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Add workaround to XMC4000 silicon bug to Tasking Cortex-M4F port layer.

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This commit is contained in:
Richard Barry 2013-10-14 14:03:05 +00:00
parent c1353bb12d
commit 94607d83f9
3 changed files with 119 additions and 8 deletions
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30
FreeRTOS/Source/portable/Tasking/ARM_CM4F/port.c
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@ -88,6 +88,15 @@
#define portINITIAL_XPSR ( 0x01000000 )
#define portINITIAL_EXEC_RETURN ( 0xfffffffd )
/* Let the user override the pre-loading of the initial LR with the address of
prvTaskExitError() in case is 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
/* The priority used by the kernel is assigned to a variable to make access
from inline assembler easier. */
const unsigned long ulKernelPriority = configKERNEL_INTERRUPT_PRIORITY;
@ -112,6 +121,11 @@ void SysTick_Handler( void );
extern void vPortEnableVFP( void );
extern void vPortStartFirstTask( void );
/*
* Used to catch tasks that attempt to return from their implementing function.
*/
static void prvTaskExitError( void );
/* This exists purely to allow the const to be used from within the
port_asm.asm assembly file. */
const unsigned long ulMaxSyscallInterruptPriorityConst = configMAX_SYSCALL_INTERRUPT_PRIORITY;
@ -134,7 +148,7 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
pxTopOfStack--;
*pxTopOfStack = ( portSTACK_TYPE ) pxCode; /* PC */
pxTopOfStack--;
*pxTopOfStack = 0; /* LR */
*pxTopOfStack = ( portSTACK_TYPE ) portTASK_RETURN_ADDRESS; /* LR */
/* Save code space by skipping register initialisation. */
pxTopOfStack -= 5; /* R12, R3, R2 and R1. */
@ -151,6 +165,20 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
}
/*-----------------------------------------------------------*/
static void prvTaskExitError( void )
{
/* 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();
for( ;; );
}
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/