examples: add initial examples for RFC

Add hello_world and random(generate UUID) examples

Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
diff --git a/random/ta/random_example_ta.c b/random/ta/random_example_ta.c
new file mode 100644
index 0000000..8f7506a
--- /dev/null
+++ b/random/ta/random_example_ta.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2017, Linaro Limited
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define STR_TRACE_USER_TA "RANDOM_EXAMPLE_TA"
+
+#include <tee_internal_api.h>
+#include <tee_internal_api_extensions.h>
+
+#include "random_example_ta.h"
+
+TEE_Result TA_CreateEntryPoint(void)
+{
+	return TEE_SUCCESS;
+}
+
+void TA_DestroyEntryPoint(void)
+{
+}
+
+TEE_Result TA_OpenSessionEntryPoint(uint32_t param_types,
+		TEE_Param __maybe_unused params[4],
+		void __maybe_unused **sess_ctx)
+{
+	uint32_t exp_param_types = TEE_PARAM_TYPES(TEE_PARAM_TYPE_NONE,
+						   TEE_PARAM_TYPE_NONE,
+						   TEE_PARAM_TYPE_NONE,
+						   TEE_PARAM_TYPE_NONE);
+	if (param_types != exp_param_types)
+		return TEE_ERROR_BAD_PARAMETERS;
+
+	(void)&params;
+	(void)&sess_ctx;
+
+	return TEE_SUCCESS;
+}
+
+void TA_CloseSessionEntryPoint(void __maybe_unused *sess_ctx)
+{
+	(void)&sess_ctx;
+}
+
+static TEE_Result random_number_generate(uint32_t param_types,
+	TEE_Param params[4])
+{
+	uint32_t exp_param_types = TEE_PARAM_TYPES
+					(TEE_PARAM_TYPE_MEMREF_OUTPUT, TEE_PARAM_TYPE_NONE,
+					 TEE_PARAM_TYPE_NONE, TEE_PARAM_TYPE_NONE);
+
+	DMSG("has been called");
+	if (param_types != exp_param_types)
+		return TEE_ERROR_BAD_PARAMETERS;
+
+	IMSG("Generating random data over %u bytes.", params[0].memref.size);
+	/*
+	 * The TEE_GenerateRandom function is a part of TEE Internal Core API,
+	 * which generates random data
+	 *
+	 * Parameters:
+	 * @ randomBuffer : Reference to generated random data
+	 * @ randomBufferLen : Byte length of requested random data
+	 */
+	TEE_GenerateRandom(params[0].memref.buffer, params[0].memref.size);
+
+	return TEE_SUCCESS;
+}
+
+TEE_Result TA_InvokeCommandEntryPoint(void __maybe_unused *sess_ctx,
+			uint32_t cmd_id,
+			uint32_t param_types, TEE_Param params[4])
+{
+	(void)&sess_ctx;
+
+	switch (cmd_id) {
+	case TA_EXAMPLE_RANDOM_GENERATE:
+		return random_number_generate(param_types, params);
+	default:
+		return TEE_ERROR_BAD_PARAMETERS;
+	}
+}