[Moto Z Guides, News, & Discussion] enetec:
Disclaimer: I know this could be a bit OT here, but these experiences could help my Z friends to avoid to brick their phones... so MODs, be patient... and read! :p

Yesterday afternoon I made my first "soft brick" of my "long" career... on an Oukitel C4! :rolleyes:

(...*great* phone for the price! ;))

I after fixed it in less than an hour (including download time... :p), BUT the interesting is *how* this happened.

I haven't done anything wrong BUT trust my TWRP... or, better, my twrp...

When I first time tested my new Moto Z I liked a lot the TWRP officially realized for it... now I'll explain better why.

There are some wide spreaded statements about TWRP (and recovery in general...):

- TWRP/recovery is not involved with normal system booting (e.g.: a not working one for-whatever-reason can't interfere with standard system boot);

- Kernel (boot.img) & system are not involved with TWRP (e.g.: you can even have formatted boot/system partitions and you can still boot to TWRP;

- boot.img & recovery.img are two partition where boot from in indipendent way. Normally of the same size. In some emergency cases, it is even possible to (with intention...) flash a recovery on boot.img to try to fix some soft bricks...

- more...

All these statement are often true *but* not ever, as I teach myself... the hard way! :silly:

If I should base my knowledge on what I've directly experienced on some LG (p880, d802...), Sony (X10 mini, Xperia U) and, *probably* on Moto Z, I will say they are right. Ever.

BUT then I've had some opposite experiences with other devices that I'll list with no comment for now:

- Samsung Galaxy Tab 10.1 3G: CWM recovery "hardly flicker" with some ROM versions become unusable. Fixed with successive update anyway...

- Samsung Galaxy Tab S 10.1 4G: both stock & TWRP recovery suffer of "black screen bug until timeout" only with Lollipop+ installed ROMs...

- Oneplus X: first version of TWRP available is able to boot and/or can be flashed only to phones with Lollipop until a xx release. After that release a new TWRP version is mandatory, otherwise it doesn't boot (and will be substituted by stock one if just flashed at first system boot) and system is booted instead...

- and now yesterday, Oukitel C4: double! :eek:

1. flashing TWRP interferes with normal system boot, giving a continuous bootloop. Only way to fix it is by flashing SuperSU, then the system boots up fine again! :eek:

This weird behaviour is reported/confirmed on a thread on 4pda forum too (if you know russian... :p)

2. flashing Magisk v.9 (that, as developer says "it modifies only boot.img"...) produces a bootloop too (different from the above). Ok, this can happens...

No problem I said "...I've my stock TWRP full backup just in case... ". Yes.... problem is that this time bootloop affects TWRP too! :eek:

Only way to fix: flash again stock boot.img by PC... (recovery don't even needed..!)

This last one is the one which worried me most, since this could be happen on Moto Z too, during my "hacking experiences"...

How all this could happen?

I don't know for sure... but I've some theories...

One is that while some TWRPs are developed to be "fully indipendent" from boot/system firmware (LG d802, Moto Z??) other (let's call them twrps...) are developed not only "based" on a specific system software version (and this is often "declared" too, but it wouldn't be a problem...) but probably "call" some boot.img parts too, becoming "system (kernel) dependent" to work...

My knowledge is not so deep to give a "certain" answer (and if somebody with the needed knowledge wants to correct me/explaim better is the welcome!), BUT on the meanwhile, try to use needed cautions... :fingers-crossed: