/* mbed Microcontroller Library
* Copyright (c) 2018 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*/
#include "hal/mpu_api.h"
#include "platform/mbed_assert.h"
#include "cmsis.h"
#if ((__ARM_ARCH_7M__ == 1U) || (__ARM_ARCH_7EM__ == 1U) || (__ARM_ARCH_6M__ == 1U)) && \
defined (__MPU_PRESENT) && (__MPU_PRESENT == 1U) && \
!defined(MBED_MPU_CUSTOM)
#if !DEVICE_MPU
#error "Device has v7m MPU but it is not enabled. Add 'MPU' to device_has in targets.json"
#endif
#ifdef MBED_CONF_TARGET_MPU_ROM_END
#define MBED_MPU_ROM_END MBED_CONF_TARGET_MPU_ROM_END
#else
#define MBED_MPU_ROM_END (0x10000000 - 1)
#endif
#define MBED_MPU_RAM_START (MBED_MPU_ROM_END + 1)
static_assert(
MBED_MPU_ROM_END == 0x04000000 - 1 ||
MBED_MPU_ROM_END == 0x08000000 - 1 ||
MBED_MPU_ROM_END == 0x0C000000 - 1 ||
MBED_MPU_ROM_END == 0x10000000 - 1 ||
MBED_MPU_ROM_END == 0x14000000 - 1 ||
MBED_MPU_ROM_END == 0x18000000 - 1 ||
MBED_MPU_ROM_END == 0x1C000000 - 1 ||
MBED_MPU_ROM_END == 0x20000000 - 1,
"Unsupported value for MBED_MPU_ROM_END");
void mbed_mpu_init()
{
// Flush memory writes before configuring the MPU.
__DMB();
const uint32_t regions = (MPU->TYPE & MPU_TYPE_DREGION_Msk) >> MPU_TYPE_DREGION_Pos;
// Our MPU setup requires 3 or 4 regions - if this assert is hit, remove
// a region by setting MPU_ROM_END to 0x1fffffff, or remove MPU from device_has
#if MBED_MPU_RAM_START == 0x20000000
MBED_ASSERT(regions >= 3);
#else
MBED_ASSERT(regions >= 4);
#endif
// Disable the MCU
MPU->CTRL = 0;
// Reset all mapping
for (uint32_t i = 0; i < regions; i++) {
ARM_MPU_ClrRegion(i);
}
/*
* ARMv6m and ARMv7-M memory map:
*
* Start End Name Executable by default Mbed MPU protection
* 0x00000000 - 0x1FFFFFFF Code Yes Write disabled for first portion and execute disabled for the rest
* 0x20000000 - 0x3FFFFFFF SRAM Yes Execute disabled
* 0x40000000 - 0x5FFFFFFF Peripheral No
* 0x60000000 - 0x7FFFFFFF RAM Yes Execute disabled
* 0x80000000 - 0x9FFFFFFF RAM Yes Execute disabled
* 0xA0000000 - 0xBFFFFFFF Device No
* 0xC0000000 - 0xDFFFFFFF Device No
* 0xE0000000 - 0xFFFFFFFF System No
*/
// Select region 0 and use it for the WT read-only rom region
// - Code 0x00000000 to MBED_MPU_ROM_END
ARM_MPU_SetRegion(
ARM_MPU_RBAR(
0, // Region
0x00000000), // Base
ARM_MPU_RASR(
0, // DisableExec
ARM_MPU_AP_RO, // AccessPermission
0, // TypeExtField
0, // IsShareable
1, // IsCacheable
0, // IsBufferable
// SubRegionDisable - based on where ROM ends
((MBED_MPU_ROM_END >= 0x00000000) ? 0 : (1 << 0)) | // 0 to enable, 1 << n to disable
((MBED_MPU_ROM_END >= 0x04000000) ? 0 : (1 << 1)) |
((MBED_MPU_ROM_END >= 0x08000000) ? 0 : (1 << 2)) |
((MBED_MPU_ROM_END >= 0x0C000000) ? 0 : (1 << 3)) |
((MBED_MPU_ROM_END >= 0x10000000) ? 0 : (1 << 4)) |
((MBED_MPU_ROM_END >= 0x14000000) ? 0 : (1 << 5)) |
((MBED_MPU_ROM_END >= 0x18000000) ? 0 : (1 << 6)) |
((MBED_MPU_ROM_END >= 0x1C000000) ? 0 : (1 << 7)),
ARM_MPU_REGION_SIZE_512MB) // Size
);
#if MBED_MPU_RAM_START < 0x20000000
// Select region 3 and use it for a WT ram region in the Code area
// - Code MBED_MPU_ROM_END + 1 to 0x1FFFFFFF
ARM_MPU_SetRegion(
ARM_MPU_RBAR(
3, // Region
0x00000000), // Base
ARM_MPU_RASR(
1, // DisableExec
ARM_MPU_AP_FULL, // AccessPermission
0, // TypeExtField
0, // IsShareable
1, // IsCacheable
0, // IsBufferable
// SubRegionDisable - based on where RAM starts
((MBED_MPU_RAM_START <= 0x04000000) ? 0 : (1 << 0)) | // 0 to enable, 1 << n to disable
((MBED_MPU_RAM_START <= 0x08000000) ? 0 : (1 << 1)) |
((MBED_MPU_RAM_START <= 0x0C000000) ? 0 : (1 << 2)) |
((MBED_MPU_RAM_START <= 0x10000000) ? 0 : (1 << 3)) |
((MBED_MPU_RAM_START <= 0x14000000) ? 0 : (1 << 4)) |
((MBED_MPU_RAM_START <= 0x18000000) ? 0 : (1 << 5)) |
((MBED_MPU_RAM_START <= 0x1C000000) ? 0 : (1 << 6)) |
((MBED_MPU_RAM_START <= 0x20000000) ? 0 : (1 << 7)),
ARM_MPU_REGION_SIZE_512MB) // Size
);
#define LAST_RAM_REGION 3
#else
#define LAST_RAM_REGION 2
#endif
// Select region 1 and use it for WBWA ram regions
// - SRAM 0x20000000 to 0x3FFFFFFF
// - RAM 0x60000000 to 0x7FFFFFFF
ARM_MPU_SetRegion(
ARM_MPU_RBAR(
1, // Region
0x00000000), // Base
ARM_MPU_RASR(
1, // DisableExec
ARM_MPU_AP_FULL, // AccessPermission
1, // TypeExtField
0, // IsShareable
1, // IsCacheable
1, // IsBufferable
// SubRegionDisable
(1 << 0) | // Disable Sub-region
(0 << 1) | // Enable Sub-region SRAM 0x20000000 - 0x3FFFFFFF
(1 << 2) | // Disable Sub-region
(0 << 3) | // Enable Sub-region RAM 0x60000000 - 0x7FFFFFFF
(1 << 4) | // Disable Sub-region
(1 << 5) | // Disable Sub-region
(1 << 6) | // Disable Sub-region
(1 << 7), // Disable Sub-region
ARM_MPU_REGION_SIZE_4GB) // Size
);
// Select region 2 and use it for the WT ram region
// - RAM 0x80000000 to 0x9FFFFFFF
ARM_MPU_SetRegion(
ARM_MPU_RBAR(
2, // Region
0x80000000), // Base
ARM_MPU_RASR(
1, // DisableExec
ARM_MPU_AP_FULL, // AccessPermission
0, // TypeExtField
0, // IsShareable
1, // IsCacheable
0, // IsBufferable
0U, // SubRegionDisable
ARM_MPU_REGION_SIZE_512MB) // Size
);
// Enable the MPU
MPU->CTRL =
(1 << MPU_CTRL_PRIVDEFENA_Pos) | // Use the default memory map for unmapped addresses
(1 << MPU_CTRL_HFNMIENA_Pos) | // Keep MPU turned on for faults
(1 << MPU_CTRL_ENABLE_Pos); // Enable MPU
// Ensure changes take effect
__DSB();
__ISB();
}
void mbed_mpu_free()
{
// Flush memory writes before configuring the MPU.
__DMB();
// Disable the MPU
MPU->CTRL = 0;
// Ensure changes take effect
__DSB();
__ISB();
}
static void enable_region(bool enable, uint32_t region)
{
MPU->RNR = region;
MPU->RASR = (MPU->RASR & ~MPU_RASR_ENABLE_Msk) | (enable << MPU_RASR_ENABLE_Pos);
}
void mbed_mpu_enable_rom_wn(bool enable)
{
// Flush memory writes before configuring the MPU.
__DMB();
enable_region(enable, 0);
// Ensure changes take effect
__DSB();
__ISB();
}
void mbed_mpu_enable_ram_xn(bool enable)
{
// Flush memory writes before configuring the MPU.
__DMB();
for (uint32_t region = 1; region <= LAST_RAM_REGION; region++) {
enable_region(enable, region);
}
// Ensure changes take effect
__DSB();
__ISB();
}
#endif
