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/*
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the ARM CM4F MPU port.
*----------------------------------------------------------*/
/* IAR includes. */
#include <intrinsics.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "mpu_syscall_numbers.h"
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
#ifndef __ARMVFP__
#error This port can only be used when the project options are configured to enable hardware floating point support.
#endif
#if ( configMAX_SYSCALL_INTERRUPT_PRIORITY == 0 )
#error configMAX_SYSCALL_INTERRUPT_PRIORITY must not be set to 0. See http: /*www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
#endif
#ifndef configSYSTICK_CLOCK_HZ
#define configSYSTICK_CLOCK_HZ configCPU_CLOCK_HZ
/* Ensure the SysTick is clocked at the same frequency as the core. */
#define portNVIC_SYSTICK_CLK_BIT ( 1UL << 2UL )
#else
/* The way the SysTick is clocked is not modified in case it is not the same
* as the core. */
#define portNVIC_SYSTICK_CLK_BIT ( 0 )
#endif
#ifndef configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS
#warning "configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS is not defined. We recommend defining it to 0 in FreeRTOSConfig.h for better security."
#define configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS 1
#endif
/* Prototype of all Interrupt Service Routines (ISRs). */
typedef void ( * portISR_t )( void );
/* Constants required to manipulate the core. Registers first... */
#define portNVIC_SYSTICK_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000e010 ) )
#define portNVIC_SYSTICK_LOAD_REG ( *( ( volatile uint32_t * ) 0xe000e014 ) )
#define portNVIC_SYSTICK_CURRENT_VALUE_REG ( *( ( volatile uint32_t * ) 0xe000e018 ) )
#define portNVIC_SHPR3_REG ( *( ( volatile uint32_t * ) 0xe000ed20 ) )
#define portNVIC_SHPR2_REG ( *( ( volatile uint32_t * ) 0xe000ed1c ) )
#define portNVIC_SYS_CTRL_STATE_REG ( *( ( volatile uint32_t * ) 0xe000ed24 ) )
#define portNVIC_MEM_FAULT_ENABLE ( 1UL << 16UL )
/* Constants required to access and manipulate the MPU. */
#define portMPU_TYPE_REG ( *( ( volatile uint32_t * ) 0xe000ed90 ) )
#define portMPU_REGION_BASE_ADDRESS_REG ( *( ( volatile uint32_t * ) 0xe000ed9C ) )
#define portMPU_REGION_ATTRIBUTE_REG ( *( ( volatile uint32_t * ) 0xe000edA0 ) )
#define portMPU_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000ed94 ) )
#define portEXPECTED_MPU_TYPE_VALUE ( configTOTAL_MPU_REGIONS << 8UL )
#define portMPU_ENABLE ( 0x01UL )
#define portMPU_BACKGROUND_ENABLE ( 1UL << 2UL )
#define portPRIVILEGED_EXECUTION_START_ADDRESS ( 0UL )
#define portMPU_REGION_VALID ( 0x10UL )
#define portMPU_REGION_ENABLE ( 0x01UL )
#define portPERIPHERALS_START_ADDRESS 0x40000000UL
#define portPERIPHERALS_END_ADDRESS 0x5FFFFFFFUL
/* ...then bits in the registers. */
#define portNVIC_SYSTICK_INT_BIT ( 1UL << 1UL )
#define portNVIC_SYSTICK_ENABLE_BIT ( 1UL << 0UL )
#define portNVIC_SYSTICK_COUNT_FLAG_BIT ( 1UL << 16UL )
#define portNVIC_PENDSVCLEAR_BIT ( 1UL << 27UL )
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
/* Constants used to detect Cortex-M7 r0p0 and r0p1 cores, and ensure
* that a work around is active for errata 837070. */
#define portCPUID ( *( ( volatile uint32_t * ) 0xE000ed00 ) )
#define portCORTEX_M7_r0p1_ID ( 0x410FC271UL )
#define portCORTEX_M7_r0p0_ID ( 0x410FC270UL )
#define portMIN_INTERRUPT_PRIORITY ( 255UL )
#define portNVIC_PENDSV_PRI ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 16UL )
#define portNVIC_SYSTICK_PRI ( ( ( uint32_t ) portMIN_INTERRUPT_PRIORITY ) << 24UL )
/* Constants used to check the installation of the FreeRTOS interrupt handlers. */
#define portSCB_VTOR_REG ( *( ( portISR_t ** ) 0xE000ED08 ) )
#define portVECTOR_INDEX_SVC ( 11 )
#define portVECTOR_INDEX_PENDSV ( 14 )
/* Constants required to check the validity of an interrupt priority. */
#define portFIRST_USER_INTERRUPT_NUMBER ( 16 )
#define portNVIC_IP_REGISTERS_OFFSET_16 ( 0xE000E3F0 )
#define portAIRCR_REG ( *( ( volatile uint32_t * ) 0xE000ED0C ) )
#define portMAX_8_BIT_VALUE ( ( uint8_t ) 0xff )
#define portTOP_BIT_OF_BYTE ( ( uint8_t ) 0x80 )
#define portMAX_PRIGROUP_BITS ( ( uint8_t ) 7 )
#define portPRIORITY_GROUP_MASK ( 0x07UL << 8UL )
#define portPRIGROUP_SHIFT ( 8UL )
/* Masks off all bits but the VECTACTIVE bits in the ICSR register. */
#define portVECTACTIVE_MASK ( 0xFFUL )
/* Constants required to manipulate the VFP. */
#define portFPCCR ( ( volatile uint32_t * ) 0xe000ef34 ) /* Floating point context control register. */
#define portASPEN_AND_LSPEN_BITS ( 0x3UL << 30UL )
/* Constants required to set up the initial stack. */
#define portINITIAL_XPSR ( 0x01000000 )
#define portINITIAL_EXC_RETURN ( 0xfffffffd )
#define portINITIAL_CONTROL_IF_UNPRIVILEGED ( 0x03 )
#define portINITIAL_CONTROL_IF_PRIVILEGED ( 0x02 )
/* Constants used during system call enter and exit. */
#define portPSR_STACK_PADDING_MASK ( 1UL << 9UL )
#define portEXC_RETURN_STACK_FRAME_TYPE_MASK ( 1UL << 4UL )
/* Offsets in the stack to the parameters when inside the SVC handler. */
#define portOFFSET_TO_LR ( 5 )
#define portOFFSET_TO_PC ( 6 )
#define portOFFSET_TO_PSR ( 7 )
/* The systick is a 24-bit counter. */
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
/* A fiddle factor to estimate the number of SysTick counts that would have
* occurred while the SysTick counter is stopped during tickless idle
* calculations. */
#define portMISSED_COUNTS_FACTOR ( 45UL )
/* For strict compliance with the Cortex-M spec the task start address should
* have bit-0 clear, as it is loaded into the PC on exit from an ISR. */
#define portSTART_ADDRESS_MASK ( ( StackType_t ) 0xfffffffeUL )
/* Does addr lie within [start, end] address range? */
#define portIS_ADDRESS_WITHIN_RANGE( addr, start, end ) \
( ( ( addr ) >= ( start ) ) && ( ( addr ) <= ( end ) ) )
/* Is the access request satisfied by the available permissions? */
#define portIS_AUTHORIZED( accessRequest, permissions ) \
( ( ( permissions ) & ( accessRequest ) ) == accessRequest )
/* Max value that fits in a uint32_t type. */
#define portUINT32_MAX ( ~( ( uint32_t ) 0 ) )
/* Check if adding a and b will result in overflow. */
#define portADD_UINT32_WILL_OVERFLOW( a, b ) ( ( a ) > ( portUINT32_MAX - ( b ) ) )
/*-----------------------------------------------------------*/
/*
* Configure a number of standard MPU regions that are used by all tasks.
*/
static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
/*
* Return the smallest MPU region size that a given number of bytes will fit
* into. The region size is returned as the value that should be programmed
* into the region attribute register for that region.
*/
static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes ) PRIVILEGED_FUNCTION;
/*
* Setup the timer to generate the tick interrupts. The implementation in this
* file is weak to allow application writers to change the timer used to
* generate the tick interrupt.
*/
void vPortSetupTimerInterrupt( void );
/*
* Exception handlers.
*/
void xPortSysTickHandler( void ) PRIVILEGED_FUNCTION;
/*
* Start first task is a separate function so it can be tested in isolation.
*/
extern void vPortStartFirstTask( void ) PRIVILEGED_FUNCTION;
/*
* Turn the VFP on.
*/
extern void vPortEnableVFP( void );
/*
* The C portion of the SVC handler.
*/
void vPortSVCHandler_C( uint32_t * pulParam ) PRIVILEGED_FUNCTION;
/*
* Called from the SVC handler used to start the scheduler.
*/
extern void vPortRestoreContextOfFirstTask( void ) PRIVILEGED_FUNCTION;
/**
* @brief Enter critical section.
*/
#if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 )
void vPortEnterCritical( void ) FREERTOS_SYSTEM_CALL;
#else
void vPortEnterCritical( void ) PRIVILEGED_FUNCTION;
#endif
/**
* @brief Exit from critical section.
*/
#if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 )
void vPortExitCritical( void ) FREERTOS_SYSTEM_CALL;
#else
void vPortExitCritical( void ) PRIVILEGED_FUNCTION;
#endif
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
/**
* @brief Sets up the system call stack so that upon returning from
* SVC, the system call stack is used.
*
* @param pulTaskStack The current SP when the SVC was raised.
* @param ulLR The value of Link Register (EXC_RETURN) in the SVC handler.
* @param ucSystemCallNumber The system call number of the system call.
*/
void vSystemCallEnter( uint32_t * pulTaskStack,
uint32_t ulLR,
uint8_t ucSystemCallNumber ) PRIVILEGED_FUNCTION;
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
/**
* @brief Raise SVC for exiting from a system call.
*/
void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
/**
* @brief Sets up the task stack so that upon returning from
* SVC, the task stack is used again.
*
* @param pulSystemCallStack The current SP when the SVC was raised.
* @param ulLR The value of Link Register (EXC_RETURN) in the SVC handler.
*/
void vSystemCallExit( uint32_t * pulSystemCallStack,
uint32_t ulLR ) PRIVILEGED_FUNCTION;
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/**
* @brief Checks whether or not the calling task is privileged.
*
* @return pdTRUE if the calling task is privileged, pdFALSE otherwise.
*/
BaseType_t xPortIsTaskPrivileged( void ) PRIVILEGED_FUNCTION;
/**
* @brief Make a task unprivileged.
*/
void vPortSwitchToUserMode( void );
/*
* FreeRTOS handlers implemented in assembly.
*/
extern void vPortSVCHandler( void ) PRIVILEGED_FUNCTION;
extern void xPortPendSVHandler( void ) PRIVILEGED_FUNCTION;
/*-----------------------------------------------------------*/
/* Each task maintains its own interrupt status in the critical nesting
* variable. */
static UBaseType_t uxCriticalNesting = 0xaaaaaaaa;
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
/*
* This variable is set to pdTRUE when the scheduler is started.
*/
PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*
* Used by the portASSERT_IF_INTERRUPT_PRIORITY_INVALID() macro to ensure
* FreeRTOS API functions are not called from interrupts that have been assigned
* a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.
*/
#if ( configASSERT_DEFINED == 1 )
static uint8_t ucMaxSysCallPriority = 0;
static uint32_t ulMaxPRIGROUPValue = 0;
static const volatile uint8_t * const pcInterruptPriorityRegisters = ( const volatile uint8_t * const ) portNVIC_IP_REGISTERS_OFFSET_16;
#endif /* configASSERT_DEFINED */
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
TaskFunction_t pxCode,
void * pvParameters,
BaseType_t xRunPrivileged,
xMPU_SETTINGS * xMPUSettings )
{
if( xRunPrivileged == pdTRUE )
{
xMPUSettings->ulTaskFlags |= portTASK_IS_PRIVILEGED_FLAG;
xMPUSettings->ulContext[ 0 ] = portINITIAL_CONTROL_IF_PRIVILEGED;
}
else
{
xMPUSettings->ulTaskFlags &= ( ~( portTASK_IS_PRIVILEGED_FLAG ) );
xMPUSettings->ulContext[ 0 ] = portINITIAL_CONTROL_IF_UNPRIVILEGED;
}
xMPUSettings->ulContext[ 1 ] = 0x04040404; /* r4. */
xMPUSettings->ulContext[ 2 ] = 0x05050505; /* r5. */
xMPUSettings->ulContext[ 3 ] = 0x06060606; /* r6. */
xMPUSettings->ulContext[ 4 ] = 0x07070707; /* r7. */
xMPUSettings->ulContext[ 5 ] = 0x08080808; /* r8. */
xMPUSettings->ulContext[ 6 ] = 0x09090909; /* r9. */
xMPUSettings->ulContext[ 7 ] = 0x10101010; /* r10. */
xMPUSettings->ulContext[ 8 ] = 0x11111111; /* r11. */
xMPUSettings->ulContext[ 9 ] = portINITIAL_EXC_RETURN; /* EXC_RETURN. */
xMPUSettings->ulContext[ 10 ] = ( uint32_t ) ( pxTopOfStack - 8 ); /* PSP with the hardware saved stack. */
xMPUSettings->ulContext[ 11 ] = ( uint32_t ) pvParameters; /* r0. */
xMPUSettings->ulContext[ 12 ] = 0x01010101; /* r1. */
xMPUSettings->ulContext[ 13 ] = 0x02020202; /* r2. */
xMPUSettings->ulContext[ 14 ] = 0x03030303; /* r3. */
xMPUSettings->ulContext[ 15 ] = 0x12121212; /* r12. */
xMPUSettings->ulContext[ 16 ] = 0; /* LR. */
xMPUSettings->ulContext[ 17 ] = ( ( uint32_t ) pxCode ) & portSTART_ADDRESS_MASK; /* PC. */
xMPUSettings->ulContext[ 18 ] = portINITIAL_XPSR; /* xPSR. */
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
{
/* Ensure that the system call stack is double word aligned. */
xMPUSettings->xSystemCallStackInfo.pulSystemCallStack = &( xMPUSettings->xSystemCallStackInfo.ulSystemCallStackBuffer[ configSYSTEM_CALL_STACK_SIZE - 1 ] );
xMPUSettings->xSystemCallStackInfo.pulSystemCallStack = ( uint32_t * ) ( ( uint32_t ) ( xMPUSettings->xSystemCallStackInfo.pulSystemCallStack ) &
( uint32_t ) ( ~( portBYTE_ALIGNMENT_MASK ) ) );
/* This is not NULL only for the duration of a system call. */
xMPUSettings->xSystemCallStackInfo.pulTaskStack = NULL;
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
return &( xMPUSettings->ulContext[ 19 ] );
}
/*-----------------------------------------------------------*/
void vPortSVCHandler_C( uint32_t * pulParam ) /* PRIVILEGED_FUNCTION */
{
uint8_t ucSVCNumber;
uint32_t ulPC;
#if ( ( configUSE_MPU_WRAPPERS_V1 == 1 ) && ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) )
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* #if ( ( configUSE_MPU_WRAPPERS_V1 == 1 ) && ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) ) */
/* The stack contains: r0, r1, r2, r3, r12, LR, PC and xPSR. The first
* argument (r0) is pulParam[ 0 ]. */
ulPC = pulParam[ portOFFSET_TO_PC ];
ucSVCNumber = ( ( uint8_t * ) ulPC )[ -2 ];
switch( ucSVCNumber )
{
case portSVC_START_SCHEDULER:
vPortRestoreContextOfFirstTask();
break;
case portSVC_YIELD:
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
/* Barriers are normally not required
* but do ensure the code is completely
* within the specified behaviour for the
* architecture. */
__asm volatile ( "dsb" ::: "memory" );
__asm volatile ( "isb" );
break;
#if ( configUSE_MPU_WRAPPERS_V1 == 1 )
#if ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 )
case portSVC_RAISE_PRIVILEGE: /* Only raise the privilege, if the
* svc was raised from any of the
* system calls. */
if( ( ulPC >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulPC <= ( uint32_t ) __syscalls_flash_end__ ) )
{
__asm volatile
(
" mrs r1, control \n" /* Obtain current control value. */
" bic r1, r1, #1 \n" /* Set privilege bit. */
" msr control, r1 \n" /* Write back new control value. */
::: "r1", "memory"
);
}
break;
#else /* if ( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) */
case portSVC_RAISE_PRIVILEGE:
__asm volatile
(
" mrs r1, control \n" /* Obtain current control value. */
" bic r1, r1, #1 \n" /* Set privilege bit. */
" msr control, r1 \n" /* Write back new control value. */
::: "r1", "memory"
);
break;
#endif /* #if( configENFORCE_SYSTEM_CALLS_FROM_KERNEL_ONLY == 1 ) */
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
default: /* Unknown SVC call. */
break;
}
}
/*-----------------------------------------------------------*/
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
void vSystemCallEnter( uint32_t * pulTaskStack,
uint32_t ulLR,
uint8_t ucSystemCallNumber ) /* PRIVILEGED_FUNCTION */
{
extern TaskHandle_t pxCurrentTCB;
extern UBaseType_t uxSystemCallImplementations[ NUM_SYSTEM_CALLS ];
xMPU_SETTINGS * pxMpuSettings;
uint32_t * pulSystemCallStack;
uint32_t ulStackFrameSize, ulSystemCallLocation, i;
#if defined( __ARMCC_VERSION )
/* Declaration when these variable are defined in code instead of being
* exported from linker scripts. */
extern uint32_t * __syscalls_flash_start__;
extern uint32_t * __syscalls_flash_end__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __syscalls_flash_start__[];
extern uint32_t __syscalls_flash_end__[];
#endif /* #if defined( __ARMCC_VERSION ) */
ulSystemCallLocation = pulTaskStack[ portOFFSET_TO_PC ];
pxMpuSettings = xTaskGetMPUSettings( pxCurrentTCB );
/* Checks:
* 1. SVC is raised from the system call section (i.e. application is
* not raising SVC directly).
* 2. pxMpuSettings->xSystemCallStackInfo.pulTaskStack must be NULL as
* it is non-NULL only during the execution of a system call (i.e.
* between system call enter and exit).
* 3. System call is not for a kernel API disabled by the configuration
* in FreeRTOSConfig.h.
* 4. We do not need to check that ucSystemCallNumber is within range
* because the assembly SVC handler checks that before calling
* this function.
*/
if( ( ulSystemCallLocation >= ( uint32_t ) __syscalls_flash_start__ ) &&
( ulSystemCallLocation <= ( uint32_t ) __syscalls_flash_end__ ) &&
( pxMpuSettings->xSystemCallStackInfo.pulTaskStack == NULL ) &&
( uxSystemCallImplementations[ ucSystemCallNumber ] != ( UBaseType_t ) 0 ) )
{
pulSystemCallStack = pxMpuSettings->xSystemCallStackInfo.pulSystemCallStack;
if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
{
/* Extended frame i.e. FPU in use. */
ulStackFrameSize = 26;
__asm volatile (
" vpush {s0} \n" /* Trigger lazy stacking. */
" vpop {s0} \n" /* Nullify the affect of the above instruction. */
::: "memory"
);
}
else
{
/* Standard frame i.e. FPU not in use. */
ulStackFrameSize = 8;
}
/* Make space on the system call stack for the stack frame. */
pulSystemCallStack = pulSystemCallStack - ulStackFrameSize;
/* Copy the stack frame. */
for( i = 0; i < ulStackFrameSize; i++ )
{
pulSystemCallStack[ i ] = pulTaskStack[ i ];
}
/* Use the pulSystemCallStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulSystemCallStack ) );
/* Raise the privilege for the duration of the system call. */
__asm volatile (
" mrs r1, control \n" /* Obtain current control value. */
" bic r1, #1 \n" /* Clear nPRIV bit. */
" msr control, r1 \n" /* Write back new control value. */
::: "r1", "memory"
);
/* Remember the location where we should copy the stack frame when we exit from
* the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
/* Store the value of the Link Register before the SVC was raised.
* It contains the address of the caller of the System Call entry
* point (i.e. the caller of the MPU_<API>). We need to restore it
* when we exit from the system call. */
pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry = pulTaskStack[ portOFFSET_TO_LR ];
/* Start executing the system call upon returning from this handler. */
pulSystemCallStack[ portOFFSET_TO_PC ] = uxSystemCallImplementations[ ucSystemCallNumber ];
/* Raise a request to exit from the system call upon finishing the
* system call. */
pulSystemCallStack[ portOFFSET_TO_LR ] = ( uint32_t ) vRequestSystemCallExit;
/* Record if the hardware used padding to force the stack pointer
* to be double word aligned. */
if( ( pulTaskStack[ portOFFSET_TO_PSR ] & portPSR_STACK_PADDING_MASK ) == portPSR_STACK_PADDING_MASK )
{
pxMpuSettings->ulTaskFlags |= portSTACK_FRAME_HAS_PADDING_FLAG;
}
else
{
pxMpuSettings->ulTaskFlags &= ( ~portSTACK_FRAME_HAS_PADDING_FLAG );
}
/* We ensure in pxPortInitialiseStack that the system call stack is
* double word aligned and therefore, there is no need of padding.
* Clear the bit[9] of stacked xPSR. */
pulSystemCallStack[ portOFFSET_TO_PSR ] &= ( ~portPSR_STACK_PADDING_MASK );
}
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
void vRequestSystemCallExit( void ) /* __attribute__( ( naked ) ) PRIVILEGED_FUNCTION */
{
__asm volatile ( "svc %0 \n" ::"i" ( portSVC_SYSTEM_CALL_EXIT ) : "memory" );
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
void vSystemCallExit( uint32_t * pulSystemCallStack,
uint32_t ulLR ) /* PRIVILEGED_FUNCTION */
{
extern TaskHandle_t pxCurrentTCB;
xMPU_SETTINGS * pxMpuSettings;
uint32_t * pulTaskStack;
uint32_t ulStackFrameSize, ulSystemCallLocation, i;
#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__;
#else
/* Declaration when these variable are exported from linker scripts. */
extern uint32_t __privileged_functions_start__[];
extern uint32_t __privileged_functions_end__[];
#endif /* #if defined( __ARMCC_VERSION ) */
ulSystemCallLocation = pulSystemCallStack[ portOFFSET_TO_PC ];
pxMpuSettings = xTaskGetMPUSettings( pxCurrentTCB );
/* Checks:
* 1. SVC is raised from the privileged code (i.e. application is not
* raising SVC directly). This SVC is only raised from
* vRequestSystemCallExit which is in the privileged code section.
* 2. pxMpuSettings->xSystemCallStackInfo.pulTaskStack must not be NULL -
* this means that we previously entered a system call and the
* application is not attempting to exit without entering a system
* call.
*/
if( ( ulSystemCallLocation >= ( uint32_t ) __privileged_functions_start__ ) &&
( ulSystemCallLocation <= ( uint32_t ) __privileged_functions_end__ ) &&
( pxMpuSettings->xSystemCallStackInfo.pulTaskStack != NULL ) )
{
pulTaskStack = pxMpuSettings->xSystemCallStackInfo.pulTaskStack;
if( ( ulLR & portEXC_RETURN_STACK_FRAME_TYPE_MASK ) == 0UL )
{
/* Extended frame i.e. FPU in use. */
ulStackFrameSize = 26;
__asm volatile (
" vpush {s0} \n" /* Trigger lazy stacking. */
" vpop {s0} \n" /* Nullify the affect of the above instruction. */
::: "memory"
);
}
else
{
/* Standard frame i.e. FPU not in use. */
ulStackFrameSize = 8;
}
/* Make space on the task stack for the stack frame. */
pulTaskStack = pulTaskStack - ulStackFrameSize;
/* Copy the stack frame. */
for( i = 0; i < ulStackFrameSize; i++ )
{
pulTaskStack[ i ] = pulSystemCallStack[ i ];
}
/* Use the pulTaskStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulTaskStack ) );
/* Drop the privilege before returning to the thread mode. */
__asm volatile (
" mrs r1, control \n" /* Obtain current control value. */
" orr r1, #1 \n" /* Set nPRIV bit. */
" msr control, r1 \n" /* Write back new control value. */
::: "r1", "memory"
);
/* Return to the caller of the System Call entry point (i.e. the
* caller of the MPU_<API>). */
pulTaskStack[ portOFFSET_TO_PC ] = pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry;
/* Ensure that LR has a valid value.*/
pulTaskStack[ portOFFSET_TO_LR ] = pxMpuSettings->xSystemCallStackInfo.ulLinkRegisterAtSystemCallEntry;
/* If the hardware used padding to force the stack pointer
* to be double word aligned, set the stacked xPSR bit[9],
* otherwise clear it. */
if( ( pxMpuSettings->ulTaskFlags & portSTACK_FRAME_HAS_PADDING_FLAG ) == portSTACK_FRAME_HAS_PADDING_FLAG )
{
pulTaskStack[ portOFFSET_TO_PSR ] |= portPSR_STACK_PADDING_MASK;
}
else
{
pulTaskStack[ portOFFSET_TO_PSR ] &= ( ~portPSR_STACK_PADDING_MASK );
}
/* This is not NULL only for the duration of the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = NULL;
}
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
BaseType_t xPortIsTaskPrivileged( void ) /* PRIVILEGED_FUNCTION */
{
BaseType_t xTaskIsPrivileged = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) == portTASK_IS_PRIVILEGED_FLAG )
{
xTaskIsPrivileged = pdTRUE;
}
return xTaskIsPrivileged;
}
/*-----------------------------------------------------------*/
void vPortSwitchToUserMode( void )
{
/* Load the current task's MPU settings from its TCB. */
xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL );
/* Mark the task as unprivileged. */
xTaskMpuSettings->ulTaskFlags &= ( ~( portTASK_IS_PRIVILEGED_FLAG ) );
/* Lower the processor's privilege level. */
vResetPrivilege();
}
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
BaseType_t xPortStartScheduler( void )
{
/* Errata 837070 workaround must only be enabled on Cortex-M7 r0p0
* and r0p1 cores. */
#if ( configENABLE_ERRATA_837070_WORKAROUND == 1 )
configASSERT( ( portCPUID == portCORTEX_M7_r0p1_ID ) || ( portCPUID == portCORTEX_M7_r0p0_ID ) );
#else
/* When using this port on a Cortex-M7 r0p0 or r0p1 core, define
* configENABLE_ERRATA_837070_WORKAROUND to 1 in your
* FreeRTOSConfig.h. */
configASSERT( portCPUID != portCORTEX_M7_r0p1_ID );
configASSERT( portCPUID != portCORTEX_M7_r0p0_ID );
#endif
/* An application can install FreeRTOS interrupt handlers in one of the
* following ways:
* 1. Direct Routing - Install the functions vPortSVCHandler and
* xPortPendSVHandler for SVCall and PendSV interrupts respectively.
* 2. Indirect Routing - Install separate handlers for SVCall and PendSV
* interrupts and route program control from those handlers to
* vPortSVCHandler and xPortPendSVHandler functions.
*
* Applications that use Indirect Routing must set
* configCHECK_HANDLER_INSTALLATION to 0 in their FreeRTOSConfig.h. Direct
* routing, which is validated here when configCHECK_HANDLER_INSTALLATION
* is 1, should be preferred when possible. */
#if ( configCHECK_HANDLER_INSTALLATION == 1 )
{
const portISR_t * const pxVectorTable = portSCB_VTOR_REG;
/* Validate that the application has correctly installed the FreeRTOS
* handlers for SVCall and PendSV interrupts. We do not check the
* installation of the SysTick handler because the application may
* choose to drive the RTOS tick using a timer other than the SysTick
* timer by overriding the weak function vPortSetupTimerInterrupt().
*
* Assertion failures here indicate incorrect installation of the
* FreeRTOS handlers. For help installing the FreeRTOS handlers, see
* https://www.FreeRTOS.org/FAQHelp.html.
*
* Systems with a configurable address for the interrupt vector table
* can also encounter assertion failures or even system faults here if
* VTOR is not set correctly to point to the application's vector table. */
configASSERT( pxVectorTable[ portVECTOR_INDEX_SVC ] == vPortSVCHandler );
configASSERT( pxVectorTable[ portVECTOR_INDEX_PENDSV ] == xPortPendSVHandler );
}
#endif /* configCHECK_HANDLER_INSTALLATION */
#if ( configASSERT_DEFINED == 1 )
{
volatile uint8_t ucOriginalPriority;
volatile uint32_t ulImplementedPrioBits = 0;
volatile uint8_t * const pucFirstUserPriorityRegister = ( volatile uint8_t * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );
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. */
ucOriginalPriority = *pucFirstUserPriorityRegister;
/* Determine the number of priority bits available. First write to all
* possible bits. */
*pucFirstUserPriorityRegister = portMAX_8_BIT_VALUE;
/* Read the value back to see how many bits stuck. */
ucMaxPriorityValue = *pucFirstUserPriorityRegister;
/* Use the same mask on the maximum system call priority. */
ucMaxSysCallPriority = configMAX_SYSCALL_INTERRUPT_PRIORITY & ucMaxPriorityValue;
/* Check that the maximum system call priority is nonzero after
* accounting for the number of priority bits supported by the
* hardware. A priority of 0 is invalid because setting the BASEPRI
* register to 0 unmasks all interrupts, and interrupts with priority 0
* cannot be masked using BASEPRI.
* See https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
configASSERT( ucMaxSysCallPriority );
/* Check that the bits not implemented in hardware are zero in
* configMAX_SYSCALL_INTERRUPT_PRIORITY. */
configASSERT( ( configMAX_SYSCALL_INTERRUPT_PRIORITY & ( uint8_t ) ( ~( uint32_t ) ucMaxPriorityValue ) ) == 0U );
/* Calculate the maximum acceptable priority group value for the number
* of bits read back. */
while( ( ucMaxPriorityValue & portTOP_BIT_OF_BYTE ) == portTOP_BIT_OF_BYTE )
{
ulImplementedPrioBits++;
ucMaxPriorityValue <<= ( uint8_t ) 0x01;
}
if( ulImplementedPrioBits == 8 )
{
/* When the hardware implements 8 priority bits, there is no way for
* the software to configure PRIGROUP to not have sub-priorities. As
* a result, the least significant bit is always used for sub-priority
* and there are 128 preemption priorities and 2 sub-priorities.
*
* This may cause some confusion in some cases - for example, if
* configMAX_SYSCALL_INTERRUPT_PRIORITY is set to 5, both 5 and 4
* priority interrupts will be masked in Critical Sections as those
* are at the same preemption priority. This may appear confusing as
* 4 is higher (numerically lower) priority than
* configMAX_SYSCALL_INTERRUPT_PRIORITY and therefore, should not
* have been masked. Instead, if we set configMAX_SYSCALL_INTERRUPT_PRIORITY
* to 4, this confusion does not happen and the behaviour remains the same.
*
* The following assert ensures that the sub-priority bit in the
* configMAX_SYSCALL_INTERRUPT_PRIORITY is clear to avoid the above mentioned
* confusion. */
configASSERT( ( configMAX_SYSCALL_INTERRUPT_PRIORITY & 0x1U ) == 0U );
ulMaxPRIGROUPValue = 0;
}
else
{
ulMaxPRIGROUPValue = portMAX_PRIGROUP_BITS - ulImplementedPrioBits;
}
/* 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 = ucOriginalPriority;
}
#endif /* configASSERT_DEFINED */
/* Make PendSV and SysTick the lowest priority interrupts, and make SVCall
* the highest priority. */
portNVIC_SHPR3_REG |= portNVIC_PENDSV_PRI;
portNVIC_SHPR3_REG |= portNVIC_SYSTICK_PRI;
portNVIC_SHPR2_REG = 0;
/* 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;
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
{
xSchedulerRunning = pdTRUE;
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/* Ensure the VFP is enabled - it should be anyway. */
vPortEnableVFP();
/* Lazy save always. */
*( portFPCCR ) |= portASPEN_AND_LSPEN_BITS;
/* Start the first task. */
vPortStartFirstTask();
/* 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 )
{
#if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 )
if( portIS_PRIVILEGED() == pdFALSE )
{
portRAISE_PRIVILEGE();
portMEMORY_BARRIER();
portDISABLE_INTERRUPTS();
uxCriticalNesting++;
/* This is not the interrupt safe version of the enter critical function so
* assert() if it is being called from an interrupt context. Only API
* functions that end in "FromISR" can be used in an interrupt. Only assert if
* the critical nesting count is 1 to protect against recursive calls if the
* assert function also uses a critical section. */
if( uxCriticalNesting == 1 )
{
configASSERT( ( portNVIC_INT_CTRL_REG & portVECTACTIVE_MASK ) == 0 );
}
portMEMORY_BARRIER();
portRESET_PRIVILEGE();
portMEMORY_BARRIER();
}
else
{
portDISABLE_INTERRUPTS();
uxCriticalNesting++;
/* This is not the interrupt safe version of the enter critical function so
* assert() if it is being called from an interrupt context. Only API
* functions that end in "FromISR" can be used in an interrupt. Only assert if
* the critical nesting count is 1 to protect against recursive calls if the
* assert function also uses a critical section. */
if( uxCriticalNesting == 1 )
{
configASSERT( ( portNVIC_INT_CTRL_REG & portVECTACTIVE_MASK ) == 0 );
}
}
#else /* if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 ) */
portDISABLE_INTERRUPTS();
uxCriticalNesting++;
/* This is not the interrupt safe version of the enter critical function so
* assert() if it is being called from an interrupt context. Only API
* functions that end in "FromISR" can be used in an interrupt. Only assert if
* the critical nesting count is 1 to protect against recursive calls if the
* assert function also uses a critical section. */
if( uxCriticalNesting == 1 )
{
configASSERT( ( portNVIC_INT_CTRL_REG & portVECTACTIVE_MASK ) == 0 );
}
#endif /* if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 ) */
}
/*-----------------------------------------------------------*/
void vPortExitCritical( void )
{
#if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 )
if( portIS_PRIVILEGED() == pdFALSE )
{
portRAISE_PRIVILEGE();
portMEMORY_BARRIER();
configASSERT( uxCriticalNesting );
uxCriticalNesting--;
if( uxCriticalNesting == 0 )
{
portENABLE_INTERRUPTS();
}
portMEMORY_BARRIER();
portRESET_PRIVILEGE();
portMEMORY_BARRIER();
}
else
{
configASSERT( uxCriticalNesting );
uxCriticalNesting--;
if( uxCriticalNesting == 0 )
{
portENABLE_INTERRUPTS();
}
}
#else /* if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 ) */
configASSERT( uxCriticalNesting );
uxCriticalNesting--;
if( uxCriticalNesting == 0 )
{
portENABLE_INTERRUPTS();
}
#endif /* if ( configALLOW_UNPRIVILEGED_CRITICAL_SECTIONS == 1 ) */
}
/*-----------------------------------------------------------*/
void xPortSysTickHandler( void )
{
/* The SysTick runs at the lowest interrupt priority, so when this interrupt
* executes all interrupts must be unmasked. There is therefore no need to
* save and then restore the interrupt mask value as its value is already
* known. */
portDISABLE_INTERRUPTS();
traceISR_ENTER();
{
/* Increment the RTOS tick. */
if( xTaskIncrementTick() != pdFALSE )
{
traceISR_EXIT_TO_SCHEDULER();
/* A context switch is required. Context switching is performed in
* the PendSV interrupt. Pend the PendSV interrupt. */
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
}
else
{
traceISR_EXIT();
}
}
portENABLE_INTERRUPTS();
}
/*-----------------------------------------------------------*/
/*
* Setup the systick timer to generate the tick interrupts at the required
* frequency.
*/
__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_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT );
}
/*-----------------------------------------------------------*/
static void prvSetupMPU( void )
{
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__[];
/* The only permitted number of regions are 8 or 16. */
configASSERT( ( configTOTAL_MPU_REGIONS == 8 ) || ( configTOTAL_MPU_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 ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( ( 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 );
}
/*-----------------------------------------------------------*/
void vPortStoreTaskMPUSettings( xMPU_SETTINGS * xMPUSettings,
const struct xMEMORY_REGION * const xRegions,
StackType_t * pxBottomOfStack,
configSTACK_DEPTH_TYPE uxStackDepth )
{
extern uint32_t __SRAM_segment_start__[];
extern uint32_t __SRAM_segment_end__[];
extern uint32_t __privileged_data_start__[];
extern uint32_t __privileged_data_end__[];
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 ); /* Region number. */
xMPUSettings->xRegion[ 0 ].ulRegionAttribute =
( portMPU_REGION_READ_WRITE ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( ( 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 );
xMPUSettings->xRegionSettings[ 0 ].ulRegionStartAddress = ( uint32_t ) __SRAM_segment_start__;
xMPUSettings->xRegionSettings[ 0 ].ulRegionEndAddress = ( uint32_t ) __SRAM_segment_end__;
xMPUSettings->xRegionSettings[ 0 ].ulRegionPermissions = ( tskMPU_READ_PERMISSION |
tskMPU_WRITE_PERMISSION );
/* Invalidate user configurable regions. */
for( ul = 1UL; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
{
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = ( ( ul - 1UL ) | portMPU_REGION_VALID );
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionStartAddress = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionEndAddress = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionPermissions = 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( uxStackDepth > 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 ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( prvGetMPURegionSizeSetting( uxStackDepth * ( configSTACK_DEPTH_TYPE ) 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 );
xMPUSettings->xRegionSettings[ 0 ].ulRegionStartAddress = ( uint32_t ) pxBottomOfStack;
xMPUSettings->xRegionSettings[ 0 ].ulRegionEndAddress = ( uint32_t ) ( ( uint32_t ) ( pxBottomOfStack ) +
( uxStackDepth * ( configSTACK_DEPTH_TYPE ) sizeof( StackType_t ) ) - 1UL );
xMPUSettings->xRegionSettings[ 0 ].ulRegionPermissions = ( tskMPU_READ_PERMISSION |
tskMPU_WRITE_PERMISSION );
}
lIndex = 0;
for( ul = 1UL; 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 ) |
( ul - 1UL ); /* Region number. */
xMPUSettings->xRegion[ ul ].ulRegionAttribute =
( prvGetMPURegionSizeSetting( xRegions[ lIndex ].ulLengthInBytes ) ) |
( xRegions[ lIndex ].ulParameters ) |
( portMPU_REGION_ENABLE );
xMPUSettings->xRegionSettings[ ul ].ulRegionStartAddress = ( uint32_t ) xRegions[ lIndex ].pvBaseAddress;
xMPUSettings->xRegionSettings[ ul ].ulRegionEndAddress = ( uint32_t ) ( ( uint32_t ) xRegions[ lIndex ].pvBaseAddress + xRegions[ lIndex ].ulLengthInBytes - 1UL );
xMPUSettings->xRegionSettings[ ul ].ulRegionPermissions = 0UL;
if( ( ( xRegions[ lIndex ].ulParameters & portMPU_REGION_READ_ONLY ) == portMPU_REGION_READ_ONLY ) ||
( ( xRegions[ lIndex ].ulParameters & portMPU_REGION_PRIVILEGED_READ_WRITE_UNPRIV_READ_ONLY ) == portMPU_REGION_PRIVILEGED_READ_WRITE_UNPRIV_READ_ONLY ) )
{
xMPUSettings->xRegionSettings[ ul ].ulRegionPermissions = tskMPU_READ_PERMISSION;
}
if( ( xRegions[ lIndex ].ulParameters & portMPU_REGION_READ_WRITE ) == portMPU_REGION_READ_WRITE )
{
xMPUSettings->xRegionSettings[ ul ].ulRegionPermissions = ( tskMPU_READ_PERMISSION | tskMPU_WRITE_PERMISSION );
}
}
else
{
/* Invalidate the region. */
xMPUSettings->xRegion[ ul ].ulRegionBaseAddress = ( ( ul - 1UL ) | portMPU_REGION_VALID );
xMPUSettings->xRegion[ ul ].ulRegionAttribute = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionStartAddress = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionEndAddress = 0UL;
xMPUSettings->xRegionSettings[ ul ].ulRegionPermissions = 0UL;
}
lIndex++;
}
}
}
/*-----------------------------------------------------------*/
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
BaseType_t xPortIsAuthorizedToAccessBuffer( const void * pvBuffer,
uint32_t ulBufferLength,
uint32_t ulAccessRequested ) /* PRIVILEGED_FUNCTION */
{
uint32_t i, ulBufferStartAddress, ulBufferEndAddress;
BaseType_t xAccessGranted = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
if( xSchedulerRunning == pdFALSE )
{
/* Grant access to all the kernel objects before the scheduler
* is started. It is necessary because there is no task running
* yet and therefore, we cannot use the permissions of any
* task. */
xAccessGranted = pdTRUE;
}
else if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) == portTASK_IS_PRIVILEGED_FLAG )
{
xAccessGranted = pdTRUE;
}
else
{
if( portADD_UINT32_WILL_OVERFLOW( ( ( uint32_t ) pvBuffer ), ( ulBufferLength - 1UL ) ) == pdFALSE )
{
ulBufferStartAddress = ( uint32_t ) pvBuffer;
ulBufferEndAddress = ( ( ( uint32_t ) pvBuffer ) + ulBufferLength - 1UL );
for( i = 0; i < portTOTAL_NUM_REGIONS_IN_TCB; i++ )
{
if( portIS_ADDRESS_WITHIN_RANGE( ulBufferStartAddress,
xTaskMpuSettings->xRegionSettings[ i ].ulRegionStartAddress,
xTaskMpuSettings->xRegionSettings[ i ].ulRegionEndAddress ) &&
portIS_ADDRESS_WITHIN_RANGE( ulBufferEndAddress,
xTaskMpuSettings->xRegionSettings[ i ].ulRegionStartAddress,
xTaskMpuSettings->xRegionSettings[ i ].ulRegionEndAddress ) &&
portIS_AUTHORIZED( ulAccessRequested, xTaskMpuSettings->xRegionSettings[ i ].ulRegionPermissions ) )
{
xAccessGranted = pdTRUE;
break;
}
}
}
}
return xAccessGranted;
}
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#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:
* https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html
* https://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 unpredictable behaviour. */
configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) <= ulMaxPRIGROUPValue );
}
#endif /* configASSERT_DEFINED */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) )
void vPortGrantAccessToKernelObject( TaskHandle_t xInternalTaskHandle,
int32_t lInternalIndexOfKernelObject ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
xMPU_SETTINGS * xTaskMpuSettings;
ulAccessControlListEntryIndex = ( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit = ( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
xTaskMpuSettings = xTaskGetMPUSettings( xInternalTaskHandle );
xTaskMpuSettings->ulAccessControlList[ ulAccessControlListEntryIndex ] |= ( 1U << ulAccessControlListEntryBit );
}
#endif /* #if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) )
void vPortRevokeAccessToKernelObject( TaskHandle_t xInternalTaskHandle,
int32_t lInternalIndexOfKernelObject ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
xMPU_SETTINGS * xTaskMpuSettings;
ulAccessControlListEntryIndex = ( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit = ( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
xTaskMpuSettings = xTaskGetMPUSettings( xInternalTaskHandle );
xTaskMpuSettings->ulAccessControlList[ ulAccessControlListEntryIndex ] &= ~( 1U << ulAccessControlListEntryBit );
}
#endif /* #if ( ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( configUSE_MPU_WRAPPERS_V1 == 0 )
#if ( configENABLE_ACCESS_CONTROL_LIST == 1 )
BaseType_t xPortIsAuthorizedToAccessKernelObject( int32_t lInternalIndexOfKernelObject ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulAccessControlListEntryIndex, ulAccessControlListEntryBit;
BaseType_t xAccessGranted = pdFALSE;
const xMPU_SETTINGS * xTaskMpuSettings;
if( xSchedulerRunning == pdFALSE )
{
/* Grant access to all the kernel objects before the scheduler
* is started. It is necessary because there is no task running
* yet and therefore, we cannot use the permissions of any
* task. */
xAccessGranted = pdTRUE;
}
else
{
xTaskMpuSettings = xTaskGetMPUSettings( NULL ); /* Calling task's MPU settings. */
ulAccessControlListEntryIndex = ( ( uint32_t ) lInternalIndexOfKernelObject / portACL_ENTRY_SIZE_BITS );
ulAccessControlListEntryBit = ( ( uint32_t ) lInternalIndexOfKernelObject % portACL_ENTRY_SIZE_BITS );
if( ( xTaskMpuSettings->ulTaskFlags & portTASK_IS_PRIVILEGED_FLAG ) == portTASK_IS_PRIVILEGED_FLAG )
{
xAccessGranted = pdTRUE;
}
else
{
if( ( xTaskMpuSettings->ulAccessControlList[ ulAccessControlListEntryIndex ] & ( 1U << ulAccessControlListEntryBit ) ) != 0 )
{
xAccessGranted = pdTRUE;
}
}
}
return xAccessGranted;
}
#else /* #if ( configENABLE_ACCESS_CONTROL_LIST == 1 ) */
BaseType_t xPortIsAuthorizedToAccessKernelObject( int32_t lInternalIndexOfKernelObject ) /* PRIVILEGED_FUNCTION */
{
( void ) lInternalIndexOfKernelObject;
/* If Access Control List feature is not used, all the tasks have
* access to all the kernel objects. */
return pdTRUE;
}
#endif /* #if ( configENABLE_ACCESS_CONTROL_LIST == 1 ) */
#endif /* #if ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/