Red Hat developers are porting OpenJDK to ARMv8, the 64-bit ARM architecture (also known as A64). According to a blog postby Andrew Haley of Red Hat, the development is taking place because "the current OpenJDK ARM situation is rather unsatisfactory, and we want to do better with A64".
As ARM created a new instruction set for 64-bit, rather than just extending the 32-bit instruction set, this means that "to take advantage of the A64, we're going to need new compilers and Java virtual machines".
He explained that currently, for 32-bit ARM, there are two versions of the HotSpot Java VM; one owned by Oracle which is proprietary and one which is free that was written for ARM. The Oracle VM with its JIT engine performs better than the free one with its lightweight JIT. "We really don't want this situation for A64," says Haley. The company will be writing a port which will be entirely free software and will be submitted as an OpenJDK project which others can take part in.