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Hi, I am a relative newbie to ROM flashing and the like. Additionally I dont have a very deep computer knowledge base. I have rooted my Samsung Captivate and have flashed a ROM (which flashed properly, but didn't quite work). I have three questions about ROM usage and such:
1. I know kernels basically add aspects to the ROM you are running, but when should you flash these? How do you flash them (same process as with ROMs? do you just do it over-top of the Rom you currently have loaded? etc...)
2. If a newer version of the ROM you have running comes out, do you have to start over and completely wipe the device over again and do the whole process from start, or can you load a newer version of your current ROM over the one you have?
3. I have been hearing/reading about some problems with the Android Market disappearing on certain ROMs when the market updates, how can i avoid this/fix this?
Thanks. Sorry the basic/stupid questions.
1. Yes
2. There are WIPE versions and NO WIPE version. Usually you can use the NO WIPE version and keep everything. But sometimes if the roms are too different you get problems and errors, then it is recommended to flash a WIPE version.
3. Hm did not experience this yet, but there are fixes somewhere .
Whats up... No question is a stupid one buddy.... (Sometimes )
To answer your first question about kernels. Flashing kernels aren't a must. You don't have to flash them really, unless there is a need. Kernels for the most part can often change the way Android handles stuff like memory management, battery resources and even multitasking. They change (tweak) the way the Android OS itself interacts with the phones hardware. That's all a kernel is really. So read up on them before flashing them because each has their advantages and disadvantages. For example, the kernel I use gives me a good RAM boost and much better battery life but it suffers on the multitasking side and I have to do other stuff to compensate for that. That's how it is. As far as flashing them is concerned. That depends. Usually, you just flash them through recovery (Like a ROM) but I would suggest you follow the instructions they give you (if it exists).
Your second question is simple. Just follow the instructions they give you for installation. Some ROMS require a full wipe and others don't. It just depends on the ROM. When in doubt, follow the instructions (again if it exists).
Your third question is a weird one, I've never heard about that really. BUT.... Some ROMS may or may not include the GAPPS applications (Google Apps).
If the ROM you flash doesn't have Google Apps built in, it would literally be missing. You would have to flash it separately. Usually in those cases though, at the download location for that ROM, they would also provide links for GAPPS zip files to flash separately so you can have the option to go with Android Market, Gmail and such OR you can use an alternative. Short of that..... never heard of that issue before..... If the issue is happening after the Market app updates, in that case it might be some type of ROM issue, you'll probably have to somehow get the updated Vending.apk (Android Market) remove/backup the original and reinstall it manually (the way you would a regular apk). I'm guessing though....
Don't you just love research........
Thanks. And now, inevitably, answers lead to more questions.
With regards to kernels, how do I know which one's do what, are compatible with which ROMs etc. I feel like its the kinda thing that needs a giant database for them, but i know there isn't.
Also, is the process for flashing other .zip files the same (though either Rom manager or a built in Recovery option). For example, a bootanimation.zip?
Ultimately I hate the idea of asking overly simply questions, but I just don't know what I dont know, nor what is supposedly implied. Thanks.
Don't sweat it...... I'm in the same boat so I have no hangups....
I think I know what you mean when it comes to kernels. Ultimately, learning about kernels requires a lot of reading in many forums (Just like this one)... Why?.... Because in many instances the persons posting the kernels might not always give you an exact breakdown on exactly what it does..... so I understand. Your best bet would be scanning XDA. I've found all sorts of really excellent kernels lying around and the devs here love documentation so there is a good chance you'll know what it does...
You could also try DroidBasement: http://droidbasement.com/db-blog/
They actually have just what you wanted, a database....kind of. They have a very large variety of kernels for different devices so its a good place to start as well.
They also tend to do a breakdown of what each kernel is capable of, the device it should be used on and so on.
About flashing zip files. Generally speaking, most zip files are flashed through recovery but its not written in stone. Following the instructions concerning said zip files are always very important. Always look for instructions before you do so at least at first. In the case of bootanimation.zip.... They are not always flashable. But if it is flashable, you can flash it through recovery which would be the best method....
If you want though, you can replace the original bootanimation.zip file with the new one manually, once you have root and some type of root explorer (for example RootExplorer for Android).
Generally, the boot animation directory is usually, /System/Media so you can check to see if its there and if it is, just backup the original and replace it with the new one.... That should work... Always nandroid before doing so though.... before doing anything really....
Thanks. I actually had a question about nandroid but forgot. Basically, what is it. I realize contextually that it's a backup program and apparently works through the recovery menus. I read a ROM flashing step-by-step that mentioned it but couldnt figure out where to get it (not in the market unlike Ti-bu which i use currently).
Nandroid is a backup program that basically creates a flash image of your phone... If you've ever heard of "Ghosting" or "Imaging" a Hard Drive, its exactly the same thing.
Its really as good as it gets as far as data backup is concerned. Its also a low level backup, so even file structures would be recorded.. In other words, you can completely screw up your phone (file partitions everything!!!!) but once you can boot to recovery, your phone can be restored. That's why its so important because its your safety net....
Its not something that you can install like an apk, so its not in the market.
You would have to flash a custom recovery. If you have one already, it should be located in one of the menus (It changes depending on the type (brand) of recovery).
If you don't see the option in your recovery then its probably not custom and you're going to have to do some digging on these forums and maybe a bit of googling for instructions on exactly how to do so. Because it could change from device to device.
Nandroid also allows you to backup your sd-ext partition as well, so if you switch cards, you can restore to another card.... Its really incredibly handy and I wouldn't suggest you do anything until you can create nandroid backups....
Now, I'm having an interesting problem I posted this same thing in general Captivate forums but maybe someone who is looking at this/answering me knows. here's what i posted there:
have a Captivate that I recently flashed Di11i's 7.1.1 to, before that I had flashed my first ROM which was Serendipity 6.2. Both times I have found that I don't get incoming calls. People calling me get 2-3 rings, and then a traditional "busy signal" sound. On my end, either the phone vibrates once but the screen doesnt change from whatever screen I'm on. Or, The screen goes black like its going to the incoming call screen, but the black screens only flashes and goes away, as does a force close message box that goes away quickly without me clicking it.
Everything else on my phone works as far as I can tell, I've been running my current ROM for about 5 days without issues other than this one. This same exact problem also happened when I flashed Serendipity 6.2 (which I only kept for like a day because of this problem)
Ok....I currently use a G1 and most of my experience has been on HTC Devices. I'm not sure of how to reply to this as I have never really modded Samsung devices before. So I'm not really familiar with software and hardware differences (Like Bootloader, Recoveries, Radios and such). But based on what you're describing.... It sounds like a ROM or maybe a radio issue. Maybe its an issue with the phone app itself. If the app is somehow buggy then thats exactly what would happen. When the phone rings the phone app would try to run but then force close....
I'm guessing here, but it could also be a radio issue because you're getting a busy tone as well which is not good. Maybe the ROM requires a specific Radio version BEFORE its flashed.... Check the source of the download and determine if it requires a specific Radio version.
In my experience though, if the correct radio version isn't used for a ROM that requires it, the phone just won't boot..... but then again, I don't know what would happen on a Samsung Captivate.... Not sure if I can help on this one because I don't have any info on that type of hardware. I don't own one you see.....
What about if you found out a new kernel isn't as good as the old kernel, how would you go on to take away the new kernel to replace it with the old kernel? Is it the same process or even harder?
vlen22 said:
What about if you found out a new kernel isn't as good as the old kernel, how would you go on to take away the new kernel to replace it with the old kernel? Is it the same process or even harder?
Click to expand...
Click to collapse
NOW THIS IS ANNOYING..
u have to flash ur rom again..
but fortunately u dont need to do and wiping data or partitioning sd card.. jus flash rom..
Its not something that you can install like an apk, so its not in the market.
zeemar007 said:
NOW THIS IS ANNOYING..
u have to flash ur rom again..
but fortunately u dont need to do and wiping data or partitioning sd card.. jus flash rom..
Click to expand...
Click to collapse
The rom kernel that I downloaded, or flashing clockwork recovery mod? Like adrenylyne's kernel for the thunderbolt.
EDIT: Never mind, I found out. I didn't mean any harm if MY POST was annoying.
If you have two kernels, in a flashable zip, you can just flash them over each other to exchange them (turn off any modification the kernel did befor though, like lagfix).
New question, I had an app (quick office) that came on my captivate. Now that I've flashed di11i's 7.1 I don't have it anymore. This is particularly peculiar because all the other native apps are still here:samsungs media player from example. How do I go about getting this missing app back on my phone. I have all the backup files on my computer so I should have the .apk (although I'm not entirely sure how to install those properly) thanks
Sent from my SAMSUNG-SGH-I897 using XDA App
So i am here with a new idea. A rescue.zip which can be used to rescue any android device which have a recovery like the famous cwm.
So here is it..
Some times we people screw up our android os like hell, and to reboot the device we usualy do a recovery flash of a new os, flash back our nandroid backup ( both on worst conditions) or even do permission fix, clean cache or dalvic cache( those in 'not that worse' conditions) . So thats are all the options we got. Rit?
Although flashing recovery backups, new roms can fix all, it will also eatup our apps, current setups, contacts, msgs, etc( in case we dont have backups) and will probably screw us. All we can do is say " WTF..WTF..WTF.."
SO here is my idea,
Find out the causes of what causes a reboot, non-boot, hang,fc etc.
And keep a zip that can be flashed through recovery, that has a solution for our problem. They may be including..
1) fix permission of system, data, and user data.
2) zipalign the apps
3) fix the default clock speed of processor
4) defragment memory
5) flash a new copy of su and busy box
6)wipe data or system or ext or cache or dalvic cache
7) flash a new copy of framework.res, system-ui.apk, settings.apk with default permissions( those files are kept in separate "custom" folder on the zip, so that end user can put their own files to that "custom" folder for flashing., the reason behind it is known to all, yap. Not all devices have them in common, every device have its own files)
These are all i got for now, pls post ur ideas and knowledge for any possible cure about any problem u faced/ cured. So that we can make it an ultimate rescue.zip that have a cure for 99% problems android os have. The rest 1% will go with a clean flash.( well we cant avoid that if we did something that bad).
So my plan is to use aroma installer( now on hard learning to find how it works). Throw in some scripts, files etc. Into the zip.
And since its not a device specific .zip file, i want to know how and why any problems are caused in any device( there are many common problems, but that is not what i ask for. I ask for device/os specific problems, and not for a problem that we can cure after booting, but for a problem that can make the device un-bootable) . So u people may help me to find those problems and cures for it. For my knowledge i have experience with wildfire and hd2.
Well i will keep this thread for a week or two, so that u can post ur knowledge, and info. after that i will release the file for u.
To the admin. Of the forum, pls keep this thread as announcement so that all can take a look.
HYPERDROID EXTREEM EDITION-THE NEW BENCHMARK ROM FOR HD2.
I like Aroma, thanks for pointing that out! And yes... good idea... and a lot of work
Sorry but this is not development but merely an idea.
As soon as you have something that can be downloaded or something that shows active development (Git, sources, progress reports, individual scripts) then you can pm me to reopen the thread.
PS: You can also open such a thread in the general subforum.
Introduction to Rooting:
This is meant as a very basic discussion for people relatively new to rooting and Android or people that go through the steps but don't have a good idea of WHY. As a result, it will omit many details and simplify others. Also, it's not meant to be a rooting guide (as there are excellent ones out there already) so much as an explanation of concepts most of us take for granted, but noobies don't. All of this info is out there, but when you're new you may not know how to find it or even that you should be looking for it.
DISCLAIMER: I, nor anyone else, am not responsible for what you do with your phone. Rooting and otherwise altering your phone has the potential to brick your device, void your warranty, and many other bad things. Perform these actions at your own risk.
Post 1: before you root
What is rooting?
Phone Partitions
Intro to ROMS and kernels
Post 2: rooting and flashing
Steps of rooting
How to flash ROMs
What is root/rooting?
In Unix-style operating systems, "root" is the name of the user who has all permissions and is therefore able to run/modify/change/delete just about anything. If you're familiar with Windows, this account is called Administrator. The default account (that's you!) on an Android phone does NOT have these privileges. Rooting is the process of obtaining them (i.e. obtaining root access). Once you root, you can "flash" new software onto your phone without (much) restriction. This is great because you now have control over what programs are on your phone, how your phone handles resources, what kernels you run, and more!
Once your phone is rooted, you don't always wield all of that power. You control your access to all these new abilities with a program called SuperUser (available on the market and baked into ROMS). This program can grant these special rights to any other program that requests them. So let's say a program wants to write data to a place it's not normally allowed. It will ask SuperUser to up its privileges and then BAM! it can write where it wants to. You yourself can gain SuperUser privileges in a shell by typing su. Then YOU can read, write, and execute to your hearts desire.
Before you root:
Before rooting, there are some basic things you should know.
Phone partitions: Your phone has a number of partitions. The important ones to know at first are:
1. System - this partition is essentially what you think of when you think of the operating system, the Android UI, and preinstalled apps. When people talk about flashing ROMs (e.g. CyanogenMod, Synergy, etc), they are talking about flashing a new system partition...with some exceptions to be discusse later.
2. Boot - this is the kernel and ramdisk. The kernel is responsible for managing the interactions between the phones software (including the ROM) and the hardware. Altering the kernel can increase/decrease performance, battery life, and more because it manages applications and system resources. When you flash a new kernel, it flashes to the boot partition. You may not notice a big difference like you do when changing ROMS, but behind the scenes, your phone's performance can be drastically altered. A *LOOSE* analogy is that the ROM is like the body and interior of your car (including color, AC, stereo, heated seats, TV in headrests, etc.) and the kernel is like the engine. You may not see it, but you'll know it's there if it's awesome or it sucks.
3. Aboot - this was largely unimportant for newbies until the bootloader lock/unlock situation. The short story is that aboot contains functions which authenticate the boot partition (that's the kernel, remember?). It checks to see if your boot partition is Verizon legal and if not, it aborts the boot process and politely tells you to contact Verizon. This authentication is what is referred to as a "locked" bootloader. It prevents you from completely booting the phone with a custom kernel. The bootloader is "unlocked" by replacing the stock aboot partition with one that does NOT check up on the boot partition. This is important because it allows us to run whatever kernel we want without bothering with kexec.
4. Data - this contains user installed apps, settings, contacts, bookmarks, etc, etc, etc. You can wipe this partition (as opposed to the above partitions) and still boot into the operating system. However, you will have lost all your setting and user installed apps. This is also called a factory/data reset.
5. Cache - this is stuff that you frequently use so it's kept available by Android. You can wipe it without much consequence and SHOULD wipe it when flashing new ROMs.
6. Recovery - this partition contains a separate operating system that allows you to recover from a corrupted/absent/otherwise jacked up Android operating system. It has a number of other functions as well. The big ones are to backup your device and restore said backups, to wipe certain partitions, and to flash things to your phone (i.e. install new ROMs, recoveries, or other programs). The stock recovery is limited so you will definitely want a custom recovery, created by the fine devs in the community, on your device.
What is a ROM and what is a kernel?
I touched on this above. A ROM is what goes on the system partition. It contains what you think of as the Android OS including the UI and preinstalled apps. It controls how programs interact with you, the user. A kernel controls how those programs interact with the phones hardware. You need both a ROM and a kernel to have a functional phone. Not only that, but not all ROMs and kernels are compatible. A ROM based on Touchwiz (TW) needs a TW kernel and an AOSP (Android Open Source Project) ROM needs an AOSP kernel.
Kernels come as standard kernels, as described above, and kexec kernels. As the bootloader is unlocked, there's really no need for kexec on OUR device. However, it does bear mentioning...sooooo, kexec is a method of getting a custom kernel running without having it reside on the boot partition. Once the kernel is loaded, the phone doesn't care where it came from. Your phone has already checked the boot partition, OK'ed it, and loaded the kernel. The custom kernel that you actually WANT running is waiting patiently on your SD Card. The phone boots into a kexec enabled recovery, which loads the custom kernel while the over the current one (the boring stock kernel) while it is still running. The old bait and switch.
What is a recovery and which one should I use?
A recovery, as mentioned above, is a separate operating system that loads from the recovery partition and allows you to make changes to your phone should it need to be "recovered". It goes beyond this though, allowing you to backup and restore your phone, flash ROMs, flash a different recovery, install programs, mods, etc. On the d2vzw, you can enter recovery by powering down your phone and holding down volume up, home, and power. There are also ways to reboot into recovery easily through programs and mods commonly found in custom ROMs.
Backups of your phone are called nandroids and they contain the contents of the system, data, cache, recovery, and boot partitions. This means when you create a nandroid, you are backing up all that stuff.
I'm not going to tell you which one to use because for the most part it's a matter of preference. There are anecdotal stories about one recovery or another causing issues, but I've personally never had those issues and each recovery has its die hard supporters. I WILL say that if you want to use a ROM with a kexec kernel, you need a kexec enabled recovery. Lastly, if you decide to use kexec, your phone will look like it's bootlooping. That's normal.
I'm ready to start rooting/flashing!
There is an excellent guide stickied in the development thread here http://forum.xda-developers.com/forumdisplay.php?f=1672 (big thanks to droidstyle). However, many of us forget what it's like to be a COMPLETE newbie and to someone who has no idea about anything, even that guide can be a little intimidating. You can follow the instructions, but may not understand what you're doing. The steps to take to start out with are:
1. Make sure you understand what I've written above. Make sure you are comfortable with the possibility of bricking your phone.
2. Root your device. As I said above, this is simply gaining root/Admin/whatever you want to call it access on your phone. In and of itself, it does NOT alter the ROM or kernel. However, there are many different ways to obtain root and some of them DO alter these things. The easiest and safest way to root (IMO) is to use Noxious Ninjas excellent tool. http://forum.xda-developers.com/showthread.php?t=1792342. If you like it, I encourage you to donate or at least "Thanks" him. It works by taking advantage of debugfs permissions to get the su binary (remember this from above??) onto your phone with permissions set so you can run it. It therefore doesn't change ROMs or anything else. You won't lose data, apps, or anything else. It just sneaks su right onto your current setup.
3. Install a custom recovery. This will allow you to do all the fun stuff I talked about above. I recommend installing EZ-recovery from the market and flashing CWM 6.0.1.0.
-- Install EZ-recovery
-- Under the "Recovery" heading, click the Recovery radio button and select CWM 6.0.1.0
-- Click flash
4. Backup everything as if your life depended on it. This means backing up your NV/IMEI as shown here http://rootzwiki.com/topic/32397-tutorial-imei-backup-nv-with-qpst-us-variants/ and making a nandroid (see above). You can restore a nandroid backup and you'll be right back where you were before flashing or changing things around. You should also back up texts, anything on your internal sd card, and programs SEPARATELY from a nandroid (see below) so that you can easily replace them after flashing a new ROM. The steps to making a nandroid are (similar steps to restore):
-- Turn off your phone.
-- Hold down volume up, home, and power until recovery appears.
-- Use the volume rocker to go to "backup and restore" and hit the power button
--- Select backup and then select the external or internal SD card
5. Unlock the bootloader. See the aboot partition discussion above for what this means. You must do this seperately from flashing ROMs and kernels. Refer to this thread http://forum.xda-developers.com/showthread.php?t=1839791 and give appropriate thanks! A warning...if you mess up your aboot partition, there's really nothing (that I know of) you can do to revive your phone besides sending it to someone with JTAG.
A quick note about backing up apps. Personally, I use Titanium backup because I've used it forever...and I think it's a great app. I'm not going to go into details, because it's not too tough to do a few basic things with it and because I want to stick to things that will help prevent bricks.
You're now ready to start flashing ROMs!
As a precursor, there are ROMS that are based on TouchWiz modified Android from Verizon/Samsung and there are ROMS based on AOSP (e.g. CyanogenMod). TW roms need a TW kernel and AOSP roms need an AOSP kernel. Until you get comfortable with everything, I would stick with TW, but that's just my opinion. Don't worry, you'll get comfortable pretty quickly.
Also, some roms come with kernels and will flash the kernel to your boot partition in addition to flashing the ROM to your system partition. Some ROMs don't come with kernels. If the ROM you choose comes with a kernel, that's great. If not, you'll still have the kernel you are currently running and you need to make sure there are no incompatibilities with your new ROM. ALWAYS ALWAYS ALWAYS read the OP of a rom you want to flash to find out kernel information as well as how to install the rom and anything else you may need to know. The general steps to flashing a ROM are (remember to read the OP for specifics):
1. Backup apps, data, call log, contacts, messages, etc. My program of choice for much of this is Titanium Backup available on the market. If you choose to use it, buy it as you'll use it a billion times.
2. Download the ROM you want and check the MD5
3. Place the ROM on the root of your SD card. Do NOT unzip it.
4. Reboot into recovery and make a nandroid backup
5. Wipe data/factory reset and wipe cache. Wipe it more than once if paranoid. People sometimes talk about wiping Dalvik cache. It's an option in your recovery, but it's not necessary IF you did a factory/data reset because the Dalvik cache is on the data partition which is wiped in the reset. You may want to wipe the Dalvik cache for some other purpose however.
6. Go to "install zip from sdcard" and select the ROM you want
7. If you want/need to flash a kernel, install that zip from the sdcard too.
8. Reboot and restore all that you backed up
If you want to flash a kernel without flashing a ROM, all you need to do is reboot into recovery, make a nandroid, wipe cache and Dalvik cache, and install the zip from your sd card.
Remember:
-- ALWAYS read the OP before installing anything
-- backup before making changes
-- verify MD5 checksums
-- wipe data and cache when flashing a new ROM (unless told not to by the ROM dev...sometimes referred to as a dirty flash)
-- NEVER accept an OTA (having a custom recovery should block OTAs anyway)
That's it for now. If people like this or have requests about other good noob topics, I'll consider adding to it. If not, then screw you!
Reserved
I didn't realize it was that easy to flash a custom kernel. Cool. The guide is very helpful.
Nice writeup, a lot if good information. I think I've successfully graduated from noob but still like to read more. One minor problem I noticed. All your rooting, and unlocking links are for ICS I don't think anyone is still on it. You may want to link to open your eyes guide for JB.... which will probably require a whole post to explain what is going on.
Sent from my VS920 4G using xda app-developers app
Great post OP.
Hi guys .You all know me.
I have created this thread for the sole purpose educating every newbie and noob about ROM and it's components...
Here goes
Parts of a ROM
i. The kernel.
Android (like many other Smartphone operating systems) runs on the Linux kernel. The Linux kernel was created in the early 1990’s by a gentleman named Linus Torvalds in Helsinki, Finland. It’s incredibly stable, incredibly friendly, and incredibly difficult for the layman to understand and modify. Thankfully it’s also very popular so it has been ported on to a multitude of hardware, including our Android devices.
Think of the kernel as an interface layer between the hardware and software on your device. The kernel decides when things happen, such as the LED indicator gets lit or when the soft button's LED gets lit. An application sends a request to the operating system to blink the LED. The operating system then sends the request to the kernel, which makes the light flash for the amount of time requested by the OS.
What sounds like a round-about way to get things done is also what makes the system so scalable and robust. Application developers only have to code in a way the operating system understands and the kernel makes it work on the hardware. This also keeps the application running in it’s own user-space and separate from the kernel. That means when you run the latest uber-cool app that wasn’t designed for your particular OS version, or is still very beta and it crashes, the kernel gives you the option to Force Close the application and the kernel can run untouched.
In a standard Android ROM (we will leave developer images and the like for another discussion) the kernel is bundled along with a set of instructions that tell the device how to load the kernel and the OS during boot. This is the boot.img that you see inside a zipped ROM that your not able to easily open. The device knows to extract this image to internal memory (the ramdisk) and follow a series of scripts (init scripts) to load the kernel and then the other portions of the OS. That’s what’s happening while you’re watching the boot animation. Interestingly enough this is done the same way for a PC, your smartphone, an Android tablet, or even a smart Linux powered toaster. If you’re feeling exceptionally geeky, plug your Android phone into the USB port on your PC and let the PC boot from the USB device. No, it doesn’t actually load, but you can watch the animation while it tries to match up the hardware support with what’s inside your PC. As I said, Linux is amazingly scalable and as a result so is Android.
What is a kernel? If you spend any time reading Android forums, blogs, how-to posts or online discussion you'll soon hear people talking about the kernel. A kernel isn't something unique to Android -- iOS and MacOS have one, Windows has one, BlackBerry's QNX has one, in fact all high level operating systems have one. The one we're interested in is Linux, as it's the one Android uses. Let's try to break down what it is and what it does.
Android devices use the Linux kernel, but it's not the exact same kernel other Linux-based operating systems use. There's a lot of Android specific code built in, and Google's Android kernel maintainers have their work cut out for them. OEMs have to contribute as well, because they need to develop hardware drivers for the parts they're using for the kernel version they're using. This is why it takes a while for independent Android developers and hackers to port new versions to older devices and get everything working. Drivers written to work with the Gingerbread kernel on a phone won't necessarily work with the Ice Cream Sandwich kernel. And that's important, because one of the kernel's main functions is to control the hardware. It's a whole lot of source code, with more options while building it than you can imagine, but in the end it's just the intermediary between the hardware and the software.
When software needs the hardware to do anything, it sends a request to the kernel. And when we say anything, we mean anything. From the brightness of the screen, to the volume level, to initiating a call through the radio, even what's drawn on the display is ultimately controlled by the kernel. For example -- when you tap the search button on your phone, you tell the software to open the search application. What happens is that you touched a certain point on the digitizer, which tells the software that you've touched the screen at those coordinates. The software knows that when that particular spot is touched, the search dialog is supposed to open. The kernel is what tells the digitizer to look (or listen, events are "listened" for) for touches, helps figure out where you touched, and tells the system you touched it. In turn, when the system receives a touch event at a specific point from the kernel (through the driver) it knows what to draw on your screen. Both the hardware and the software communicate both ways with the kernel, and that's how your phone knows when to do something. Input from one side is sent as output to the other, whether it's you playing Angry Birds, or connecting to your car's Bluetooth.
It sounds complicated, and it is. But it's also pretty standard computer logic -- there's an action of some sort generated for every event. Without the kernel to accept and send information, developers would have to write code for every single event for every single piece of hardware in your device. With the kernel, all they have to do is communicate with it through the Android system API's, and hardware developers only have to make the device hardware communicate with the kernel. The good thing is that you don't need to know exactly how or why the kernel does what it does, just understanding that it's the go-between from software to hardware gives you a pretty good grasp of what's happening under the glass. Sort of gives a whole new outlook towards those fellows who stay up all night to work on kernels for your phone, doesn't it?
Click to expand...
Click to collapse
ii. The operating system.
Once the kernel is loaded, the init scripts tell the Operating System to load. Android is the user interface for a custom built Java virtual machine called Dalvik. Dalvik was written by Dan Bornstein, who named it after the fishing village of Dalvik in Iceland, where his family originated from. The debate of which Java VM is superior is best left for another discussion, so I’ll simply say that DalvikVM is a register-based machine versus true JavaVMs which are stack based.
The Dalvik machine creates executable files (.dex files) which can be interpreted by the OS and run by the end user. These .dex files are OS version dependant. That simply means that applications and core functions built to work with one version of Android may or may not work well with other versions. Google provides the tools through it’s Software Development Kit (SDK) for applications to communicate with the OS.
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iii. Core functions.
No smartphone would be complete without a set of functions that allow the device to be used as intended. Things like the phone and dialer interface, the calendar, the messaging system are core functions of the Operating System. In Android, these are run on top of the kernel as separate applications. The merits (or lack of) of providing these needed functions as separate applications is once again best left for another discussion, but this is what allows developers like HTC or Motorola to replace the standard functions with alternatives that provide a different look and feel from stock. HTC’s onscreen keyboard or Motorola’s MotoBlur contact list are great examples of this. The “little guy” isn’t left out of the mix either. Handcent SMS or Chomp SMS can integrate into the OS very well, as most of us already know.
An additional set of Core Functions are provided by Google. Popularly called GoogleBits, things like Gmail, sync, Gtalk and the Android Market are applications written by Google that give an extra set of useful functions to the OS. You’ll find these on all smartphones, as well as many other Android devices.
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iv. Optional applications.
These are applications provided by the manufacturer to give the device even more usability. Things like the Amazon MP3 store, PDF readers, Corporate Calendar etc. allow you to do even more with your device. Remember - Droid Does
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B. How is a ROM packaged?
In most cases a ROM will come packaged in a .zip file. The recovery image’s kernel (yes, it has one too!) has the ability to unzip and copy the contents into the correct place. Inside this zip file is a folder (META-INF\com\google\android\) that contains a script prepared by the ROM “cooker” (another of those techie terms - it means the person(s) who developed the ROM) that tells the system what to format, what to copy and where, and any file operations that need to be done. Each device does things a bit differently, but this script is where it all gets done. More on this folder later.
You’ll also see a /system folder. This is the meat of the ROM. It has the necessary OS files, the Core functions, and any optional applications the cooker decided to include. The folder is structured the same way it is on your device - /system/app, /system/framework, etc. The whole tree is usually copied over and the existing /system folder is overwritten. The cooker uses the script to tell the kernel to erase the existing system folder, copy the new folder over, and set the file permissions.
Sometimes you will also see a data folder. This usually is space set up for optional applications, including optional system tools like busybox or SuperUser white list. These applications could be placed in the /system folder, but placing them in the data folder makes it easier for the end user (you and I) to remove or update them as needed.
You’ll also notice a META-INF folder. This contains the update script we talked about earlier, as well as secure keys that need to be provided so the device knows the update can be trusted. A special note needs made here. Trusted means that the update is trusted to be in the correct form to load the device. It in no way means the ROM is safe from malicious code. Anyone is able to use a set of test keys and create a ROM that will flash and run your device - even those people with bad intentions. Flashing and running a custom 3rd party ROM is putting faith in the cooker that he or she not only knows what they are doing, but are honest as well. Also, some Motorola custom ROMs will have a small update.zip stored inside this folder to be run on first boot of the device.
Finally we are left with the boot.img file. This is the kernel and ramdisk image we discussed earlier. Your phone copies this over to be decompressed and run when the device boots.
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2. How do I install a ROM?
In this section we’re discussing how to install a custom 3rd party ROM. ROMs from the manufacturer usually have a utility that runs on your PC to flash and load the new image.
A. Got Root???
Yes ?:good:!!!
Custom ROM’s simply will not load on devices that aren’t rooted. In theory, it may be possible to sign a 3rd party ROM with the keys that the stock recovery image will flash, but for the most part you need to have flashed a custom recovery image before you can change your device’s ROM. Instructions and tutorials on how to root your device are all over the internet. Some are good, some are bad. The hacking forum is a great place to go and learn more about rooting and how to successfully get it done on your device.
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B. Recovery
Most Android devices have had a custom recovery image written for them. This will overwrite the stock recovery image, allowing you to flash 3rd party ROMs as well as giving extra functionality. Help with finding and flashing the custom recovery image for your device can also be found in the hacking forum. The installation of a custom recovery image also allows for a very important function. Backup and restore.
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.C. Nandroid
Nandroid is a set of bash scripts and code written by that copies the state of your system and stores it in a folder on your SD card. You can then use the restore function of Nandroid to restore to this point at any time. This is a priceless feature and reason enough to root your phone. It’s included by default in most custom recovery images, and the code is freely available to use if you’re inclined to write your own recovery image.
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In most situations, using Nandroid to back everything up is easy:
1. Verify you have a memory card with enough free space (~300MB to backup, ~500MB to restore).
2. Reboot your device into recovery. It’s slightly different for each device, once again hacking forum FTW!
3. Navigate through the menu and select the Nandroid Backup function.
4. Apply your choice and wait for the device to tell you it’s finished.
It’s always good practice to copy the entire nandroid folder from your SD card to a safe place. You can then copy it back to the SD card if the card is ever damaged, lost or erased.
D. Copy and Flash
You’re rooted, have downloaded a custom ROM, have your system backed up and are now ready to flash your device. This is not nearly as scary as it sounds.
1. Mount your SD card to your PC, and copy the .zip file to the root folder of the card. Don’t unzip the file, and don’t look for a folder called root. The root folder in this case means the base folder, what you will see when you mount your card to a PC or the device.
2. Reboot your phone into recovery.
3. Navigate through the recovery menu and select the flash update option. Depending on your recovery image, the file may need to be named update.zip, or you may be able to select any zip file on your card as long as it’s the correct format. The cooker knows this as well and if the ROM needs to be named update.zip it will be.
4. Apply your choice and wait for your device to tell you it’s finished.
5. Reboot.
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It’s worth noting that many times a new ROM will require that you wipe and factory reset your devices data. While inconvenient, it’s often necessary to get rid of the old data as it may be incompatible. As long as you’re using the cloud for calendar and contacts, they will be re- downloaded and stored back on your device automatically.
Credits
The internet
And other sites related to android development
And of course me
My Galaxy R forum friends !!
ERRORS encountered in CWM Recovery
.
What is CWM Recovery ?
ClockworkMod Recovery is a custom recovery for many Android devices. It is considered to be the most popular recovery for Android due to its easily-ported nature, and integration with ClockworkMod ROM Manager by Koush(Koushik Dutta). The easiest way to recognize it is by the printed name when it first starts, and the background logo of a gear and hat.
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ERROR STATUS 6
This is usually caused by CR/LF EOL(Windows style End Of Line) in updater-script. Change it to LF EOL(Unix Style EOL) using Linux command: dos2unix updater-script, then re-signing the ZIP, will usually fix this error.
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ERROR STATUS 7
This is usually caused by a corrupt download, or bad file signature. Re-downloading (or re-signing) the ZIP will usually fix this.
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We have been consistently seen and heard people facing error “Status 7″ error while trying to flash or install
custom ROMs or firmware packages on their Android smart phones or tablets with ClockworkMod Recovery. Many
of the users are nowadays facing this problem with CWM Recovery while flashing .zip files of modded or custom
Ice Cream Sandwich (ICS) or Jelly Bean (JB) ROMs on their devices. So, you have also downloaded a custom ROM,
placed its .zip file in your phone’s or tablet’s SD card, booted into ClockworkMod Recovery, selected – “install zip
from sdcard” and then chosen the .zip file of the ROM to get it installed on your device. But instead of getting
flashed successfully, if you are facing the issue mentioned below, then just keep reading this article to find out
what’s wrong and fix up the problem :
Finding update package…
Opening update package…
Installing update…
Error in /sdcard/custom-jelly-bean-rom.zip (Status 7)
Installation aborted
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or the following error right after CWM recovery shows –
Installing update…
assert failed: getprop(“ro.product.device”) == “I9103″ || getprop(“ro.build.product”) == “I9103″ || getprop
(“ro.product.board”) == “I9103″
Error in /sdcard/android-4-1-1-ics-rom-latest.zip (status 7)
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So, if you are facing any of these errors while trying to install the desired custom ROM package on your Android
phone or tab, then you may try a various things or steps which may turn out to be the workaround of this
problem. Here are a few tips to get this “Status 7” error fixed in ClockworkMod Recovery and flash the ROM
successfully on your device :
(1) First of all, make sure your device’s bootloader is unlocked. If it is already unlocked but you are still
not able to flash the ROM, then just extract the .zip file of the ROM into a new folder, find the boot.img file from
that directory and flash it up on your phone or tablet via fastboot on your PC.
(2) Make sure that you are having the appropriate Radio or Baseband version installed on your device which is
supported by the custom ROM you are trying to flash. Most of the ROMs requires the latest version of Baseband, so
just update or upgrade your device to the latest Baseband version and then try to install the ROM once again.
(3) Update your device to the supported / latest build of official firmware before trying to install the ROM. You can
do it from – Settings > About Phone / Device > Software Update.
(4) Make sure you are having the supported or required kernel installed on your phone or tab. If it’s not, then flash
a new kernel right away and try to install your custom ROM once again.
(5) Is the ROM which you are trying to flash really works ? Find out whether it is working for other users or not.
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NOW
ERROR STATUS 0
This is usually caused by an incompatible update-binary in edify ZIPs. Replacing it with a compatible one, then re-signing the ZIP, will usually fix this error.
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Now it's time for the partitions :good:
Let’s start with a list of standard internal memory partitions on Android phones and tablets. These are:
/boot
/system
/recovery
/data
/cache
/misc
In addition, there are the SD card partitions.
/sdcard
/sd-ext
Note that only /sdcard is found in all Android devices and the rest are present only in select devices. Let’s now take a look at the purpose and contents of each of these partitions.
/boot
This is the partition that enables the phone to boot, as the name suggests. It includes the kernel and the ramdisk. Without this partition, the device will simply not be able to boot. Wiping this partition from recovery should only be done if absolutely required and once done, the device must NOT be rebooted before installing a new one, which can be done by installing a ROM that includes a /boot partition.
/system
This partition basically contains the entire operating system, other than the kernel and the ramdisk. This includes the Android user interface as well as all the system applications that come pre-installed on the device. Wiping this partition will remove Android from the device without rendering it unbootable, and you will still be able to put the phone into recovery or bootloader mode to install a new ROM.
/recovery
The recovery partition can be considered as an alternative boot partition that lets you boot the device into a recovery console for performing advanced recovery and maintenance operations on it. To learn more about this partition and its contents, see the ‘About Android Recovery’ section of our guide to ClockworkMod recovery.
/data
Also called userdata, the data partition contains the user’s data – this is where your contacts, messages, settings and apps that you have installed go. Wiping this partition essentially performs a factory reset on your device, restoring it to the way it was when you first booted it, or the way it was after the last official or custom ROM installation. When you perform a wipe data/factory reset from recovery, it is this partition that you are wiping.
/cache
This is the partition where Android stores frequently accessed data and app components. Wiping the cache doesn’t effect your personal data but simply gets rid of the existing data there, which gets automatically rebuilt as you continue using the device.
/misc
This partition contains miscellaneous system settings in form of on/off switches. These settings may include CID (Carrier or Region ID), USB configuration and certain hardware settings etc. This is an important partition and if it is corrupt or missing, several of the device’s features will will not function normally.
/sdcard
This is not a partition on the internal memory of the device but rather the SD card. In terms of usage, this is your storage space to use as you see fit, to store your media, documents, ROMs etc. on it. Wiping it is perfectly safe as long as you backup all the data you require from it, to your computer first. Though several user-installed apps save their data and settings on the SD card and wiping this partition will make you lose all that data.
On devices with both an internal and an external SD card – devices like the Samsung Galaxy S and several tablets – the /sdcard partition is always used to refer to the internal SD card. For the external SD card – if present – an alternative partition is used, which differs from device to device. In case of Samsung Galaxy S series devices, it is /sdcard/sd while in many other devices, it is /sdcard2. Unlike /sdcard, no system or app data whatsoever is stored automatically on this external SD card and everything present on it has been added there by the user. You can safely wipe it after backing up any data from it that you need to save.
/sd-ext
This is not a standard Android partition, but has become popular in the custom ROM scene. It is basically an additional partition on your SD card that acts as the /data partition when used with certain ROMs that have special features called APP2SD+ or data2ext enabled. It is especially useful on devices with little internal memory allotted to the /data partition. Thus, users who want to install more programs than the internal memory allows can make this partition and use it with a custom ROM that supports this feature, to get additional storage for installing their apps. Wiping this partition is essentially the same as wiping the /data partition – you lose your contacts, SMS, market apps and settings.
With this, we conclude our tour of Android partitions. Now whenever you install a ROM or mod that requires you to wipe certain partitions before the installation, you should be in a better position to know what you’re losing and what not and thus, you’ll know what to backup and what not.
Nice thread, maybe add error status 0 for CWM
Sent from my C6603 using xda app-developers app
krabappel2548 said:
Nice thread, maybe add error status 0 for CWM
Sent from my C6603 using xda app-developers app
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Done !!!!
Great thread, You are seriously doing well.:good:
MY thanks just ended
will use the mob app to thank u bro !!
After all you inspired me for this thread not
Moved to android general as per OP request.
( i am new to this Flashing and if these questions were already answered anywhere please give me links i will study :highfive: )
15 days back i chose Cm13 nightly, installed Gapps .. There are somethings i didnt Understand, but i blindly Followed the Tutorials , although they helped me installing everything right.. i got some doubts left in my mind .. Can anyone please make big-heart and clear my doubts :silly:
1) When ever i UPGRADE to a new Nightly, All of my previously flashed zips ( moto camera, xposed framework .. etc ) vanish , But the Apps which i installed from Playstore and 3rdparty APKS are present .. WHY ?? is it normal ?
2) Whats up with these Clearning Cache/Dalvik and DATA .. what do they actually DO?? When do we need to perform?? ( before installing zips or after installing zips? what will they delete?? )
3)( i dont get it right, because i use a PC with Windows, when we are formatting it.. even though when we format every partition [i mean literally there is nothing in HDD]and install NEW os from USB or CD .. the OperatingSystem gets copied from those USB/CD ) is it the same case with this ANDROID (copies from SD card?)?? or do we need OS running properly in background ( to make CWM/TWRP work) ?? what happens if we install a ROM from Internal memory( incase if we dont have memorcard slot like nexus phones) ?? :cyclops:
4)If i am having a GAPPS version Old, if i want to update those.. what happens when we flash GAPPS latest version ( consider Open gapps) ? Does it cause anyproblem or Will it remove present GAPPS and install Latest version with out any problem ..
These are my doubts Will anyone please explain ?
1. Every nightly (or whatever upgrade via rom.zip) cleans up and places updated system files in /system.
To survive it, some, like gapps place a script in addon.d folder that automatically copies the file to another location and then restores after flashing nightly.
2. Cant explain myself, lol have a look here, it contains the definitions-
https://m.reddit.com/r/Android/comments/sthr8/dirty_flashing_what_it_is_and_is_not_lets_set_the/
3. Twrp just extracts the zip and places the files in correct directories, often assigning them correct permissions too. In case of android, the system files are placed in /system directory (the location is different, it is something like /dev/mmcblkXX, check the first lines in twrp when upgrading it would be like 'found ext4 /dev/mmcblkXX'. That partition is mounted to /system).
Android kernel is Linux-based which itself is Unix-like so a cool concept can be remembered as-
Everything in Unix is a file.(Google it your fascinated )
So it will work regardless of where you keep the zip file, only thing is that twrp should have full access to it. And like in windows, you may be able to even swap out /system with your internal storage just like we choose the partition to be C:\ .(i think it's theoretically possible they all are just storage spaces).
And, the operating system does not run in background while in recovery, think of it like an embedded os dual booted with android. Its totally independent of the current operating system. (You think ,if the os were needed to work in background, then how twrp could install a new rom over it, or still work after formatting /system?)
4. And at last, installing a newer gapps over older one automatically removes the older gapps and flashes the latest one (In case of opengapps you can see the twrp progress log when installing 'removing current/obsolete gapps' or similar ). I only tested it on opengapps pico.
I can't say it would be safe to install two different gapps over one another without a dirty flash (like bank gapps over opengapps). But note that you should clear dalvik&cache after flashing, if not done automatically.
Some additional links-
Dalvik cache related (straight from google search )-http://androidforums.com/threads/what-is-dalvik-cache.76110/
http://forum.xda-developers.com/showthread.php?t=1752390
http://android.stackexchange.com/questions/25859/why-do-i-need-to-wipe-dalvik-cache
https://www.androidpit.com/root-recommendations-custom-rom-wipe-cache
http://stackoverflow.com/questions/7541281/what-is-dalvik-and-dalvik-cache.
Hope it helps.[emoji16] [emoji39]
Broadcasted from Zeta Reticuli
@Gravemind2015 One thanx isnt enough for your INFO :good:
i got a mild doubt,
Does flashing Nightlies Daily effect our Memory ( internal/ Os related memory - like Formatting a USB Pendrive more times will decrease its Lifetime )
Is there any limit or should we even consider the number of times we Flash Roms into our phone?? Does it harm our devices??
nandakis4 said:
@Gravemind2015 One thanx isnt enough for your INFO :good:
i got a mild doubt,[emoji14]Does flashing Nightlies Daily effect our Memory ( internal/ Os related memory - like Formatting a USB Pendrive more times will decrease its Lifetime )
Is there any limit or should we even consider the number of times we Flash Roms into our phone?? Does it harm our devices??
Click to expand...
Click to collapse
It does effect as they are permanent (block based) storages, just as SSD drives, and then we also have to consider that we are not supposed to touch system partition by phone makers.
But we need not care. The phone will go on for years (many like defy or htc dream,evo 3d still work fine today) before having bad blocks in storage.
Got links for this topic too-
http://forum.xda-developers.com/showthread.php?t=2360531
http://forums.androidcentral.com/mo...ly-flashing-roms-bad-your-droid-s-health.html
The discussions in above links are interesting. I am just as curious as you, I think I got that from my cat[emoji14] . And BTW thank you for I too learnt many things today.[emoji108]
As jobs say it, Stay hungry, Stay foolish, (my addon) Stay Paranoid.[emoji14]
Broadcasted from Zeta Reticuli
Sure, it will shorten the life of the phone. It may crash in 20 years or 5 minutes but no one really knows. It should take many more writes than you'll ever give it.
Sent from my SM-T530NU using XDA-Developers mobile app