The Armv8-A architecture introduces the ability to use 64-bit and 32-bit Execution states, known as AArch64 and AArch32 respectively. The AArch64 Execution state supports the A64 instruction set. It holds addresses in 64-bit registers and allows instructions in the base instruction set to use 64-bit registers for their processing.
The AArch32 Execution state is a 32-bit Execution state that preserves backwards compatibility with the Armv7-A architecture, enhancing that profile so that it can support some features included in the AArch64 state. It supports the T32 and A32 instruction sets. Follow the link for more information.
This port adds support for Armv8-A architecture AArch64 execution state. This port is generic and can be used as a starting point for Armv8-A application processors.