How to enable Floating Point Support in aarch64 (ARM64)

To use Floating Point instructions in aarch64 simulation, Unicorn needs to enable floating point support. In aarch64 this is done by changing some flags in the CPACR_EL1 register.

This can be done with the following code:

unicorn := Unicorn arm64.
wordSize := 8.

"Read the value of CPACR_EL1"
registerBytes := ByteArray new: wordSize.
unicorn register: UcARM64Registers cpacr_el1 value readInto: registerBytes.
cpacr_el1 := registerBytes integerAt: 1 size: wordSize signed: false.

"Set the bits"
cpacr_el1 := cpacr_el1 bitOr: 2r11 << 20.

"Write back the value in the register"
registerBytes := ByteArray new: wordSize.
registerBytes integerAt: 1 put: cpacr_el1 size: wordSize signed: false.
unicorn register: UcARM64Registers cpacr_el1 value write: registerBytes.

After executing that, the unicorn simulator instance will be able to execute floating point instructions.