Android ARM 32位64位问题集锦

答：使用 file 命令

# file /system/bin/dalvikvm64
/system/bin/dalvikvm64: ELF shared object, 64-bit LSB arm64, dynamic (/system/bin/linker64), for Android 28, BuildID=17f49e4a4ec8b7f4ace738c1146fe0a6, stripped

注：file /system/bin/dalvikvm  是个符号链接，用来兼容之前32位
/system/bin/dalvikvm: symbolic link

file libchrome.so
libchrome.so: ELF shared object, 32-bit LSB arm, for Android 28, BuildID=7b0eff684ce95745e2b2a3a2e0ad4398, stripped

答：

(1)通过看父进程是zygote还是zygote64

(2) cat /proc/4215/maps  |grep lib64

查看加载的.so库

# ps -A|grep zygote
root           935     1 4312904 155112 poll_schedule_timeout 0 S zygote64   启动64位apk
root           936     1 1632628 139536 poll_schedule_timeout 0 S zygote

u0_a11        1433   935 4483840 186160 SyS_epoll_wait      0 S com.android.systemui
u0_a7         2178   935 4412148 105000 SyS_epoll_wait      0 S android.process.media
bluetooth     2423   935 4400136  89040 SyS_epoll_wait      0 S com.android.bluetooth
system        2983   935 4389644  79828 SyS_epoll_wait      0 S com.android.keychain
u0_a8         3013   935 4395316  81680 SyS_epoll_wait      0 S android.ext.services
u0_a1        15796   935 4396308 104332 SyS_epoll_wait      0 S android.process.acore

答：删除 /data/dalvik-cache/arm64  或  /data/dalvik-cache/armlib 目录下对应的文件。

java.lang.ClassNotFoundException: Didn't find class "com.target." on path: DexPathList[[zip file "/system/priv-app

zygote64    Rejecting re-init on previously-failed class java.lang.Class: java.lang.NoClassDefFoundError: Failed resolution of: $TargetClass;

答：查看SDK版本问题、缓存问题、.so库路径。
 

在Android 8.1 由于seLinux权限管理很严格，默认app 修改属性会报 avc denied 错误.

1.在apk对应的android.mk中

LOCAL_DEX_PREOPT := nostripping
2.  /device/qcom/msmxxxx/BoardConfig.mk,
DEX_PREOPT_DEFAULT := nostripping 

上传apk到目录 /system/app 或 /system/priv-app。

把apk中的.so库上传到 /system/lib或/system/lib64