ScopedRamExecutionLock.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2018 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_SCOPEDRAMEXECUTIONLOCK_H
00017 #define MBED_SCOPEDRAMEXECUTIONLOCK_H
00018 
00019 #include "platform/mbed_mpu_mgmt.h"
00020 #include "platform/NonCopyable.h"
00021 
00022 namespace mbed {
00023 
00024 /** \addtogroup platform */
00025 /** @{*/
00026 
00027 /** RAII object for disabling, then restoring RAM execute never mode
00028   * Usage:
00029   * @code
00030   *
00031   * void f() {
00032   *     // some code here
00033   *     {
00034   *         ScopedRamExecutionLock make_ram_executable;
00035   *         // Code in this block is allowed to call functions in RAM
00036   *     }
00037   *     // Execution from RAM is no longer allowed
00038   * }
00039   * @endcode
00040   */
00041 class ScopedRamExecutionLock : private mbed::NonCopyable<ScopedRamExecutionLock> {
00042 public:
00043 
00044     /**
00045      * Allow execution from RAM
00046      *
00047      * Increment the execute never lock to ensure code can
00048      * be executed from RAM. This class uses RAII to allow
00049      * execution from ram while it is in scope.
00050      */
00051     ScopedRamExecutionLock()
00052     {
00053         mbed_mpu_manager_lock_ram_execution();
00054     }
00055 
00056     /**
00057      * Restore previous execution from RAM settings
00058      *
00059      * Decrement the execute never lock to return execute from RAM
00060      * to its prior state.
00061      */
00062     ~ScopedRamExecutionLock()
00063     {
00064         mbed_mpu_manager_unlock_ram_execution();
00065     }
00066 };
00067 
00068 /**@}*/
00069 
00070 }
00071 
00072 #endif