As the title is self-explanatory, I'd want to replace some files in system/bin/ and system/lib/ right before when the system.img is being generated.
To be more exact, I've got some prebuilt .so files which shuold be copied over the existing ones. For example libart.so. Please note that replacing art/ (source code of art) with the modified art source code is not an option.
To do this, which mk file should I investigate and put my replacing code into?
You may follow the same structure as the one proposed in this other question, but use this macro:
PRODUCT_COPY_FILES += \
device/common/my_bin.bin:cache/my_bin.bin \
device/common/my_so.so:system/art/my_so.so
This works as follows:
The file is copied from left to(:) right.
When the image is generated, in this case cache or system, it would be generated with the files contained in those folders.
As we have copied our files to that destination, when system.img is generated, our file will be contained.
Also, the order in which this files are copied, matters. For instance if you are copying a file that already exists, hence, you want it replaced. (As your libart.so), you would need YOUR call to that copy to be done before the default one.
For this, I recommend doing:
source build/envsetup.sh
lunch <<device>>
mgrep libart.so -> This does a grep through mk files, so you can see where the default copy is done.
Insert $(info whatever) calls in desired mk files to trace where is a good spot to add your PRODUCT_COPY_FILES.
It's not easy to answer where to add it. I have never modified libart.so myself, but I have copied many files this way and it works like a charm.
I hope it works for your case as well.
A quick dirty way to this:
Copy desired files to out(..)/system/lib or wherever after system.img has been built
make snod
Other way is using Android.mk. Create a new dir in device tree eg libart-prebuilt. Put here your lib, then create an Android.mk file with content
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libart-prebuilt
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE_PATH := $(TARGET_OUT)/lib
LOCAL_MODULE_STEM := libart
LOCAL_MODULE_SUFFIX := $(TARGET_SHLIB_SUFFIX)
LOCAL_SRC_FILES := libart.so
LOCAL_MODULE_CLASS := SHARED_LIBRARIES
include $(BUILD_PREBUILT)
Now just add libart-prebuilt to PRODUCT_PACKAGES in your device.mk
Also there's an option to add binary .so library as a product package, using PREBUILT_SHARED_LIBRARY option in .mk file: Include prebuilt shared library in Android AOSP or BUILD_PREBUILT https://stackoverflow.com/a/25682674/1028256
Related
I am a android NDK newbie, I am trying to follow the documentation at https://developer.android.com/ndk/guides/prebuilts and I found it is unclear on how to setup the code.
So to declare a prebuilt library, it shows the first step:
Give the module a name. This name does not need to be the same as that
of the prebuilt library, itself.
Question 1: What does this mean by giving the module a name? rename the module folder? is this the folder usually called jni/? does it matter where this folder should be?
Question 2: If I don't find this jni/ folder, should I just add one by creating a new folder or right clicked on my project in android studio to add new module? I did the right click thing and there is no such module for native c++ libs.
the second step:
In the module's Android.mk file, assign to LOCAL_SRC_FILES ...
Question 3: Should I create the 1Android.mk` file by myself? if it is a must, why not have it generated automatically?
I then tried to follow the documentation at https://developer.android.com/studio/projects/add-native-code#new-project but there is no such Android.mk file created...
Anyway, in the Android.mk file it has something like this:
include $(CLEAR_VARS)
LOCAL_MODULE := foo-user
LOCAL_SRC_FILES := foo-user.c
LOCAL_SHARED_LIBRARIES := foo-prebuilt
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)
include $(BUILD_SHARED_LIBRARY)
Question 4: On the documentation page, where variables like PREBUILT_SHARED_LIBRARY BUILD_SHARED_LIBRARY is defined? can these path can be any place in the system as long I define it with full path?
Question 5: for LOCAL_PATH, I understand it is the local path where the Android.mk file locates, does that mean 1) the system will find this file automatically, 2) I can only have one folder with Android.mk if I want to use native libs?
I need to copy a directory tree with XML files recursively to the out directory using Android.mk file
The directory structure is like this:
parent directory has three sub-directories each with an XML file. The parent directory also includes an Android.mk file.
The Android.mk file in parent has the following rules:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := file.xml
LOCAL_MODULE_TAGS := optional debug
LOCAL_MODULE_CLASS := ETC
LOCAL_MODULE_PATH := $(TARGET_OUT_ETC)
LOCAL_SRC_FILES := file.xml
include $(BUILD_PREBUILT)
I need to define LOCAL_SRC_FILES and LOCAL_MODULE_PATH as the source and target directories.
Could someone please let me know how to do it?
Basically the issue here is the "LOCAL_MODULE" needs to be defined for each file in this case. And it needs to be unique. If we try to have the same name for all three subdirectories, make fails with an 'already defined' error.
As a workaround, I defined LOCAL_MODULE for each of the three files with unique filenames. I don't think there is any other option of resolving this.
As an aside, I ought to mention that it is possible to copy files by running cp command directly from make. Please see Copy multiple txt files in /system using Android.mk
However, please note that running shell commands directly from within Android.mk files is deprecated starting from Android N.
I'm trying to build a project using the android ndk (on Windows), and I'm having some issues specifically with the source files (LOCAL_SRC_FILES in the Android.mk)
I'm trying to use relative paths to a parent folder such as
LOCAL_SRC_FILES := ../../../src/main.cpp
And when running ndk_build.cmd, it outputs the following error:
Compile++ thumb : GTP <= main.cpp
The system cannot find the file specified.
make: *** [obj/local/armeabi/objs/GTP/__/__/__/src/.o] Error 1
So I tried using absolute paths:
LOCAL_SRC_FILES := D:/Path/To/src/main.cpp
Unfortunately this doesn't work because the : causes issues on windows
Is there any way I can specify source files in a relative directory (or absolute)? The reason I am asking is because I want to avoid making a symbolic link to the src folder if possible.
According to ndk documentation it is recommended to use relative paths and the following macro (Android.mk uses syntax of make files):
LOCAL_PATH := $(call my-dir)
An Android.mk file must begin with the definition of the LOCAL_PATH variable.
It is used to locate source files in the development tree. In this example,
the macro function 'my-dir', provided by the build system, is used to return
the path of the current directory (i.e. the directory containing the
Android.mk file itself).
So you can replace your LOCAL_SRC_FILES with something similar to:
LOCAL_SRC_FILES := $(LOCAL_PATH)/../../../src/main.cpp
The easiest way to work with source files spread across many directories, is to compile separate static libraries for each directory or group of directories. In NDK, these libraries are called "modules". For each module, you specify LOCAL_SRC_PATH in Android.mk. LOCAL_SRC_FILES are relative to this path. The caveat is that LOCAL_C_INCLUDES etc. are relative to project root directory (usually, the one above the jni directory).
You can have many Android.mk files in your project, but you can build many modules with single Android.mk.
Try this:
LOCAL_PATH:=$(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES := YOUR_SRC_IN_LIB_JNI
This question seems to have been asked a lot but all were trying to use eclipse to package the library inside the APK.
However, my requirement is to package the library inside the APK (which will later be loaded using System.loadLibrary() through Java) using the Android build system, i.e. i want to write an Android.mk file that does this job.
Requirement:
1. Prebuilt shared library: libTest.so
2. Write an Android.mk file that will package this to libs/armeabi-7 inside the apk.
I don't know much about the build system I am using but the compilation is done using "mm" command after exporting the required environment variables.
When I provide libTest for LOCAL_JNI_SHARED_LIBRARIES, it tries to find it inside its exported paths and fails to find it there and hence build fails.
Can anyone please give any pointers on writing an Android.mk file that will package my prebuild shared library into the APK?
In order to prebuild your native library you have to
Create jni folder in your project folder
Create libs folder in your project folder
Add Adnroid.mk make file to the jni folder, it should looks like
this:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_LDLIBS := -llog
LOCAL_MODULE := Test
LOCAL_SRC_FILES := Test.cpp
include $(BUILD_SHARED_LIBRARY)
Note 1: Test.cpp is the main library source file containing implementation of native methods. You can add more sources as a space separated list.
Note 2: Do not include headers, they are included automatically.
Note 3: If you need to enable C++ STL, then create another make file - Application.mk, add it to the jni folder and set APP_STL := stlport_static flag in it.
Then you will have to set up a builder. Refer to this article for how to do that:
After these steps, the builder will create your library in the libs folder which will be automatically packed into the apk when building the whole application.
Note: Your library name should be lowercase, it is a Linux convention. The "lib" prefix will be automatically added, so the final library name will be libtest.so.
Let's say there is one libxxx.so shared library under libs/armeabi/ of project which you want to pack into apk. There are 2 things you need to do in the Android.mk as below:
# 1. Copy .so to out/target/product/***/obj/lib
$(shell cp $(wildcard $(LOCAL_PATH)/libs/armeabi/*.so $(TARGET_OUT_INTERMEDIATE_LIBRARIES))
# 2. Make libxxx to be packed into apk
LOCAL_JNI_SHARED_LIBRARIES := libs/libxxxx
Then you can use apktool to unpack the built apk, you will find the libxxx.so will be located in libs/armeabi*/. It is indeed packed into the apk.
I had two LOCAL_JNI_SHARED_LIBRARIES that I wanted to build into my APK. I manage to do it by setting the following in my Android.mk:
LOCAL_MODULE_TAGS := samples
After re-compiling the module I was able to find both libraries inside the .apk under /lib/.
Is there a macro or command to copy files? I'd like a 3rd party library (libThirdParty.so) to be copied to the output directory (lib). This is the contents of my Android.mk file
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := ndkFoo
LOCAL_SRC_FILES := ndkFoo.c
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)
I have a build step I added for one of my .cpp files that's generated; you could do something similar.
Note that I was told that what I was doing was Not Supported by Google, so use at your own risk. I've been using something like the code below for more than a year, though. Here's a rough idea of what it would look like:
LOCAL_PATH:= $(call my-dir)
# this was important for some cases; can't remember if it's important here, but I don't want to steer you wrong if it isn't
REAL_LOCAL_PATH:=$(LOCAL_PATH)
include $(CLEAR_VARS)
LOCAL_MODULE := ndkFoo
# again, I'm being paranoid here
REAL_LOCAL_MODULE := $(LOCAL_MODULE)
LOCAL_SRC_FILES := ndkFoo.c
$(REAL_LOCAL_PATH)/obj/local/armeabi/$(REAL_LOCAL_MODULE).so : $(REAL_LOCAL_PATH)/libs/armeabi/libThirdParty.so
$(REAL_LOCAL_PATH)/libs/armeabi/libThirdParty.so : $(PATH_TO_LIB_THIRD_PARTY)/libThirdParty.so
cp $(PATH_TO_LIB_THIRD_PARTY)/libThirdParty.so $(REAL_LOCAL_PATH)/libs/armeabi/libThirdParty.so
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)
Note you'll need to define PATH_TO_LIB_THIRD_PARTY.
ALSO note that copy-and-paste may or may not work. Makefiles are notoriously picky about indents. I'd make sure that the "cp" line has a real tab indent, and that nothing else is indented. If "cp" doesn't work, then make may be delegating to CMD, and you can try "copy" instead.
Good luck.
I know this thread is old, but found it while searching for something myself.
From the PowerVR SDK, Android.mk file.
You can create folders and copy files.
PVRSDKDIR := $(LOCAL_PATH)
ASSETDIR := $(PVRSDKDIR)/TrainingCourse/IntroducingPOD/OGLES2/Build/Android/assets
$(ASSETDIR):
-mkdir $(ASSETDIR)
$(ASSETDIR)/tex_base.pvr: $(ASSETDIR) $(PVRSDKDIR)/TrainingCourse/IntroducingPOD/OGLES2/tex_base.pvr
cp "$(PVRSDKDIR)/TrainingCourse/IntroducingPOD/OGLES2/tex_base.pvr" "$(ASSETDIR)/"
Google has a feature that is exactly intended for your use case: PREBUILT_SHARED_LIBRARY
If you check the documentation in the docs directory included in the NDK, you will find ANDROID-MK.html which mentions this feature briefly, and PREBUILTS.html which completely documents the feature. You can specify the source and destination directories, and you can specify a new name for the file when it is copied.
There is also PREBUILD_STATIC_LIBRARY which does the same thing for a static library.
It might be possible to trick it into copying arbitrary files... the above features are implemented by files called, respectively, prebuilt-shared-library.mk and prebuilt-static-library.mk. Inside, they define an extension that must be on the file (respectively .so and .a). You could probably make another .mk file that defined some other extension to enable copying some other kind of file. But we have only needed to copy libraries and we haven't experimented with trying to trick the build system.
P.S. This blog posting is interesting. It refers to BUILD_PREBUILT, which doesn't exist in my copy of the NDK. I wonder if this blog posting refers to an earlier version of the NDK, which had BUILD_PREBUILT to copy any kind of file (with no check for a required extension).
http://karthiksden.blogspot.com/2011/03/copying-data-files-using-androidmk.html