Diff: hal/mpu/mbed_mpu_v8m.c

Revision:

0:5b88d5760320

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hal/mpu/mbed_mpu_v8m.c	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,211 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018 ARM Limited
+ *
+ * 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_8M_BASE__ == 1U) || (__ARM_ARCH_8M_MAIN__ == 1U)) && \
+    defined (__MPU_PRESENT) && (__MPU_PRESENT == 1U) && \
+    !defined(MBED_MPU_CUSTOM)
+
+#if !DEVICE_MPU
+#error "Device has v8m 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)
+
+MBED_STATIC_ASSERT(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 4 or 5 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 >= 4);
+#else
+    MBED_ASSERT(regions >= 5);
+#endif
+
+    // Disable the MCU
+    MPU->CTRL = 0;
+
+    // Reset all mapping
+    for (uint32_t i = 0; i < regions; i++) {
+        ARM_MPU_ClrRegion(i);
+    }
+
+    /*
+     * ARMv8-M memory map:
+     *
+     * Start        End            Name            Executable by default    Default cache       Mbed MPU protection
+     * 0x00000000 - 0x1FFFFFFF     Code            Yes                      WT, WA              Write disabled for first portion and execute disabled for the rest
+     * 0x20000000 - 0x3FFFFFFF     SRAM            Yes                      WB, WA, RA          Execute disabled
+     * 0x40000000 - 0x5FFFFFFF     Peripheral      No
+     * 0x60000000 - 0x7FFFFFFF     RAM             Yes                      WB, WA, RA          Execute disabled
+     * 0x80000000 - 0x9FFFFFFF     RAM             Yes                      WT, RA              Execute disabled
+     * 0xA0000000 - 0xBFFFFFFF     Device          No
+     * 0xC0000000 - 0xDFFFFFFF     Device          No
+     * 0xE0000000 - 0xFFFFFFFF     System          No
+     */
+
+    const uint8_t WTRA = ARM_MPU_ATTR_MEMORY_(1, 0, 1, 0);      // Non-transient, Write-Through, Read-allocate, Not Write-allocate
+    const uint8_t WBWARA = ARM_MPU_ATTR_MEMORY_(1, 1, 1, 1);    // Non-transient, Write-Back, Read-allocate, Write-allocate
+    enum {
+        AttrIndex_WTRA,
+        AttrIndex_WBWARA,
+    };
+
+    ARM_MPU_SetMemAttr(AttrIndex_WTRA, ARM_MPU_ATTR(WTRA, WTRA));
+    ARM_MPU_SetMemAttr(AttrIndex_WBWARA, ARM_MPU_ATTR(WBWARA, WBWARA));
+
+    ARM_MPU_SetRegion(
+        0,                          // Region
+        ARM_MPU_RBAR(
+            0x00000000,             // Base
+            ARM_MPU_SH_NON,         // Non-shareable
+            1,                      // Read-Only
+            1,                      // Non-Privileged
+            0),                     // Execute Never disabled
+        ARM_MPU_RLAR(
+            MBED_MPU_ROM_END,       // Limit
+            AttrIndex_WTRA)         // Attribute index - Write-Through, Read-allocate
+    );
+
+#if MBED_MPU_RAM_START != 0x20000000
+    ARM_MPU_SetRegion(
+        4,                          // Region
+        ARM_MPU_RBAR(
+            MBED_MPU_RAM_START,     // Base
+            ARM_MPU_SH_NON,         // Non-shareable
+            0,                      // Read-Write
+            1,                      // Non-Privileged
+            1),                     // Execute Never enabled
+        ARM_MPU_RLAR(
+            0x1FFFFFFF,             // Limit
+            AttrIndex_WTRA)         // Attribute index - Write-Through, Read-allocate
+    );
+#define LAST_RAM_REGION 4
+#else
+#define LAST_RAM_REGION 3
+#endif
+
+    ARM_MPU_SetRegion(
+        1,                          // Region
+        ARM_MPU_RBAR(
+            0x20000000,             // Base
+            ARM_MPU_SH_NON,         // Non-shareable
+            0,                      // Read-Write
+            1,                      // Non-Privileged
+            1),                     // Execute Never enabled
+        ARM_MPU_RLAR(
+            0x3FFFFFFF,             // Limit
+            AttrIndex_WBWARA)       // Attribute index - Write-Back, Write-allocate
+    );
+
+    ARM_MPU_SetRegion(
+        2,                          // Region
+        ARM_MPU_RBAR(
+            0x60000000,             // Base
+            ARM_MPU_SH_NON,         // Non-shareable
+            0,                      // Read-Write
+            1,                      // Non-Privileged
+            1),                     // Execute Never enabled
+        ARM_MPU_RLAR(
+            0x7FFFFFFF,             // Limit
+            AttrIndex_WBWARA)       // Attribute index - Write-Back, Write-allocate
+    );
+
+    ARM_MPU_SetRegion(
+        3,                          // Region
+        ARM_MPU_RBAR(
+            0x80000000,             // Base
+            ARM_MPU_SH_NON,         // Non-shareable
+            0,                      // Read-Write
+            1,                      // Non-Privileged
+            1),                     // Execute Never enabled
+        ARM_MPU_RLAR(
+            0x9FFFFFFF,             // Limit
+            AttrIndex_WTRA)         // Attribute index - Write-Through, Read-allocate
+    );
+
+    // 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 MCU
+    MPU->CTRL = 0;
+
+    // Ensure changes take effect
+    __DSB();
+    __ISB();
+}
+
+static void enable_region(bool enable, uint32_t region)
+{
+    MPU->RNR = region;
+    MPU->RLAR = (MPU->RLAR & ~MPU_RLAR_EN_Msk) | (enable << MPU_RLAR_EN_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