SVC

Supervisor Call causes a Supervisor Call exception. For more information, see Supervisor Call (SVC) exception.

Software can use this instruction as a call to an operating system to provide a service.

In the following cases, the Supervisor Call exception generated by the SVC instruction is taken to Hyp mode:

• If the SVC is executed in Hyp mode.
• If HCR.TGE is set to 1, and the SVC is executed in Non-secure User mode. For more information, see Supervisor Call exception, when HCR.TGE is set to 1

In these cases, the HSR, Hyp Syndrome Register identifies that the exception entry was caused by a Supervisor Call exception, EC value 0x11, see Use of the HSR. The immediate field in the HSR:

• If the SVC is unconditional:
  • For the T32 instruction, is the zero-extended value of the imm8 field.
  • For the A32 instruction, is the least-significant 16 bits the imm24 field.
• If the SVC is conditional, is unknown.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

A1

constant imm32 = ZeroExtend(imm24, 32);

T1

constant imm32 = ZeroExtend(imm8, 32);