[Wear OS General] Mr.Jlu:
I have good news, I was able to solve this issue for TicWatch Pro 3 ULTRA GPS.

Below are the steps I followed.

Prerequisites:

i) TicWatch Pro 3 ULTRA GPS should be on official PMRB.220703.001 build.

ii) Modified USB cable to make connection with the Watch

iii) Linux based OS

iv) Basic understanding of Linux based file structure

Credits:

If you are interested on how imgpatchtools works then you can checkout the following video.

Demo:

Repo: https://github.com/erfanoabdi/imgpatchtools

Process:

1) Download the STOCK rom for PMRB.220111.001 from the following link:

1007.68 MB file on MEGA

mega.nz

Reference: https://wear.lunawolf.es/en/OneOSWear/downloads/rubyfish/

2) Download the OTA update for PMRB.220703.001 from the following link:

https://xdaforums.com/attachments/official_ota-update_rubyfish_pmrb-220703-001-zip.5684255/

Reference: https://xdaforums.com/t/hacks-trick...gen-xiaomi-oppo-suunto.4233055/post-87274937/

3) Copy the system.img from

PMRB.220111.001

and copy the system.new.dat, system.patch.dat and system.transfer.list from

PMRB.220703.001

to a separate folder in this case we shall name it 220111_system_image.

4] Clone the following repo and build it using the following command:

git clone https://github.com/erfanoabdi/imgpatchtools.git
cd imgpatchtools
make
cd bin
./BlockImageVerify 220111_system_image/system.img 220111_system_image/system.transfer.list 220111_system_image/system.new.dat 220111_system_image/system.patch.dat

performing verification
creating cache dir cache
cache dir: cache
blockimg version is 4
maximum stash entries 0
creating stash cache/537ed49fb5f6c32dc3d205d78b6084fe54f70cd3/
verified partition contents; update may be resumed
rmdir "cache" failed
deleting stash 537ed49fb5f6c32dc3d205d78b6084fe54f70cd3
Done

./BlockImageUpdate 220111_system_image/system.img 220111_system_image/system.transfer.list 220111_system_image/system.new.dat 220111_system_image/system.patch.dat

...
..
.
zeroing 1024 blocks
zeroing 678 blocks
zeroing 3115 blocks
wrote 250171 blocks; expected 250171
stashed 176540 blocks
max alloc needed was 9302016
deleting stash 537ed49fb5f6c32dc3d205d78b6084fe54f70cd3
Done

If you get the above output, then Copy the system.img to another folder let's name it 220703_system_image

5] Download the OTA update for RMRB.231020.007 from the following link and save it in the folder by the name wearos_3.5_OTA_update :

update.zip

This file has been shared with you on pixeldrain

pixeldrain.com

Reference: https://xdaforums.com/t/guide-ticwa...3-5-for-open-bootloader.4647312/post-89362530

6] Copy the system.new.dat, system.patch.dat and system.transfer.list from

wearos_3.5_OTA_update/update.zip

to the folder 220703_system_image.

7] Again run the following commands to build system.img of RMRB.231020.007

./BlockImageVerify 220703_system_image/system.img 220703_system_image/system.transfer.list 220703_system_image/system.new.dat 220703_system_image/system.patch.dat

performing verification
creating cache dir cache
cache dir: cache
blockimg version is 4
maximum stash entries 0
creating stash cache/537ed49fb5f6c32dc3d205d78b6084fe54f70cd3/
verified partition contents; update may be resumed
rmdir "cache" failed
deleting stash 537ed49fb5f6c32dc3d205d78b6084fe54f70cd3
Done

./BlockImageUpdate 220703_system_image/system.img 220703_system_image/system.transfer.list 220703_system_image/system.new.dat 220703_system_image/system.patch.dat

...
..
.
zeroing 1024 blocks
zeroing 1024 blocks
zeroing 144 blocks
wrote 353415 blocks; expected 353415
stashed 9174 blocks
max alloc needed was 20664320
deleting stash 537ed49fb5f6c32dc3d205d78b6084fe54f70cd3
Done

If you get the above output, then Copy the system.img to another folder let's name it 231020_system_image

8] Now reboot into bootloader mode and unlock flashing.

fastboot oem unlock

Watch reboots, bring it back into bootloader mode

fastboot flash system 231020_system_image/system.img

9] Now reboot into bootloader mode and let relock the bootloader.

fastboot oem lock

Watch reboots, bring it back into bootloader mode and boot into recovery mode

10] Within the recovery mode, select Apply update from ADB and sideload the OTA update file of RMRB.231020.007 which you had downloaded eariler.

adb sideload wearos_3.5_OTA_update/update.zip

11] If everything goes well, your watch should be updated and you can proceed to select Reboot system now.

Note:

If you want do not want to build the system.img used in Step 8 then you can you download it from the following link. I am not sure for how long this link will be active.

system.img

This file has been shared with you on pixeldrain

pixeldrain.com