[Android General] rmleonard:
hmmmm.... I see both IDs --- MT8161P and MT6735

if I bring up "Z-DeviceTest" -- on the CPU page -- it says MT8161P, on the Android OS page --- it shows mt6735 and the Mali-T720 graphics chip

(and interestingly --- Z-DeviceTest says that the GSM/UMTS hardware is just waiting for a phone sim to be plugged in....)

>=> that is the main difference betwixt the 850F and the 850M right? one has the active phone slot and the other is wifi only?

almost done with my "helper" doc ---

---------- Post added at 10:00 AM ---------- Previous post was at 09:30 AM ----------

help needed!!!

I am trying to edit/update the TWRP image file such that in the 'default.prop' file all occcurances of 850M get replaced with 850F.

so fasten your seat belts and follow along -- and maybe you will figure out where I am making mistake.

to begin:

let us make a working directory "working" and place a copy of the TWRP recovery image there.

$ ls -l

total 12452

-rwxr----- 1 rmleonard rmleonard 12750848 Aug 1 08:27 twrp_3.0.3.img

so I'll be working with the [MENTION=6596524]jemmini[/MENTION] TWRP 3.0.3

Tools I know I'll need "abootimg"

(on debian/ubuntu - a quickie -- sudo apt-get install abootimg will take care of that)

and so we begin:

we'll extract the files inside of the twrp img file:

$ abootimg -x twrp_3.0.3.img

writing boot image config in bootimg.cfg

extracting kernel in zImage

extracting ramdisk in initrd.img

abootimg builds a "bootimg.cfg" file, and pulls out the kernel file and ram disk image

what we want is in the ramdisk...

so we make ramdisk subdirectory:

$ mkdir initrd

$ cd initrd

$ cat ../initrd.img | gunzip | cpio -vid

that will unpack all of the files and sub-directories in the img into our present directory.

that being done: now let's edit the default.prop file. It is in the "root" of the ram disk

(pick the editor of your choice -- I'll use nano in this example)

$ nano default.prop

we want to change all 5 occurances of 850M with 850F

(lines 44, 57, 58, 59, 60) - save and quit

now we rebuild the ram disk img and re-pack the twrp recovery img

still in the initrd directory...

$ find . | cpio --create --format='newc' | gzip > ../initrd_850F.img

now we go up a step and rebuild the main boot file

$ cd ..

$ abootimg --create twrp_303_rml.img -f bootimg.cfg -k zImage -r initrd_850F.img

reading config file bootimg.cfg

reading kernel from zImage

reading ramdisk from initrd_850F.img

twrp_303_850F.img: updated is too big for the Boot Image (12767232 vs 12750848 bytes)

the file is a different size than the original from the bootimg.cfg --- so we cheat a little bit

delete the file we just created and re-run the command as:

$ rm twrp_303_850F.img

$ abootimg --create twrp_303_rml.img -f bootimg.cfg -k zImage -r initrd_850F.img -c "bootsize=12767232"

reading config file bootimg.cfg

reading config args

reading kernel from zImage

reading ramdisk from initrd_850F.img

Writing Boot Image twrp_303_850F.img

taa-daa!

we now (in theory) have an updated twrp recovery file ---

in my case here though --- I get a "dead Andy" ---

to test the file ---

$ adb reboot bootloader

this brings up "Burt Reynolds Andy" -- all stretched out...

$ fastboot boot twrp_303_850F.img

downloading 'boot.img'...

OKAY [ 1.369s]

booting...

OKAY [ 0.062s]

finished. total time: 1.431s

this should download the boot.img file and boot into TWRP

I get a 3D dead Andy with a caption of "No Command"

I am guessing that a start address or something in the bootimg.cfg file has to get changed - but I don't know to what....

thoughts?

Other issues that are "bugging" me ---

how to I "unroot" the device?

when I run "fastboot oem lock" -- I get an error

The files from [MENTION=5862702]hempi[/MENTION]z ---

https://xdaforums.com/android/general/rom-lenovo-tab-3-8-tb3-850f-android-6-0-t3593043

will allow you to return to a "stock" state (as near as I can tell) --- but I can't relock the bootloader

boot into an external copy of TWRP ---

get Andy into the fastboot mode and from your prompt...

$ fastboot boot TWRP_FILE.IMG

that will push a boot image down the wire and boot without writing the image into the recovery partition.

now -- in TWRP ---

go into "WIPE"

then ADVANCED WIPE

check the boxes for

Dalvik/ART Cache

System

Cache

Data

Then Install (from the main menu)

navigate to where you have the 4 Hempiz image files

boot.img, logo.img, recovery.img, system.img

select them one by one and install them to the appropriate partition.

Boot.img goes to Boot

logo.img to logo

recovery.img to Recovery

system.img to System Image

after you've rebooted and gone through the configuration - you can go back into the external TWRP and install SuperSU (I've installed SuperSu - SR3)

So ---

How do we "re-lock" the tablet?

Why won't the tablet take the OTA update

It is possible that I've mixmastered so many attempts of installs that I've "broken" something and it won't do the OTA downloads and installs anymore ---

Any ideas here?

Any other Questions I can help with?

Rich Leonard