The Java property sun.arch.abi is set for 32-bit ARM builds in order to allow developers to determine which ABI is in effect in a running JRE/JDK. The values of "gnueabi" and "gnueabihf' are set for soft-float and hard-float ABIs.

The "release" file generated during JDK/JRE builds is also populated with SUN_ARCH_ABI={value} if these properties are set.

The Oracle 64-bit ARM builds that are produced in JDK 8 set this property to "gnu". JDK 9 however, does not set this property at all. Since aarch64 only supports one ABI, there is really no need to have this property set for 64-bit ARM builds but it's still a regression in behavior.