How to upgrade a Trio Stealth 7 (Model 7c A13) From ICS to JB

A couple weeks ago, I ran across an amazing deal for a cheap 7 inch android tablet. I had been thinking about getting a tablet, but hadn't bitten as I'm saving up for other things at the moment. However, this particular tablet was $20 after rebate, so I couldn't pass it up.

When it arrived, I was surprised and pleased to find ICS (Ice Cream Sandwich aka Android 4.0) installed, and the tablet was pre-rooted. This meant I could do whatever I wanted to it. My first thought was to find a ROM update to install Jelly Bean (Android 4.1).

After much painstaking research, I determined that my Trio Stealth Pro 7 has several sub-models. My particular model lacks an HDMI port, and the architecture is different enough that most ROMs wouldn't work. The Trio Stealth Pro is a clone of the LY-F1 tablet, which uses the Allwinner A10 chipset (though in my case, it was the A13 chipset). To install a new firmware, you use software called LiveSuit (local / mirror), a Windows-only program. There is a Linux port, but it didn't work for my model (likely because I have the A13 chipset).

Compiling the A13 Rom

Here are the full directions to install Android 4.1 onto the Trio Stealth Pro 7c A13 tablet. This requires a Windows computer, as most or all of these tools are Windows only. A lot of these instructions were copied or modified from a forum post here.

If you simply want the final output, download the attached jb_final.img file. Then go to the LiveSuit section of this post.

ImageSuite Extract

The first thing to do is download the base image for Android 4.1 (local / mirror).

Next, download ImageSuite (local / mirror {free registration required}). This program will extract (and later repackage) the LiveSuit-formatted image so that we can modify it to our needs.

After uncompressing ImageSuite, open a command prompt and run extract_img.bat DOWNLOADED_IMAGE.img. Now you should see a folder with the image unpackaged.

Modify the repack_ics file in the ImageSuite folder. Type "REM" in front of each of the last two lines to comment them out.

Magic ISO Extract

Download and install Magic ISO (local / mirror).

Next, run Magic ISO. Browsing to the newly created unpacked folder, open the RFSFAT16_BOOTLOADER_00000" file and extract script.bin and script0.bin.

Unscript and Script

Download Unscript (local / mirror {free registration required}). This decompiles the config files into a text format that can be edited.

In another command prompt, run unscript.bat to decompile script.bin. Output is sys_config1.fex. Edit this in a text editor (notepad, Notepad++, etc).

Modify the gsensor_direct_x setting - change from 1 to 0. This fixes the gyroscopic sensor so that portrait view is not upside-down.

Search for P? - replace with power. This fixes an error from the unscript.bat code; without changing this, the script.exe fails.

After saving the fex file, use script.exe to recompile the file. Rename the original script.bin to old_script.bin, and rename sys_config1.bin to script.bin.

Repeat for script0.bin.

Magic ISO Overwrite

Back in Magic ISO, copy the new files over, replacing the old ones. Remember to click save to save the image changes.

Text Editor

In a text editor, open COMMON _SYS_CONFIG100000. You only need to change gsensor_direct_x, no need to search and replace P?. Save the file.

ImageSuite Repackage

Finally, use ImageSuite repack_ics.bat image.img.dump to create a new image file, which will be called image.img

LiveSuit Flash

Install LiveSuit. During the install, it will require drivers that are unsigned; go ahead and ignore the warning Windows gives you.

Use LiveSuit to flash the image you created (or the jb_final.img image if you downloaded the end result). First, open LiveSuit, select no, then select the image. Make sure your tablet is turned off and disconnected from the computer. Press the Volume Up button, then hold it. While doing that, plug in the usb to the computer and quickly (within 3 seconds) press the power button 10 times. LiveSuit will ask to format the device. Say yes twice.

After the rom flashes, the device will boot up. Congratulations, you have Jelly Bean! Continue to the next section to gain root (as this image doesn't come pre-rooted).

Root

Download Uberizer (local / mirror), which will be used to gain root on the new image.

Use Uberizer to root the device. With the tablet booted, plut it into the computer. Run Uberizer, and after it detects your device, type in c {ENTER}, then 10 {ENTER}. This will cause your tablet to reboot a couple times, and then you will have root.

Change Screen Density

Optionally, you can modify the screen density setting so that icons are a bit smaller and the tablet feels larger.

Run Uberizer, and type b {ENTER}, then 2 {ENTER}. This will grab the build.prop file.

At the end of the file, add the line ro.sf.lcd_density=120. Save and close the file, then push the file back to your device when Uberizer asks.

Known Issues

• Volume Down key maps to the Back action. I tried modifying all of the keylayout files, but I couldn't change this. But all tablet UIs have volume soft keys in the menu.
• Volume Up key maps to the Volume Down action. Again, I couldn't figure out how to fix this.

Finished!

Enjoy Jelly Bean on your tablet! I know I do. Other than the volume key mapping issues, I have been running this Rom with very few issues. Sometimes it feels sluggish, but I chalk that off to the tablet being a cheap chinese knock-off. Feel free to comment below about your experiences or if you have questions.