The compass sensor is calculated from the accelerometer and magnetic field sensors. If the values reported by the compass sensor are not right, you can re-calibrate the magnetic field sensor with the following steps:
adb shell stop geomagneticd adb shell rm /data/sensors/yas.cfg adb shell rm /data/sensors/yas-backup.cfg adb shell start geomagneticd
Now start an application using the compass sensor. Move the device in every direction, with a rotation around each axis: the device should now be re-calibrated.
Best will be to post a recovery.log. There’s an option inside your recovery to create one.
You can get the log to your PC using adb:
$ adb pull /path/to/log/log.name
If this is not possible for your: tell the whole message you get! There are different “error 7” messages out!
Custom Roms like CyanogenMod and SlimRoms are pre-rooted by default, you only need to enable it.
Well, there are some apps out (e.g. Syslog App) which can help getting usefull logs, but i prefer using adb to get those logs:
adb shell logcat > logcat.txt
(abort/stop logging pressing ctrl + c on your keyboard)
adb logcat -b radio -v time -d > logcat_radio.log
adb shell dmesg > dmesg.txt
adb shell su -c "cat /proc/last_kmsg" > last_kmsg.txt
(make sure root is enabled!)
adb root adb pull /data/misc/audit/audit.log
First of all: the biggest part of our new kernel was done by Ziyan @ XDA-Developers. The kernel is the heart of our roms. Some words about “new” kernel:
added a property (/sys/board_properties/type) to show the board type, used by userspace drivers to configure stuff accordingly
We now use the new kernel on all of our roms (Android 5.1 an newer, but we also switched to it on some of the official 4.4 Roms like CM 11.0).
Kernel Source can be found here , History from cleanup and update here.
There’s a great tutorial by Ketut Kumajaya which i have slight updated and added
16 GB Tab 2 have a known faulty EMMC (MAG2GA). It can happen, that your EMMC get “read only”, so you can’t perform any write actions (also you can’t format) anymore.
From the EMMC data sheet:
5.1.7 End of Life Management:
The end of device life time is defined when there is no more available reserved block for bad block management in the device. When the device reaches to end of its life time, device shall change its state to permanent write protection state. In this case, write operation is not allowed any more but read operation are still allowed.
But, reliability of the operation can not be guaranteed after end of life.
On a faulty EMMC firmware it happens a lot faster.
What are the symptoms?
In most cases, the issue can be fixed by a EMMC firmware update, but you need someone who’s able to do it (possible via ISP, nothing you can do esylie at home yourself). In some bad cases you need to find someone who can replace your EMMC.