fix(rmmd): preserve x4-x7 as per SMCCCv1.1

The RMI command handling in RMMD did not preserve x4 to x7 when
returning to NS caller. Although this is allowed for SMCCCv1.0, this is
not correct as per v1.1. This fixes the same by differentiating the
onward and backward path during SMC handling.

This patch also fixes an issue with the backward path wherein the first
argument was being truncated to 32 bits.

Change-Id: Ibc85d574d5a2178a763975ddb32e456a12e7dc88
Signed-off-by: Soby Mathew <>
1 file changed