing the linux logo with splashed eyes ), it isn't redirecting any output to PC.
hi. you should first tell which software versions you are using.
Himalaya kernel is not maintained for a long time, but it's
not very difficult to update it.
Versions I use:
HaRET-0.3.6.exe (http://anymore.nl/ipaq/haret-0.3.6.exe)
zImage-2.6.12 (http://himalaya.lange.nom.fr/zImage-2.6.12)
initrd-2.6.12.gz (initrd-2.6.12.gz)
Hardware:
Processor: Intel PXA263
Model Nr. PH10A
Flash Chip type: 28F128k3

ADVICE/SUPPORT : UVC Camera on Samsung Galaxy Tab 10.1- No device Node??

HI,
I am trying to interface the UVC Camera to the Samsung Galaxy Tab 10.1(GT-7510) , but I am not able to see the device node getting created in the shell( I have installed the Linux terminal Shell Application) and rooted the device using this Video .Can somebody plz tell/advice how I can achieve it and access the device Node or at-least get it created.
Following is the log on dmesg :
usb 1-1 new high speed USB device using tegra-ehci and address 97
hub 1-0:1.0 unable to enumerate USB device on port 1 ,
usb 1-1:device v0ac8 p3420 is not supported
On My Laptop I get this output on Dmesg :
[12307.364237] uvcvideo: Found UVC 1.00 device Venus USB2.0 Camera (0ac8:3420)
[12307.366108] input: Venus USB2.0 Camera as /devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1/2-1.1:1.0/input/input14
[12308.537059] usbcore: registered new interface driver snd-usb-audio
also i can see the camera getting blinked on connection which proves that it is getting the power-supply and getting connected with the system.
I think there is a support for UVC USB devices in the kernel (not sure) otherwise I am ready with the Kernel For Samsung Tab 10.1 (GT-7500 (Higher Version: GT-7510)) from here .(GT-P7500_MEA_Opensource.zip (requires Login).
Plz assist.
Rgds,
Softy
You seem to know a bit about what you're doing. I'm not really familiar with this device. I did a search and did not find anyone who has don't this yet. The first priority is to get a Linux device in /dev/ folder. This is generally handled by a device driver and a udev rule. Try the newer kernel if you can. The android 4.0 ics has a Linux 3.x kernel. See if switching to ics helps. Try compiling a custom kernel with all modules. Once you have a device, try using SSH or sftp from your desktop under Linux to stream from that device with vlc or another media player.
Do you have any examples of this device in use on mobile Linux? It may require writing an entire kernel driver.
HI,
Yes that is the same line of thinking for us as well.We are trying to compile the kernel and load it .- Ongoing
I believe only the zImage is the one which is to be flashed.But I am little scared to do this.Couldn't find the instructions to loading the Zimage even though I can compile one.
Rgds,
Saurabh
softy007 said:
HI,
Yes that is the same line of thinking for us as well.We are trying to compile the kernel and load it .- Ongoing
I believe only the zImage is the one which is to be flashed.But I am little scared to do this.Couldn't find the instructions to loading the Zimage even though I can compile one.
Rgds,
Saurabh
Click to expand...
Click to collapse
Flash it with Heimdall, even if it won't work you will be still able to get into download mode of bootloader (which you aren't supposed to flash) and reflash the kernel with stock one.

[DEV][WIP] PyAdb Python 2.7 Package [Windows/Unix]

KEarlier I saw a thread that demonstrated a python wrapper for the adb command. I remembered a while ago that adb uses a TCP protocol (duh it's written in the docs)
I had some spare time today so I decided to write a script for you all (I know how redundant it is, but hey why not)
This script incorporates the core functionality of adb into it, such as detecting your device... that's pretty much it at this stage..
so here it is. PyAdb​
I doubt this will brick anyone's devices... but just in case..
disclaimer:
if this bricks your device, it was not my fault. you used this at your own risk.
I don't care if this crashes your computers, or shoots you in the foot. you used it, not me
Click to expand...
Click to collapse
The general concept with how this works is below:
firstly, you have to choose your command from this list
secondly: the length of that command (in hexadecimal) needs to be prefixed before the command is sent. This is probably to do with security so the adb server on the device only reads the right amount of data
thirdly:... well there's not much more to it. just enjoy, tinker with it, and remember to contribute!!
note about getting device detected:
You need to ensure that the Android Debugging Bridge driver is installed for your device. this is normally supplied with standard device drivers. please refer to your device forums for instructions on how to install these
You also need to make sure your pc is authorised with stock adb, otherwise you won't be able to connect with PyAdb (for 4.2 upwards)
note about the current shell integration:
I now have a threaded interactive console, however single commands are still not read from a thread. If you want to use grep or kmsg, launch a full session
page not found!
Fixed link: https://github.com/cybojenix/PyAdb/
Looks like OP removed the file he linked to and forgot to change the link.
404 page not found?
cybojenix said:
Earlier I saw a thread that demonstrated a python wrapper for the adb command. I remembered a while ago that adb uses a TCP protocol (duh it's written in the docs)
I had some spare time today so I decided to write a script for you all (I know how redundant it is, but hey why not)
This script incorporates the core functionality of adb into it, such as detecting your device... that's pretty much it at this stage..
so here it is. PyAdb​
I doubt this will brick anyone's devices... but just in case..
disclaimer:
The general concept with how this works is below:
firstly, you have to choose your command from this list
secondly: the length of that command (in hexadecimal) needs to be prefixed before the command is sent. This is probably to do with security so the adb server on the device only reads the right amount of data
thirdly:... well there's not much more to it. just enjoy, tinker with it, and remember to contribute!!
note about getting device detected:
You need to ensure that the Android Debugging Bridge driver is installed for your device. this is normally supplied with standard device drivers. please refer to your device forums for instructions on how to install these
note about the current shell integration:
I haven't added a threaded data capture method yet, purely because I don't have time at the moment. it will (should) work with single commands. it isn't reliable for commands that take a while to run (such as grep)
Click to expand...
Click to collapse
404 page not found?
omegavesko said:
Fixed link: https://github.com/cybojenix/PyAdb/
Looks like OP removed the file he linked to and forgot to change the link.
Click to expand...
Click to collapse
lol yeah thanks. I did some file changes and forgot I linked to the file in the thread rather than the repo

[Q] adb is not properly connected

I was trying this recovery screenshot tool http://forum.xda-developers.com/showthread.php?p=50029759#post50029759 without installing adb. I followed the instructions and wrote the width 240 and the height 320 (I am not at all sure of those) and when it tried to take the framebuffer i got the error "adb is not properly connected" and asks me to try to unplug and reinsert the usb cable. I then installed adb using this procedure http://forum.xda-developers.com/showthread.php?p=48915118#post48915118 and after successful installation i got the same error.
thanks in advance
maged rifaat said:
I was trying this recovery screenshot tool http://forum.xda-developers.com/showthread.php?p=50029759#post50029759 without installing adb. I followed the instructions and wrote the width 240 and the height 320 (I am not at all sure of those) and when it tried to take the framebuffer i got the error "adb is not properly connected" and asks me to try to unplug and reinsert the usb cable. I then installed adb using this procedure http://forum.xda-developers.com/showthread.php?p=48915118#post48915118 and after successful installation i got the same error.
thanks in advance
Click to expand...
Click to collapse
Make sure you have USB debugging enabled in your phone settings
You can test if adb is connected by doing the following
Open a command prompt where you have adb.exe
Type the following
adb devices
You will then get a list of devices connected
Remember not all kernels support adb in recovery mode
not all kernels?
marcussmith2626 said:
Make sure you have USB debugging enabled in your phone settings
You can test if adb is connected by doing the following
Open a command prompt where you have adb.exe
Type the following
adb devices
You will then get a list of devices connected
Remember not all kernels support adb in recovery mode
Click to expand...
Click to collapse
I have the debugging mode enabled and when i tried the "adb" devices command in the adb.exe directory it didnt show that there is any device connected.
about the "not all kernesupport adb" note how about stock kernel? and what best kernels work with adb and doesnt affect my systemfile and other things?
Edit: i flashed savie's kernel and i think it works
problems with the tool
I now have a problem that when i try to make a configuration file all screenshots in the pixel_formats folder are disturbed in a certain pattern (every line is a bit compressed vertically and the line is with a slope so the picture is completely disturbed)
I managed to get a clear screenshot using manual mode but the problem there that i sometimes scroll to something in the recovery and i take the screenshot i found it didnt scroll i then try to open a menu or so and take the screenshot it gives me a hollow screenshot with only the background of the CWM it happens nearly always so i cant get proper screenshots what i can do? and also i found the manual mode is a bit hard as i have to change the setting every time isnt there any tool easier than this
thanks in advance
maged rifaat said:
I have the debugging mode enabled and when i tried the "adb" devices command in the adb.exe directory it didnt show that there is any device connected.
about the "not all kernesupport adb" note how about stock kernel? and what best kernels work with adb and doesnt affect my systemfile and other things?
Edit: i flashed savie's kernel and i think it works
Click to expand...
Click to collapse
It's the kernel & cwm build - I don't know exactly what has to be enabled in the kernel & the CWM build but unless they support adb in recovery it won't work
Think manual mode is the best way as the galaxy y is ldpi - There probably are other tools out there you just have to search around
thanks !
marcussmith2626 said:
It's the kernel & cwm build - I don't know exactly what has to be enabled in the kernel & the CWM build but unless they support adb in recovery it won't work
Think manual mode is the best way as the galaxy y is ldpi - There probably are other tools out there you just have to search around
Click to expand...
Click to collapse
I cant thank you enough whenever i have a problem i find you helping me really thanks

UART access on Samsung S5302 (Galaxy Pocket Duos)?

Hello. So I've been trying to access UART console on my S5302 for quite some time. I followed instructions from here using PL2303HX-based UART-to-microUSB cable and 1MOhm variable resistor. Tried a lot of values from 150kOhm to 619kOhm, managed to get input to the device (I guess, because bashing Enter key while the device is booting seems to make it stop booting), but no output to serial console whatsoever. What am I doing wrong? Any ideas/tips?

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