Walton Primo RX5 (Primo_RX5)

[rokibhasansagar]

Device: Walton Primo RX5 (Running on mt6735)
Codename: Primo_RX5
Recovery: TWRP 3.2.1 (Unofficial, Ported from Coolpad Note 3 Lite device.)
Recovery Source > http://zerodevelopers.blogspot.com/2018/01/twrp-321-coolpad-note-3-lite.html
Kernel: 3.18.19 (Stock)
ROM: Amigo OS 3.2 (Android 6.0, Arm64)
Partition Layout: Stock Factory Layout

Dump Log: repit-dump.log

I want to shrink /system (partition no. 20) a little bit and add that bit to /data (partition no. 22)
But /cache (partition no. 21) size will be same as previous

Please help.

[Lanchon]

hi,

some newer devices have a signed GPT (partition table). on such devices, altering the GPT hard-bricks the device. this is the reason i mostly stopped development of REPIT.

make sure you read this. you can try running the strings command on images of your bootloaders (or post the images here) to get hints on the situation of your device. strings can usually rule out signatures, but it can also result in false positives.

to recover from a hard brick you would need an image of your eMMC and the ability to program the eMMC with a JTAG probe. if you do not know what JTAG is, then assume you have no way to recover your device.

please decide whether you want to risk testing a REPIT port on your device.

thanks!

[Lanchon]

hi,

sorry for the long delay. are you still interested in this?

thanks!

[rokibhasansagar]

Actually, I'm sorry.
I couldn't get the strings command and fastboot isn't working on my PC 😣

And my device does not have any bootloader image or partition available.
Typical Old MTK chipset 😐

[Lanchon]

after looking at your partition table:

Number  Start     End       Size      File system  Name         Flags
        0.00MiB   0.50MiB   0.50MiB   Free Space
 1      0.50MiB   3.50MiB   3.00MiB                proinfo
 2      3.50MiB   8.50MiB   5.00MiB                nvram
 3      8.50MiB   18.5MiB   10.0MiB   ext4         protect1
 4      18.5MiB   28.5MiB   10.0MiB   ext4         protect2
 5      28.5MiB   29.0MiB   0.50MiB                lk
 6      29.0MiB   29.5MiB   0.50MiB                para
 7      29.5MiB   45.5MiB   16.0MiB                boot
 8      45.5MiB   61.5MiB   16.0MiB                recovery
 9      61.5MiB   69.5MiB   8.00MiB                logo
10      69.5MiB   79.5MiB   10.0MiB                expdb
11      79.5MiB   80.0MiB   0.50MiB                seccfg
12      80.0MiB   82.0MiB   2.00MiB                oemkeystore
13      82.0MiB   88.0MiB   6.00MiB                secro
14      88.0MiB   96.0MiB   8.00MiB                keystore
15      96.0MiB   101MiB    5.00MiB                tee1
16      101MiB    106MiB    5.00MiB                tee2
17      106MiB    107MiB    1.00MiB                frp
18      107MiB    139MiB    32.0MiB   ext4         nvdata
19      139MiB    176MiB    37.0MiB                metadata
20      176MiB    4144MiB   3968MiB   ext4         system
21      4144MiB   4544MiB   400MiB    ext4         cache
22      4544MiB   14893MiB  10350MiB  ext4         userdata
23      14894MiB  14909MiB  16.0MiB                flashinfo
        14910MiB  14910MiB  0.50MiB   Free Space

i'm assuming your last stage bootloader is the lk partition, harboring Little Kernel.

to pull the partition to your PC, you can boot TWRP, make sure you can connect to it using adb, and issue this command on your PC:

adb pull /dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/lk lk.img

you can then run strings lk.img or post the file here and i'll take a look.

otherwise you may want to blindly try REPIT and take the risk. your MTK device is old, it might not have a signed GPT, but there is always a risk.

[rokibhasansagar]

From earlier, I didn't thought that strings can be run onto almost anything, even from TWRP.
I don't have that much CLI knowledge 😐
But I'm advancing bit by bit ☺

But, as you said, I backed up lk.img and got the strings extracted.
lk.img.strings.txt

[Lanchon]

i didn't find references to GPT signatures in those strings, but that is not a conclusive test.

let's try directly finding a signature instead.

try this command on TWRP to dump the first 0.5MB of your eMMC, which has the GPT and possibly its signature:

dd if=dev/block/mmcblk0 count=1024 of=/tmp/gpt.bin

then adb pull the gpt.bin file and post it here (you might need to zip it or change the extension).

[rokibhasansagar]

I pulled it out using terminal emulator without going to TWRP. I hope that It's okay.
gpt.zip

[Lanchon]

i see the protective MBR, the GPT partition header, and 23 GPT partitions. no trace of any signatures. i believe this devices is not protected with GPT signatures.

REPIT should work on this device.

[Lanchon]

you can debloat your OS, shrink /system to whatever you can and shrink /cache to 32MB to gain space in /data.

however you seem to have a stock OS.

stock OSes are typically protected by dm-verity, which means that any change to the /system partition will make the phone not boot.

you need a kernel without dm-verity to modify the system partition.

once /system is modified, OEM updates will not apply (but on old phones there are no updates). for this reason, the /cache partition is not needed anymore.

if your OS has dm-verity enabled, you cannot use REPIT.

a system-less version of REPIT could be made for your device that ignores system and allows you to move space from /cache to /data. i don't think it is worth the trouble though.

[rokibhasansagar]

I do use Custom ROMs of Android Nougat a lot, but still prefer the old Modified Stock Android MM ROM (that I'm still using) very much.
I have removed the device data encryption by Factory Reset from TWRP, and also modified the System Partition a little. I also removed auto encryption of Data partition (in /etc/recovery.fstab, "forceencrypt >> encryptable") by making own TWRP from source.
And I guess dm-verity is removed by SuperSU.
So, no encryption issue should be left.

And yes, my OEM stopped giving OTA in the late 2017 😩
So, /cache is really not usefull, but shrinking it from 400 MB to 100~120 MB and keeping it is not that bad I think.

P.S:
I'm also looking for an extra suggestion.
My partition table don't have a separate /vendor partition space.
If you could add script to make a Vendor partition with only 200 MB after the shrunken System Partition as well, then the partition table would be one step ahead for Treble Implementation in the future (though I have no Kernel Sources available, but if I manage to make an Upstreamed one, hopefully, one day).