Develop Bugs

[Q] How Does the Android OS Work?

Disclaimer: I am only a flasher. I do, however, contribute to the forums, donate to devs and also use the paid version of good apps.
My question is: How does Android work on our phones?
You have hardware (HTC Incredible); you have a carrier (Verizon, in my case); you have an OS (Android, obviously); you have a radio; you have a ROM; you have a kernel; you have themes, you have skins and you have apps. How do all these pieces interact? Just curious.

This is a really good question that should be answered in laymen's terms. I'm surprised it hasn't been answered yet.

I also thought it would have been answered by now. However, I think the developers (who would be the best folks to answer this question) are busy working with the Gingerbread source code to build new ROMs for us.
This is what I have figured out so far but I'm not sure if my analysis is correct:
After selecting your hardware and carrier, the OS is the most important element. Most of us are currently on Froyo (2.2). I have seen some screen shots showing the OS version to be "2.2.1" but I am not sure why. Google (I think) has released the source code for Gingerbread (2.3) and the developers ("devs") are hard at work producing new ROMs as I post this.
I gather that it is best to stay away from trying out different radios ("basebands"). Most of us are using 2.15.00.07.28.
I think the ROM takes the OS and re-works the user interface by adding, removing and changing the various screens and "features" of the OS. For example: the ROM can be written to take out the stock music player and substitute a music player that the ROM developer prefers. I think this is called "baking in an app". I believe the ROM developer can also create an overall "look and feel" that can be quite different from the stock OS. For instance, the ROM can be "colored" in black and red (rather than the stock green) and the stock font can be changed to something the developer prefers. In other words, the ROM is what you see and use on a daily basis.
Now this is where things get a little fuzzy: the kernel. I think this is kind of a behind the scenes element that governs the performance of a ROM. It greatly affects things like battery life, time to charge the battery and the "speed" of the phone. The kernel is where the phone can be "over-clocked" and "under-volted" should you want to do those things. I gather that once you select a ROM, you can try different kernels without changing what the various screens look like on the phone. I believe this is the way most people do it (pick a ROM and try different kernels with it). I don't think the other way really works (pick a kernel and try different ROMs with the kernel).
Next comes themes and skins which really only affect what you see on the various screens without do anything about battery life or the speed of the phone. I haven't played with these much.
Finally, I forgot to put WALLPAPER on the list in the original post. I believe this only appears as a background image on the home screens.
If any reader sees errors in my layman's analysis, please, by all means jump in and correct me. Per my disclaimer in Post #1, I am just an ordinary user and this analysis could be flawed or incorrect in whole or in part.

Everytime I try to answer a question like this, I get too complex about it and leave more questions than answers. Then someone comes along and says "It's like Windows or Linux or MacOS on a PC", and that's that. Well they're right. Those OS's tell the PC's that they are PC's and essentially all OS's do the same things.
Here's my simplified new list:
1) Hardware on phone :: meaningless without OS
-- (android OS - or any other OS)
2) Linux kernel understands hardware like touchscreen, radios, I/O (drivers/modules). Of course it also understands how to schedule processes and all those "kernel tasks".
3) Libraries provide APIs (Application programming interface) to userspace code (like APPS).
4) Userspace (apps, scripts, libraries) provide user control over the phone.
--
Together they work in harmony (we hope) to make the phone realize it is a phone and allow us to use it as such. (well, a smartphone, so many things other than a phone).
Here's a simple example: You touch the phone icon which is in userspace, and it brings up the userspace phone app. As soon (or before) as you touch some buttons, dial a number, it is using the API to the driver in the kernel that actually understands the phone hardware/radio. Also userspace controls GUI which is also requiring API to some form of OPENGL API that is requiring device drivers that get the touchscreen/LCD display. and so on.
--- Hashi
PS: I realize there are a thousand things wrong with this representation, but hey, it's a start. Feel free to fix it up if you're inclined.

What is special about Cyanogenmod?

Excuse my ignorance, I am new to android. I get that everyone loves them some CM, but what about it makes it special over any other ROM? Thanks.
Sent from my SPH-D710 using Tapatalk

It has a ton of extra options/customizations. That's what I like a out it. The rest is....meh..about the same.
Bada Bing Bada Boom!

not really true duce cyanogen is different because its not made by any of the cell manufacturers and has all there bloat and customizations removed. it is the closest you can get to a nexux device on a standard android phone.

The most important thing is its the most popular AOSP ROM. So even if you don't run it (which I don't) you have to respect the fact that you can truly own your hardware without any cell phone provider interference. That and its for the community by the community is impressive.

Ah, so it's like ultimate stock, so it doesnt put tweaked ROMs like calkulin's or phantomhacker's out of business then?
Sent from my SPH-D710 using Tapatalk

drksilenc said:
not really true duce cyanogen is different because its not made by any of the cell manufacturers and has all there bloat and customizations removed. it is the closest you can get to a nexux device on a standard android phone.
Click to expand...
Click to collapse
I know what CM is, ran it for quite some time myself. It's nice and I respect everything about it.
I put it lightly I guess, which is pretty much the same (more of a true android experience that is clear).
As far as daily driver it offers more at customization, options, themes, and mods. No need to get defensive about CM...... Some like it more and some less. >"Personally"< with the way the et4g runs ATM, and the roms we have, I'm not worried about it. If a stable version with working gps, no f/c, and extreme battery drainage ever gets released for this phone , it's definitely worth using. Or at least try it out.
Bada Bing Bada Boom!

JoeBruin32 said:
Ah, so it's like ultimate stock, so it doesnt put tweaked ROMs like calkulin's or phantomhacker's out of business then?
Sent from my SPH-D710 using Tapatalk
Click to expand...
Click to collapse
No it does not. It's a personal preference. Definitely worth trying out for sure.
Bada Bing Bada Boom!

Agreed, usually the folks that run CM tend to be on the Diva side of things, at least my experience on the OG Evo, but its nice to know that there are high end alternatives to what the carriers provide (CM/MIUI)

its a rom built on the theory of the old warcraft cheat code: make it so

Well,I like the real miui rom
Sent from my SPH-D710 using xda premium

Cyanogenmod is based off of stock Android. Some Cyanogenmod features:
- Lockscreen Gestures - launch apps & activities from the lock screen
- Phone Goggles - Lets you filter what goes in and out of your phone
- OpenVPN
- Incognito Mode - private browsing
- DSP Manger - Amazing audio compressor & equalizer for great sound
- Theme Support - CM7 comes stock with 2 or 3 themes, and has the T-Mobile Theme Chooser app integrated. You can download theme packages from XDA & Android Market to re-skin your phone. So, instead of having to flash themes you can install them like APKs.
- Its fast and clean - No bloatware, and has great battery life.
Its also very customizable. For instance, you can set the toggles in your status bar to what ever order you would like, and there are a huge amount to choose from. I personally throw up music back/play/forward toggles, brightness, 2g/3g/4g toggle, and so on. It also features multiple lock screen styles to choose from.
Read more here: http://www.cyanogenmod.com/about

^ those are true but none of those are original, you can do most of that without rooting and all of it on a stock root.
I used cm roms for half a year at least on my Evo, compared to stock I would crash every week, I would have to restart my phone every other day because my keyboard would disappear, you have to deal with rom bloatware which is at least a lot lighter than carrier bloatware, and they never included the simple user fixes I wanted like screen res fix so stuff didn't look blurry and pixely or user profiles on common apps.
now I'm on midnight rom (a more stock rom than cm) on E4gT and it's running infinitely better than cm7.1 was on my evo. it's only crashed on me twice in a month, the customization is basically the same as even roms have a standard of what's included now, and the only thing worse is no built in wifi.
the main appeal of CM roms is getting system upgrades before they're released. they've released ICS roms for phones already, i'm waiting for the e4gt rom. besides that, all the people you see praising CM roms are android fanboys

xvsanx said:
^ those are true but none of those are original, you can do most of that without rooting and all of it on a stock root.
I used cm roms for half a year at least on my Evo, compared to stock I would crash every week, I would have to restart my phone every other day because my keyboard would disappear, you have to deal with rom bloatware which is at least a lot lighter than carrier bloatware, and they never included the simple user fixes I wanted like screen res fix so stuff didn't look blurry and pixely or user profiles on common apps.
now I'm on midnight rom (a more stock rom than cm) on E4gT and it's running infinitely better than cm7.1 was on my evo. it's only crashed on me twice in a month, the customization is basically the same as even roms have a standard of what's included now, and the only thing worse is no built in wifi.
the main appeal of CM roms is getting system upgrades before they're released. they've released ICS roms for phones already, i'm waiting for the e4gt rom. besides that, all the people you see praising CM roms are android fanboys
Click to expand...
Click to collapse
Did you never upgrade your version of CM? Especially if you are running a nightly build, there are likely to be bugs. Run a stable and there is a solid chance you won't ever have issues. This applies to the EVO and any other phone that supports CM7. Call me a fanboy if you'd like, there is obviously reasoning behind my love for Cyanogenmod.

Cell_phone_privacy_guide_(Android)

Is any of this being done for the roms here?
http://wiki.pirateparty.ca/index.php/Cell_phone_privacy_guide_(Android)
Mainly these parts??
"Using a free and open source firmware
Many phones will be compatible with the open source firmware Cyanogenmod. Check the devices page and follow the instructions for your device. Users interested in a fully free and open source firmware may wish to look into Replicant. Using one of these firmwares will give your phone a system without advertisements, programs you dont need that slow down the phone (bloatware), and invasive software like Carrier IQ.
Using free and open source software (FOSS)
Using FOSS on your Android is one of the best ways to preserve your privacy. If the software has it's source public, you know there isn't anything hidden that might violate your privacy or take control of your device. For this reason free (as in freedom) software is incredibly important for personal privacy and control over your device. Given the existence of SOPA and C-11, programs like Carrier IQ, and the warrantless surveillance in C-30, now more than ever it is becoming increasingly clear how important free software is. Out of respect for your freedom this guide uses only free or at the very least open source software."

no6969el said:
Is any of this being done for the roms here?
http://wiki.pirateparty.ca/index.php/Cell_phone_privacy_guide_(Android)
Mainly these parts??
"Using a free and open source firmware
Click to expand...
Click to collapse
Most of the custom ROMs you'll find for this phone are not built from source, but are modifications of factory ROMs (eg. removing T-mobile bloatware, removing Carrier IQ, change the icon colors/theme) with a 3rd party custom kernel, and maybe some other bits cherry-picked from other ROMs/projects. So you might get some of the privacy benefits from those, however claims vary widely on the performance and stability gains and losses with these. YMMV. It is also possible to root your phone and modify your stock ROM yourself, and there are guides in these forums for doing so. Just bear in mind that you're voiding your warranty by doing any of the above, and you run the risk of bricking your device. Most folks with good reading comprehension skills and a modicum of technical aptitude seem to do just fine.
As for ROMs built from modified AOSP source, unfortunately, there is not a stable Cyanogenmod ROM for this phone yet. I've heard tell of another project called AOKP, but I haven't looked into that one at all.

The page says there's no text in it. What happened
Sent from my very own Galaxy.

SGS2 D4 Rom with heavy customization features. Portable?

This was on the front page. Would it be possible to port this feature to our AOSP roms? A flashable standalone would be pretty EPIC (and thats what we're all about on this phone )
http://www.xda-developers.com/android/d4-rom-for-the-sgs2-brings-modular-goodness/
We all like customizing our Android devices. In fact, for many of our 4.4 million members, that is the main reason we chose Android in the first place, rather than going with some unnamed fruit company. It is in this customization that we make our mobile devices truly our own. Many prefer to do the customization with themes and other mods, but sometimes it can go even deeper.
We’ve covered methods of customizing ROM installations in the past using the Aroma Installer. The installer, which is similar to nLite for Windows power users, allows end users to customize how exactly their ROM of choice is installed. However, this requires both a porting effort to your device and implementation into the target ROM. Unfortunately, this leaves many users out in the cold. Furthermore, other users would like a modular ROM that can be tweaked well after installation.
Luckily for Samsung Galaxy S II owners, however, XDA Recognized Developer D4rKn3sSyS has released a CyanogenMod 9-based ROM that includes some modular functionality. Using the built-in control app, you can easily modify things such as battery style, LCD density tweaks, enabling or disabling system sounds, switching recording video format, switching USB mode (UMS or MTP), and much more.
D4 ROM goal is to offer the maximum stability possible, and easy-to-user features, like changing LCD density, Recorded video format and so on. But it’s main aim is allow user to choose what mods he wants, and enable them with just a tap.
Have in mind, that what differs from this rom, is not the base, but the options that can be added via OTA. Some of the features are:
*OTA App for adding features on the air, like:
-Battery Styles
-MP4 / 3GP Recording
-MTP / Mass Storage
-Sound Management
*Minor inbuilt tweaks
*Custom bootanimation
And more
Those lucky SGS2 owners looking to get started with D4 ROM should head over to the ROM thread.
Click to expand...
Click to collapse

[Q] The problem with ROM developement?

The problem with a lot of these popular high maintenance ROM's is that if the Dev's ever get taken away from their work on the ROM at any time, the project can collapse. This seemed to be to me, kind of what happened with AOKP.
What I've suggested in the past and still wondering if it's possible... is to create an app with access to "mount /system..." root privileges etc that is able to add mod's as installable updates/patches? If we had a system like this then all the developers could create mod's instead of an entire ROM and base it off a AOSP, which is technically what all ROM's are based off of anyway.
Then you could install each mod as you wish, just making sure it's compatible with your current firmware/software version.
This would be somewhat of a Cydia approach, the way jailbroken iPhones apply patches to the ROM.
I personally think this is a better idea than having a dedicated Developer OR Set of Developers for each ROM that continually have to be relied upon in order to maintain updates.
Does anybody think I'm speaking any sense here??

AOKP, first off, is very much alive.
Secondly, projects LIKE this exist.
FNV, for example, where everyone is encouraged to push their commits over for review.
There is no "lead developer" and it is the closest you'll get to what you're describing.
As far as just...installing patches and such to get a "flash what you want" type experience...
It isn't that simple.
Even if an open commit is left alone for a few days; it may need rebasing to merge into the branch.
Each little piece of each commit has to build on the previous merges and not interfere with them.
It's a cool thought, bit I can't see it being even slightly plausible.

Jubakuba said:
AOKP, first off, is very much alive.
Secondly, projects LIKE this exist.
FNV, for example, where everyone is encouraged to push their commits over for review.
There is no "lead developer" and it is the closest you'll get to what you're describing.
As far as just...installing patches and such to get a "flash what you want" type experience...
It isn't that simple.
Even if an open commit is left alone for a few days; it may need rebasing to merge into the branch.
Each little piece of each commit has to build on the previous merges and not interfere with them.
It's a cool thought, bit I can't see it being even slightly plausible.
Click to expand...
Click to collapse
Yea I see what you mean, im just wondering how Cydia for iOS interacts with the ROM to apply patches then..?? how have they managed to implement this kind of system?
FNV looks interesting but a little dead. On the other hand, I like how actively updated CM10 is, and it doesn't look like support is going to stop there anytime soon which is a big plus.

UKROB86 said:
The problem with a lot of these popular high maintenance ROM's is that if the Dev's ever get taken away from their work on the ROM at any time, the project can collapse. This seemed to be to me, kind of what happened with AOKP.
What I've suggested in the past and still wondering if it's possible... is to create an app with access to "mount /system..." root privileges etc that is able to add mod's as installable updates/patches? If we had a system like this then all the developers could create mod's instead of an entire ROM and base it off a AOSP, which is technically what all ROM's are based off of anyway.
Then you could install each mod as you wish, just making sure it's compatible with your current firmware/software version.
This would be somewhat of a Cydia approach, the way jailbroken iPhones apply patches to the ROM.
I personally think this is a better idea than having a dedicated Developer OR Set of Developers for each ROM that continually have to be relied upon in order to maintain updates.
Does anybody think I'm speaking any sense here??
Click to expand...
Click to collapse
Remember, the performance of a jail broken iPhone once you install those tweaks, let's just say, all hell breaks loose. My friends who jailbreak and use the simplest of jailbreak scripts and stuff all complain of lag on their iPad 2/3. I personally think its a hack job.
We have the source code unlike iOS, in the spirit of open source, developers download the source, make modifications, compile and make ROMs. They also give out the source to the public again so if anyone wants to base off any existing work, its okay. A great example is cm and perhaps Paranoid Android. And this method is flawed as other devices don't have AOSP support. I'm talking about S2/S3/HTC One X, etc. How are we supposed to make a single stable rom for them that's a clean aosp rom? Usually lots of hacking and tinkering and waiting for kernel sources is required to get AOSP on those devices. Its unlike the nexus where we have everything (source, proprietary drivers, etc) straight from Google. Anyway, that's my view. From the practical standpoint, you have to talk with other developers as ROMs come with their own framework and things.
Sent from my Galaxy Nexus using Tapatalk 2
---------- Post added at 01:31 PM ---------- Previous post was at 01:27 PM ----------
And another note, have a problem with a dead rom? Its probably stable enough for the developer. Or the developer has other important things in life. You can't blame them. What you can do is switch your ROM easily. If your looking for AOKP like ROMs, there's slimbean, CNA and Sourcery and even more that cram in all the tweaks. If you want a clean and minimal ROM, fast and stable, there are roms like Minco and rasbean jelly. Its seriously a different ecosystem than the apple cydia stuff, but it isn't a bad thing.
Sent from my Galaxy Nexus using Tapatalk 2

akash3656 said:
Remember, the performance of a jail broken iPhone once you install those tweaks, let's just say, all hell breaks loose. My friends who jailbreak and use the simplest of jailbreak scripts and stuff all complain of lag on their iPad 2/3. I personally think its a hack job.
We have the source code unlike iOS, in the spirit of open source, developers download the source, make modifications, compile and make ROMs. They also give out the source to the public again so if anyone wants to base off any existing work, its okay. A great example is cm and perhaps Paranoid Android. And this method is flawed as other devices don't have AOSP support. I'm talking about S2/S3/HTC One X, etc. How are we supposed to make a single stable rom for them that's a clean aosp rom? Usually lots of hacking and tinkering and waiting for kernel sources is required to get AOSP on those devices. Its unlike the nexus where we have everything (source, proprietary drivers, etc) straight from Google. Anyway, that's my view. From the practical standpoint, you have to talk with other developers as ROMs come with their own framework and things.
Sent from my Galaxy Nexus using Tapatalk 2
---------- Post added at 01:31 PM ---------- Previous post was at 01:27 PM ----------
And another note, have a problem with a dead rom? Its probably stable enough for the developer. Or the developer has other important things in life. You can't blame them. What you can do is switch your ROM easily. If your looking for AOKP like ROMs, there's slimbean, CNA and Sourcery and even more that cram in all the tweaks. If you want a clean and minimal ROM, fast and stable, there are roms like Minco and rasbean jelly. Its seriously a different ecosystem than the apple cydia stuff, but it isn't a bad thing.
Sent from my Galaxy Nexus using Tapatalk 2
Click to expand...
Click to collapse
Yea I get what your saying.
Im not complaining about dead ROMs just was trying to think if there was a workaround. But yes I see your point about how a ROM developed from source would be less likely to lag.
I've been on CNA for awhile now, since AOKP slowed right now, and CNA is amazing. I guess CM10 is always a good backup if any of these ROM's stop updates.
thanks anyways.

Dont worry, you'll get your precious roms - this is an aosp device, after all.
Sent from my i9250