is an expression evaluating to an integer in the range 0-65535.
In a processor that implements the Virtualization Extensions, the
instruction causes a Hypervisor Call exception. This means that the processor enters
Hyp mode, the CPSR value is saved to the Hyp mode SPSR, and execution branches to
the HVC vector.
HVC must not be used if the processor is in Secure state, or in User
mode in Non-secure state.
imm is ignored by the processor.
However, it can be retrieved by the exception handler to determine what service is
HVC cannot be conditional, and is not permitted in an IT block.
ERET instruction performs an exception return from Hyp mode.
This ARM and 32-bit Thumb instruction is available in ARMv7 architectures that include the Virtualization Extensions.
There is no 16-bit version of this instruction in Thumb