Root Checker Tool (RCT) Analysis

Hey guys,

So there are some on the H810 G4 that are having trouble updating to AT&T's 10o software after having rooted 10i. Based on some old forums for the G2, we have a hunch that it comes down to a flag in /persist/rct, which is nothing more than a set of 4 Hex keys. I am wondering resetting this key to look like an unrooted phone will get us past the failure during the OTA where it stops due to root suspected (error 0x1123004, around 5% through the OTA).

If you are reading this and happen to be unrooted, would you mind posting in the comments the values in your /persist/rct? Maybe there is a common set of keys that stand for "unrooted".

The file is hidden to non-root people, so getting the file is a little tricky. Basically, follow the steps in Part 1 (aka Step 1) of http://forum.xda-developers.com/g4/g...-root-t3180586, but replace Step 9 with the following command, instead of the one it tells you to go get:

Quote:

dd if=/dev/block/mmcblk0 bs=8192 skip=18432 count=4096 of=/data/media/0/persist.img

Note that all you are doing here is backing up the /persist partition to your sd. Once done, you can mount the .img in Linux and extract /persist/rct. Open with a hex editor and paste the 4 keys below (but first, can someone provide any opinions on if this hex key is unique to our device? Would it be unsecure to post it here?).

If you don't have Linux, I am sure there is an app out there to let you mount the .img in Windows.

Alternatively, the LG G2 also had a loop hole where you could add a file called "RCT_security" to /sdcard with the value "forel.lee" in it. This would somehow tell rctd (the rct daemon) that you were unrooted. I am going to try this but am not holding my breath.

Let me know what you guys think!

Sent from my LG-H810 using Tapatalk

Xiaomi Mi 4c Charging Analysis Part-2

Last month we finished the Xiaomi Mi 4c Charging Analysis Part-1. Today we continue to check the charging performance on Xiaomi Mi 4C.



You should read a lot of Xiaomi Mi 4C reviews from different sites, but as a brand which concentrates on chargers, Tronsmart focuses on different chargers’ charging performance for Xiaomi Mi 4C. We will test the original power adapter, suggest how to quickly charge your device, and help to pick up the correct alternative chargers.

In the following analysis, you will see we test with regular 5V/2A charger ( no quick charge), and original xiaomi charger (support quick charge 2.0), also tronsmart charger(support quick charge 2.0).

Here we go:

The specification of Xiao Mi 4c original power adapter:

INPUT : AC100-240V
OUTPUT: DC5V/2.0A , 9V/1.2A , 12V/1.0A,max 12W
Type-C male to USB2.0 A male 1.0 m Cable



We are the first time to see the 12w quick charger. We even doubt if this is certified quick charge at first, because, Our quick charge are all 18W, support 5V/2A, 9V/2A, 12V/1.5A. After check on qualcomm site, we found, this charger is really certified by qualcomm, xiaomi should consider the cost and use this 12w solution, In this area, more volt means more cost.

Now, let’s do some real test to check the performance:

1)Test with the above xiaomi 12w quick charger:

Total Charging time from battery 0% to 100% is 2 hours and 7 mins with the original charger.


When we first connect the charger, the Mi 4c and the charger have the “communicate” and directly change the charging volt from 5V to 9V. and in the whole charging time, the volt is always keep in around 9v to make sure get the fastest charging speed.

In the first 10 mins, it can charge the Mi 4c from 0%-14%, it’s fast! and after 30 mins, Mi 4c get 34% battery. It take about 1.5hours to get 90% battery, but for the rest 10%,it take another 30 mins.

The charging current is becoming smaller as the battery is full.

2) Test with the regular 5V/2A 10W charger(no quick charge support) , We use the original charger from Oneplus 2.

The total charging time for Mi4c from 0%-100% is about 2H 43min.

The original adapter of OnePlus Two is built-in standard 5V/2.0A output power, don’t support Quick Charge. So the charger just can give 5V volt to Mi 4c.

In the first 10 mins, the mi4c just get 9% battery, and 30mins later, it has 26% battery. Which is slower than the xiaomi’s quick charger.

3) Test with Tronsmart QC 2.0 Wall Charge (18W)

We are a big surprised by the result, at first we thought our 18W charger should make it faster than the xiaomi’s 12w charger, however, from he above test, we found, the charging time is almost the same, Xiaomi must limit the total watt which Mi4c can hold. Our charger can successfully “communicate” with Mi4c, and change the charging volt to 9V, however, the current can’t go up than 1.2A. total watt is still lower than 12W.


For the same charger, we test in zenfone 2, it can give 16w. so it’s not our charge problem, but Xiaomi make some limit.

4)Test with Tronsmart Type-C Car Charger
Because our ammeter don’t have type c female port, we can’t read the volt/current in the charging, but we can see the charging time, and battery change.
Total charging time with our type c for mi 4c is just 1 hour 58mins. It’s the best result in all of test!




If like we talked above, xiaomi limit the charging power, why our tronsmart type c charger still can make it a little faster?

Our engineer did some analysis, and find because our charger with built-in type c cable, it can reduce the power consumption effective, so the total charging speed is better than original charger, even usb port wall charger. But since xiaomi limit the total charging power, we still can’t improve the charging speed a lot, just 7% from the analysis.

Conclusion

1)XiaoMi 4C is the few device which support Type C and Quick Charge 2.0 technology together.

2)The Charging performance is not as good as we expected, thought 2 hours 7 mins fully charge is not a very bad result, but we are very upset to see xiaomi did some trick in the charger, even they state it support quick charge 2.0, however, the total power just 12W.

Check OnePlus 2 charging analysis, Though it don’t support quick charge 2.0, the battery is also bigger(3300mA) than Mi 4C(3080mA) , The total charging time for Oneplus 2 just 2 hour 10mins. Almost same as the XiaoMi Mi4C (2 hours 7 mins) , which claim to support quick charge 2.0 technology.

So some suggestions for the Xiaomi Mi 4C users:

1)Use quick charger to charge Xiaomi Mi 4C instead of the ordinary charger. Tronsmart offer the world’s most abundant quick chargers. From 1 port usb wall charger to 5 port and from 1 port usb car charger to 4 port.

2)A charger with built-in cable can reduce the power consumption. Suggest to buy charger with such form preferentially. If you need a car charger for your xiaomi mi 4c, Tronsmart type-c car charger will be a good choice for you.

About Tronsmart

As the world’s leading Quick Charge accessories brand, Tronsmart designs and builds a complete Quick Charge product line including wall, car and desktop chargers. All Tronsmart products have passed Qualcomm Certification and are the featured quick charger brand on Qualcomm official site.

Source:http://www.tronsmart.com/xiaomi-mi-4...lytisis-part-2