How to modify and create a refresh quota on the Android platform

From: http://www.g3top.com/

 

Here, we need to explicitly declare:
Because the Android platform has been updated too frequently, it may not be easy to use or be completely correct (just record some experiments I have performed on my Nexus One ). I am not responsible for any problems with your mobile phone !!

If you are a good English friend, you can simply look at the official reference website in English without having to look at the noise:
Http://forum.xda-developers.com/showthread.php? T = 566235

Users who only use the android source code to do some simple experiments can refer to the following websites:
Http://nhenze.net /? Tag = build-android
Http://developer.htc.com/adp.html

Speaking of Android refresh, it sounds mysterious. In fact, it is just a digital zip package. If you want to create a refresh box by yourself, you must understand the basic working principle of the refresh box. Let's start with the Android system:

When the Android system starts, it first performs operations such as hardware self-check. After these operations are completed (at least it should know whether the current machine has electricity ), check the current mobile phone button status (next, the so-called flash mode switch, different Android phones have different key combinations to enter the flash mode). If the key status is in the flash mode, then the system will call a program called Recovery in ROM (this is the so-called Flash program, it is just a tool program, it is used to check the integrity of the refresh and the validity of the digital signature. At present, the legitimacy of the digital signature will not be a problem for most root machines. Then, the Recovery Program will decompress the recovery program and then write the files in the recovery into the Rom, to complete the flash process). If the key is not marked as the flash mode, the system will create a memory disk and start loading the corresponding file system from the Rom, and copy the relevant files to the memory disk, and then boot Linux, then start the Virtual Machine Dalvik, then create a working process to load and run the framework, and then you will see the standby screen. Of course there are still many things happening in this process, and many services are started. To simplify the process, I will only explain it here, if you are interested, you can compare them with the Linux Startup Process.

To sum up, in fact, the Recovery Program is a compressed ROM file package. After the flash mode is enabled, the Recovery Program will write the files in the flash drive into the ROM storage area to replace the original files in the ROM storage area; when you start the phone next time, the system will load the replaced files from the ROM and use these files to start and run the system. This is all the functions and functions of the Refresh. If you don't understand it, you can read it several times. The essence of the refresh is file coverage and replacement operations. I believe you can understand it!

OK. Now we know that the zip package of the ROM file is called the "refresh. The process of creating a refresh is to prepare these files and then compress these files into a zip package. At the end of the process, sign the file using the signature tool, you can test and release the refresh feature. Although it is just one sentence, the process of preparing these files is very painful and long.

What files are contained in the update.zip package? How are these files made? Hohoat: Now, the problem is solved by starting from the beginning. After Uncompressing this update.zip package, we can see two directories and one file:

Boot. IMG <--- file, which is the kernel image generated by compiling the kernel source code, and then ramdisk compiled with the android source code. IMG was created through the mkbootimg tool together. Friends who save time can copy a usable image from other online refresh tools, which is almost the same.

META-INF <--- directory, this directory is manually created, mainly used to store an upgrade script Update-script (the content of this script is highly associated with the files contained in the system directory) and save the signature of several APK files in the refresh folder.

System <--- Directory, which is generated by compiling the source code of the Android platform,

The best learning method is to unpack the update.zip package on the Internet now, read and analyze the package one by one, modify the package one by one, and try to do your own refresh.

For this boot. IMG, the basic idea is to compile the android kernel code, generate the kernel image, and then use mkbootimg to refer to the following two wiki websites:
Http://android-dls.com/wiki/index.php? Title = HOWTO: _ unpack % 2c_edit % 2c_and_re-pack_boot_images

Http://android-dls.com/wiki/index.php? Title = replace_recovery_partition

The following practices are even completed in Linux (slackware 13.1 ):
(1) download and compile the android source code.
If you do not know the commands such as repo sync, you can refer to the articles on the Internet about downloading Android source code and compiling. These articles are very rich as I know. You must pay attention to the platform selection before compiling. Drivers for different platforms are different! You can use the following parameters:
$ CD Android-Src <--- enter the android source code directory
$. Build/envsetup. sh <--- set environment variables. After running the command, you can enter the HELP command to see how many convenient commands the Google team provides, this is very helpful for us to modify the code and re-compile it later.
$ Lunch generic-Eng <--- start to configure the compilation options of the android source code
After running the preceding command, the following output is displayed:
Wayne @ WAYNE :~ /Android-Src $ lunch generic-Eng

========================================================== ====
Platform_version_codename = REL
Platform_version = 2.1-update1
Target_product = generic
Target_build_variant = ENG
Target_simulator = false
Target_build_type = release
Target_arch = arm
Host_arch = x86
Host_ OS = Linux
Host_build_type = release
Build_id = eclair
========================================================== ====

$ Make-J2 <--- only single-core CPU users can try this parameter. dual-core users can try-J3. Otherwise, they can run make in an honest manner.

Then there is a long wait, which takes about 1-2 hours (even if the machine is slow). After the compilation is complete, the hard disk will take about 8 GB.

(2) After compilation, enter Wayne @ WAYNE :~ The/Android-src/out/target/product/Generic Directory should see the following file:
Android-info.txt
Data
OBJ
Ramdisk. img
SDK
System
Userdata. img
Clean_steps.mk
Installed-files.txt
Previous_build_config.mk
Root
Symbols
System. img
Is system. IMG very familiar ?! In this case, the refresh folder also seems to have a directory named system. What are there in this system. IMG? This is actually the content in a directory named system in the current directory, but it is saved as the format of the yaffs file system. We can use the unyaffs tool to parse system. IMG to understand what we are talking about.
The unyaffs code is:
Http://code.google.com/p/unyaffs/downloads/list

Or download the Win32 version.

Http://jiggawatt.org/badc0de/android/index.html
Note that you need to download cygwin1.dll and cygz. dll (zlib0 package) at cygwin.com ).

In Linux, the compilation method is very simple. You only need to download the source code and then run:

$ Gcc-C unyaffs. c
$ Gcc-O unyaffs. o
You can generate the unyaffs unpack tool. You can use this tool to unpack your own system. IMG, and then modify the content.
Unyaffs is easy to use:
$ Unyaffs system. IMG [Press enter]
You can decompress system. IMG into a directory named system, which contains the entire android file system.

(3) At the beginning, it is not suitable for everything from the beginning. We should be honest with each other. Let's start by modifying the refresh of other experts.
First, copy a refresh token downloaded from the internet and find a directory to decompress the package (of course, this is the safest practice. It is not a problem to make these directories by yourself, but it takes a lot of time)
$ Unzip xxxxxx.zip <--- this xxxxx.zip is a refresh token downloaded from the Internet (it must be basically the same as your code version. Here I use a refresh token of 2.1)

(4) replace the original system directory
After decompressing and refreshing, you will see the two directories mentioned at the beginning, one file:
Boot. img
META-INF
System
All right, you can copy the system directory to another path and back it up to prevent other problems from these modifications. Then run Wayne @ WAYNE :~ Copy the system in the/Android-src/out/target/product/Generic Directory to the current working directory. Note that many "Symbolic Links" in this system directory point to toolbox. These links are useless and can be automatically created using the update-script later. Therefore, you need to delete these links using a script.
Refer:
Http://forum.xda-developers.com/showthread.php? T = 566235
The attachment of this webpage is changed to deleteextras.txt to a deleteextras. Sh script to clear these symbolic links.

(5) modify the update-Script script
Modify the update-Script script in the META-INF/COM/Google/Android directory, it mainly deletes some non-existing files and adds definitions such as the permissions of some files (the syntax is very clear and clear at a glance ). Prepare the APK installer that requires "pre-installation" to the refresh box and copy the APK to the system/APP directory. The boot. IMG won't be changed if it can be changed, because it involves driver and kernel issues and cannot be started when a problem occurs.

(6)re-package into update.zip
$ Zip-r update.zip. <--- note that the last "." is indispensable, which indicates the meaning of the current path.

(7) signatures for well-prepared refresh accounts

In the link mentioned above, there is a tool named autosign. It is a jar toolkit.

/Files/shenhaocn/autosign.zip

Run the following command to sign the hacker:
$ Java-jar autosign. Jar update.zip update_signed.zip

OK. After the signature is completed, you can back up the items in the mobile phone and test it.

 

 

Below are related posts and content

How to create your own Rom update.zip for the T-Mobile mytouch
3G

Things you will need to perform this:
Java SE Dev Kit from sun.
Java.sun.com
May need cygwin with zlib0 package, from
Cygwin.com

This will give you Android 1.6 with all the Google
Applications, root access.
I never found one place where all this information
Is all together, so that is why I compiled this together.
Now anyone can do
This themselves.

Thanks to all the hard work others have done before
This.

1.
First root your phone and install a new recovery image,
Either Amon Ra or cyanogens recovery image.
Instructions for one-click root:
Http://theunlockr.com/2009/08/22/how...-in-one-click/

2.
Download
The Android 1.6 system image from
Http://developer.htc.com/google-io-device.html

Extract
The contents of signed-google_ion-img-14721.zip.

3.
You now need
Extract the contents of system. IMG using a tool called unyaffs. The source code
Is here:
Http://code.google.com/p/unyaffs/downloads/list
Or download
A prebuilt Win32 version here.
Http://jiggawatt.org/badc0de/android/index.html
Note you
May also need cygwin1.dll and cygz. dll (zlib0 Package). Found
Cygwin.com

Of course if you already have cygwin installed with the GCC
Packages, you can just compile it yourself. Then also
If you comment out
Line 67 to "// symlink (OH-> alias, full_path_name );"
Then it will not
Create the copies of the symbolic link file, and you will not have to worry
About deleting duplicate
Symbolic Link files later.

Now in
Directory where system. IMG exists, create a new directory called "system"
Go
Into the "System" directory.
Type the following command:
Unyaffs
.. \ System. img

That shoshould extract all the files from the system. IMG File
Into the system directory.

4.
Now we just need to clean up some items.
Since the system. IMG is a Linux file system, it has symbolic
Links built
Into it, but when we extracted it, it just created duplicate files, if you used
The prebuilt unyaffs.exe.
So we can just delete the duplicates and have
Script recreate the symlink on install.

So we need to delete some extra
Files from the System \ bin directory.
Run the attached deleteextras. BAT file
From the same directory where system. IMG is in.
If you notice, all the files
It deletes are 28 byte files, and if you open them in Notepad only
Contain:
"! <Symlink> toolbox ..."
And we will remake the Symbolic Link
When it is installed.

5.
Now from the directory where
System. IMG is, enter the following commands
Mkdir META-INF
Mkdir
META-INF \ com
Mkdir META-INF \ com \ google
Mkdir
META-INF \ com \ google \ android

Now copy the encoded file
"Update-script.txt" into the "META-INF \ com \ google \ android" Directory
And
Rename it to just "Update-script ".
This update-script gets run to recreate
The symbolic links.

Not sure if these two are needed but they are in some
Custom ROMs here:
Copy the two files "fix_permissions" and "flash_image"
The "SYSTEM \ bin" directory.

6.
-- Optional --
These add Root
And superuser access to the Rom, plus the terminal emulator
Application.

Copy the file "Su" from cyanogen's Rom to the folder
"SYSTEM \ bin"
Copy the file "superuser.apk" to the folder "SYSTEM \ app"
Copy
The file "term.apk" to the folder "SYSTEM \ app"

You can also replace
"SYSTEM \ etc \ apns-conf.xml" with a more complete one from here:
Http://forum.xda-developers.com/showthread.php? T = 547718
Or
Here
Http://docs.google.com/Doc? Docid = 0az... g3ejn3eg & HL = en

Turn
Data roaming off by default by editing line in the build. Prop
File:
Ro.com. Android. dataroaming = false

Also to fix the market Program
To show "protected" applications change the Ro. Build. Fingerprint line to
Following:
Ro. Build. Fingerprint = tmobile/opal/Sapphire: 1.5/coc10/150449: User/Ota-rel-keys, release-keys

Only
Phones with a fingerprint of a "released" device can access some market
Applications.

--------------

7.
Now we just need to create
ZIP file for the final Rom

Zip up the following file and two
Folders:

Boot. img
META-INF
System

8.
Now sign the zip
File.
See here how to sign a zip file for flashing it.
Http://androidforums.com/developer-1...ning-roms.html

9.
Copy
It To Your SD card, boot into recovery, wipe, apply the update, reboot.

You
Are now running Android 1.6!

/Files/shenhaocn/update-script.txt

/Files/shenhaocn/deleteextras..txt