[Galaxy S III Original Android Development] droidphile:
FAQS and More

FAQS and More

In no particular order.

1. "How the heck do i flash the kernel.tar within device. I see a boot.img and recovery.img in the tar and not zimage like before?? I don't wanna increase flash counter by using odin from PC!"

A. Use mobile odin. (Paid on market, free on XDA).

Open the app, Click on "kernel", select the kernel.tar. Scroll down, select "flash firmware". Reboot.

2. "Why two mountable image files in tar?"

A. GS3 has separate kernel and recovery partition.

Kernel partition : /dev/block/mmcblk0p5

Recovery Partition: /dev/block/mmcblk0p6

Both partitions has a max size limit of 8 MB each.

3. "Does that mean i can flash only kernel/only recovery if i don't need the other?"

A. Yes. However, if recovery was modified to support a new feature in kernel, you may want to flash both.

4. "If i flash tar from Odin on PC, both kernel and recovery is flashed and i can't choose to flash only one?"

A. Yes, both are flashed.

5. "How to flash only kernel/only recovery with cwm flashable zip?"

A. If you know what you're doing, open updater-script in the zip and comment out the line that starts with write_raw_image for the one you don't need - kernel or recovery.

6. "Should i wipe cache and dalvik before flashing kernel?"

A. NO

7. "Best governor, best i/o scheduler for this kernel?"

A. Define best governor and best i/o scheduler!

Pegasusq is good enough to be responsive, battery friendly and quad core friendly if tweaked properly. Use any i/o scheduler. Sio/deadline are good.

8. "Why is Idle+Lpa default on STweaks and the recommended settings. In Siyah kernel for GS2, Aftr+Lpa was recommended!"

A. Aftr ofcourse saves more power than Idle if you consider what each of those low power state modes do. But combination of quad core architecture and pegasusq governor (or any external hotplugging logic combined with other governors) which need to respect rq values along with load thresholds makes it a little slower to turn off last 3 cores (if all the cores are ON obviously). AFTR requires that all cores except first (cpu0) be turned off - to kick in. So we're better off with Idle+Lpa.

However if you're using forced single core mode always (which is non sense in this powerful device), you can go for Aftr+Lpa.

9. "How do i overclock/underclock/undervolt GPU?"

A. Either use STweaks app or use a script

Ex:

#Frequency steps

echo 160 > /sys/module/mali/parameters/step0_clk

echo 266 > /sys/module/mali/parameters/step1_clk

echo 350 > /sys/module/mali/parameters/step2_clk

echo 440 > /sys/module/mali/parameters/step3_clk

echo 533 > /sys/module/mali/parameters/step4_clk

#Voltages

echo "875000 900000 950000 1025000 1075000" > /sys/class/misc/mali_control/voltage_control

10. "My device is not stable at 1.8 Ghz. But i still wanna overclock the device to possible maximum and show off to friends"

A. Try setting last frequency as 1750 mhz. (Modify 1.8 to 1.75 ghz with 1.7 ghz still in place)

Use kmemhelper interface. Put this line in your initd script.

kmemhelper -n exynos4x12_apll_pms_table -t int -o 0 14353152

11. "I OCed to 1.7/1.8 Ghz. My device is able to handle it. But i can't get high benchmark scores. Why?"

A. Your CPU is getting throttled during benchmark during benchmarking because of heating. This is a thermal safeguard measure. It might be getting throttled to 800 mhz or so.

Forget benchmarks, treat the overall responsiveness in daily usage as the criteria to determine if the device is fast enough for you or not.

12. "Any rule of thumb to increase life span of the battery? And I see percentage drops to 99 immediately after a charge till 100%"

A. Do not recharge to 100% often and even if you do, don't keep it plugged in 100% for long time. Best is to charge till 98%. And make sure charge does not drop below 10% while on normal use.

Charge dropping to 99% swiftly is a protection mechanism, not a fault with your battery or kernel or rom.

13. "I adjust the voltage by some mV in STweaks. I checked SetCpu and voltage has not changed!"

A. Voltage settings in STweaks follow VDD interface. They're applied ONLY during boot time. Why? The code is to reduce X mV specified by you in STweaks, for all voltages. If the settings is applied real time, it will cause reduction of voltage every time and instabilities.

14. "If I have no root, and flash this kernel using desktop odin will i get root?"

A. YES. However, if you don't see a CWM recovery, download and flash a recovery from Chainfire thread.

15. "Does the kernel backup EFS partition automatically?"

A. YES.

16. "Is there NTFS support?"

A. YES. Mounted to mnt/ntfs in Read only mode. Unmount and remount in Read Write mode if you need to.

17. "What voltage step does GS3 support while UV/OV?"

A. Regulator supports increments of +/-12.5 mV (Those who had GS2 will remember it's regulator supported +/- 25mV)

18. "Why is resetting STweaks profile recommended sometimes after a kernel flash?"

A. Your profiles are stored under /data/.siyah with ".profile" extension. ".active.profile" file under the same directory stores the name of your active profile. Contents in profiles are in the format parameter = <default_value>

There could be changes in Stweaks interface for a new build:-

i) Some new tunables were added

ii) Some tunables were removed

iii) Transposition of some tunables

iv) Default value of some tunable was changed.

When such a change occurs, your profiles should know it too so that it can contain all the parameters. That's why you have to reset profiles after a new kernel flash if it changes something in STweaks.

Resetting simply copies .profile files from /res/customconfig to /data/.siyah . You can do it manually using a file manager to avoid a reboot to recovery and back to rom. Kernel already detects STweaks changes to reset profile automatically on first boot after flashing.

19. "How to insert a module that's available in /system/lib/modules?"

A. Safe to be root. In terminal or adb

su

insmod /lib/modules/<module_name.ko>

20. "How to know which modules are pre-loaded by kernel?"

A. Terminal or adb:

lsmod

21. "I don't see an init.d folder in my rom. I wanna create some initd scripts. What to do?"

A. Using a root explorer create init.d directory under /system/etc. Set perm 777.

22. "After flashing a new kernel i see there are some stuffs missing from STweaks"

A. Either the support for those missing tunables were removed or just the STweaks interface was removed. The parameters might still be accessible through scripts. Check the file path to make sure.

23. "Does notification LED cause wakelock and lot of drain?"

A. Hm Yes and No. CPU has to wake to help turn on notif led and to turn off when it's timeout. When LED is blinking, no wakelocks are held. Notif led is controlled by a diff h/w and not directly by CPU.

24. "How do I know if my modified charge current settings (using STweaks) are effective?"

A. Use CurrentWidget from playstore. Monitor the reading while charging.

25. "What happens if my smooth scaling frequency is greater than my scaling max frequency?"

A. Smooth scaling will be inactive/disabled.

26. "Can I flash this kernel on a non-international variant - At&T/Korean/Japanese...?"

A. NO. Don't risk 800 dollars. Dev might release different variants for these devices later.

27. "I tried setting a negative value for a symbol using kmemhelper interface. I see the value is not applied properly. What could be wrong"

A. The negative value might be detected my kmemhelper as an argument. To prevent that, use two minus signs (--) before the negative value.

Ex: "kmemhelper t int -n touch_boost_level -- -1" (This resets touch boost frequency to default).

28. "I wanna disable all the audio enhancement stuffs. How?"

A. In your script

echo 0 > /sys/class/misc/scoobydoo_sound_control/enable

29. "Least voltage for a CPU frequency I can undervolt to?"

A. 600 mV. Maximum = 1500 mV

30. "Does sound enhancements in stweaks applies to bluetooth headsets?"

A. NO. Only for wired headphones.

31. "Do we have temperature sensor in our CPU?"

A. YES

32. "I have this habbit of unknowingly pressing home button multiple times and that result in inverting colors on my screen."

A. Disable "mDNIe negative toggle under Screen tab in STweaks.

33. "I sometimes get unexpected reboots. What could be wrong?"

A. Number of reasons.

- Problem from ROM side - wrong dpi setting for an app, wrong build.prop tweaks, etc.

- Too much UV on CPU/GPU

- Too much CPU OC/GPU OC

- CPU/Battery heated up too much because of weather/benchmarking/faulty charger, etc

34. "I want to help dev debug an issue providing a kmsg. How to?"

A. After the problem (random reboot/freeze/lockup), do not pull out battery to recover. Just long press power button so that device can reboot. Then connect device to PC, (provided you have setup adb), type

adb pull /proc/last_kmsg

Save the file as .txt and post in the thread along with description of the problem and possible way to reproduce it.

If you can't use adb from pc, just copy last_kmsg file from /proc directory to internal sd, copy it to your PC and post in the thread.

35. "I'm not able to copy Person X's undervolting settings. Why? Sometimes, across different builds of Siyah, my UV settings are stable in one version and not in another. Why?"

A. One or more of the following

- Every device is different - diff grades of CPU

- CPU drivers might change across different builds

- Power requirements may differ depending on the temperature, altitude or the defaults.

36. "GPU OC/UC range?"

A. 54 to 700 mhz. With voltage range of 600mv to 1200mv at 25mv steps.

more might follow..