arch/stm32h7: add RPTUN support

arch/arm/src/stm32h7/CMakeLists.txt

@@ -45,6 +45,10 @@ if(CONFIG_STM32H7_HSEM)
   list(APPEND SRCS stm32_hsem.c)
 endif()
 
+if(CONFIG_RPTUN)
+  list(APPEND SRCS stm32_rptun.c)
+endif()
+
 if(CONFIG_SCHED_TICKLESS)
   list(APPEND SRCS stm32_tickless.c)
 else()
@@ -55,8 +59,12 @@ if(CONFIG_STM32H7_ONESHOT)
   list(APPEND SRCS stm32_oneshot.c stm32_oneshot_lowerhalf.c)
 endif()
 
+if(CONFIG_ARM_MPU)
+  list(APPEND SRCS stm32_mpuinit.c)
+endif()
+
 if(CONFIG_BUILD_PROTECTED)
-  list(APPEND SRCS stm32_userspace.c stm32_mpuinit.c)
+  list(APPEND SRCS stm32_userspace.c)
 endif()
 
 if(CONFIG_ARMV7M_DTCM)

arch/arm/src/stm32h7/Kconfig

@@ -522,13 +522,13 @@ endif
 
 config STM32H7_CORTEXM7_FLASH_SIZE
 	int "Flash reserved for M7 core"
-	default 1048576 if STM32_CORTEXM4_ENABLED || ARCH_CHIP_STM32H7_CORTEXM4
+	default 1048576 if STM32H7_CORTEXM4_ENABLED || ARCH_CHIP_STM32H7_CORTEXM4
 	default 2097152
 
 config STM32H7_CORTEXM7_SHMEM
 	bool
 	select ARM_MPU if ARCH_CHIP_STM32H7_CORTEXM7
-	default y if STM32H7_CORTEXM4_ENABLED
+	default y if STM32H7_CORTEXM4_ENABLED || ARCH_CHIP_STM32H7_CORTEXM4
 	default n
 
 config STM32H7_SHMEM_SRAM3
@@ -2156,6 +2156,7 @@ config STM32H7_CUSTOM_CLOCKCONFIG
 
 config STM32H7_SRAM4EXCLUDE
 	bool "Exclude SRAM4 from the heap"
+	default y if RPTUN
 	default n
 	---help---
 		Exclude SRAM4 from the HEAP in order to use this 64 KB region

arch/arm/src/stm32h7/Make.defs

@@ -37,6 +37,10 @@ ifeq ($(CONFIG_STM32H7_HSEM),y)
 CHIP_CSRCS += stm32_hsem.c
 endif
 
+ifeq ($(CONFIG_RPTUN),y)
+CHIP_CSRCS += stm32_rptun.c
+endif
+
 # Required STM32H7 files
 
 CHIP_CSRCS += stm32_allocateheap.c stm32_exti_gpio.c stm32_gpio.c stm32_irq.c
@@ -53,8 +57,12 @@ ifeq ($(CONFIG_STM32H7_ONESHOT),y)
 CHIP_CSRCS += stm32_oneshot.c stm32_oneshot_lowerhalf.c
 endif
 
+ifeq ($(CONFIG_ARM_MPU),y)
+CHIP_CSRCS += stm32_mpuinit.c
+endif
+
 ifeq ($(CONFIG_BUILD_PROTECTED),y)
-CHIP_CSRCS += stm32_userspace.c stm32_mpuinit.c
+CHIP_CSRCS += stm32_userspace.c
 endif
 
 ifeq ($(CONFIG_ARMV7M_DTCM),y)

arch/arm/src/stm32h7/stm32_allocateheap.c

@@ -57,7 +57,7 @@
 #if defined(CONFIG_ARCH_CHIP_STM32H7_CORTEXM7) && \
     !defined(CONFIG_STM32H7_CORTEXM4_ENABLED)
 
-/* Configuration for M7 core and M4 core support disabled */
+/* Configuration for M7 core when M4 core support disabled */
 
 /* At startup the kernel will invoke arm_addregion() so that platform code
  * may register available memories for use as part of system heap.
@@ -117,7 +117,7 @@
 #elif defined(CONFIG_ARCH_CHIP_STM32H7_CORTEXM7) && \
       defined(CONFIG_STM32H7_CORTEXM4_ENABLED)
 
-/* Configuration for M7 core and M4 core support enabled */
+/* Configuration for M7 core when M4 core support enabled */
 
 #  define SRAM_START STM32_AXISRAM_BASE
 #  define SRAM_END   (SRAM_START + STM32H7_SRAM_SIZE)

arch/arm/src/stm32h7/stm32_mpuinit.c

@@ -27,12 +27,28 @@
 #include <assert.h>
 #include <sys/param.h>
 
-#include <nuttx/userspace.h>
+#ifdef CONFIG_BUILD_PROTECTED
+#  include <nuttx/userspace.h>
+#endif
 
 #include "mpu.h"
+#include "hardware/stm32_memorymap.h"
 #include "stm32_mpuinit.h"
 
-#if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_ARM_MPU)
+#ifdef CONFIG_ARM_MPU
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_RPTUN
+#  ifdef CONFIG_STM32H7_SHMEM_SRAM3
+#    define STM32_SHMEM_BASE STM32_SRAM3_BASE
+#    define STM32_SHMEM_SIZE STM32H7_SRAM3_SIZE
+#  else
+#    error missing shmem MPU configuration
+#  endif
+#endif
 
 /****************************************************************************
  * Public Functions
@@ -42,18 +58,25 @@
  * Name: stm32_mpuinitialize
  *
  * Description:
- *   Configure the MPU to permit user-space access to only restricted SAM3U
+ *   Configure the MPU.
- *   resources.
+ *
+ *   If PROTECTED build:
+ *     - permit user-space access to only restricted STM32 resources.
+ *
+ *   If RPTUN:
+ *     - configure shared memory as non-cacheable
  *
  ****************************************************************************/
 
 void stm32_mpuinitialize(void)
 {
+#ifdef CONFIG_BUILD_PROTECTED
   uintptr_t datastart = MIN(USERSPACE->us_datastart, USERSPACE->us_bssstart);
   uintptr_t dataend   = MAX(USERSPACE->us_dataend,   USERSPACE->us_bssend);
 
   DEBUGASSERT(USERSPACE->us_textend >= USERSPACE->us_textstart &&
               dataend >= datastart);
+#endif
 
   /* Show MPU information */
 
@@ -63,18 +86,27 @@ void stm32_mpuinitialize(void)
 
   mpu_reset();
 
+#ifdef CONFIG_BUILD_PROTECTED
   /* Configure user flash and SRAM space */
 
   mpu_user_flash(USERSPACE->us_textstart,
                  USERSPACE->us_textend - USERSPACE->us_textstart);
 
   mpu_user_intsram(datastart, dataend - datastart);
+#endif
+
+#ifdef CONFIG_RPTUN
+  /* Configure shared memory as non-cacheable */
+
+  mpu_priv_shmem((uintptr_t)STM32_SHMEM_BASE, STM32_SHMEM_SIZE);
+#endif
 
   /* Then enable the MPU */
 
   mpu_control(true, false, true);
 }
 
+#ifdef CONFIG_BUILD_PROTECTED
 /****************************************************************************
  * Name: stm32_mpu_uheap
  *
@@ -89,5 +121,6 @@ void stm32_mpu_uheap(uintptr_t start, size_t size)
 {
   mpu_user_intsram(start, size);
 }
+#endif
 
-#endif /* CONFIG_BUILD_PROTECTED && CONFIG_ARM_MPU */
+#endif /* CONFIG_ARM_MPU */

arch/arm/src/stm32h7/stm32_mpuinit.h

@@ -22,7 +22,6 @@
 #define __ARCH_ARM_SRC_STM32H7_STM32_MPUINIT_H
 
 /****************************************************************************
- * Name: stm32_mpuinitialize
  * Included Files
  ****************************************************************************/
 
@@ -31,28 +30,8 @@
 #include <sys/types.h>
 #include <stdint.h>
 
-/****************************************************************************
- * Name: stm32_mpuinitialize
- * Pre-processor Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Name: stm32_mpuinitialize
- * Public Types
- ****************************************************************************/
-
-/****************************************************************************
- * Name: stm32_mpuinitialize
- * Inline Functions
- ****************************************************************************/
-
 #ifndef __ASSEMBLY__
 
-/****************************************************************************
- * Name: stm32_mpuinitialize
- * Public Data
- ****************************************************************************/
-
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
@@ -70,12 +49,11 @@ extern "C"
  * Name: stm32_mpuinitialize
  *
  * Description:
- *   Configure the MPU to permit user-space access to only unrestricted
+ *   Configure the MPU.
- *   STM32H7 resources.
  *
  ****************************************************************************/
 
-#ifdef CONFIG_BUILD_PROTECTED
+#ifdef CONFIG_ARM_MPU
 void stm32_mpuinitialize(void);
 #else
 #  define stm32_mpuinitialize()

arch/arm/src/stm32h7/stm32_rptun.h

@@ -0,0 +1,61 @@
+/****************************************************************************
+ * arch/arm/src/stm32h7/stm32_rptun.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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.
+ *
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_STM32H7_STM32_RPTUN_H
+#define __ARCH_ARM_SRC_STM32H7_STM32_RPTUN_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_rptun_init
+ ****************************************************************************/
+
+int stm32_rptun_init(const char *shmemname, const char *cpuname);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_ARM_SRC_STM32H7_STM32_RPTUN_H */

arch/arm/src/stm32h7/stm32_start.c

@@ -36,6 +36,9 @@
 #include "barriers.h"
 #include "nvic.h"
 #include "mpu.h"
+#ifdef CONFIG_ARM_MPU
+#  include "stm32_mpuinit.h"
+#endif
 
 #include "stm32_rcc.h"
 #include "stm32_userspace.h"
@@ -282,6 +285,12 @@ void __start(void)
 #ifdef CONFIG_BUILD_PROTECTED
   stm32_userspace();
 #endif
+
+#ifdef CONFIG_ARM_MPU
+  /* Configure the MPU */
+
+  stm32_mpuinitialize();
+#endif
   showprogress('E');
 
   /* Then start NuttX */

arch/arm/src/stm32h7/stm32_userspace.c

@@ -87,10 +87,6 @@ void stm32_userspace(void)
     {
       *dest++ = *src++;
     }
-
-  /* Configure the MPU to permit user-space access to its FLASH and RAM */
-
-  stm32_mpuinitialize();
 }
 
 #endif /* CONFIG_BUILD_PROTECTED */