Diff: hal/mpu_api.h

Revision:

189:f392fc9709a3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hal/mpu_api.h	Wed Feb 20 22:31:08 2019 +0000
@@ -0,0 +1,122 @@
+
+/** \addtogroup hal */
+/** @{*/
+/* mbed Microcontroller Library
+ * Copyright (c) 2018-2018 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.
+ */
+#ifndef MBED_MPU_API_H
+#define MBED_MPU_API_H
+
+#include "device.h"
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if DEVICE_MPU
+
+/**
+ * \defgroup hal_mpu MPU hal
+ *
+ * The MPU hal provides a simple MPU API to enhance device security by preventing
+ * execution from ram.
+ *
+ * # Defined behavior
+ * * The function ::mbed_mpu_init is safe to call repeatedly - Verified by ::mpu_init_test
+ * * The function ::mbed_mpu_free disables MPU protection - Verified by ::mpu_free_test
+ * * Execution from RAM results in a fault when execute never is enabled.
+ *      This RAM includes heap, stack, data and zero init - Verified  by ::mpu_fault_test_data,
+ *      ::mpu_fault_test_bss, ::mpu_fault_test_stack and ::mpu_fault_test_heap.
+ * * Writing to ROM results in a fault when write never is enabled - Not verified
+ *
+ * # Undefined behavior
+ * * Calling any function other than ::mbed_mpu_init before the initialization of the MPU.
+ *
+ * @see hal_mpu_tests
+ *
+ * @{
+ */
+
+/**
+ * \defgroup hal_mpu_tests MPU hal tests
+ * The MPU test validates proper implementation of the MPU hal.
+ *
+ * To run the MPU hal tests use the command:
+ *
+ *     mbed test -t <toolchain> -m <target> -n tests-mbed_hal-mpu*
+ */
+
+
+/**
+ * Initialize the MPU
+ *
+ * Initialize or re-initialize the memory protection unit.
+ * After initialization or re-initialization, ROM and RAM protection
+ * are both enabled.
+ */
+void mbed_mpu_init(void);
+
+/**
+ * Enable or disable ROM MPU protection
+ *
+ * This function is used to mark all of ROM as read and execute only.
+ * When enabled writes to ROM cause a fault.
+ *
+ * By default writes to ROM are disabled.
+ *
+ * @param enable true to disable writes to ROM, false otherwise
+ */
+void mbed_mpu_enable_rom_wn(bool enable);
+
+/**
+ * Enable or disable ram MPU protection
+ *
+ * This function is used to mark all of RAM as execute never.
+ * When enabled code is only allowed to execute from flash.
+ *
+ * By default execution from RAM is disabled.
+ *
+ * @param enable true to disable execution from RAM, false otherwise
+ */
+void mbed_mpu_enable_ram_xn(bool enable);
+
+/** Deinitialize the MPU
+ *
+ * Powerdown the MPU in preparation for powerdown, reset or jumping to another application.
+ */
+void mbed_mpu_free(void);
+
+/**@}*/
+
+#else
+
+#define mbed_mpu_init()
+
+#define mbed_mpu_enable_rom_wn(enable) (void)enable
+
+#define mbed_mpu_enable_ram_xn(enable) (void)enable
+
+#define mbed_mpu_free()
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+/** @}*/