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This article mainly explains "what are the knowledge points of Android4.4 source code compilation", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Next let the editor to take you to learn "what are the knowledge points of Android4.4 source code compilation?"

5.4.1.1 compilation of uboot

Android4.4.4 corresponds to uboot source code, compiler, parameter configuration, compilation script, compilation parameters and

Android4.0.3 's uboot is all exactly the same.

5.4.1.2 compilation of Linux kernel

Source code directory

Download the source code corresponding to Android4.4.4 on the network disk. On the iTOP-4412 development board system source code and mirror image (its

He) under the "→" android_4.4.4 source code and image directory, under the folder of the latest date, the "iTop4412-"

Android4.4-kernel_xxxx.tar.gz "compressed package, xxxx represents the date.

Compiler

The Android4.4.4 kernel compiler is exactly the same as the Android4.0.3 kernel compiler.

Parameter configuration

Kernel compilation is a combined configuration file, and the basic configuration file name is "config_for_android_XX_YY"

XX,YY means to replace with the parameters shown in the following table. POP and SCP correspond to the POP and SCP;elite of the core board, respectively.

Super corresponds to elite version and all-around version respectively; no_wifi parameter is only used for elite version, which means that WiFi module is not supported (if not

If you have a WiFI module, you need to configure it as no_wifi).

As shown in the table above, if you need Android4.4.4 to support WiFi, you need to configure the corresponding parameters. WiFi is not supported.

Corresponding configuration is also required.

Examples of compiling and generating kernel images

Like the Android4.0.3 kernel, if you need to compile the kernel corresponding to the core board, first use the cp command to match the

The configuration file overrides ".config".

If you want to use a 5-inch screen, you should first refer to the user's manual "5.5 kernel patch file that supports 5-inch screen".

Patch the kernel, and then use the command "vim .config" to search for keywords in the file.

"CONFIG_TOUCHSCREEN_GT9XX=y", in the "CONFIG_TOUCHSCREEN_GT9XX=y"

Add a line of "CONFIG_TOPEET_LCD5X0=y" after that, and after adding it, as shown in the following figure. If the user does not use

You can skip this step with a 5-inch screen.

Finally, execute the compilation command "make zImage".

The directory where the kernel image is generated is also "arch"-- > "arm"-- > "boot".

For example: the development board is elite version, POP core board, need to support WiFi module, then the default file needs to be configured as

"config_for_android_pop_elite".

The development board is elite version, POP core board, does not support WiFi module, then the default file needs to be configured as

"config_for_android_pop_no_wifi".

5.4.1.3 compilation of Android4.4.4

Update environment javap

To compile Android4.4.4, a "javap" command is also missing. Use the command:

"update-alternatives-- install" / usr/bin/javap ">

"/ usr/lib/jvm/jdk1.6.0_43/bin/javap" 1 "

Update, as shown in the following figure.

Kernel and Android source path

When compiling Android4.4 source code, be sure to pay attention to the directory of the kernel source code. In and Android source directory

Under the same level directory of "iTop4412_KK4.4_git", decompress the kernel source code.

For example, as shown in the following figure, the author puts the kernel source code and the Android4.4 source code compression package into "/ home/iTOP-"

Under the "4412-Android4.4" directory, extract "iTop4412_KK4.4_git_xxx.tar.gz" and "iTop4412-"

Android4.4-kernel_xxx.tar.gz ", the Android source code is decompressed to get" iTop4412_KK4.4_git "and" iTop4412_KK4.4_git "

"kernel" directory. "iTop4412_KK4.4_git" directory is the Android source code

The kernel source code is in the "kernel/iTop4412_Kernel_3.0" directory.

In addition, before compiling Android4.4, the kernel corresponding to Android4.4 must be compiled successfully.

Then go to the folder "iTop4412_KK4.4_git" after decompressing the Android4.4.4 source code, and use the command

". / build_android.sh", run the one-click compilation script to start compiling Android4.4.4. Note: compile

Android4.4.4 must ensure that more than 3G memory is provided to Ubuntu systems. The meaning of "providing more than 3G memory"

Thinking is not just about setting up the allocation of 3G memory in the VMware Workstations virtual machine. For example, the user is compiling the

At that time, the total memory of the PC machine is 4G, and the 3G memory is set to be allocated in the virtual machine, but under the Windows system,

With QQ, antivirus software, music player, browser, etc., it takes up almost 2 gigabytes of memory under Windows.

Then the virtual machine is automatically adjusted to occupy only 2 gigabytes or even less than 2 gigabytes of memory, which cannot be compiled and passed.

The correct way to allocate memory is to first allocate more than 3G memory to the virtual machine, and then turn it off under Windows as much as possible.

If there are more unnecessary applications, turn off the background programs for as many applications as possible.

Of course, if the user's PC is 8 gigabytes or 16 gigabytes of memory, whatever you want.

After the compilation is complete, in the folder "iTop4412_KK4.4_git/out/target/product/smdk4x12"

Generate images "system.img" and "ramdisk-uboot.img".

It should also be noted that the Android4.4.4 source code needs to take up a large amount of space, and users need to make sure that there is enough.

The space can be compiled successfully. After the completion of Android4.0.3 compilation, a total of about 18G of space is occupied, compiled by Android4.4.4.

After the completion of the translation, it takes up a total of about 36G of space.

The user completely follows the steps to compile the error. You can use "df-l" to check how much space is left in the drive letter. If

If 100% has been used, there is not enough space.

At this point, I believe that everyone on the "Android4.4 source code compilation of what knowledge points" have a deeper understanding, might as well to the actual operation of it! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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