Function sbi_rt::cppc_read

source ·

pub fn cppc_read(cppc_reg_id: u32) -> SbiRet

Expand description

Read the CPPC register identified by given cppc_reg_id.

§Parameters

The cppc_reg_id parameter specifies the CPPC register ID.

§Return value

SbiRet.value will contain the register value. When supervisor mode XLEN is 32, the SbiRet.value will only contain the lower 32 bits of the CPPC register value.

The possible error codes returned in SbiRet.error are shown in the table below:

Return code	Description
`SbiRet::success()`	Read completed successfully.
`SbiRet::invalid_param()`	`cppc_reg_id` is reserved.
`SbiRet::not_supported()`	`cppc_reg_id` is not implemented by the platform.
`SbiRet::denied()`	`cppc_reg_id` is a write-only register.
`SbiRet::failed()`	The read request failed for unspecified or unknown other reasons.

This function is defined in RISC-V SBI Specification chapter 14.2.