Initial commit

Initial commit.

bootloader/mcuboot/boot/zephyr/os.c

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 <zephyr/kernel.h>
+#include <string.h>
+
+#include "os/os_heap.h"
+
+#ifdef CONFIG_BOOT_USE_MBEDTLS
+
+#include <mbedtls/platform.h>
+#include <mbedtls/memory_buffer_alloc.h>
+
+/*
+ * This is the heap for mbed TLS.  The value needed depends on the key
+ * size and algorithm used.
+ *
+ * - RSA-2048 signing without encryption is known to work well with 6144 bytes;
+ * - When using RSA-2048-OAEP encryption + RSA-2048 signing, or RSA-3072
+ *   signing (no encryption) 10240 bytes seems to be enough.
+ *
+ * NOTE: RSA-3072 signing + RSA-2048-OAEP might require growing the size...
+ */
+#if (CONFIG_BOOT_SIGNATURE_TYPE_RSA_LEN == 2048) && !defined(CONFIG_BOOT_ENCRYPT_RSA)
+#define CRYPTO_HEAP_SIZE 6144
+#else
+#  if !defined(MBEDTLS_RSA_NO_CRT)
+#  define CRYPTO_HEAP_SIZE 12032
+#  else
+#  define CRYPTO_HEAP_SIZE 16384
+#  endif
+#endif
+
+static unsigned char mempool[CRYPTO_HEAP_SIZE];
+
+/*
+ * Initialize mbedtls to be able to use the local heap.
+ */
+void os_heap_init(void)
+{
+    mbedtls_memory_buffer_alloc_init(mempool, sizeof(mempool));
+}
+#else
+void os_heap_init(void)
+{
+}
+#endif