Summary
Make Secure Monitor Call (SMC) from user space.
Declaration
#include <zircon/syscalls.h>
#include <zircon/syscalls/smc.h>
zx_status_t zx_smc_call(zx_handle_t handle,
const zx_smc_parameters_t* parameters,
zx_smc_result_t* out_smc_result);
Description
zx_smc_call() makes a Secure Monitor Call (SMC) from user space. It supports the ARM SMC Calling
Convention using the zx_smc_parameters_t input parameter and zx_smc_result_t output parameter.
The input handle must be a resource object with sufficient privileges in order to be executed.
The majority of the parameters are opaque from zx_smc_call() perspective because they are
dependent upon the func_id. The func_id informs the Secure Monitor the service and function
to be invoked. The client_id is an optional field intended for secure software to track and
index the calling client OS. The secure_os_id is an optional field intended for use when there
are multiple secure operating systems at S-EL1, so that the caller may specify the intended
secure OS.
More information is available in the ARM SMC Calling Convention documentation.
Rights
TODO(https://fxbug.dev/42107318)
Return value
zx_smc_call() returns ZX_OK if handle has sufficient privilege. The
return value of the smc call is returned via out_smc_result on success. In the event of
failure, a negative error value is returned.
Errors
ZX_ERR_BAD_HANDLE handle is not a valid handle.
ZX_ERR_WRONG_TYPE handle is not a resource handle.
ZX_ERR_ACCESS_DENIED handle does not have sufficient privileges.
ZX_ERR_NOT_SUPPORTED smc_call is not supported on this system.
ZX_ERR_INVALID_ARGS parameters or out_smc_result a null pointer