Difference between user version and ENG version

[Description]
Differences between Android user and ENG
 
[Keyword]
Project version difference of user Eng
 
[Solution]
Google official description: User/userdebug/eng version differences, refer to the detailed description of Alps/build/CORE/build-system.html
Eng this is the default flavor. A plain make is the same as make Eng.
* Installmodules tagged with: ENG, debug, user, and/or development.
* Installnon-APK modules that have no tags specified.
* Installapks according to the product definition files, in addition to tagged apks.
* Ro. Secure = 0
* Ro. debuggable = 1
* Ro. kernel. Android. checkjni = 1
* ADB is enabled by default.
* Setupwizard is optional
User make user
This is the flavor intended to be the final release bits.
* Installmodules tagged with user.
* Installnon-APK modules that have no tags specified.
* Installapks according to the product definition files; tags are ignored for APK modules.
* Ro. Secure = 1
* Ro. debuggable = 0
* ADB is disabled by default.
* Enable Dex pre-optimization for all target projects in default to speed up device first boot-up
Userdebug make userdebug
The same as user, doesn t:
* Also installmodules tagged with debug.
* Ro. debuggable = 1
* ADB is enabled by default. MTK supplement differences:
(1) In terms of DEBUG/log, in principle, the user version can only capture limited information, while Eng can capture more information. The debug version is more powerful, and The ENG version is recommended for development and testing.
* Due to the different Ro. Secure Settings of user/eng versions, the user version ADB only has shell permissions, while the Eng version has root permissions.
* MTK System Log after ICS, all logs are disabled by default in the user version, which is enabled by default in the Eng version to capture complete information.
* In the Eng version, the log volume is greater than or equal to the log volume of the user version. In some cases, check the eng/user version to check whether the log is printed.
* UART is disabled by default in user and UART is enabled in Eng by default.
* In the Eng version, enabling ANR predump will capture ftrace and get more information about ANR.
* In the Eng version, you can use RTT to capture backtrace. You can enable KDB for Kernel debug and use ftrace to capture CPU execution scenarios.
* MTK aee captures more exception information in the Eng version. For example, native exception captures core dump Information (2) performance. In principle, use the user version for performance testing.
* The user version uses DVM pre-optimization to speed up the first boot. The Dex file is decomposed into odex files that can be directly loaded and run. The ENG version does not enable this optimization.
* Fewer log printing and UART shutdown. In principle, the performance of the user version is superior to that of the Eng version (3) how to confirm the user/eng version
* At the Java layer, check the type value in the Android. OS. Build class.
* Native layer, property_get ("Ro. Build. Type", char * value, "eng"); then check the value
* When debugging, ADB shell getprop Ro. Build. Type returns the user or user version, and ENG or Eng version.
* Log: Check the Ro. Build. Type attribute in Mobile Log/aplog_xxxxx/versions. (4) how to compile the user/eng version.
* The ENG version is compiled by default. To compile the user version, add the parameter-O = target_build_variant = user, for example:
./MK-O = target_build_variant = user mt6577_phone new