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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
*
*/
/* 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"
/* MPU includes. */
#include "mpu_wrappers.h"
#include "mpu_syscall_numbers.h"
/* Portasm includes. */
#include "portasm.h"
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
/*-----------------------------------------------------------*/
/**
* @brief Prototype of all Interrupt Service Routines (ISRs).
*/
typedef void ( * portISR_t )( void );
/*-----------------------------------------------------------*/
/**
* @brief Constants required to manipulate the NVIC.
*/
#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_SYSTICK_ENABLE_BIT ( 1UL << 0UL )
#define portNVIC_SYSTICK_INT_BIT ( 1UL << 1UL )
#define portNVIC_SYSTICK_CLK_BIT ( 1UL << 2UL )
#define portNVIC_SYSTICK_COUNT_FLAG_BIT ( 1UL << 16UL )
#define portNVIC_PEND_SYSTICK_CLEAR_BIT ( 1UL << 25UL )
#define portNVIC_PEND_SYSTICK_SET_BIT ( 1UL << 26UL )
#define portMIN_INTERRUPT_PRIORITY ( 255UL )
#define portNVIC_PENDSV_PRI ( portMIN_INTERRUPT_PRIORITY << 16UL )
#define portNVIC_SYSTICK_PRI ( portMIN_INTERRUPT_PRIORITY << 24UL )
/*-----------------------------------------------------------*/
/**
* @brief Constants required to manipulate the SCB.
*/
#define portSCB_VTOR_REG ( *( ( portISR_t ** ) 0xe000ed08 ) )
#define portSCB_SYS_HANDLER_CTRL_STATE_REG ( *( ( volatile uint32_t * ) 0xe000ed24 ) )
#define portSCB_MEM_FAULT_ENABLE_BIT ( 1UL << 16UL )
/*-----------------------------------------------------------*/
/**
* @brief Constants used to check the installation of the FreeRTOS interrupt handlers.
*/
#define portVECTOR_INDEX_SVC ( 11 )
#define portVECTOR_INDEX_PENDSV ( 14 )
/*-----------------------------------------------------------*/
/**
* @brief Constants used during system call enter and exit.
*/
#define portPSR_STACK_PADDING_MASK ( 1UL << 9UL )
#define portEXC_RETURN_STACK_FRAME_TYPE_MASK ( 1UL << 4UL )
/*-----------------------------------------------------------*/
/**
* @brief 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 )
/*-----------------------------------------------------------*/
/**
* @brief Constants required to manipulate the MPU.
*/
#define portMPU_TYPE_REG ( *( ( volatile uint32_t * ) 0xe000ed90 ) )
#define portMPU_CTRL_REG ( *( ( volatile uint32_t * ) 0xe000ed94 ) )
#define portMPU_RBAR_REG ( *( ( volatile uint32_t * ) 0xe000ed9c ) )
#define portMPU_RASR_REG ( *( ( volatile uint32_t * ) 0xe000eda0 ) )
/* MPU Region Attribute and Size Register (RASR) bitmasks. */
#define portMPU_RASR_AP_BITMASK ( 0x7UL << 24UL )
#define portMPU_RASR_S_C_B_BITMASK ( 0x7UL )
#define portMPU_RASR_S_C_B_LOCATION ( 16UL )
#define portMPU_RASR_SIZE_BITMASK ( 0x1FUL << 1UL )
#define portMPU_RASR_REGION_ENABLE_BITMASK ( 0x1UL )
/* MPU Region Base Address Register (RBAR) bitmasks. */
#define portMPU_RBAR_ADDRESS_BITMASK ( 0xFFFFFF00UL )
#define portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ( 0x1UL << 4UL )
#define portMPU_RBAR_REGION_NUMBER_BITMASK ( 0x0000000FUL )
/* MPU Control Register (MPU_CTRL) bitmasks. */
#define portMPU_CTRL_ENABLE_BITMASK ( 0x1UL )
#define portMPU_CTRL_PRIV_BACKGROUND_ENABLE_BITMASK ( 0x1UL << 2UL ) /* PRIVDEFENA bit. */
/* Expected value of the portMPU_TYPE register. */
#define portEXPECTED_MPU_TYPE_VALUE ( 0x8UL << 8UL ) /* 8 DREGION unified. */
/* Extract first address of the MPU region as encoded in the
* RBAR (Region Base Address Register) value. */
#define portEXTRACT_FIRST_ADDRESS_FROM_RBAR( rbar ) \
( ( rbar ) & portMPU_RBAR_ADDRESS_BITMASK )
/* Extract size of the MPU region as encoded in the
* RASR (Region Attribute and Size Register) value. */
#define portEXTRACT_REGION_SIZE_FROM_RASR( rasr ) \
( 1 << ( ( ( ( rasr ) & portMPU_RASR_SIZE_BITMASK ) >> 1 )+ 1 ) )
/* Does addr lies 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 ) ) )
/*-----------------------------------------------------------*/
/**
* @brief The maximum 24-bit number.
*
* It is needed because the systick is a 24-bit counter.
*/
#define portMAX_24_BIT_NUMBER ( 0xffffffUL )
/**
* @brief 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 ( 94UL )
/*-----------------------------------------------------------*/
/**
* @brief Constants required to set up the initial stack.
*/
#define portINITIAL_XPSR ( 0x01000000 )
/**
* @brief Initial EXC_RETURN value.
*
* FF FF FF FD
* 1111 1111 1111 1111 1111 1111 1111 1101
*
* Bit[3] - 1 --> Return to the Thread mode.
* Bit[2] - 1 --> Restore registers from the process stack.
* Bit[1] - 0 --> Reserved, 0.
* Bit[0] - 0 --> Reserved, 1.
*/
#define portINITIAL_EXC_RETURN ( 0xfffffffdUL )
/**
* @brief CONTROL register privileged bit mask.
*
* Bit[0] in CONTROL register tells the privilege:
* Bit[0] = 0 ==> The task is privileged.
* Bit[0] = 1 ==> The task is not privileged.
*/
#define portCONTROL_PRIVILEGED_MASK ( 1UL << 0UL )
/**
* @brief Initial CONTROL register values.
*/
#define portINITIAL_CONTROL_UNPRIVILEGED ( 0x3 )
#define portINITIAL_CONTROL_PRIVILEGED ( 0x2 )
/**
* @brief Let the user override the default SysTick clock rate. If defined by the
* user, this symbol must equal the SysTick clock rate when the CLK bit is 0 in the
* configuration register.
*/
#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_CONFIG ( portNVIC_SYSTICK_CLK_BIT )
#else
/* Select the option to clock SysTick not at the same frequency as the core. */
#define portNVIC_SYSTICK_CLK_BIT_CONFIG ( 0 )
#endif
/**
* @brief Let the user override the pre-loading of the initial LR with the
* address of prvTaskExitError() in case it messes up unwinding of the stack
* in the debugger.
*/
#ifdef configTASK_RETURN_ADDRESS
#define portTASK_RETURN_ADDRESS configTASK_RETURN_ADDRESS
#else
#define portTASK_RETURN_ADDRESS prvTaskExitError
#endif
/**
* @brief If portPRELOAD_REGISTERS then registers will be given an initial value
* when a task is created. This helps in debugging at the cost of code size.
*/
#define portPRELOAD_REGISTERS 1
/*-----------------------------------------------------------*/
/**
* @brief Used to catch tasks that attempt to return from their implementing
* function.
*/
static void prvTaskExitError( void );
#if ( configENABLE_MPU == 1 )
/**
* @brief Setup the Memory Protection Unit (MPU).
*/
static void prvSetupMPU( void ) PRIVILEGED_FUNCTION;
#endif /* configENABLE_MPU */
/**
* @brief 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 ) PRIVILEGED_FUNCTION;
/**
* @brief Checks whether the current execution context is interrupt.
*
* @return pdTRUE if the current execution context is interrupt, pdFALSE
* otherwise.
*/
BaseType_t xPortIsInsideInterrupt( void );
/**
* @brief Yield the processor.
*/
void vPortYield( void ) PRIVILEGED_FUNCTION;
/**
* @brief Enter critical section.
*/
void vPortEnterCritical( void ) PRIVILEGED_FUNCTION;
/**
* @brief Exit from critical section.
*/
void vPortExitCritical( void ) PRIVILEGED_FUNCTION;
/**
* @brief SysTick handler.
*/
void SysTick_Handler( void ) PRIVILEGED_FUNCTION;
/**
* @brief C part of SVC handler.
*/
portDONT_DISCARD void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) PRIVILEGED_FUNCTION;
#if ( ( configENABLE_MPU == 1 ) && ( 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 /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
/**
* @brief Raise SVC for exiting from a system call.
*/
void vRequestSystemCallExit( void ) __attribute__( ( naked ) ) PRIVILEGED_FUNCTION;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( ( configENABLE_MPU == 1 ) && ( 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 /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
#if ( configENABLE_MPU == 1 )
/**
* @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;
#endif /* configENABLE_MPU == 1 */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
/**
* @brief This variable is set to pdTRUE when the scheduler is started.
*/
PRIVILEGED_DATA static BaseType_t xSchedulerRunning = pdFALSE;
#endif
/**
* @brief Each task maintains its own interrupt status in the critical nesting
* variable.
*/
PRIVILEGED_DATA static volatile uint32_t ulCriticalNesting = 0xaaaaaaaaUL;
#if ( configUSE_TICKLESS_IDLE == 1 )
/**
* @brief The number of SysTick increments that make up one tick period.
*/
PRIVILEGED_DATA static uint32_t ulTimerCountsForOneTick = 0;
/**
* @brief The maximum number of tick periods that can be suppressed is
* limited by the 24 bit resolution of the SysTick timer.
*/
PRIVILEGED_DATA static uint32_t xMaximumPossibleSuppressedTicks = 0;
/**
* @brief Compensate for the CPU cycles that pass while the SysTick is
* stopped (low power functionality only).
*/
PRIVILEGED_DATA static uint32_t ulStoppedTimerCompensation = 0;
#endif /* configUSE_TICKLESS_IDLE */
/*-----------------------------------------------------------*/
#if ( configUSE_TICKLESS_IDLE == 1 )
__attribute__( ( weak ) ) void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime )
{
uint32_t ulReloadValue, ulCompleteTickPeriods, ulCompletedSysTickDecrements, ulSysTickDecrementsLeft;
TickType_t xModifiableIdleTime;
/* Make sure the SysTick reload value does not overflow the counter. */
if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks )
{
xExpectedIdleTime = xMaximumPossibleSuppressedTicks;
}
/* Enter a critical section but don't use the taskENTER_CRITICAL()
* method as that will mask interrupts that should exit sleep mode. */
__asm volatile ( "cpsid i" ::: "memory" );
__asm volatile ( "dsb" );
__asm volatile ( "isb" );
/* If a context switch is pending or a task is waiting for the scheduler
* to be unsuspended then abandon the low power entry. */
if( eTaskConfirmSleepModeStatus() == eAbortSleep )
{
/* Re-enable interrupts - see comments above the cpsid instruction
* above. */
__asm volatile ( "cpsie i" ::: "memory" );
}
else
{
/* Stop the SysTick momentarily. The time the SysTick is stopped for
* is accounted for as best it can be, but using the tickless mode will
* inevitably result in some tiny drift of the time maintained by the
* kernel with respect to calendar time. */
portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT_CONFIG | portNVIC_SYSTICK_INT_BIT );
/* Use the SysTick current-value register to determine the number of
* SysTick decrements remaining until the next tick interrupt. If the
* current-value register is zero, then there are actually
* ulTimerCountsForOneTick decrements remaining, not zero, because the
* SysTick requests the interrupt when decrementing from 1 to 0. */
ulSysTickDecrementsLeft = portNVIC_SYSTICK_CURRENT_VALUE_REG;
if( ulSysTickDecrementsLeft == 0 )
{
ulSysTickDecrementsLeft = ulTimerCountsForOneTick;
}
/* Calculate the reload value required to wait xExpectedIdleTime
* tick periods. -1 is used because this code normally executes part
* way through the first tick period. But if the SysTick IRQ is now
* pending, then clear the IRQ, suppressing the first tick, and correct
* the reload value to reflect that the second tick period is already
* underway. The expected idle time is always at least two ticks. */
ulReloadValue = ulSysTickDecrementsLeft + ( ulTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) );
if( ( portNVIC_INT_CTRL_REG & portNVIC_PEND_SYSTICK_SET_BIT ) != 0 )
{
portNVIC_INT_CTRL_REG = portNVIC_PEND_SYSTICK_CLEAR_BIT;
ulReloadValue -= ulTimerCountsForOneTick;
}
if( ulReloadValue > ulStoppedTimerCompensation )
{
ulReloadValue -= ulStoppedTimerCompensation;
}
/* Set the new reload value. */
portNVIC_SYSTICK_LOAD_REG = ulReloadValue;
/* Clear the SysTick count flag and set the count value back to
* zero. */
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
/* Restart SysTick. */
portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;
/* Sleep until something happens. configPRE_SLEEP_PROCESSING() can
* set its parameter to 0 to indicate that its implementation contains
* its own wait for interrupt or wait for event instruction, and so wfi
* should not be executed again. However, the original expected idle
* time variable must remain unmodified, so a copy is taken. */
xModifiableIdleTime = xExpectedIdleTime;
configPRE_SLEEP_PROCESSING( xModifiableIdleTime );
if( xModifiableIdleTime > 0 )
{
__asm volatile ( "dsb" ::: "memory" );
__asm volatile ( "wfi" );
__asm volatile ( "isb" );
}
configPOST_SLEEP_PROCESSING( xExpectedIdleTime );
/* Re-enable interrupts to allow the interrupt that brought the MCU
* out of sleep mode to execute immediately. See comments above
* the cpsid instruction above. */
__asm volatile ( "cpsie i" ::: "memory" );
__asm volatile ( "dsb" );
__asm volatile ( "isb" );
/* Disable interrupts again because the clock is about to be stopped
* and interrupts that execute while the clock is stopped will increase
* any slippage between the time maintained by the RTOS and calendar
* time. */
__asm volatile ( "cpsid i" ::: "memory" );
__asm volatile ( "dsb" );
__asm volatile ( "isb" );
/* Disable the SysTick clock without reading the
* portNVIC_SYSTICK_CTRL_REG register to ensure the
* portNVIC_SYSTICK_COUNT_FLAG_BIT is not cleared if it is set. Again,
* the time the SysTick is stopped for is accounted for as best it can
* be, but using the tickless mode will inevitably result in some tiny
* drift of the time maintained by the kernel with respect to calendar
* time*/
portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT_CONFIG | portNVIC_SYSTICK_INT_BIT );
/* Determine whether the SysTick has already counted to zero. */
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
{
uint32_t ulCalculatedLoadValue;
/* The tick interrupt ended the sleep (or is now pending), and
* a new tick period has started. Reset portNVIC_SYSTICK_LOAD_REG
* with whatever remains of the new tick period. */
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL ) - ( ulReloadValue - portNVIC_SYSTICK_CURRENT_VALUE_REG );
/* Don't allow a tiny value, or values that have somehow
* underflowed because the post sleep hook did something
* that took too long or because the SysTick current-value register
* is zero. */
if( ( ulCalculatedLoadValue <= ulStoppedTimerCompensation ) || ( ulCalculatedLoadValue > ulTimerCountsForOneTick ) )
{
ulCalculatedLoadValue = ( ulTimerCountsForOneTick - 1UL );
}
portNVIC_SYSTICK_LOAD_REG = ulCalculatedLoadValue;
/* As the pending tick will be processed as soon as this
* function exits, the tick value maintained by the tick is stepped
* forward by one less than the time spent waiting. */
ulCompleteTickPeriods = xExpectedIdleTime - 1UL;
}
else
{
/* Something other than the tick interrupt ended the sleep. */
/* Use the SysTick current-value register to determine the
* number of SysTick decrements remaining until the expected idle
* time would have ended. */
ulSysTickDecrementsLeft = portNVIC_SYSTICK_CURRENT_VALUE_REG;
#if ( portNVIC_SYSTICK_CLK_BIT_CONFIG != portNVIC_SYSTICK_CLK_BIT )
{
/* If the SysTick is not using the core clock, the current-
* value register might still be zero here. In that case, the
* SysTick didn't load from the reload register, and there are
* ulReloadValue decrements remaining in the expected idle
* time, not zero. */
if( ulSysTickDecrementsLeft == 0 )
{
ulSysTickDecrementsLeft = ulReloadValue;
}
}
#endif /* portNVIC_SYSTICK_CLK_BIT_CONFIG */
/* Work out how long the sleep lasted rounded to complete tick
* periods (not the ulReload value which accounted for part
* ticks). */
ulCompletedSysTickDecrements = ( xExpectedIdleTime * ulTimerCountsForOneTick ) - ulSysTickDecrementsLeft;
/* How many complete tick periods passed while the processor
* was waiting? */
ulCompleteTickPeriods = ulCompletedSysTickDecrements / ulTimerCountsForOneTick;
/* The reload value is set to whatever fraction of a single tick
* period remains. */
portNVIC_SYSTICK_LOAD_REG = ( ( ulCompleteTickPeriods + 1UL ) * ulTimerCountsForOneTick ) - ulCompletedSysTickDecrements;
}
/* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG again,
* then set portNVIC_SYSTICK_LOAD_REG back to its standard value. If
* the SysTick is not using the core clock, temporarily configure it to
* use the core clock. This configuration forces the SysTick to load
* from portNVIC_SYSTICK_LOAD_REG immediately instead of at the next
* cycle of the other clock. Then portNVIC_SYSTICK_LOAD_REG is ready
* to receive the standard value immediately. */
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
#if ( portNVIC_SYSTICK_CLK_BIT_CONFIG == portNVIC_SYSTICK_CLK_BIT )
{
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
}
#else
{
/* The temporary usage of the core clock has served its purpose,
* as described above. Resume usage of the other clock. */
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT;
if( ( portNVIC_SYSTICK_CTRL_REG & portNVIC_SYSTICK_COUNT_FLAG_BIT ) != 0 )
{
/* The partial tick period already ended. Be sure the SysTick
* counts it only once. */
portNVIC_SYSTICK_CURRENT_VALUE_REG = 0;
}
portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT_CONFIG | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
}
#endif /* portNVIC_SYSTICK_CLK_BIT_CONFIG */
/* Step the tick to account for any tick periods that elapsed. */
vTaskStepTick( ulCompleteTickPeriods );
/* Exit with interrupts enabled. */
__asm volatile ( "cpsie i" ::: "memory" );
}
}
#endif /* configUSE_TICKLESS_IDLE */
/*-----------------------------------------------------------*/
__attribute__( ( weak ) ) void vPortSetupTimerInterrupt( void ) /* PRIVILEGED_FUNCTION */
{
/* Calculate the constants required to configure the tick interrupt. */
#if ( configUSE_TICKLESS_IDLE == 1 )
{
ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ );
xMaximumPossibleSuppressedTicks = portMAX_24_BIT_NUMBER / ulTimerCountsForOneTick;
ulStoppedTimerCompensation = portMISSED_COUNTS_FACTOR / ( configCPU_CLOCK_HZ / configSYSTICK_CLOCK_HZ );
}
#endif /* configUSE_TICKLESS_IDLE */
/* Stop and reset SysTick.
*
* QEMU versions older than 7.0.0 contain a bug which causes an error if we
* enable SysTick without first selecting a valid clock source. We trigger
* the bug if we change clock sources from a clock with a zero clock period
* to one with a nonzero clock period and enable Systick at the same time.
* So we configure the CLKSOURCE bit here, prior to setting the ENABLE bit.
* This workaround avoids the bug in QEMU versions older than 7.0.0. */
portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT_CONFIG;
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_CONFIG | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;
}
/*-----------------------------------------------------------*/
static void prvTaskExitError( void )
{
volatile uint32_t ulDummy = 0UL;
/* A function that implements a task must not exit or attempt to return to
* its caller as there is nothing to return to. If a task wants to exit it
* should instead call vTaskDelete( NULL ). Artificially force an assert()
* to be triggered if configASSERT() is defined, then stop here so
* application writers can catch the error. */
configASSERT( ulCriticalNesting == ~0UL );
portDISABLE_INTERRUPTS();
while( ulDummy == 0 )
{
/* This file calls prvTaskExitError() after the scheduler has been
* started to remove a compiler warning about the function being
* defined but never called. ulDummy is used purely to quieten other
* warnings about code appearing after this function is called - making
* ulDummy volatile makes the compiler think the function could return
* and therefore not output an 'unreachable code' warning for code that
* appears after it. */
}
}
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
static uint32_t prvGetMPURegionSizeSetting( uint32_t ulActualSizeInBytes )
{
uint32_t ulRegionSize, ulReturnValue = 7UL;
/* 256 is the smallest region size, 31 is the largest valid value for
* ulReturnValue. */
for( ulRegionSize = 256UL; 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 );
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
static void prvSetupMPU( void ) /* PRIVILEGED_FUNCTION */
{
#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_sram_start__;
extern uint32_t * __privileged_sram_end__;
#else /* if defined( __ARMCC_VERSION ) */
/* 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_sram_start__[];
extern uint32_t __privileged_sram_end__[];
#endif /* defined( __ARMCC_VERSION ) */
/* Ensure that the MPU is present. */
configASSERT( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE );
/* Check that the MPU is present. */
if( portMPU_TYPE_REG == portEXPECTED_MPU_TYPE_VALUE )
{
/* Setup privileged flash as Read Only so that privileged tasks can
* read it but not modify. */
portMPU_RBAR_REG = ( ( ( uint32_t ) __privileged_functions_start__ ) | /* Base address. */
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( portPRIVILEGED_FLASH_REGION ) );
portMPU_RASR_REG = ( ( portMPU_REGION_PRIV_RO_UNPRIV_NA ) |
( ( configS_C_B_FLASH & portMPU_RASR_S_C_B_BITMASK ) << portMPU_RASR_S_C_B_LOCATION ) |
( prvGetMPURegionSizeSetting( ( uint32_t ) __privileged_functions_end__ - ( uint32_t ) __privileged_functions_start__ ) ) |
( portMPU_RASR_REGION_ENABLE_BITMASK ) );
/* Setup unprivileged flash as Read Only by both privileged and
* unprivileged tasks. All tasks can read it but no-one can modify. */
portMPU_RBAR_REG = ( ( ( uint32_t ) __FLASH_segment_start__ ) | /* Base address. */
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( portUNPRIVILEGED_FLASH_REGION ) );
portMPU_RASR_REG = ( ( portMPU_REGION_PRIV_RO_UNPRIV_RO ) |
( ( configS_C_B_FLASH & portMPU_RASR_S_C_B_BITMASK ) << portMPU_RASR_S_C_B_LOCATION ) |
( prvGetMPURegionSizeSetting( ( uint32_t ) __FLASH_segment_end__ - ( uint32_t ) __FLASH_segment_start__ ) ) |
( portMPU_RASR_REGION_ENABLE_BITMASK ) );
/* Setup RAM containing kernel data for privileged access only. */
portMPU_RBAR_REG = ( ( uint32_t ) __privileged_sram_start__ ) | /* Base address. */
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( portPRIVILEGED_RAM_REGION );
portMPU_RASR_REG = ( ( portMPU_REGION_PRIV_RW_UNPRIV_NA ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( ( configS_C_B_SRAM & portMPU_RASR_S_C_B_BITMASK ) << portMPU_RASR_S_C_B_LOCATION ) |
prvGetMPURegionSizeSetting( ( uint32_t ) __privileged_sram_end__ - ( uint32_t ) __privileged_sram_start__ ) |
( portMPU_RASR_REGION_ENABLE_BITMASK ) );
/* Enable MPU with privileged background access i.e. unmapped
* regions have privileged access. */
portMPU_CTRL_REG |= ( portMPU_CTRL_PRIV_BACKGROUND_ENABLE_BITMASK |
portMPU_CTRL_ENABLE_BITMASK );
}
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
void vPortYield( void ) /* PRIVILEGED_FUNCTION */
{
/* Set a PendSV to request a context switch. */
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" );
}
/*-----------------------------------------------------------*/
void vPortEnterCritical( void ) /* PRIVILEGED_FUNCTION */
{
portDISABLE_INTERRUPTS();
ulCriticalNesting++;
/* 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" );
}
/*-----------------------------------------------------------*/
void vPortExitCritical( void ) /* PRIVILEGED_FUNCTION */
{
configASSERT( ulCriticalNesting );
ulCriticalNesting--;
if( ulCriticalNesting == 0 )
{
portENABLE_INTERRUPTS();
}
}
/*-----------------------------------------------------------*/
void SysTick_Handler( void ) /* PRIVILEGED_FUNCTION */
{
uint32_t ulPreviousMask;
ulPreviousMask = portSET_INTERRUPT_MASK_FROM_ISR();
traceISR_ENTER();
{
/* Increment the RTOS tick. */
if( xTaskIncrementTick() != pdFALSE )
{
traceISR_EXIT_TO_SCHEDULER();
/* Pend a context switch. */
portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
}
else
{
traceISR_EXIT();
}
}
portCLEAR_INTERRUPT_MASK_FROM_ISR( ulPreviousMask );
}
/*-----------------------------------------------------------*/
void vPortSVCHandler_C( uint32_t * pulCallerStackAddress ) /* PRIVILEGED_FUNCTION portDONT_DISCARD */
{
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) )
#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 /* defined( __ARMCC_VERSION ) */
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
uint32_t ulPC;
uint8_t ucSVCNumber;
/* Register are stored on the stack in the following order - R0, R1, R2, R3,
* R12, LR, PC, xPSR. */
ulPC = pulCallerStackAddress[ portOFFSET_TO_PC ];
ucSVCNumber = ( ( uint8_t * ) ulPC )[ -2 ];
switch( ucSVCNumber )
{
case portSVC_START_SCHEDULER:
/* Setup the context of the first task so that the first task starts
* executing. */
vRestoreContextOfFirstTask();
break;
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 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__ ) )
{
vRaisePrivilege();
}
break;
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 1 ) */
#if ( configENABLE_MPU == 1 )
case portSVC_YIELD:
vPortYield();
break;
#endif /* configENABLE_MPU == 1 */
default:
/* Incorrect SVC call. */
configASSERT( pdFALSE );
}
}
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( 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 ulSystemCallLocation, i;
const uint32_t ulStackFrameSize = 8;
#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;
/* 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 ];
}
/* 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 ];
/* Use the pulSystemCallStack in thread mode. */
__asm volatile ( "msr psp, %0" : : "r" ( pulSystemCallStack ) );
/* 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;
/* Remember the location where we should copy the stack frame when we exit from
* the system call. */
pxMpuSettings->xSystemCallStackInfo.pulTaskStack = pulTaskStack + ulStackFrameSize;
/* 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 );
/* Raise the privilege for the duration of the system call. */
__asm volatile
(
" .syntax unified \n"
" mrs r0, control \n" /* Obtain current control value. */
" movs r1, #1 \n" /* r1 = 1. */
" bics r0, r1 \n" /* Clear nPRIV bit. */
" msr control, r0 \n" /* Write back new control value. */
::: "r0", "r1", "memory"
);
}
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
void vRequestSystemCallExit( void ) /* __attribute__( ( naked ) ) PRIVILEGED_FUNCTION */
{
__asm volatile ( "svc %0 \n" ::"i" ( portSVC_SYSTEM_CALL_EXIT ) : "memory" );
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( 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 ulSystemCallLocation, i;
const uint32_t ulStackFrameSize = 8;
#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;
/* 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 ) );
/* 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;
/* Drop the privilege before returning to the thread mode. */
__asm volatile
(
" .syntax unified \n"
" mrs r0, control \n" /* Obtain current control value. */
" movs r1, #1 \n" /* r1 = 1. */
" orrs r0, r1 \n" /* Set nPRIV bit. */
" msr control, r0 \n" /* Write back new control value. */
::: "r0", "r1", "memory"
);
}
}
#endif /* ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
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;
}
#endif /* configENABLE_MPU == 1 */
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
TaskFunction_t pxCode,
void * pvParameters,
BaseType_t xRunPrivileged,
xMPU_SETTINGS * xMPUSettings ) /* PRIVILEGED_FUNCTION */
{
xMPUSettings->ulContext[ 0 ] = 0x04040404; /* r4. */
xMPUSettings->ulContext[ 1 ] = 0x05050505; /* r5. */
xMPUSettings->ulContext[ 2 ] = 0x06060606; /* r6. */
xMPUSettings->ulContext[ 3 ] = 0x07070707; /* r7. */
xMPUSettings->ulContext[ 4 ] = 0x08080808; /* r8. */
xMPUSettings->ulContext[ 5 ] = 0x09090909; /* r9. */
xMPUSettings->ulContext[ 6 ] = 0x10101010; /* r10. */
xMPUSettings->ulContext[ 7 ] = 0x11111111; /* r11. */
xMPUSettings->ulContext[ 8 ] = ( uint32_t ) pvParameters; /* r0. */
xMPUSettings->ulContext[ 9 ] = 0x01010101; /* r1. */
xMPUSettings->ulContext[ 10 ] = 0x02020202; /* r2. */
xMPUSettings->ulContext[ 11 ] = 0x03030303; /* r3. */
xMPUSettings->ulContext[ 12 ] = 0x12121212; /* r12. */
xMPUSettings->ulContext[ 13 ] = ( uint32_t ) portTASK_RETURN_ADDRESS; /* LR. */
xMPUSettings->ulContext[ 14 ] = ( uint32_t ) pxCode; /* PC. */
xMPUSettings->ulContext[ 15 ] = portINITIAL_XPSR; /* xPSR. */
xMPUSettings->ulContext[ 16 ] = ( uint32_t ) ( pxTopOfStack - 8 ); /* PSP with the hardware saved stack. */
if( xRunPrivileged == pdTRUE )
{
xMPUSettings->ulTaskFlags |= portTASK_IS_PRIVILEGED_FLAG;
xMPUSettings->ulContext[ 17 ] = ( uint32_t ) portINITIAL_CONTROL_PRIVILEGED; /* CONTROL. */
}
else
{
xMPUSettings->ulTaskFlags &= ( ~portTASK_IS_PRIVILEGED_FLAG );
xMPUSettings->ulContext[ 17 ] = ( uint32_t ) portINITIAL_CONTROL_UNPRIVILEGED; /* CONTROL. */
}
xMPUSettings->ulContext[ 18 ] = portINITIAL_EXC_RETURN; /* LR (EXC_RETURN). */
#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 /* configUSE_MPU_WRAPPERS_V1 == 0 */
return &( xMPUSettings->ulContext[ 19 ] );
}
#else /* configENABLE_MPU */
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
TaskFunction_t pxCode,
void * pvParameters ) /* PRIVILEGED_FUNCTION */
{
/* Simulate the stack frame as it would be created by a context switch
* interrupt. */
#if ( portPRELOAD_REGISTERS == 0 )
{
pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxCode; /* PC. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR. */
pxTopOfStack -= 5; /* R12, R3, R2 and R1. */
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0. */
pxTopOfStack -= 9; /* R11..R4, EXC_RETURN. */
*pxTopOfStack = portINITIAL_EXC_RETURN;
}
#else /* portPRELOAD_REGISTERS */
{
pxTopOfStack--; /* Offset added to account for the way the MCU uses the stack on entry/exit of interrupts. */
*pxTopOfStack = portINITIAL_XPSR; /* xPSR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxCode; /* PC. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) portTASK_RETURN_ADDRESS; /* LR. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x12121212UL; /* R12. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x03030303UL; /* R3. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x02020202UL; /* R2. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x01010101UL; /* R1. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pvParameters; /* R0. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x11111111UL; /* R11. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x10101010UL; /* R10. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x09090909UL; /* R09. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x08080808UL; /* R08. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x07070707UL; /* R07. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x06060606UL; /* R06. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x05050505UL; /* R05. */
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) 0x04040404UL; /* R04. */
pxTopOfStack--;
*pxTopOfStack = portINITIAL_EXC_RETURN; /* EXC_RETURN. */
}
#endif /* portPRELOAD_REGISTERS */
return pxTopOfStack;
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
BaseType_t xPortStartScheduler( void ) /* PRIVILEGED_FUNCTION */
{
/* An application can install FreeRTOS interrupt handlers in one of the
* following ways:
* 1. Direct Routing - Install the functions SVC_Handler and PendSV_Handler
* 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
* SVC_Handler and PendSV_Handler 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/Why-FreeRTOS/FAQs.
*
* 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 ] == SVC_Handler );
configASSERT( pxVectorTable[ portVECTOR_INDEX_PENDSV ] == PendSV_Handler );
}
#endif /* configCHECK_HANDLER_INSTALLATION */
/* 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;
#if ( configENABLE_MPU == 1 )
{
/* Setup the Memory Protection Unit (MPU). */
prvSetupMPU();
}
#endif /* configENABLE_MPU */
/* Start the timer that generates the tick ISR. Interrupts are disabled
* here already. */
vPortSetupTimerInterrupt();
/* Initialize the critical nesting count ready for the first task. */
ulCriticalNesting = 0;
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
{
xSchedulerRunning = pdTRUE;
}
#endif
/* Start the first task. */
vStartFirstTask();
/* Should never get here as the tasks will now be executing. Call the task
* exit error function to prevent compiler warnings about a static function
* not being called in the case that the application writer overrides this
* functionality by defining configTASK_RETURN_ADDRESS. Call
* vTaskSwitchContext() so link time optimization does not remove the
* symbol. */
vTaskSwitchContext();
prvTaskExitError();
/* Should not get here. */
return 0;
}
/*-----------------------------------------------------------*/
void vPortEndScheduler( void ) /* PRIVILEGED_FUNCTION */
{
/* Not implemented in ports where there is nothing to return to.
* Artificially force an assert. */
configASSERT( ulCriticalNesting == 1000UL );
}
/*-----------------------------------------------------------*/
#if ( configENABLE_MPU == 1 )
void vPortStoreTaskMPUSettings( xMPU_SETTINGS * xMPUSettings,
const struct xMEMORY_REGION * const xRegions,
StackType_t * pxBottomOfStack,
configSTACK_DEPTH_TYPE uxStackDepth )
{
#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_sram_start__;
extern uint32_t * __privileged_sram_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_sram_start__[];
extern uint32_t __privileged_sram_end__[];
#endif /* defined( __ARMCC_VERSION ) */
int32_t lIndex;
uint32_t ul;
if( xRegions == NULL )
{
/* No MPU regions are specified so allow access to all RAM. */
xMPUSettings->xRegionsSettings[ 0 ].ulRBAR =
( ( ( uint32_t ) __SRAM_segment_start__ ) | /* Base address. */
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( portSTACK_REGION ) ); /* Region number. */
xMPUSettings->xRegionsSettings[ 0 ].ulRASR =
( ( portMPU_REGION_PRIV_RW_UNPRIV_RW ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( ( configS_C_B_SRAM & portMPU_RASR_S_C_B_BITMASK ) << portMPU_RASR_S_C_B_LOCATION ) |
( prvGetMPURegionSizeSetting( ( uint32_t ) __SRAM_segment_end__ - ( uint32_t ) __SRAM_segment_start__ ) ) |
( portMPU_RASR_REGION_ENABLE_BITMASK ) );
/* Invalidate user configurable regions. */
for( ul = 1UL; ul <= portNUM_CONFIGURABLE_REGIONS; ul++ )
{
xMPUSettings->xRegionsSettings[ ul ].ulRBAR = ( ( ul - 1UL ) | portMPU_RBAR_REGION_NUMBER_VALID_BITMASK );
xMPUSettings->xRegionsSettings[ ul ].ulRASR = 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->xRegionsSettings[ 0 ].ulRBAR =
( ( ( uint32_t ) pxBottomOfStack ) |
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( portSTACK_REGION ) ); /* Region number. */
xMPUSettings->xRegionsSettings[ 0 ].ulRASR =
( ( portMPU_REGION_PRIV_RW_UNPRIV_RW ) |
( portMPU_REGION_EXECUTE_NEVER ) |
( prvGetMPURegionSizeSetting( uxStackDepth * ( uint32_t ) sizeof( StackType_t ) ) ) |
( ( configS_C_B_SRAM & portMPU_RASR_S_C_B_BITMASK ) << portMPU_RASR_S_C_B_LOCATION ) |
( portMPU_RASR_REGION_ENABLE_BITMASK ) );
}
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 CM0+ specific MPU settings that are then
* stored in xMPUSettings. */
xMPUSettings->xRegionsSettings[ ul ].ulRBAR =
( ( uint32_t ) xRegions[ lIndex ].pvBaseAddress ) |
( portMPU_RBAR_REGION_NUMBER_VALID_BITMASK ) |
( ul - 1UL ); /* Region number. */
xMPUSettings->xRegionsSettings[ ul ].ulRASR =
( prvGetMPURegionSizeSetting( xRegions[ lIndex ].ulLengthInBytes ) ) |
( xRegions[ lIndex ].ulParameters ) |
( portMPU_RASR_REGION_ENABLE_BITMASK );
}
else
{
/* Invalidate the region. */
xMPUSettings->xRegionsSettings[ ul ].ulRBAR = ( ( ul - 1UL ) | portMPU_RBAR_REGION_NUMBER_VALID_BITMASK );
xMPUSettings->xRegionsSettings[ ul ].ulRASR = 0UL;
}
lIndex++;
}
}
}
#endif /* configENABLE_MPU */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) )
BaseType_t xPortIsAuthorizedToAccessBuffer( const void * pvBuffer,
uint32_t ulBufferLength,
uint32_t ulAccessRequested ) /* PRIVILEGED_FUNCTION */
{
uint32_t i, ulBufferStartAddress, ulBufferEndAddress;
uint32_t ulRegionStart, ulRegionSize, ulRegionEnd;
uint32_t ulMPURegionAccessPermissions;
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; i++ )
{
/* Is the MPU region enabled? */
if( ( xTaskMpuSettings->xRegionsSettings[ i ].ulRASR &
portMPU_RASR_REGION_ENABLE_BITMASK ) == portMPU_RASR_REGION_ENABLE_BITMASK )
{
ulRegionStart = portEXTRACT_FIRST_ADDRESS_FROM_RBAR( xTaskMpuSettings->xRegionsSettings[ i ].ulRBAR );
ulRegionSize = portEXTRACT_REGION_SIZE_FROM_RASR( xTaskMpuSettings->xRegionsSettings[ i ].ulRASR );
ulRegionEnd = ulRegionStart + ulRegionSize;
if( portIS_ADDRESS_WITHIN_RANGE( ulBufferStartAddress,
ulRegionStart,
ulRegionEnd ) &&
portIS_ADDRESS_WITHIN_RANGE( ulBufferEndAddress,
ulRegionStart,
ulRegionEnd ) )
{
ulMPURegionAccessPermissions = xTaskMpuSettings->xRegionsSettings[ i ].ulRASR &
portMPU_RASR_AP_BITMASK;
if( ulAccessRequested == tskMPU_READ_PERMISSION ) /* RO. */
{
if( ( ulMPURegionAccessPermissions == portMPU_REGION_PRIV_RW_UNPRIV_RO ) ||
( ulMPURegionAccessPermissions == portMPU_REGION_PRIV_RO_UNPRIV_RO ) ||
( ulMPURegionAccessPermissions == portMPU_REGION_PRIV_RW_UNPRIV_RW ) )
{
xAccessGranted = pdTRUE;
break;
}
}
else if( ( ulAccessRequested & tskMPU_WRITE_PERMISSION ) != 0UL ) /* W or RW. */
{
if( ulMPURegionAccessPermissions == portMPU_REGION_PRIV_RW_UNPRIV_RW )
{
xAccessGranted = pdTRUE;
break;
}
}
}
}
}
}
}
return xAccessGranted;
}
#endif /* #if ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) ) */
/*-----------------------------------------------------------*/
BaseType_t xPortIsInsideInterrupt( void )
{
uint32_t ulCurrentInterrupt;
BaseType_t xReturn;
/* Obtain the number of the currently executing interrupt. Interrupt Program
* Status Register (IPSR) holds the exception number of the currently-executing
* exception or zero for Thread mode.*/
__asm volatile ( "mrs %0, ipsr" : "=r" ( ulCurrentInterrupt )::"memory" );
if( ulCurrentInterrupt == 0 )
{
xReturn = pdFALSE;
}
else
{
xReturn = pdTRUE;
}
return xReturn;
}
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( 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 ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( 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 ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) && ( configENABLE_ACCESS_CONTROL_LIST == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( ( configENABLE_MPU == 1 ) && ( 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 ( ( configENABLE_MPU == 1 ) && ( configUSE_MPU_WRAPPERS_V1 == 0 ) ) */
/*-----------------------------------------------------------*/