Having got the Android Runtime to build, eventually, does it actually work ?
Running art the immediate answer is no,
$art
E/JniInvocation(46765): Failed to dlopen libart.so: dlopen(libart.so, 2): image not found
Failed to initialize JNI invocation API from libart.so
The art executable is a script which contains the following so it looks as though this problem is easily fixed.
...
invoke_with=
DALVIKVM=dalvikvm
LIBART=libart.so
...
Trying again after modifying the art script appropriately we get
$art
art I 46796 66656 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
/Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
--input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
--output-image-file=/Users/simon/Scratch/xper/art/android-data46788/dalvik-cache/x86_64/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art \
--input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
--output-oat-file=/Users/simon/Scratch/xper/art/android-data46788/dalvik-cache/x86_64/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat \
--instruction-set=x86_64 --base-offset-delta=9420800
patchoat W 46797 66657 art/runtime/gc/heap.cc:216] \
Could not create image space with image file '/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art'. \
Attempting to fall back to imageless running. \
Error was: Failed to load /system image '/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/x86_64/core.art': \
Failed to mmap at expected address, mapped at 0x100b06000 instead of 0x60000000and then it hangs/spins.
The address
0x100b06000
in the error message from patchoat shows that it is a 64-bit executable, so it needs to be rebuilt as a 32-bit executable.
Modifying the file
art/patchoat/Android.mk
in the same way as we did for dex2oat, rebuilding and trying again, remembering to specify that we want to use a 32-bit VM, we get
$art --32
art I 24835 34536 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
/Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
--input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
--output-image-file=/Users/simon/Scratch/xper/art/android-data24827/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art \
--input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
--output-oat-file=/Users/simon/Scratch/xper/art/android-data24827/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat \
--instruction-set=x86 \
--base-offset-delta=-11399168
Class name requiredwhich is definitely an improvement.
Trying again with
-help
to find out how to actually run something we get a long list of arguments we can use and an equally long list of arguments we cannot.
$art --32 -help
dalvikvm: [options] class [argument ...]
The following standard options are supported:
-classpath classpath (-cp classpath)
-Dproperty=value
-verbose:tag ('gc', 'jni', or 'class')
-showversion
-help
-agentlib:jdwp=options
The following extended options are supported:
-Xrunjdwp:<options>
-Xbootclasspath:bootclasspath
-Xcheck:tag (e.g. 'jni')
-XmsN (min heap, must be multiple of 1K, >= 1MB)
-XmxN (max heap, must be multiple of 1K, >= 2MB)
-XssN (stack size)
-Xint
The following Dalvik options are supported:
-Xzygote
-Xjnitrace:substring (eg NativeClass or nativeMethod)
-Xstacktracefile:<filename>
-Xgc:[no]preverify
-Xgc:[no]postverify
-XX:HeapGrowthLimit=N
-XX:HeapMinFree=N
-XX:HeapMaxFree=N
-XX:NonMovingSpaceCapacity=N
-XX:HeapTargetUtilization=doublevalue
-XX:ForegroundHeapGrowthMultiplier=doublevalue
-XX:LowMemoryMode
-Xprofile:{threadcpuclock,wallclock,dualclock}
The following unique to ART options are supported:
-Xgc:[no]preverify_rosalloc
-Xgc:[no]postsweepingverify_rosalloc
-Xgc:[no]postverify_rosalloc
-Xgc:[no]presweepingverify
-Ximage:filename
-XX:+DisableExplicitGC
-XX:ParallelGCThreads=integervalue
-XX:ConcGCThreads=integervalue
-XX:MaxSpinsBeforeThinLockInflation=integervalue
-XX:LongPauseLogThreshold=integervalue
-XX:LongGCLogThreshold=integervalue
-XX:DumpGCPerformanceOnShutdown
-XX:IgnoreMaxFootprint
-XX:UseTLAB
-XX:BackgroundGC=none
-XX:LargeObjectSpace={disabled,map,freelist}
-XX:LargeObjectThreshold=N
-Xmethod-trace
-Xmethod-trace-file:filename -Xmethod-trace-file-size:integervalue
-Xenable-profiler
-Xprofile-filename:filename
-Xprofile-period:integervalue
-Xprofile-duration:integervalue
-Xprofile-interval:integervalue
-Xprofile-backoff:doublevalue
-Xprofile-start-immediately
-Xprofile-top-k-threshold:doublevalue
-Xprofile-top-k-change-threshold:doublevalue
-Xprofile-type:{method,stack}
-Xprofile-max-stack-depth:integervalue
-Xcompiler:filename
-Xcompiler-option dex2oat-option
-Ximage-compiler-option dex2oat-option
-Xpatchoat:filename
-X[no]relocate
-X[no]dex2oat (Whether to invoke dex2oat on the application)
-X[no]image-dex2oat (Whether to create and use a boot image)
The following previously supported Dalvik options are ignored:
-ea[:<package name>... |:<class name>]
-da[:<package name>... |:<class name>]
(-enableassertions, -disableassertions)
-esa
-dsa
(-enablesystemassertions, -disablesystemassertions)
-Xverify:{none,remote,all}
-Xrs
-Xint:portable, -Xint:fast, -Xint:jit
-Xdexopt:{none,verified,all,full}
-Xnoquithandler
-Xjniopts:{warnonly,forcecopy}
-Xjnigreflimit:integervalue
-Xgc:[no]precise
-Xgc:[no]verifycardtable
-X[no]genregmap
-Xverifyopt:[no]checkmon
-Xcheckdexsum
-Xincludeselectedop
-Xjitop:hexopvalue[-endvalue][,hexopvalue[-endvalue]]*
-Xincludeselectedmethod
-Xjitthreshold:integervalue
-Xjitcodecachesize:decimalvalueofkbytes
-Xjitblocking
-Xjitmethod:signature[,signature]* (eg Ljava/lang/String\;replace)
-Xjitclass:classname[,classname]*
-Xjitoffset:offset[,offset]
-Xjitconfig:filename
-Xjitcheckcg
-Xjitverbose
-Xjitprofile
-Xjitdisableopt
-Xjitsuspendpoll
-XX:mainThreadStackSize=NWriting a very simple ‘hello world’
package xper.hw;
public final class HelloWorldART
{
public static void main(String[] theArgs)
{
System.out.println("Hello World courtesy of the Android Runtime (ART)");
System.exit(0);
}
}
and turning it to a .dex and trying again we get
art --32 -classpath hw.dex xper.hw.HelloWorldART
art I 24871 35716 art/runtime/gc/space/image_space.cc:269] RelocateImage: \
/Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/patchoat \
--input-image-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
--output-image-file=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.art\
--input-oat-location=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.oat \
--output-oat-file=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@art@out@host@darwin-x86@bin@..@framework@core.oat --instruction-set=x86\
--base-offset-delta=-4640768
dex2oat I 24873 35749 art/dex2oat/dex2oat.cc:1266] \
/Users/simon/Scratch/art/out/host/darwin-x86/bin/../bin/dex2oat \
--runtime-arg -classpath \
--runtime-arg hw.dex \
--instruction-set=x86 \
--instruction-set-features=default \
--runtime-arg -Xrelocate
--host \
--boot-image=/Users/simon/Scratch/art/out/host/darwin-x86/bin/../framework/core.art \
--dex-file=/Users/simon/Scratch/xper/art/hw.dex \
--oat-fd=3 \
--oat-location=/Users/simon/Scratch/xper/art/android-data24863/dalvik-cache/x86/Users@simon@Scratch@xper@art@hw.dex
dex2oat I 24873 35749 art/dex2oat/dex2oat.cc:284] dex2oat took 246.341ms (threads: 8)
Hello World courtesy of the Android Runtime (ART)
art I 24871 35716 art/runtime/native/java_lang_Runtime.cc:41] System.exit called, status: 0And there you have it. Possibly the longest and most convoluted way of getting a Java ‘hello world’ program to run short of writing your own Java runtime.
Copyright (c) 2014 By Simon Lewis. All Rights Reserved.
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