The SMC transport in the XilPM client is enabled at build time when all of the following conditions are met:
- The XilPM client is built with XPM_SUPPORT defined.
- The build target is AArch64.
- The application is compiled for EL1 Non-secure (EL1_NONSECURE = 1).
When any of these conditions is not met, the XilPM client uses the IPI mailbox transport, as documented in the other sub-sections under XilPM Client Implementation Details.