Tag Archives: Android

Upgrade your Nexus 5 using factory images without wiping your data

This is a tutorial how you can upgrade with Google’s Nexus factory images without wiping your apps or sdcard, based in a post I found in reddit.

This guide can be easily adapted to other Nexus devices.

NOTE: You must have your bootloader unlocked. If you’ve never unlocked your bootloader, I don’t know there’s any way to do this without wiping your data.

WARNING: If you’re moving between ROMs, you generally should do a complete reset, including wiping data. Many users have reported problems going from Kitkat to Lollipop without wiping data and recommend a factory reset anyway. If you’re okay with wiping everything, you can simply use Google’s included flash-all scripts, or flash the userdata.img file yourself.

STEP 1: Install fastboot and related software

Fastboot is Google’s utility for flashing factory images. You can also use it to flash custom recoveries like TWRP and CWM. The standard way to get is is through Google’s Android SDK, but that’s a bit heavy-duty, so you can also download just the most important tools (fastboot and adb) separately, packaged by users. Here are some links:

Official Google Android SDK (cross-platform): http://developer.android.com/sdk/index.html#Other
Unofficial for Windows: http://developer.android.com/sdk/index.html#Other
Unofficial Mac/Linux: http://code.google.com/p/adb-fastboot-install/
Windows users might also need to install drivers: http://developer.android.com/sdk/win-usb.html (can any Windows users confirm whether it’s necessary?)

To check if the adb is detecting the device, just plug the USB to the computer and write the command inside a terminal:

$adb devices -l

You must see your device listed

Custom recoveries are extremely useful for rooting your phone, installing system tweaks, creating backups, and troubleshooting problems. There are two main options: TWRP and CWM. These are the instructions for the one I use:

Root your phone: In case you would like to do that (you can find arguments here), download the latest SuperSU on your phone from: http://download.chainfire.eu/supersu

STEP 2: Prepare factory image

STEP 3: Flash the new image

  • Connect your phone to your computer via USB, and enter the bootloader. You can enter the bootloader in two ways:
    1. by holding down the power and volume-down buttons to boot. Once you see the bootloader, you can release the buttons.
    2. Running the command:
      $adb reboot bootloader
  • The following syntax might be slightly different on Windows than on Mac or Linux, but basically the same. Anything you see in <> you need to replace, e.g. with the actual path to your factory image folder. The rest you should be able to copy and paste. (Tip: you can easily enter a folder path into your terminal/command prompt by simply dragging the folder onto your terminal window. This works on Mac, Windows, and the vast majority of Linux GUIs.) Enter these commands:
cd </path/to/downloaded files>
$fastboot flash bootloader bootloader-hammerhead-*.img
$fastboot reboot-bootloader
$fastboot flash radio radio-hammerhead-*.img
$fastboot reboot-bootloader
$fastboot flash boot boot.img
$fastboot flash cache cache.img
$fastboot flash system system.img
  • If you DO NOT use a custom recovery (like TWRP or CWM), then also:
$fastboot flash recovery recovery.img

Don’t worry if you see messages like “target reported max download size of 1073741824 bytes”. Just wait and let it finish.

  • If you want to use a custom recovery, see STEP 4.
  • Reboot your phone and enjoy. It’s normal for the first boot to take a while, several minutes in case a a large update (from Kitkat to Lollipop up to 20 minutes).

BONUS STEP 4: Install custom recovery, root and custom kernel


  • Boot your phone into the bootloader (see below)
  • From the command line:
$fastboot flash recovery twrp-*-hammerhead.img
  • Boot into recovery (use the volume up/down buttons to select recovery from the bootloader, then the power button to select)
  • In TWRP, go to “mount”, then check “system”
  • Optional: go back to the main TWRP screen, then click through Advanced > File Manager > system > recovery-from-boot.p > Rename File. Rename it to something like recovery-from-boot.p.bak (this is necessary to ensure that Android doesn’t overwrite your custom recovery with the stock recovery on startup)


  • In TWRP, select “Install”, then navigate to wherever you saved the TWRP zip (probably in /sdcard/Download)
  • Swipe to confirm flash
  • In case you want to install a custom kernel (recommended), go to the next paragraph
  • Reboot your phone


WARNING: Installing a custom kernel can broke the system. If you get strange behaviours, like infinite boot looping, repeat the procedures from STEP 2, and try to not install the custom kernel (or try a different one).

  • Download a custom kernel on your phone. ElementalX and Franco Kernel are quite popular and can be downloaded from their websites. I am using ElementalX.
  • In TWRP, select “Install”, then navigate to wherever you saved the kernel zip (probably in /sdcard/Download)
  • Swipe to confirm flash.
  • System reboot. In case you choose ElementalX, don’t let twrp fix root when it prompts!

Why RAM Boosters And Task Killers Are Bad For Your Android

Stop killing your Android phone! There’s a lot of misinformation out there regarding the usefulness of RAM booster apps and task killer apps. At first glance they sound incredibly useful, but a closer look shows that they could actually be harming your phone instead.

Long story short: Simply avoid using RAM booster and task killer apps. They may have once been useful, but Android has progressed far enough that these sorts of apps are now outdated, unnecessary, and counterproductive. If you want to know why they’re bad, keep reading.

How Android Handles RAM and Apps


To understand how Android handles RAM, we first need to understand what RAM is and how it works.

There’s a lot of technobabble that could be said about it, but for our purposes, it’s enough to know that RAM means random access memory and it’s a type of storage that’s incredibly fast but disappears when the device shuts down. Therefore, RAM is useful for holding temporary information that changes a lot and gets frequently accessed.

On Windows, you want to keep as much RAM available as you can so that programs have enough room to operate. When RAM fills up, Windows is forced to start using hard drive space as virtual RAM and hard drives are much slowerthan physical RAM.

This is not true for Android.

Android’s operating system has its own native handler for assigning RAM to apps and making sure that all of it is being used in the most optimal way. In fact, Android purposely tries to keep apps loaded into RAM for better performance. RAM is fast, remember? On mobile devices, every bit of speed is critical for a good user experience, so keeping apps in RAM is actually a good thing.

If you use a lot of different apps, you may want to consider a model with more RAM the next time you buy a smartphone.

Not only does Android handle RAM assignment, but it also keeps track of background apps so they don’t use up unnecessary processor resources. There’s no noticeable performance hit for leaving apps loaded in RAM. There’s one exception to this, but we’ll cover that in the last section of this article.

The Deceit of RAM Boosters & Task Killers


At this point, it might seem like RAM boosters and task killers are neutral. They might not necessarily help with Android performance, but they aren’t bad to have around, right? Maybe they provide some marginal benefits? Unfortunately, no. They are detrimental.

Typical Windows wisdom says to kill RAM-hogging processes and defragment your hard drive for faster speeds. This is good in the context of Windows, but applying it to Android results in negative gain.

For one, Android uses an SD card for file storage rather than a traditional hard drive. SD cards are a type of flash memory — similar to solid state drives — and don’t need to be defragmented. In fact, one of the downsides to flash memory is a limited number of times that data can be written to the card before it expires. By defragmenting an SD card, you can decrease its lifespan.

When you clear apps from RAM, Android is just going to load them into RAM again the next time it needs to access those apps (for notifications, updates, and other background details). This is actually slower for you since SD cards are slower than RAM.

And in the case of automatic task killers, you end up having to sacrifice some of your RAM and CPU to the task killer app itself, which is always running and monitoring for opportunities when tasks should be killed. This can be a big drain on battery life — and you aren’t getting anything useful in return!

Improving Android Performance & Battery Life


If you’re using a task killer, it’s likely the case that you just aren’t happy about your device’s performance. It’s slow, perhaps even sluggish, and using it is more of a nuisance than a joy. If a task killer isn’t going to help, what can you do to boost Android performance?

Kill misbehaving apps. You should avoid killing apps just to free up RAM, but always be on the lookout for apps that use an unusual amount of CPU. These can seriously slow down performance and kill battery life. Watchdog Task Manager is a great app for this.

Use lightweight apps. Many times, poor performance can be attributed to a particular app rather than the Android device itself. For frequently used apps (e.g., browsers, notebooks, music players, etc.) always go for the ones that are most lightweight and battery friendly.

Toggle unnecessary features. It’s convenient to keep your data on all of the time, but it’s going to have an impact on performance. The same goes for always keeping your WiFi, Bluetooth, and GPS on. Toggle them off when you aren’t using them to preserve resources. Use a toggle widget to make it even easier to handle.

Install a custom ROM. This tip is a bit more advanced and should only be considered by those who are familiar with Android troubleshooting. Installing a custom ROM is like installing a different distribution of Linux: some ROMs are faster and less battery intensive, which is great for weaker devices.

For more tips, check out Guy’s roundup of nine ways to extend Android battery life.

What are your experiences with task killer apps? Do you use one for your Android right now? Have they been helpful or have they just been placebo? Share your thoughts with us in the comments below!

Image Credits: Phone Apps Via Shutterstock, Phone Circuitry Via Shutterstock, Charging Battery Via Shutterstock

This article originally appeared on makeuseof.com