The Challenges of Installing a Tablet ROM: Why Is It So Hard?
If you’re a regular MakeUseOf reader, you’re probably no stranger to replacing the original operating system on your computer with another. We’ve covered Linux on Macs , macOS on PCs , and Windows on barebones systems in prior posts.
But what about tablets? They’re just like smaller and thinner notebook computers, right?
Actually, a number of differences make installing a new operating system on a tablet more complicated. In this article we’ll look at some of these challenges.
How Tablets Differ From Notebooks and Other PCs
Before we dive into the specifics let’s consider how tablets are different from computers.
PC users can add different components to their machines at their whim. In contrast, devices like tablets are more like consumer electronics. In order to provide a fault-free experience, manufacturers control what hardware can go into the device. It follows that when manufacturers don’t need to worry about accommodating all the different hardware a user may try, they don’t need the software side that interfaces with that hardware.
And this is the main difference. PCs (most, anyway) are expandable and customizable systems. Tablets try to provide users with a specific function (even if that function is a fairly standard computing experience). And the software that comes with tablets has a lot more in common with device firmware (despite the inclusion of an operating system, e.g. Android).
Note: While I’ve used the term “tablet,” the following also applies to most phones and other types of devices running Android, for example the NVIDIA Shield console . While the concepts also apply to iOS devices, they can all be remedied by jailbreaking the device.
How to Prepare Before Replacing Your Tablet’s OS
While some tools such as ClockworkMod’s ROM Manager provide a point-and-click method to swap ROMs around based on your device model, you may need to do so by hand. Let’s look at some of the things you’ll need to prepare for prior to starting.
Tablets Don’t Provide Root-Level Access by Default
We’ve covered how to do this in our in-depth guide on rooting Android phones . In a nutshell, most devices don’t allow you access to system files, only your own data and apps. “Rooting” a device is the simple process of granting full read/write access to those files and directories.
Jailbreaking your iOS device or using an application such as SuperSU for Android will grant access to these system files. Gaining root access can make backing your device up much easier, with more sophisticated tools.
Pro Tip: Unlock root-level access. Seriously. If you want to change your OS, you’re already altering your device in a big way. Gaining access to these files is pretty tame by comparison.
Tablet Backup and Restore Isn’t Straightforward
As with any OS replacement, you should first back-up your existing system and make sure you can restore it if something goes wrong. On a PC, this can be as simple as cloning your hard drive or backing up select pieces of your system using software tools .
But on an Android tablet, the system lives on a few different partitions within the device’s memory, including:
- The boot partition, which contains the kernel and other data needed to start up the system.
- The system partition, which contains the bulk of the operating system such as applications and libraries.
- The recovery partition, which contains the tools needed to reset the device back to a “factory” state.
The above image shows Android app DiskInfo illustrating details of partitions like boot and /system. Some device models may have others that are important for backup purposes. You should confirm what these are and back them up before trying out a new tablet OS. Since all these partitions can be overwhelming, consider using some special tools. You can do it all at once with a NANdroid backup , or use one of the more powerful backup tools (both of these require root access).
Pro Tip: Make sure you’ve taken a backup of your device that can be easily restored.
Tablets Have Locked Bootloaders
In order to install an OS, you will typically boot your computer into some sort of installer. This may be a recovery disc you received with your hardware or a thumb drive you created yourself . Regardless, both the venerable BIOS and the modernized (but annoying) UEFI allow the user to boot other operating systems on some level.
But manufacturers typically lock the bootloader on a tablet, and you will need to unlock it. Some manufacturers provide applications to do the unlocking for you, while other devices have easily accessible commands to do so. Nonetheless, you’ll need to unlock that bootloader in order to install a new ROM.
Pro Tip: Ensure you have the right bootloader unlock tool for your tablet model. And before you start, understand what the consequences of using it are (e.g. voiding your warranty).
System Software Installation for Tablets Requires Care
With desktop and server operating systems, the installer is a sophisticated program. It can catalog a machine’s hardware, take some user input on what they’d like to do, and configure drivers or software as a result. Device makers know exactly what the hardware is going to be, and they’re defining the experience. They just need to push that OS to the device’s memory.
This involves the use of low-level tools like ADB or fastboot . One function of fastboot is writing system images, byte by byte, to the device flash memory. You’ll probably find yourself copying and pasting detailed commands like the following:
fastboot flash recovery twrp.img
Be very careful when entering these commands: if you were to replace “recovery” with “bootloader,” it might try to overwrite the boot partition with an image that’s too large. Then when you reboot, there’d be no valid bootloader and it’d time to break out the backups.
Depending on your ROM, you might issue commands like the above for:
- the bootloader,
- the recovery image (a sort of minimal system like when using the Windows Advanced Boot Options or Safe Mode ),
- and the system itself.
Otherwise, the recovery image provides tools to update the device’s ROM. At this point you should have little trouble copying ROM files to your device, flashing them with the recovery tool, and testing them out.
Pro Tip: Find a tutorial for your exact device model and copy/paste the commands carefully. For more precision (and confidence), look for two tutorials with similar content, and use the easiest to understand.
Do You Still Want to Brave a Tablet Upgrade?
While the rewards of installing a fancy new tablet OS are tempting, bear in mind that it’s a delicate process. There is very little hand-holding when it comes to these operations, and just about anything you do above will cancel your warranty.
However, if you want to delve in, XDA Forums are great place for Android owners to start. They’ve got specific steps on rooting, unlocking, and more, for just about any Android device model. iOS users can head to the Jailbreak and iOS Hacks forum over at MacRumors, another information goldmine.
Are you ready to dive into the world of custom ROMs and unlocked devices? Have you been burned by an upgrade process gone wrong? Let us know if you think it’s all worth it in the comments below!