Diff: targets/TARGET_Silicon_Labs/TARGET_EFM32/emlib/src/em_mpu.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

Child:

150:02e0a0aed4ec

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Silicon_Labs/TARGET_EFM32/emlib/src/em_mpu.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,124 @@
+/***************************************************************************//**
+ * @file em_mpu.c
+ * @brief Memory Protection Unit (MPU) Peripheral API
+ * @version 4.2.1
+ *******************************************************************************
+ * @section License
+ * <b>(C) Copyright 2015 Silicon Labs, 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 EM_Library
+ * @{
+ ******************************************************************************/
+
+
+/***************************************************************************//**
+ * @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 EM_Library) */
+#endif /* defined(__MPU_PRESENT) && (__MPU_PRESENT == 1) */