Import Mbed OS hard-float snapshot

targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/trng_api.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2017-2018 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "trng_api.h"
+#include "tztrng.h"
+
+#define BITS_PER_BYTE 8
+
+void trng_init(trng_t *obj)
+{
+    /* Initialization is made in the driver */
+    (void)obj;
+}
+
+void trng_free(trng_t *obj)
+{
+    /* The current implementation only contains a dummy version of TRNG */
+    (void)obj;
+}
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
+{
+    uint32_t retval;
+
+    (void)obj;
+    /* The TRNG driver expects a number of bits. */
+    retval = CC_TrngGetSource(TRNG_BASE, output, output_length,
+                              length * BITS_PER_BYTE);
+
+    if (retval != 0) {
+        return -1;
+    }
+    return 0;
+}