I know I was a bit confused when initially rooting and installing custom ROMs on my Android device and while I don’t consider myself an expert there are a few terms that could use a quick definition to know your way around custom ROM installations.
When you start your device you can boot into 1 of 3 modes
- Bootloader: a mode that can boot into Recovery or start the regular boot process (into Android) and also shows some details of your device. ROMs can be flashed in the bootloader but it is not the typical case
- Recovery: a mode to flash ROMs (stock / custom)
- Regular system boot: boots into the operating system while would typically be Android
These tools can be used to communicate and even transfer files with your device
- adb: when in recovery mode / standard Android
- fastboot : when in bootloader
Unlocking the Bootloader
Boot loaders can be locked which prevents custom ROMS from being flashed. Unlocking the bootloader can be done with the following commands (this was done on a Nexus 7 2013, other devices may need other commands)
- Reboot into the bootloader
adb reboot bootloader
- Unlock the bootloader
fastboot oem unlock
Once the bootloader is unlocked you can install a custom ROM. While I believe it is possible to install custom ROMs without a custom recovery program, the typical way to install a ROM is with one. I’ve used ClockWorkMod Recovery and Team Win Recovery Project (TWRP) but there are others other there. Just make sure you install the right one for your device.
Flashing a Custom ROM
- Install a custom recovery
- Install it on your device
- Download your custom ROM
- Reboot your device into recovery
adb reboot recovery
- Follow the on screen instructions to install the ROM
- Typically you have to wipe your device (dalvik cache, system and personal data)
- Install the custom ROM from a zip file
- Reboot into your new ROM
- Custom builds/implementation of Android with some famous ones such as CyanogenMod and ParanoidAndroid (currently I’m using OmniROM)
- Stock ROMs are the original ROM that came with the device
- Custom ROMs typically will not have the Google services and usually need to be manually installed. Typically packaged / called gapps
- Some problem with custom ROMs is usually hardware support: some things may not work as well as they do on stock ROMs. Thus custom ROMs that are based on stock ROMs will probably have better hardware support compared to generic custom ROMs
- Rooting gives you more control on your device and lets you run apps that have special abilities. Some features that I use are
- Rooting can be done on a device with a stock ROM or can be automatically bundled with a custom ROM
- Applications that use root privileges have to request for these functions to be run and these can be managed using superuser apps such as Superuser from ChainsDD / Superuser from ClockworkMod / SuperSU from Chainfire
- “Unlocked”: this can mean several things
- Unlocked from a carrier: it can us SIM cards from any carrier
- Unlocked bootloader: it can load custom ROMs
Things I’m still unsure of
- If the bootloader needs to be unlocked in order to flash a custom recovery
- “Secure boot”: shown on the boot loader but doesn’t affect flashing a custom ROM
Thanks to the Ubuntu Touch install page I found out that you can do a full Android backup of apps and data.
adb backup -apk -shared -all
That will create a backup.ab file on your computer which can get huge
adb restore backup.ab
Restoration can be done even on a different ROM and it even maintains settings apps which require you to log in.
Full details of adb backup are as follows and you could selectively backup important app data and such.
adb backup [-f <file>] [-apk|-noapk] [-obb|-noobb] [-shared|-noshared] [-all] [-system|-nosystem] [<packages...>]
- write an archive of the device's data to <file>.
If no -f option is supplied then the data is written
to "backup.ab" in the current directory.
(-apk|-noapk enable/disable backup of the .apks themselves
in the archive; the default is noapk.)
(-obb|-noobb enable/disable backup of any installed apk expansion
(aka .obb) files associated with each application; the default
(-shared|-noshared enable/disable backup of the device's
shared storage / SD card contents; the default is noshared.)
(-all means to back up all installed applications)
(-system|-nosystem toggles whether -all automatically includes
system applications; the default is to include system apps)
(<packages...> is the list of applications to be backed up. If
the -all or -shared flags are passed, then the package
list is optional. Applications explicitly given on the
command line will be included even if -nosystem would
ordinarily cause them to be omitted.)
Another great adb command is screen recording which I believe is only in Android 4.4 (KitKat) and above
adb shell screenrecord /sdcard/test.mp4
Ctrl+C to stop recording the video
If you have multiple devices connected, use -s deviceID to spec
# List of devices attached
# 00bb1122 device
# 0022334455 device
adb -s 0063686250152c5a shell
This was the talk I gave at GDG Brunei DevFest 2013 and I aimed for the content to be basic and accessible with a workable app, so that the attendees could use it as a starting off point for the hackathon, should they want to learn how to build an Android app.
I should have published the APK on the Play Store before the talk so that people could have downloaded the app and see what I was building as part of the talk
Source code: https://github.com/CornerGeeks/GDGBruneiDevFest2013/
So my Linux install going messed up somehow and I was left with no wireless driver installed. I know that you can use Android phones to USB tether mobile data (e.g. 3G/4G/LTE) but I didn’t know that you can do the same over WiFi!
Now while in OSX I’m pretty sure it worked out of the box previously, it seems that you need now need to download the HoRNDIS driver. With Linux (Ubuntu) it worked out of the box and in my previous usage of USB tethering, Windows should work automatically as well.
A simple network utility that:
- lists all network interfaces and their IPs
- is a small package (51KB apk file)
Play Store link | Direct APK link
This spawned out of me noticing that many network capable Android apps ignore the Bluetooth or WiFi Direct Peer-to-Peer networks: they don’t seem to work despite it being a network with an IP (e.g. AirDroid). While this app doesn’t solve that problem, it does help me to know what IPs I have. Some may ask, why didn’t I just look through the Play Store, and while that is a valid question, it probably would take more time looking for an app that meets the 3 key points of IP and Me and also, is a good learning platform to start learning Android development in a more structured manner.
A couple years back I though that Android had a big problem with Low Available Phone Storage Space for apps and after reading Ausdroid’s recent review of the Medion 4, it seems that this is still an on-going issue.
The device in question is the Medion 4 which is advertised with “4GB Memory” on Aldi’s site, but according to AusDroid, there is only 500MB allocated for apps (the rest of the space can still be used to store photos/files but not apps without some rooting and hacking).
Filesystem Size Used Free Blksize
/data 503M 151M 351M 4096
My 16GB Nexus 4 has 12.9GB allocated to the /data partition which is a bit less than 13.6GB of a 16GB iPhone 4 (can’t seem to find a definitive answer for the iPhone 5) but is still a majority of its storage unlike the Medion 4. The Samsung Galaxy S4 has a separate issue which is not exactly the same but gives the same results to the end user: a false sense of storage space (only 8.8GB free from the 16GB model due to Samsung’s customization of Android with its own skin & apps). While it’s not as bad as the Microsoft’s Surface RT storage debacle (15GB free in a 32GB Surface RT, 28GB free in a 64GB Surface Pro. Source: Microsoft’s Surface Disk Page FAQ), both of these situations don’t give me much confidence when recommending non-Nexus Android devices with X GB of storage.
At least if it is just Android customization (ala Samsung), flashing a custom ROM should be able to solve the problem. I’m not sure if the partitioning (ala the Medion 4) can be solved using a custom ROM, but even if it does, you will need to find a ROM that supports your device: so you hope that your devices isn’t a weird obscure one.
So when you buy an Android device, you can’t say for certain that you have a majority of the advertised storage available for apps. I can only assume that Nexus devices would give you the best experience in terms of not being ‘cheated’ for storage space, but I guess this gives more credence to the fact that Google has lost control of Android and that some manufacturers are still giving Android a bad name.
It is now available at: https://github.com/thewheat/SMARTER-eVCS-Android
The Android app is currently meant to be used in conjunction with the SMARTER eVCS webapp but hopefully I’ll get time to upgrade both the Android app the make it a standalone app.
Also once again, anybody interested in helping in this community development project, do get in contact or just get the code, make some changes and submit pull requests.