/***************************************************************************//** | |
* @file em_mpu.c | |
* @brief Memory Protection Unit (MPU) Peripheral API | |
* @version 5.1.2 | |
******************************************************************************* | |
* @section License | |
* <b>Copyright 2016 Silicon Laboratories, Inc. http://www.silabs.com</b> | |
******************************************************************************* | |
* | |
* Permission is granted to anyone to use this software for any purpose, | |
* including commercial applications, and to alter it and redistribute it | |
* freely, subject to the following restrictions: | |
* | |
* 1. The origin of this software must not be misrepresented; you must not | |
* claim that you wrote the original software. | |
* 2. Altered source versions must be plainly marked as such, and must not be | |
* misrepresented as being the original software. | |
* 3. This notice may not be removed or altered from any source distribution. | |
* | |
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no | |
* obligation to support this Software. Silicon Labs is providing the | |
* Software "AS IS", with no express or implied warranties of any kind, | |
* including, but not limited to, any implied warranties of merchantability | |
* or fitness for any particular purpose or warranties against infringement | |
* of any proprietary rights of a third party. | |
* | |
* Silicon Labs will not be liable for any consequential, incidental, or | |
* special damages, or any other relief, or for any claim by any third party, | |
* arising from your use of this Software. | |
* | |
******************************************************************************/ | |
#include "em_mpu.h" | |
#if defined(__MPU_PRESENT) && (__MPU_PRESENT == 1) | |
#include "em_assert.h" | |
/***************************************************************************//** | |
* @addtogroup emlib | |
* @{ | |
******************************************************************************/ | |
/***************************************************************************//** | |
* @addtogroup MPU | |
* @brief Memory Protection Unit (MPU) Peripheral API | |
* @details | |
* This module contains functions to enable, disable and setup the MPU. | |
* The MPU is used to control access attributes and permissions in the | |
* memory map. The settings that can be controlled are: | |
* | |
* @li Executable attribute. | |
* @li Cachable, bufferable and shareable attributes. | |
* @li Cache policy. | |
* @li Access permissions: Priviliged or User state, read or write access, | |
* and combinations of all these. | |
* | |
* The MPU can be activated and deactivated with functions: | |
* @verbatim | |
* MPU_Enable(..); | |
* MPU_Disable();@endverbatim | |
* The MPU can control 8 memory regions with individual access control | |
* settings. Section attributes and permissions are set with: | |
* @verbatim | |
* MPU_ConfigureRegion(..);@endverbatim | |
* It is advisable to disable the MPU when altering region settings. | |
* | |
* | |
* @{ | |
******************************************************************************/ | |
/******************************************************************************* | |
************************** GLOBAL FUNCTIONS ******************************* | |
******************************************************************************/ | |
/***************************************************************************//** | |
* @brief | |
* Configure an MPU region. | |
* | |
* @details | |
* Writes to MPU RBAR and RASR registers. | |
* Refer to Cortex-M3 Reference Manual, MPU chapter for further details. | |
* To disable a region it is only required to set init->regionNo to the | |
* desired value and init->regionEnable = false. | |
* | |
* @param[in] init | |
* Pointer to a structure containing MPU region init information. | |
******************************************************************************/ | |
void MPU_ConfigureRegion(const MPU_RegionInit_TypeDef *init) | |
{ | |
EFM_ASSERT(init->regionNo < ((MPU->TYPE & MPU_TYPE_DREGION_Msk) >> | |
MPU_TYPE_DREGION_Pos)); | |
MPU->RNR = init->regionNo; | |
if (init->regionEnable) | |
{ | |
EFM_ASSERT(!(init->baseAddress & ~MPU_RBAR_ADDR_Msk)); | |
EFM_ASSERT(init->tex <= 0x7); | |
MPU->RBAR = init->baseAddress; | |
MPU->RASR = ((init->disableExec ? 1 : 0) << MPU_RASR_XN_Pos) | |
| (init->accessPermission << MPU_RASR_AP_Pos) | |
| (init->tex << MPU_RASR_TEX_Pos) | |
| ((init->shareable ? 1 : 0) << MPU_RASR_S_Pos) | |
| ((init->cacheable ? 1 : 0) << MPU_RASR_C_Pos) | |
| ((init->bufferable ? 1 : 0) << MPU_RASR_B_Pos) | |
| (init->srd << MPU_RASR_SRD_Pos) | |
| (init->size << MPU_RASR_SIZE_Pos) | |
| (1 << MPU_RASR_ENABLE_Pos); | |
} | |
else | |
{ | |
MPU->RBAR = 0; | |
MPU->RASR = 0; | |
} | |
} | |
/** @} (end addtogroup CMU) */ | |
/** @} (end addtogroup emlib) */ | |
#endif /* defined(__MPU_PRESENT) && (__MPU_PRESENT == 1) */ |