This mod was made thanks to the help of: @tys0n
Tested on Samsung A30 (SM-A305G)
The warning message that appears when you turn on the cell phone after having unlocked the bootloader and rooted the phone with Magisk Canary is really annoying.
However, with the help of an XDA member, I have learned to modify the bootloader param.bin file and then flash with ODIN.
For ROOT users, I am not responsible for damages, or loss of the guarantee or data of your cell phone. If you proceed with this tutorial ... you are accepting that you do it at your own risk according to your previous knowledge:
Download the correct firmware of your Samsung from SAMMOBILE (A10, A30, A50, etc).
Unzip the firmware files with an extractor (winrar, etc)
Open the BL file WITH 7-ZIP EXTRACTOR (example) BL_A305GUBU2ASF2_CL16214341_QB24234542_REV00_user_ low_ship.tar.md5
Extract the param.bin.lz4 file WITH 7-ZIP EXTRACTOR
Open the param.bin.lz4 file WITH 7-ZIP EXTRACTOR and extract the param.bin file
Extract param.bin WITH 7-ZIP EXTRACTOR. Here some images are extracted in a folder.
Look for the jpg image: booting_warning (contains the yellow triangle image and red bootloader unlock warning text). We will replace this image later with a black one. Attached file 870x 473 pixels:
OPTIONAL: The svb_orange.jpg file (1080 x 2340 pixels) contains the warning message with the option that says PRESS POWER KEY TO CONTINUE. If you want you can change it to an image identical to the boot or leave it unmodified. In my case I changed to another image in which I added the google logo:
Open param.bin with 7-zip and replace booting_warning.jpg and svb_orange.jpg (optional) by dragging the files into the window.
Close 7-zip, now you have modified param.bin.
Convert param.bin to TAR format to flash with ODIN: Select param.bin, right click, choose 7-zip ZS, then add to the file, finally click on file format and change to tar. Accept (OK) and ready we will have the param.tar file ready for ODIN.
Open ODIN 3.13.3, start your phone in download mode, load the param.tar file in the BL section and click on start.
Note: At the end of the flashing with ODIN the phone restarts showing the modified image, but it starts in recovery mode, you just have to accept restarting the phone, and it will start normally without losing data or the configuration of your Samsung A30.
OTHER BOOTLOADER UNLOCK IMAGE (rename to svb_orange):
I hope it is very useful. Param.tar archive mod for Samsung A30 SM-A305G: