It is well-known that a complex valued function on a bounded symmetric domain \(X=G/K\) satisfying the associated Hua system has an \(L^p\)-Poisson integral representation over the Shilov boundary of \(X\), if and only if it satisfies a Hardy type condition on a family of \(K\)-orbits; the paper extends this result to any boundary component of a Riemannian symmetric space of noncompact type.