Successor: ThumbEE
The ARMv7 architecture has de-emphasized Jazelle and Direct Bytecode Execution of JVM bytecodes. In implementation terms, only trivial hardware support for Jazelle is now required: support for entering and exiting Jazelle mode, but not for executing any Java bytecodes.
Instead, the Thumb Execution Environment (ThumbEE) is now preferred. Support for this is mandatory in ARMv7-A processors (such as the Cortex-A8 and Cortex-A9), and optional in ARMv7-R processors. ThumbEE targets compiled environments, perhaps using JIT technologies. It is not at all specific to Java, and is fully documented; much broader adoption is anticipated than Jazelle was able to achieve.
ThumbEE is a variant of the Thumb2 16/32-bit instruction set. It integrates null pointer checking; defines some new fault mechanisms; and repurposes the 16-bit LDM and STM opcode space to support a few instructions such as range checking, a new handler invocation scheme, and more. Accordingly, compilers that produce Thumb or Thumb2 code can be modified to work with ThumbEE-based runtime environments.
Read more about this topic: Jazelle