The Samsung Galaxy J7’s hardware looks great from the outside, but without the software that you see on the device’s display after turning it on, it wouldn’t be able to do very much.
That software that you see when the operating system boots up is also what is known as a “ROM.” The ROM, or stock ROM as most people like to call it, is made by Android.
The very foundation of Android is actually Linux, which is another operating system in itself. If you know anything about Linux, then you’ll probably also know that there are lots and lots of different “distros,” which is short for a Linux distribution. All up there are about 50 Linux distros that you can choose from, and all of them are free.
The Android operating system doesn’t offer users a choice between distros, or anything else for that matter by way of customization options. The software and choices that you see from the Settings app is what you get, and that’s all there is to it. If you wanted to use different software you’d have to look at installing a custom ROM.
A custom ROM is custom software that has been made by third-party developers. It’s still always based on Android because the developers are playing with the Android open source code, but after using the Android foundation, the features can then be changed or just removed.
You’ll find some custom ROMs out there that have completely changed the design, have added heaps of new features, have added changes to customize what you see, or just different ROMs that have removed the manufacturer skins and system applications that were put there by the manufacturer and phone carrier networks.
Details of Note
- The custom recovery images available in this guide are only to be installed on the Samsung Galaxy J7 (2015 Qualcomm Sprint) smartphone. Most devices have a custom recovery image developed specifically for it, and you shouldn’t install one that is intended for another device unless advised it is okay by a professional.
- The codename for the Samsung Galaxy J7 (2015 Qualcomm Sprint) TWRP Recovery image is “j7ltespr.” You will see that codename in the TWRP image file path and also from your About Device menu so you know you are flashing the right file on the right device.
- You can find the device tree files over at its GitHub page.
- You can install the official TWRP Recovery application from the Google Play Store or from the TWRP website as an apk, if you have root access on the device already, and get the TWRP installed that way, no adb required. Once the app is installed, it will be in your Downloads folder. Navigate to the Downloads folder and select the TWRP application. When the application opens tap on the option for flashing the TWRP.
- Download on your computer the latest version of TWRP Recovery: Primary (Americas) | Primary (Europe).
How to Install TWRP Recovery on Samsung Galaxy J1 Ace (SM-J110)
1. Firstly, you need to know that the Odin flashing tool is really easy to use, but it only works on the Windows operating system. You won’t get the flashing tool to load on a Mac or Linux computer. It doesn’t really matter what version of the Windows operating system that you’re using as long as it is something above Windows XP.
2. Download and install the Samsung USB drivers on the computer if you don’t have them already.
3. Download the stock ROM from the links above directly to the computer. Extract the file by right-clicking on it and choosing the option to extract. When you do, you’ll see the tar.md5 file inside. That’s the file you’ll be using to do the flashing.
4. Download the Odin flashing tool. It doesn’t really matter what version, but the latest is the most up to date so grab that one. Extract the Odin file and then double-click on the Odin executable file (.exe) that is found from within the Odin folder after extraction. You should now have the Odin interface open on the computer and waiting for you to connect to it.
5. Boot the Samsung mobile device into the Download Mode by first powering it down and then rebooting by holding the “Volume Down + Home + Power” keys at the same time.
6. A yellow warning triangle will come up on the device’s display. At this time you need to press the “Volume Up” button. You’ll then see the device getting into the Download Mode. It’s then ready for the flashing.
7. When in Download Mode, connect the Samsung mobile device to the computer with the USB cable.
8. If you have installed the USB drivers correctly, the Odin flashing tool should detect your device. You can tell this by observing the ID: COM port lighting up with a color, usually yellow or blue. (It doesn’t matter what color, it’s the lighting up that counts.)
9. After the device is picked up by Odin, click on the “PDA” or “AP” button, depending on what button your version of the Odin flashing tool has.
10. Navigate to the stock ROM folder and upload the tar.md5 file to this location in Odin.
11. Without changing any of the default settings, click on the “Start” button in Odin, and the flashing then begins.
12. Wait until Odin shows a “Pass” message before disconnecting your device.
TWRP App Installation Method (Root Required)
If you decided to download the TWRP application from the Google Play Store or the APK file from the official TWRP website, then after you open the application you will be given a few different options to choose from. But before even going that far, it’s important to note that you should only install the TWRP APK file from the official TWRP website. If you’re installing it from Git, or any other file hosting website, it might not be the official version, and thus, it won’t have been built or tested by the official TWRP developers and maintainers.
Once the application is open, you’ll need to agree to not hold anyone from TWRP responsible for any issues that your device may face while using the application. This is a standard disclaimer that Team Win puts on top of each of the recovery image files from the official website as well, so it’s nothing new. It just explains that it is your decision to put the custom recovery on your device, and while they work hard to provide a quality product, there are no guarantees that your device isn’t susceptible to damages relating to TWRP while the custom recovery is installed. You can grant the application root permissions now as well. Root access can be obtained by flashing SuperSU, or other appropriate rooting files, from the custom recovery itself. Without root, you won’t have access to some of the app’s features, such as image flashing. It’s here also where you can enable InsightCore (a feature to monitor and record the network performance of your device).
Once you’ve accepted the agreements, you’ll see the TWRP application’s home screen, where you can choose to flash TWRP or view the network statistics. When choosing to flash the custom recovery, you’ll need to scroll and select your device from the list to make sure you are flashing the correct file. When the device is chosen, the TWRP application automatically then searches for the latest version of the TWRP for that device and will continue doing so every day for as long as the app is installed. This interval can also be altered from the Settings in the top right-hand corner of the device’s display when the apps open.
If root access has been enabled, you’ll see the chance to select the custom recovery image and the buttons for flashing the images to boot or from recovery. You should choose to flash the images to recovery. Only use the boot image flashing when you are flashing full boot images, not just kernel zimages.
DD Installation Method
You can also get the custom recovery installed on the Samsung Galaxy J7 Exynos SM-J700 smartphone by using the DD install method. To do it this way, download the latest recovery image file for your device from its downloads page on the official TWRP website (Primary [Americas]| Primary [Europe]) and then place the file in the root of your /sdcard folder. Rename the image “twrp.img.”
You then need to run the following commands from the ADB shell or a Terminal Emulator application:
dd if=/sdcard/twrp.img of=/dev/block/bootdevice/by-name/recovery
After you’ve installed the custom recovery image, you should be good to start using it for the duration of your devices life. If ever you get a message that states that there is “no OS installed!” then it probably means that you have, in some way or another, managed to delete the system partition. This is not a good thing, given that making changes to the system partition and then going back to the stock Google Android firmware can cause you to experience unexpected behavior. Nevertheless, it is also not the end of the world. If you’ve taken a backup before, then you should be able to restore it, and when that happens, you’ll have the system partition and operating system as a whole, working on the device again. If you didn’t take a backup yet, then you should still be able to flash a stock ROM on the device, which will then remove the custom recovery image but give you the operating system and system partition back. Flashing the stock ROM in this instance is not the ideal way to go about it, due to the complications that can arise.
Official Google Android software updates, whether they be OTA updates or just firmware files flashed manually, are not supported by custom recovery images such as TWRP. When you find over-the-air updates arriving to be installed, usually they are differential updates, which means that they don’t necessarily replace the entire files, and can instead just do patchwork over the top of existing files. This is a good thing for the data-continues user, but it also means that anyone who has modified the system partition with root access, BusyBox or any other way, like removing the system applications that are hiding in the system partition, could experience unexpected behavior after installing a differential update.
Installing an official software update usually takes away root access and custom recovery images. Instead of doing that, you should consider installing custom software if you’ve already got a custom recovery image installed on your device. Most custom ROMs are available within a few days of the official updates, so you should have no issues finding a ROM for the Android version that you’re looking to try.
If, however, you are certain that you would like to remove the custom recovery image and replace it with a stock recovery again, there are ways for you to do that as well, provided you’ve already read and understood the risks. There isn’t technically a way to delete or uninstall the custom recovery; instead, you need to just flash another one over it. To do that, you can find the stock recovery image file inside as part of the stock ROM zip files after unpacking it. You may then flash the recovery image file using the same method for flashing the custom recovery image. If that’s too complicated, the alternative is just to flash the entire stock ROM file using the appreciate flashing tool for your device, which in the case of anything Samsung, is the Odin flashing tool.
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