Hi,

I am planning to implement ACPI5.0 on an SOC having Cortex A5 and Atlas cpu( based on armv8 architecture) running linux on top of them.

As per the ACPI 5.0 hardware specification(Fixed Hardware/ Generic Hardware  model) of ACPI5.0, the processor needs to support various low power modes(C0, C1, C2, C3) and sleep states(S1, S2, S3, S4, S5) via register interfaces as well as OEM provided AML(ACPI Machine Language).

Therefore, which instructions in armv7 and armv8 put the processor into the afore-mentioned low power modes and sleep states?

( The arm instruction manual specifies “wfe” and “wfi” to put the processor in a sleep state, but I am not sure if this confirms to the ACPI 5.0 requirements )

Besides, does arm provide any AML(ACPI Machine Language) code to put the processor to low power modes? If not, then how do we create an ACPI machine language code for armv7 and armv8 architecture and do we have an AML interpreter for armv7 and armv8 architecture?

Regards,

Ayan Kumar Halder