Silent install apk programmatically by system app (without root)

I`ve found the issue.

1. Added “android.permission.INSTALL_PACKAGES” permission.
2. I signed my application using “signapk.jar” with certificate that I`ve got from manufacturer of my device.
3. And now this app can install others using “pm install /.../app.apk” without “su”.

It works!

P.S. Updating application using just “pm install” doesn`t replace existing application with new one, but returns exit_value = 0. So to update there are two ways:

• use “pm install -r /.../app.apk“;
• firstly delete app using “pm uninstall com.mydomain.myapp” (you need “android.permission.DELETE_PACKAGES” permission) and then install new one.