[ASK]Stripped Down Version of Android

The Question

Seeing how our device support multi-booting into several ROMs and a few weeks ago the HTC M8 came out. The M8 features an ultra battery saving mode by dumbing down the phone into only the essential function such as messaging and phone calls.

Is it possible to make a stripped-down version of AOSP/other custom ROM?

The ROM itself could only feature a few apps such as:

• Messaging
• Phone
• Browser
• Camera
• Music Player
• File Manager
• Gallery
• WiFi
• Bluetooth

With the Location and Account Sync turned off also multi-tasking turned off (make only 1 app in background), this could save a lot of battery. Also since it won't need that much horse power to run the ROM, you can turn off a few cores to save battery even further. So if one day you're in need for a longer life battery but still want to use your phone, you can boot into this ROM.

The "Lite" ROM

So instead of waiting for someone to heavily strip down an Android ROM I tried the following:

1. Installed MultiROM
2. Add a new ROM
3. Flashed the ROM's zip file (Slimkat Build 4 Stable) without flashing the gapps afterward
4. Flashed Photosphere since I need it
5. Flashed a custom kernel (hellscore b44)
6. Booted into the "Lite" version of ROM and set things up.
7. Remove some apps that is not needed and added some apps that are needed

The result is the following, just a simple ROM with no widgets on the homescreen and only a few apps that do not have services running on background.


Phone Settings:

• Keep WiFi on during sleep = Always
• WiFi Always Scanning = Off
• Optimize WiFi = On
• NFC = Off
• Lock + Touch sound and vibration = Off
• Runtime = ART
• Background Process = Standard Limit (since it causes FC in Google Camera if you disabled background process)
• All transtion effect = 0.5x to make it feel faster

Kernel Settings:

• Min Core Online = 1
• Max Core Online= 2
• Cores boosted on touch = 2
• Min Freq = 192 MHz
• Max Freq = 1242 MHz
• CPU Governor = intellidemand
• GPU Governor = conservative
• GPU Max Clock = 320 MHz
• Sweep2Wake + Sweep2Sleep = On

The Test

Still coming

Konstantinos said:

(1)Developer Options ----> Background Process Limit (At most, 1 process)


(2) You can install a kernel(you obviously need custom recovery and root for that) Then you can set the Maximum and Minimum CPUs online. This can be achieved with ak latest kernel.


Sorry I couldn't answer the previous "demands", but those 2 can be achieved on a normal ROM.

Click to expand...

Click to collapse

I know this can be done on normal ROMs, I used to turn off some cores with hellscore too but it ends up laggy but at least it charges faster -_-"

As for background process, it just kill the apps when it's on background, opening it again will start it up again which in opposite, decrease battery life if multi-tasking. Even if the limit is enabled, some services still runs, I tried sending Whatsapp and it still receives it thus service still running.

If devs can make like a S40/Java-like ROM and with our spec, it can last days on battery like the days of Nokia 3100. :laugh:

Mashed_Potatoes said:

A) Don't use apps. Only use vital apps like SMS and Phone? (Imagine that you have Ultra saving mode?)
B) Set CPU to 192mhz - 1350mhz and Intellidemand
C) Don't use a lot of 3G - Set wifi to turn off on lock
D) Undervolt
E) DONT PLAY GAMES
F) Underclock GPU to 320mhz
G) Greenify all apps except Clock and Launcher

This should easily give you 5 hours of screen on time or at least 2-3 days on one charge.

Click to expand...

Click to collapse

Actually I flashed a new ROM (Slimkat) without flashing the gapps + hellscore b44 and added Hellscore Manager to tweak all the above, also in Developer Settings enabled "No Background Process". The size doesn't even reach 300mb. I haven't tested the battery life though. Anyone wanna try?

Sent from my blazing fast Nexus 4

bamsbamx said:

Hey, and why dont you try to take the zip file from a rom and manually remove its unnecessary apks???

Also, I suggest you to flash a kernel... I used faux kernel... Great battery

This thread could be interesting for those who leave home for some days

EDIT: You can install the stripped down version of that rom with MultiROM so you can have access to all functionalities again with only one reboot

Click to expand...

Click to collapse

Yeah, actually that's what I did. So I have two ROMs intalled, 1. a full Slimkat version installed with gapps and all my 100 apps and games, and 2. a simplified Slimkat version where gapps are no more and some apps removed + a few basic apps that I use daily such as Opera Mini, XDA Forum, Hellscore Manager, and Android Central App, also the new Google Camera for taking pictures. No chatting apps installed at all.

I'll test how long it last since tomorrow I'll be travelling.

Sure thing bro but I'll only use the standard battery detail thing found on the Settings.

Sent from my Nexus 4

Konstantinos said:

Why dont you just delete some system and priv-app apks? My CM11 from 210 mb goes down to 140mb when I delete all those things. Even SlimRom and PA went down to 130. Battery life is ok with me. 1 day with ak's kernel.

Click to expand...

Click to collapse

Yeah it's rather small so it doesn't significantly affect my main ROM. I don't want just one day, it's normal getting a day of use using hellscore. I want to test if an Android smartphone can achieve 3-4 days of use like the days where Nokia 3100 was still around.

So unfortunately I couldn't test a full whole day since I had some stuff I need to do on my main ROM, so I only used it for 3-4 hours. Battery was kinda good though, it only drops 2-3% surfing the internet on WiFi for 30 minutes with low brightness.

It took 20% of battery with 1 hour of screen on time which consist of 20 minutes of music through speaker, 30 minutes on full browser (WiFi), 15 minutes on Opera Mini (EDGE), and took 10 pictures with the camera. But I don't think that's good enough.

I'll post my phone and kernel settings on the first post, any suggestion on reducing battery life please tell. I'll try using the Slimkat Lite ROM until the battery dies when I'm fully charged again and post the result here.