mpu.c

Go to the documentation of this file.

//*****************************************************************************
//
// mpu.c - Driver for the Cortex-M3 memory protection unit (MPU).
//
// Copyright (c) 2007-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
//   Redistribution and use in source and binary forms, with or without
//   modification, are permitted provided that the following conditions
//   are met:
// 
//   Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
// 
//   Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the  
//   distribution.
// 
//   Neither the name of Texas Instruments Incorporated nor the names of
//   its contributors may be used to endorse or promote products derived
//   from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 
// This is part of revision 2.1.0.12573 of the Tiva Peripheral Driver Library.
//
//*****************************************************************************

//*****************************************************************************
//
//
//*****************************************************************************

#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_ints.h"
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/interrupt.h"
#include "driverlib/mpu.h"

//*****************************************************************************
//
//
//*****************************************************************************
void
MPUEnable(uint32_t ui32MPUConfig)
{
    //
    // Check the arguments.
    //
    ASSERT(!(ui32MPUConfig & ~(MPU_CONFIG_PRIV_DEFAULT |
                               MPU_CONFIG_HARDFLT_NMI)));

    //
    // Set the MPU control bits according to the flags passed by the user,
    // and also set the enable bit.
    //
    HWREG(NVIC_MPU_CTRL) = ui32MPUConfig | NVIC_MPU_CTRL_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPUDisable(void)
{
    //
    // Turn off the MPU enable bit.
    //
    HWREG(NVIC_MPU_CTRL) &= ~NVIC_MPU_CTRL_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
MPURegionCountGet(void)
{
    //
    // Read the DREGION field of the MPU type register and mask off
    // the bits of interest to get the count of regions.
    //
    return((HWREG(NVIC_MPU_TYPE) & NVIC_MPU_TYPE_DREGION_M) >>
           NVIC_MPU_TYPE_DREGION_S);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPURegionEnable(uint32_t ui32Region)
{
    //
    // Check the arguments.
    //
    ASSERT(ui32Region < 8);

    //
    // Select the region to modify.
    //
    HWREG(NVIC_MPU_NUMBER) = ui32Region;

    //
    // Modify the enable bit in the region attributes.
    //
    HWREG(NVIC_MPU_ATTR) |= NVIC_MPU_ATTR_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPURegionDisable(uint32_t ui32Region)
{
    //
    // Check the arguments.
    //
    ASSERT(ui32Region < 8);

    //
    // Select the region to modify.
    //
    HWREG(NVIC_MPU_NUMBER) = ui32Region;

    //
    // Modify the enable bit in the region attributes.
    //
    HWREG(NVIC_MPU_ATTR) &= ~NVIC_MPU_ATTR_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPURegionSet(uint32_t ui32Region, uint32_t ui32Addr, uint32_t ui32Flags)
{
    //
    // Check the arguments.
    //
    ASSERT(ui32Region < 8);
    ASSERT(ui32Addr ==
           (ui32Addr & ~0 << (((ui32Flags & NVIC_MPU_ATTR_SIZE_M) >> 1) + 1)));

    //
    // Program the base address, use the region field to select the
    // region at the same time.
    //
    HWREG(NVIC_MPU_BASE) = ui32Addr | ui32Region | NVIC_MPU_BASE_VALID;

    //
    // Program the region attributes.  Set the TEX field and the S, C,
    // and B bits to fixed values that are suitable for all Tiva C and
    // E Series memory.
    //
    HWREG(NVIC_MPU_ATTR) = ((ui32Flags & ~(NVIC_MPU_ATTR_TEX_M |
                                           NVIC_MPU_ATTR_CACHEABLE)) |
                            NVIC_MPU_ATTR_SHAREABLE | NVIC_MPU_ATTR_BUFFRABLE);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPURegionGet(uint32_t ui32Region, uint32_t *pui32Addr, uint32_t *pui32Flags)
{
    //
    // Check the arguments.
    //
    ASSERT(ui32Region < 8);
    ASSERT(pui32Addr);
    ASSERT(pui32Flags);

    //
    // Select the region to get.
    //
    HWREG(NVIC_MPU_NUMBER) = ui32Region;

    //
    // Read and store the base address for the region.
    //
    *pui32Addr = HWREG(NVIC_MPU_BASE) & NVIC_MPU_BASE_ADDR_M;

    //
    // Read and store the region attributes.
    //
    *pui32Flags = HWREG(NVIC_MPU_ATTR);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPUIntRegister(void (*pfnHandler)(void))
{
    //
    // Check the arguments.
    //
    ASSERT(pfnHandler);

    //
    // Register the interrupt handler.
    //
    IntRegister(FAULT_MPU, pfnHandler);

    //
    // Enable the memory management fault.
    //
    IntEnable(FAULT_MPU);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
MPUIntUnregister(void)
{
    //
    // Disable the interrupt.
    //
    IntDisable(FAULT_MPU);

    //
    // Unregister the interrupt handler.
    //
    IntUnregister(FAULT_MPU);
}

//*****************************************************************************
//
// Close the Doxygen group.
//
//*****************************************************************************