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975 lines
43 KiB
C
975 lines
43 KiB
C
/*
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* FreeRTOS Kernel V10.3.1
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* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* https://www.FreeRTOS.org
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* https://github.com/FreeRTOS
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*
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*/
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/*-----------------------------------------------------------
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* Implementation of functions defined in portable.h for the ARM CM4 MPU port.
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*----------------------------------------------------------*/
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/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
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* all the API functions to use the MPU wrappers. That should only be done when
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* task.h is included from an application file. */
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#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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#ifndef __VFP_FP__
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#error This port can only be used when the project options are configured to enable hardware floating point support.
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#endif
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#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
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#ifndef configSYSTICK_CLOCK_HZ
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#define configSYSTICK_CLOCK_HZ configCPU_CLOCK_HZ
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/* Ensure the SysTick is clocked at the same frequency as the core. */
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#define portNVIC_SYSTICK_CLK ( 1UL << 2UL )
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#else
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/* The way the SysTick is clocked is not modified in case it is not the same
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* as the core. */
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#define portNVIC_SYSTICK_CLK ( 0 )
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#endif
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/* Constants required to access and manipulate the NVIC. */
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#define portNVIC_SYSTICK_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000e010 ) )
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#define portNVIC_SYSTICK_LOAD_REG ( *( ( volatile uint32_t * ) 0xe000e014 ) )
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#define portNVIC_SYSTICK_CURRENT_VALUE_REG ( *( ( volatile uint32_t * ) 0xe000e018 ) )
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#define portNVIC_SHPR3_REG ( *( ( volatile uint32_t * ) 0xe000ed20 ) )
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#define portNVIC_SHPR2_REG ( *( ( volatile uint32_t * ) 0xe000ed1c ) )
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#define portNVIC_SYS_CTRL_STATE_REG ( *( ( volatile uint32_t * ) 0xe000ed24 ) )
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#define portNVIC_MEM_FAULT_ENABLE ( 1UL << 16UL )
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/* Constants required to access and manipulate the MPU. */
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#define portMPU_TYPE_REG ( *( ( volatile uint32_t * ) 0xe000ed90 ) )
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#define portMPU_REGION_BASE_ADDRESS_REG ( *( ( volatile uint32_t * ) 0xe000ed9C ) )
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#define portMPU_REGION_ATTRIBUTE_REG ( *( ( volatile uint32_t * ) 0xe000edA0 ) )
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#define portMPU_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000ed94 ) )
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#define portEXPECTED_MPU_TYPE_VALUE ( portTOTAL_NUM_REGIONS << 8UL )
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#define portMPU_ENABLE ( 0x01UL )
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#define portMPU_BACKGROUND_ENABLE ( 1UL << 2UL )
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#define portPRIVILEGED_EXECUTION_START_ADDRESS ( 0UL )
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#define portMPU_REGION_VALID ( 0x10UL )
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#define portMPU_REGION_ENABLE ( 0x01UL )
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#define portPERIPHERALS_START_ADDRESS 0x40000000UL
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#define portPERIPHERALS_END_ADDRESS 0x5FFFFFFFUL
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/* Constants required to access and manipulate the SysTick. */
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#define portNVIC_SYSTICK_INT ( 0x00000002UL )
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#define portNVIC_SYSTICK_ENABLE ( 0x00000001UL )
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#define portNVIC_PENDSV_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )
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#define portNVIC_SYSTICK_PRI ( ( ( uint32_t ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )
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#define portNVIC_SVC_PRI ( ( ( uint32_t ) configMAX_SYSCALL_INTERRUPT_PRIORITY - 1UL ) << 24UL )
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/* Constants required to manipulate the VFP. */
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#define portFPCCR ( ( volatile uint32_t * ) 0xe000ef34UL ) /* Floating point context control register. */
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#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )
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/* Constants required to set up the initial stack. */
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#define portINITIAL_XPSR ( 0x01000000UL )
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#define portINITIAL_EXC_RETURN ( 0xfffffffdUL )
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#define portINITIAL_CONTROL_IF_UNPRIVILEGED ( 0x03 )
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#define portINITIAL_CONTROL_IF_PRIVILEGED ( 0x02 )
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/* Constants required to check the validity of an interrupt priority. */
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#define portFIRST_USER_INTERRUPT_NUMBER ( 16 )
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#define portNVIC_IP_REGISTERS_OFFSET_16 ( 0xE000E3F0 )
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#define portAIRCR_REG ( *( ( volatile uint32_t * ) 0xE000ED0C ) )
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#define portMAX_8_BIT_VALUE ( ( uint8_t ) 0xff )
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#define portTOP_BIT_OF_BYTE ( ( uint8_t ) 0x80 )
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#define portMAX_PRIGROUP_BITS ( ( uint8_t ) 7 )
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#define portPRIORITY_GROUP_MASK ( 0x07UL << 8UL )
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#define portPRIGROUP_SHIFT ( 8UL )
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/* Offsets in the stack to the parameters when inside the SVC handler. */
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#define portOFFSET_TO_PC ( 6 )
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/* For strict compliance with the Cortex-M spec the task start address should
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* have bit-0 clear, as it is loaded into the PC on exit from an ISR. */
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#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )
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/*
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* Configure a number of standard MPU regions that are used by all tasks.
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*/
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static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
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/*
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* Return the smallest MPU region size that a given number of bytes will fit
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* into. The region size is returned as the value that should be programmed
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* into the region attribute register for that region.
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*/
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static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes ) PRIVILEGED_FUNCTION;
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/*
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* Setup the timer to generate the tick interrupts. The implementation in this
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* file is weak to allow application writers to change the timer used to
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* generate the tick interrupt.
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*/
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void vPortSetupTimerInterrupt( void );
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/*
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* Standard FreeRTOS exception handlers.
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*/
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void xPortPendSVHandler( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
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void xPortSysTickHandler( void ) PRIVILEGED_FUNCTION;
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void vPortSVCHandler( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
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/*
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* Starts the scheduler by restoring the context of the first task to run.
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*/
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static void prvRestoreContextOfFirstTask( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
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/*
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* C portion of the SVC handler. The SVC handler is split between an asm entry
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* and a C wrapper for simplicity of coding and maintenance.
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*/
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static void prvSVCHandler( uint32_t * pulRegisters ) __attribute__( ( noinline ) ) PRIVILEGED_FUNCTION;
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/*
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* Function to enable the VFP.
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*/
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static void vPortEnableVFP( void ) __attribute__( ( naked ) );
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/**
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* @brief Checks whether or not the processor is privileged.
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*
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* @return 1 if the processor is already privileged, 0 otherwise.
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*/
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BaseType_t xIsPrivileged( void ) __attribute__( ( naked ) );
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/**
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* @brief Lowers the privilege level by setting the bit 0 of the CONTROL
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* register.
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*
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* Bit 0 of the CONTROL register defines the privilege level of Thread Mode.
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* Bit[0] = 0 --> The processor is running privileged
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* Bit[0] = 1 --> The processor is running unprivileged.
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*/
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void vResetPrivilege( void ) __attribute__( ( naked ) );
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/**
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* @brief Calls the port specific code to raise the privilege.
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*
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* @return pdFALSE if privilege was raised, pdTRUE otherwise.
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*/
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extern BaseType_t xPortRaisePrivilege( void );
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/**
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* @brief If xRunningPrivileged is not pdTRUE, calls the port specific
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* code to reset the privilege, otherwise does nothing.
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*/
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extern void vPortResetPrivilege( BaseType_t xRunningPrivileged );
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/*-----------------------------------------------------------*/
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/* Each task maintains its own interrupt status in the critical nesting
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* variable. Note this is not saved as part of the task context as context
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* switches can only occur when uxCriticalNesting is zero. */
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static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;
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/*
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* Used by the portASSERT_IF_INTERRUPT_PRIORITY_INVALID() macro to ensure
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* FreeRTOS API functions are not called from interrupts that have been assigned
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* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.
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*/
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#if ( configASSERT_DEFINED == 1 )
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static uint8_t ucMaxSysCallPriority = 0;
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static uint32_t ulMaxPRIGROUPValue = 0;
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static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;
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#endif /* configASSERT_DEFINED */
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/*-----------------------------------------------------------*/
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/*
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* See header file for description.
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*/
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StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
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TaskFunction_t pxCode,
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void * pvParameters,
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BaseType_t xRunPrivileged )
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{
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/* Simulate the stack frame as it would be created by a context switch
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* interrupt. */
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pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
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*pxTopOfStack = portINITIAL_XPSR; /* xPSR */
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pxTopOfStack--;
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*pxTopOfStack = ( ( StackType_t ) pxCode ) & portSTART_ADDRESS_MASK; /* PC */
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pxTopOfStack--;
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*pxTopOfStack = 0; /* LR */
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pxTopOfStack -= 5; /* R12, R3, R2 and R1. */
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*pxTopOfStack = ( StackType_t ) pvParameters; /* R0 */
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/* A save method is being used that requires each task to maintain its
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* own exec return value. */
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pxTopOfStack--;
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*pxTopOfStack = portINITIAL_EXC_RETURN;
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pxTopOfStack -= 9; /* R11, R10, R9, R8, R7, R6, R5 and R4. */
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if( xRunPrivileged == pdTRUE )
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{
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*pxTopOfStack = portINITIAL_CONTROL_IF_PRIVILEGED;
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}
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else
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{
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*pxTopOfStack = portINITIAL_CONTROL_IF_UNPRIVILEGED;
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}
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return pxTopOfStack;
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}
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/*-----------------------------------------------------------*/
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void vPortSVCHandler( void )
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{
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/* Assumes psp was in use. */
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__asm volatile
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(
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#ifndef USE_PROCESS_STACK /* Code should not be required if a main() is using the process stack. */
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" tst lr, #4 \n"
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" ite eq \n"
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" mrseq r0, msp \n"
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" mrsne r0, psp \n"
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#else
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" mrs r0, psp \n"
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#endif
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" b %0 \n"
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::"i" ( prvSVCHandler ) : "r0", "memory"
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);
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}
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/*-----------------------------------------------------------*/
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static void prvSVCHandler( uint32_t * pulParam )
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{
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uint8_t ucSVCNumber;
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uint32_t ulPC;
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#if ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 )
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#if defined( __ARMCC_VERSION )
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/* Declaration when these variable are defined in code instead of being
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* exported from linker scripts. */
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extern uint32_t * __syscalls_flash_start__;
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extern uint32_t * __syscalls_flash_end__;
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#else
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/* Declaration when these variable are exported from linker scripts. */
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extern uint32_t __syscalls_flash_start__[];
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extern uint32_t __syscalls_flash_end__[];
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#endif /* #if defined( __ARMCC_VERSION ) */
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#endif /* #if( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) */
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/* The stack contains: r0, r1, r2, r3, r12, LR, PC and xPSR. The first
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* argument (r0) is pulParam[ 0 ]. */
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ulPC = pulParam[ portOFFSET_TO_PC ];
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ucSVCNumber = ( ( uint8_t * ) ulPC )[ -2 ];
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switch( ucSVCNumber )
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{
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case portSVC_START_SCHEDULER:
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portNVIC_SHPR2_REG |= portNVIC_SVC_PRI;
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prvRestoreContextOfFirstTask();
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break;
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case portSVC_YIELD:
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portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
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/* Barriers are normally not required
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* but do ensure the code is completely
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* within the specified behaviour for the
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* architecture. */
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__asm volatile ( "dsb" ::: "memory" );
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__asm volatile ( "isb" );
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break;
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#if ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 )
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case portSVC_RAISE_PRIVILEGE: /* Only raise the privilege, if the
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* svc was raised from any of the
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* system calls. */
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if( ( ulPC >= ( uint32_t ) __syscalls_flash_start__ ) &&
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( ulPC <= ( uint32_t ) __syscalls_flash_end__ ) )
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{
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__asm volatile
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(
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" mrs r1, control \n"/* Obtain current control value. */
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" bic r1, #1 \n"/* Set privilege bit. */
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" msr control, r1 \n"/* Write back new control value. */
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::: "r1", "memory"
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);
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}
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break;
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#else /* if ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) */
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case portSVC_RAISE_PRIVILEGE:
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__asm volatile
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(
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" mrs r1, control \n"/* Obtain current control value. */
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" bic r1, #1 \n"/* Set privilege bit. */
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" msr control, r1 \n"/* Write back new control value. */
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::: "r1", "memory"
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);
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break;
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#endif /* #if( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) */
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default: /* Unknown SVC call. */
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break;
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}
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}
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/*-----------------------------------------------------------*/
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static void prvRestoreContextOfFirstTask( void )
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{
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__asm volatile
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(
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" ldr r0, =0xE000ED08 \n"/* Use the NVIC offset register to locate the stack. */
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" ldr r0, [r0] \n"
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" ldr r0, [r0] \n"
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" msr msp, r0 \n"/* Set the msp back to the start of the stack. */
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" ldr r3, pxCurrentTCBConst2 \n"/* Restore the context. */
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" ldr r1, [r3] \n"
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" ldr r0, [r1] \n"/* The first item in the TCB is the task top of stack. */
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" add r1, r1, #4 \n"/* Move onto the second item in the TCB... */
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" \n"
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" dmb \n"/* Complete outstanding transfers before disabling MPU. */
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" ldr r2, =0xe000ed94 \n"/* MPU_CTRL register. */
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" ldr r3, [r2] \n"/* Read the value of MPU_CTRL. */
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" bic r3, #1 \n"/* r3 = r3 & ~1 i.e. Clear the bit 0 in r3. */
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" str r3, [r2] \n"/* Disable MPU. */
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" \n"
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" ldr r2, =0xe000ed9c \n"/* Region Base Address register. */
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" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 4 - 7]. */
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" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers [MPU Region # 4 - 7]. */
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" \n"
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#if ( portTOTAL_NUM_REGIONS == 16 )
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" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 8 - 11]. */
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" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers. [MPU Region # 8 - 11]. */
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" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 12 - 15]. */
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" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers. [MPU Region # 12 - 15]. */
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#endif /* portTOTAL_NUM_REGIONS == 16. */
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" \n"
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" ldr r2, =0xe000ed94 \n"/* MPU_CTRL register. */
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" ldr r3, [r2] \n"/* Read the value of MPU_CTRL. */
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" orr r3, #1 \n"/* r3 = r3 | 1 i.e. Set the bit 0 in r3. */
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" str r3, [r2] \n"/* Enable MPU. */
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" dsb \n"/* Force memory writes before continuing. */
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" \n"
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" ldmia r0!, {r3-r11, r14} \n"/* Pop the registers that are not automatically saved on exception entry. */
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" msr control, r3 \n"
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" msr psp, r0 \n"/* Restore the task stack pointer. */
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" mov r0, #0 \n"
|
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" msr basepri, r0 \n"
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" bx r14 \n"
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" \n"
|
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" .align 4 \n"
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"pxCurrentTCBConst2: .word pxCurrentTCB \n"
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|
);
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
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|
* See header file for description.
|
|
*/
|
|
BaseType_t xPortStartScheduler( void )
|
|
{
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|
/* configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See
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* https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
|
|
configASSERT( ( configMAX_SYSCALL_INTERRUPT_PRIORITY ) );
|
|
|
|
#if ( configASSERT_DEFINED == 1 )
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{
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volatile uint32_t ulOriginalPriority;
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volatile uint8_t * const pucFirstUserPriorityRegister = ( volatile uint8_t * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );
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|
volatile uint8_t ucMaxPriorityValue;
|
|
|
|
/* Determine the maximum priority from which ISR safe FreeRTOS API
|
|
* functions can be called. ISR safe functions are those that end in
|
|
* "FromISR". FreeRTOS maintains separate thread and ISR API functions to
|
|
* ensure interrupt entry is as fast and simple as possible.
|
|
*
|
|
* Save the interrupt priority value that is about to be clobbered. */
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|
ulOriginalPriority = *pucFirstUserPriorityRegister;
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|
|
|
/* Determine the number of priority bits available. First write to all
|
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* possible bits. */
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|
*pucFirstUserPriorityRegister = portMAX_8_BIT_VALUE;
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|
|
|
/* Read the value back to see how many bits stuck. */
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|
ucMaxPriorityValue = *pucFirstUserPriorityRegister;
|
|
|
|
/* Use the same mask on the maximum system call priority. */
|
|
ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;
|
|
|
|
/* Calculate the maximum acceptable priority group value for the number
|
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* of bits read back. */
|
|
ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS;
|
|
|
|
while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )
|
|
{
|
|
ulMaxPRIGROUPValue--;
|
|
ucMaxPriorityValue <<= ( uint8_t ) 0x01;
|
|
}
|
|
|
|
#ifdef __NVIC_PRIO_BITS
|
|
{
|
|
/* Check the CMSIS configuration that defines the number of
|
|
* priority bits matches the number of priority bits actually queried
|
|
* from the hardware. */
|
|
configASSERT( ( portMAX_PRIGROUP_BITS - ulMaxPRIGROUPValue ) == __NVIC_PRIO_BITS );
|
|
}
|
|
#endif
|
|
|
|
#ifdef configPRIO_BITS
|
|
{
|
|
/* Check the FreeRTOS configuration that defines the number of
|
|
* priority bits matches the number of priority bits actually queried
|
|
* from the hardware. */
|
|
configASSERT( ( portMAX_PRIGROUP_BITS - ulMaxPRIGROUPValue ) == configPRIO_BITS );
|
|
}
|
|
#endif
|
|
|
|
/* Shift the priority group value back to its position within the AIRCR
|
|
* register. */
|
|
ulMaxPRIGROUPValue <<= portPRIGROUP_SHIFT;
|
|
ulMaxPRIGROUPValue &= portPRIORITY_GROUP_MASK;
|
|
|
|
/* Restore the clobbered interrupt priority register to its original
|
|
* value. */
|
|
*pucFirstUserPriorityRegister = ulOriginalPriority;
|
|
}
|
|
#endif /* conifgASSERT_DEFINED */
|
|
|
|
/* Make PendSV and SysTick the same priority as the kernel, and the SVC
|
|
* handler higher priority so it can be used to exit a critical section (where
|
|
* lower priorities are masked). */
|
|
portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
|
|
portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
|
|
|
|
/* Configure the regions in the MPU that are common to all tasks. */
|
|
prvSetupMPU();
|
|
|
|
/* Start the timer that generates the tick ISR. Interrupts are disabled
|
|
* here already. */
|
|
vPortSetupTimerInterrupt();
|
|
|
|
/* Initialise the critical nesting count ready for the first task. */
|
|
uxCriticalNesting = 0;
|
|
|
|
/* Ensure the VFP is enabled - it should be anyway. */
|
|
vPortEnableVFP();
|
|
|
|
/* Lazy save always. */
|
|
*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;
|
|
|
|
/* Start the first task. This also clears the bit that indicates the FPU is
|
|
* in use in case the FPU was used before the scheduler was started - which
|
|
* would otherwise result in the unnecessary leaving of space in the SVC stack
|
|
* for lazy saving of FPU registers. */
|
|
__asm volatile (
|
|
" ldr r0, =0xE000ED08 \n"/* Use the NVIC offset register to locate the stack. */
|
|
" ldr r0, [r0] \n"
|
|
" ldr r0, [r0] \n"
|
|
" msr msp, r0 \n"/* Set the msp back to the start of the stack. */
|
|
" mov r0, #0 \n"/* Clear the bit that indicates the FPU is in use, see comment above. */
|
|
" msr control, r0 \n"
|
|
" cpsie i \n"/* Globally enable interrupts. */
|
|
" cpsie f \n"
|
|
" dsb \n"
|
|
" isb \n"
|
|
" svc %0 \n"/* System call to start first task. */
|
|
" nop \n"
|
|
" .ltorg \n"
|
|
::"i" ( portSVC_START_SCHEDULER ) : "memory" );
|
|
|
|
/* Should not get here! */
|
|
return 0;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEndScheduler( void )
|
|
{
|
|
/* Not implemented in ports where there is nothing to return to.
|
|
* Artificially force an assert. */
|
|
configASSERT( uxCriticalNesting == 1000UL );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEnterCritical( void )
|
|
{
|
|
BaseType_t xRunningPrivileged = xPortRaisePrivilege();
|
|
|
|
portDISABLE_INTERRUPTS();
|
|
uxCriticalNesting++;
|
|
|
|
vPortResetPrivilege( xRunningPrivileged );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortExitCritical( void )
|
|
{
|
|
BaseType_t xRunningPrivileged = xPortRaisePrivilege();
|
|
|
|
configASSERT( uxCriticalNesting );
|
|
uxCriticalNesting--;
|
|
|
|
if( uxCriticalNesting == 0 )
|
|
{
|
|
portENABLE_INTERRUPTS();
|
|
}
|
|
|
|
vPortResetPrivilege( xRunningPrivileged );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void xPortPendSVHandler( void )
|
|
{
|
|
/* This is a naked function. */
|
|
|
|
__asm volatile
|
|
(
|
|
" mrs r0, psp \n"
|
|
" isb \n"
|
|
" \n"
|
|
" ldr r3, pxCurrentTCBConst \n"/* Get the location of the current TCB. */
|
|
" ldr r2, [r3] \n"
|
|
" \n"
|
|
" tst r14, #0x10 \n"/* Is the task using the FPU context? If so, push high vfp registers. */
|
|
" it eq \n"
|
|
" vstmdbeq r0!, {s16-s31} \n"
|
|
" \n"
|
|
" mrs r1, control \n"
|
|
" stmdb r0!, {r1, r4-r11, r14} \n"/* Save the remaining registers. */
|
|
" str r0, [r2] \n"/* Save the new top of stack into the first member of the TCB. */
|
|
" \n"
|
|
" stmdb sp!, {r0, r3} \n"
|
|
" mov r0, %0 \n"
|
|
" msr basepri, r0 \n"
|
|
" dsb \n"
|
|
" isb \n"
|
|
" bl vTaskSwitchContext \n"
|
|
" mov r0, #0 \n"
|
|
" msr basepri, r0 \n"
|
|
" ldmia sp!, {r0, r3} \n"
|
|
" \n"/* Restore the context. */
|
|
" ldr r1, [r3] \n"
|
|
" ldr r0, [r1] \n"/* The first item in the TCB is the task top of stack. */
|
|
" add r1, r1, #4 \n"/* Move onto the second item in the TCB... */
|
|
" \n"
|
|
" dmb \n"/* Complete outstanding transfers before disabling MPU. */
|
|
" ldr r2, =0xe000ed94 \n"/* MPU_CTRL register. */
|
|
" ldr r3, [r2] \n"/* Read the value of MPU_CTRL. */
|
|
" bic r3, #1 \n"/* r3 = r3 & ~1 i.e. Clear the bit 0 in r3. */
|
|
" str r3, [r2] \n"/* Disable MPU. */
|
|
" \n"
|
|
" ldr r2, =0xe000ed9c \n"/* Region Base Address register. */
|
|
" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 4 - 7]. */
|
|
" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers [MPU Region # 4 - 7]. */
|
|
" \n"
|
|
#if ( portTOTAL_NUM_REGIONS == 16 )
|
|
" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 8 - 11]. */
|
|
" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers. [MPU Region # 8 - 11]. */
|
|
" ldmia r1!, {r4-r11} \n"/* Read 4 sets of MPU registers [MPU Region # 12 - 15]. */
|
|
" stmia r2, {r4-r11} \n"/* Write 4 sets of MPU registers. [MPU Region # 12 - 15]. */
|
|
#endif /* portTOTAL_NUM_REGIONS == 16. */
|
|
" \n"
|
|
" ldr r2, =0xe000ed94 \n"/* MPU_CTRL register. */
|
|
" ldr r3, [r2] \n"/* Read the value of MPU_CTRL. */
|
|
" orr r3, #1 \n"/* r3 = r3 | 1 i.e. Set the bit 0 in r3. */
|
|
" str r3, [r2] \n"/* Enable MPU. */
|
|
" dsb \n"/* Force memory writes before continuing. */
|
|
" \n"
|
|
" ldmia r0!, {r3-r11, r14} \n"/* Pop the registers that are not automatically saved on exception entry. */
|
|
" msr control, r3 \n"
|
|
" \n"
|
|
" tst r14, #0x10 \n"/* Is the task using the FPU context? If so, pop the high vfp registers too. */
|
|
" it eq \n"
|
|
" vldmiaeq r0!, {s16-s31} \n"
|
|
" \n"
|
|
" msr psp, r0 \n"
|
|
" bx r14 \n"
|
|
" \n"
|
|
" .align 4 \n"
|
|
"pxCurrentTCBConst: .word pxCurrentTCB \n"
|
|
::"i" ( configMAX_SYSCALL_INTERRUPT_PRIORITY )
|
|
);
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void xPortSysTickHandler( void )
|
|
{
|
|
uint32_t ulDummy;
|
|
|
|
ulDummy = portSET_INTERRUPT_MASK_FROM_ISR();
|
|
{
|
|
/* Increment the RTOS tick. */
|
|
if( xTaskIncrementTick() != pdFALSE )
|
|
{
|
|
/* Pend a context switch. */
|
|
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
|
|
}
|
|
}
|
|
portCLEAR_INTERRUPT_MASK_FROM_ISR( ulDummy );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* Setup the systick timer to generate the tick interrupts at the required
|
|
* frequency.
|
|
*/
|
|
__attribute__( ( weak ) ) void vPortSetupTimerInterrupt( void )
|
|
{
|
|
/* Stop and clear the SysTick. */
|
|
portNVIC_SYSTICK_CTRL_REG = 0UL;
|
|
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
|
|
|
|
/* Configure SysTick to interrupt at the requested rate. */
|
|
portNVIC_SYSTICK_LOAD_REG = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL;
|
|
portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* This is a naked function. */
|
|
static void vPortEnableVFP( void )
|
|
{
|
|
__asm volatile
|
|
(
|
|
" ldr.w r0, =0xE000ED88 \n"/* The FPU enable bits are in the CPACR. */
|
|
" ldr r1, [r0] \n"
|
|
" \n"
|
|
" orr r1, r1, #( 0xf << 20 ) \n"/* Enable CP10 and CP11 coprocessors, then save back. */
|
|
" str r1, [r0] \n"
|
|
" bx r14 \n"
|
|
" .ltorg \n"
|
|
);
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvSetupMPU( void )
|
|
{
|
|
#if defined( __ARMCC_VERSION )
|
|
|
|
/* Declaration when these variable are defined in code instead of being
|
|
* exported from linker scripts. */
|
|
extern uint32_t * __privileged_functions_start__;
|
|
extern uint32_t * __privileged_functions_end__;
|
|
extern uint32_t * __FLASH_segment_start__;
|
|
extern uint32_t * __FLASH_segment_end__;
|
|
extern uint32_t * __privileged_data_start__;
|
|
extern uint32_t * __privileged_data_end__;
|
|
#else
|
|
/* Declaration when these variable are exported from linker scripts. */
|
|
extern uint32_t __privileged_functions_start__[];
|
|
extern uint32_t __privileged_functions_end__[];
|
|
extern uint32_t __FLASH_segment_start__[];
|
|
extern uint32_t __FLASH_segment_end__[];
|
|
extern uint32_t __privileged_data_start__[];
|
|
extern uint32_t __privileged_data_end__[];
|
|
#endif /* if defined( __ARMCC_VERSION ) */
|
|
|
|
/* The only permitted number of regions are 8 or 16. */
|
|
configASSERT( ( portTOTAL_NUM_REGIONS == 8 ) || ( portTOTAL_NUM_REGIONS == 16 ) );
|
|
|
|
/* Ensure that the configTOTAL_MPU_REGIONS is configured correctly. */
|
|
configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
|
|
|
|
/* Check the expected MPU is present. */
|
|
if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
|
|
{
|
|
/* First setup the unprivileged flash for unprivileged read only access. */
|
|
portMPU_REGION_BASE_ADDRESS_REG = ( ( uint32_t ) __FLASH_segment_start__ ) | /* Base address. */
|
|
( portMPU_REGION_VALID ) |
|
|
( portUNPRIVILEGED_FLASH_REGION );
|
|
|
|
portMPU_REGION_ATTRIBUTE_REG = ( portMPU_REGION_READ_ONLY ) |
|
|
( ( configTEX_S_C_B_FLASH & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
( prvGetMPURegionSizeSetting( ( uint32_t ) __FLASH_segment_end__ - ( uint32_t ) __FLASH_segment_start__ ) ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* Setup the privileged flash for privileged only access. This is where
|
|
* the kernel code is placed. */
|
|
portMPU_REGION_BASE_ADDRESS_REG = ( ( uint32_t ) __privileged_functions_start__ ) | /* Base address. */
|
|
( portMPU_REGION_VALID ) |
|
|
( portPRIVILEGED_FLASH_REGION );
|
|
|
|
portMPU_REGION_ATTRIBUTE_REG = ( portMPU_REGION_PRIVILEGED_READ_ONLY ) |
|
|
( ( configTEX_S_C_B_FLASH & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
( prvGetMPURegionSizeSetting( ( uint32_t ) __privileged_functions_end__ - ( uint32_t ) __privileged_functions_start__ ) ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* Setup the privileged data RAM region. This is where the kernel data
|
|
* is placed. */
|
|
portMPU_REGION_BASE_ADDRESS_REG = ( ( uint32_t ) __privileged_data_start__ ) | /* Base address. */
|
|
( portMPU_REGION_VALID ) |
|
|
( portPRIVILEGED_RAM_REGION );
|
|
|
|
portMPU_REGION_ATTRIBUTE_REG = ( portMPU_REGION_PRIVILEGED_READ_WRITE ) |
|
|
( ( configTEX_S_C_B_SRAM & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
prvGetMPURegionSizeSetting( ( uint32_t ) __privileged_data_end__ - ( uint32_t ) __privileged_data_start__ ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* By default allow everything to access the general peripherals. The
|
|
* system peripherals and registers are protected. */
|
|
portMPU_REGION_BASE_ADDRESS_REG = ( portPERIPHERALS_START_ADDRESS ) |
|
|
( portMPU_REGION_VALID ) |
|
|
( portGENERAL_PERIPHERALS_REGION );
|
|
|
|
portMPU_REGION_ATTRIBUTE_REG = ( portMPU_REGION_READ_WRITE | portMPU_REGION_EXECUTE_NEVER ) |
|
|
( prvGetMPURegionSizeSetting( portPERIPHERALS_END_ADDRESS - portPERIPHERALS_START_ADDRESS ) ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* Enable the memory fault exception. */
|
|
portNVIC_SYS_CTRL_STATE_REG |= portNVIC_MEM_FAULT_ENABLE;
|
|
|
|
/* Enable the MPU with the background region configured. */
|
|
portMPU_CTRL_REG |= ( portMPU_ENABLE | portMPU_BACKGROUND_ENABLE );
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
|
|
{
|
|
uint32_t ulRegionSize, ulReturnValue = 4;
|
|
|
|
/* 32 is the smallest region size, 31 is the largest valid value for
|
|
* ulReturnValue. */
|
|
for( ulRegionSize = 32UL; ulReturnValue < 31UL; ( ulRegionSize <<= 1UL ) )
|
|
{
|
|
if( ulActualSizeInBytes <= ulRegionSize )
|
|
{
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
ulReturnValue++;
|
|
}
|
|
}
|
|
|
|
/* Shift the code by one before returning so it can be written directly
|
|
* into the the correct bit position of the attribute register. */
|
|
return( ulReturnValue << 1UL );
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
BaseType_t xIsPrivileged( void ) /* __attribute__ (( naked )) */
|
|
{
|
|
__asm volatile
|
|
(
|
|
" mrs r0, control \n"/* r0 = CONTROL. */
|
|
" tst r0, #1 \n"/* Perform r0 & 1 (bitwise AND) and update the conditions flag. */
|
|
" ite ne \n"
|
|
" movne r0, #0 \n"/* CONTROL[0]!=0. Return false to indicate that the processor is not privileged. */
|
|
" moveq r0, #1 \n"/* CONTROL[0]==0. Return true to indicate that the processor is privileged. */
|
|
" bx lr \n"/* Return. */
|
|
" \n"
|
|
" .align 4 \n"
|
|
::: "r0", "memory"
|
|
);
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vResetPrivilege( void ) /* __attribute__ (( naked )) */
|
|
{
|
|
__asm volatile
|
|
(
|
|
" mrs r0, control \n"/* r0 = CONTROL. */
|
|
" orr r0, #1 \n"/* r0 = r0 | 1. */
|
|
" msr control, r0 \n"/* CONTROL = r0. */
|
|
" bx lr \n"/* Return to the caller. */
|
|
::: "r0", "memory"
|
|
);
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortStoreTaskMPUSettings( xMPU_SETTINGS * xMPUSettings,
|
|
const struct xMEMORY_REGION * const xRegions,
|
|
StackType_t * pxBottomOfStack,
|
|
uint32_t ulStackDepth )
|
|
{
|
|
#if defined( __ARMCC_VERSION )
|
|
|
|
/* Declaration when these variable are defined in code instead of being
|
|
* exported from linker scripts. */
|
|
extern uint32_t * __SRAM_segment_start__;
|
|
extern uint32_t * __SRAM_segment_end__;
|
|
extern uint32_t * __privileged_data_start__;
|
|
extern uint32_t * __privileged_data_end__;
|
|
#else
|
|
/* Declaration when these variable are exported from linker scripts. */
|
|
extern uint32_t __SRAM_segment_start__[];
|
|
extern uint32_t __SRAM_segment_end__[];
|
|
extern uint32_t __privileged_data_start__[];
|
|
extern uint32_t __privileged_data_end__[];
|
|
#endif /* if defined( __ARMCC_VERSION ) */
|
|
|
|
int32_t lIndex;
|
|
uint32_t ul;
|
|
|
|
if( xRegions == NULL )
|
|
{
|
|
/* No MPU regions are specified so allow access to all RAM. */
|
|
xMPUSettings->xRegion[ 0 ].ulRegionBaseAddress =
|
|
( ( uint32_t ) __SRAM_segment_start__ ) | /* Base address. */
|
|
( portMPU_REGION_VALID ) |
|
|
( portSTACK_REGION );
|
|
|
|
xMPUSettings->xRegion[ 0 ].ulRegionAttribute =
|
|
( portMPU_REGION_READ_WRITE ) |
|
|
( ( configTEX_S_C_B_SRAM & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
( prvGetMPURegionSizeSetting( ( uint32_t ) __SRAM_segment_end__ - ( uint32_t ) __SRAM_segment_start__ ) ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* Re-instate the privileged only RAM region as xRegion[ 0 ] will have
|
|
* just removed the privileged only parameters. */
|
|
xMPUSettings->xRegion[ 1 ].ulRegionBaseAddress =
|
|
( ( uint32_t ) __privileged_data_start__ ) | /* Base address. */
|
|
( portMPU_REGION_VALID ) |
|
|
( portSTACK_REGION + 1 );
|
|
|
|
xMPUSettings->xRegion[ 1 ].ulRegionAttribute =
|
|
( portMPU_REGION_PRIVILEGED_READ_WRITE ) |
|
|
( ( configTEX_S_C_B_SRAM & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
prvGetMPURegionSizeSetting( ( uint32_t ) __privileged_data_end__ - ( uint32_t ) __privileged_data_start__ ) |
|
|
( portMPU_REGION_ENABLE );
|
|
|
|
/* Invalidate all other regions. */
|
|
for( ul = 2; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
|
|
{
|
|
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = ( portSTACK_REGION + ul ) | portMPU_REGION_VALID;
|
|
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0UL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* This function is called automatically when the task is created - in
|
|
* which case the stack region parameters will be valid. At all other
|
|
* times the stack parameters will not be valid and it is assumed that the
|
|
* stack region has already been configured. */
|
|
if( ulStackDepth > 0 )
|
|
{
|
|
/* Define the region that allows access to the stack. */
|
|
xMPUSettings->xRegion[ 0 ].ulRegionBaseAddress =
|
|
( ( uint32_t ) pxBottomOfStack ) |
|
|
( portMPU_REGION_VALID ) |
|
|
( portSTACK_REGION ); /* Region number. */
|
|
|
|
xMPUSettings->xRegion[ 0 ].ulRegionAttribute =
|
|
( portMPU_REGION_READ_WRITE ) | /* Read and write. */
|
|
( prvGetMPURegionSizeSetting( ulStackDepth * ( uint32_t ) sizeof( StackType_t ) ) ) |
|
|
( ( configTEX_S_C_B_SRAM & portMPU_RASR_TEX_S_C_B_MASK ) << portMPU_RASR_TEX_S_C_B_LOCATION ) |
|
|
( portMPU_REGION_ENABLE );
|
|
}
|
|
|
|
lIndex = 0;
|
|
|
|
for( ul = 1; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
|
|
{
|
|
if( ( xRegions[ lIndex ] ).ulLengthInBytes > 0UL )
|
|
{
|
|
/* Translate the generic region definition contained in
|
|
* xRegions into the CM4 specific MPU settings that are then
|
|
* stored in xMPUSettings. */
|
|
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress =
|
|
( ( uint32_t ) xRegions[ lIndex ].pvBaseAddress ) |
|
|
( portMPU_REGION_VALID ) |
|
|
( portSTACK_REGION + ul ); /* Region number. */
|
|
|
|
xMPUSettings->xRegion[ ul ].ulRegionAttribute =
|
|
( prvGetMPURegionSizeSetting( xRegions[ lIndex ].ulLengthInBytes ) ) |
|
|
( xRegions[ lIndex ].ulParameters ) |
|
|
( portMPU_REGION_ENABLE );
|
|
}
|
|
else
|
|
{
|
|
/* Invalidate the region. */
|
|
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = ( portSTACK_REGION + ul ) | portMPU_REGION_VALID;
|
|
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0UL;
|
|
}
|
|
|
|
lIndex++;
|
|
}
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
#if ( configASSERT_DEFINED == 1 )
|
|
|
|
void vPortValidateInterruptPriority( void )
|
|
{
|
|
uint32_t ulCurrentInterrupt;
|
|
uint8_t ucCurrentPriority;
|
|
|
|
/* Obtain the number of the currently executing interrupt. */
|
|
__asm volatile ( "mrs %0, ipsr" : "=r" ( ulCurrentInterrupt )::"memory" );
|
|
|
|
/* Is the interrupt number a user defined interrupt? */
|
|
if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )
|
|
{
|
|
/* Look up the interrupt's priority. */
|
|
ucCurrentPriority = pcInterruptPriorityRegisters[ ulCurrentInterrupt ];
|
|
|
|
/* The following assertion will fail if a service routine (ISR) for
|
|
* an interrupt that has been assigned a priority above
|
|
* configMAX_SYSCALL_INTERRUPT_PRIORITY calls an ISR safe FreeRTOS API
|
|
* function. ISR safe FreeRTOS API functions must *only* be called
|
|
* from interrupts that have been assigned a priority at or below
|
|
* configMAX_SYSCALL_INTERRUPT_PRIORITY.
|
|
*
|
|
* Numerically low interrupt priority numbers represent logically high
|
|
* interrupt priorities, therefore the priority of the interrupt must
|
|
* be set to a value equal to or numerically *higher* than
|
|
* configMAX_SYSCALL_INTERRUPT_PRIORITY.
|
|
*
|
|
* Interrupts that use the FreeRTOS API must not be left at their
|
|
* default priority of zero as that is the highest possible priority,
|
|
* which is guaranteed to be above configMAX_SYSCALL_INTERRUPT_PRIORITY,
|
|
* and therefore also guaranteed to be invalid.
|
|
*
|
|
* FreeRTOS maintains separate thread and ISR API functions to ensure
|
|
* interrupt entry is as fast and simple as possible.
|
|
*
|
|
* The following links provide detailed information:
|
|
* http://www.freertos.org/RTOS-Cortex-M3-M4.html
|
|
* http://www.freertos.org/FAQHelp.html */
|
|
configASSERT( ucCurrentPriority >= ucMaxSysCallPriority );
|
|
}
|
|
|
|
/* Priority grouping: The interrupt controller (NVIC) allows the bits
|
|
* that define each interrupt's priority to be split between bits that
|
|
* define the interrupt's pre-emption priority bits and bits that define
|
|
* the interrupt's sub-priority. For simplicity all bits must be defined
|
|
* to be pre-emption priority bits. The following assertion will fail if
|
|
* this is not the case (if some bits represent a sub-priority).
|
|
*
|
|
* If the application only uses CMSIS libraries for interrupt
|
|
* configuration then the correct setting can be achieved on all Cortex-M
|
|
* devices by calling NVIC_SetPriorityGrouping( 0 ); before starting the
|
|
* scheduler. Note however that some vendor specific peripheral libraries
|
|
* assume a non-zero priority group setting, in which cases using a value
|
|
* of zero will result in unpredicable behaviour. */
|
|
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );
|
|
}
|
|
|
|
#endif /* configASSERT_DEFINED */
|
|
/*-----------------------------------------------------------*/
|