forked from Imagelibrary/rtems
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/**
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* @file
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*
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* @brief Start Thread Multitasking
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* @ingroup ScoreThread
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*/
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/*
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* COPYRIGHT (c) 1989-2006.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.com/license/LICENSE.
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*/
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#if HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <rtems/score/threadimpl.h>
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void _Thread_Start_multitasking( Context_Control *context )
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{
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Per_CPU_Control *self_cpu = _Per_CPU_Get();
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Thread_Control *heir = self_cpu->heir;
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#if defined(RTEMS_SMP)
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_Per_CPU_Change_state( self_cpu, PER_CPU_STATE_UP );
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_Per_CPU_Acquire( self_cpu );
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self_cpu->executing->is_executing = false;
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heir->is_executing = true;
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#endif
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self_cpu->dispatch_necessary = false;
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self_cpu->executing = heir;
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/*
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* Get the init task(s) running.
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*
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* Note: Thread_Dispatch() is normally used to dispatch threads. As
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* part of its work, Thread_Dispatch() restores floating point
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* state for the heir task.
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*
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* This code avoids Thread_Dispatch(), and so we have to restore
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* (actually initialize) the floating point state "by hand".
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*
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* Ignore the CPU_USE_DEFERRED_FP_SWITCH because we must always
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* switch in the first thread if it is FP.
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*/
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#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
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/*
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* don't need to worry about saving BSP's floating point state
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*/
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if ( heir->fp_context != NULL )
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_Context_Restore_fp( &heir->fp_context );
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#endif
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#if defined(RTEMS_SMP)
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if ( context != NULL ) {
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#endif
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#if defined(_CPU_Start_multitasking)
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_CPU_Start_multitasking( context, &heir->Registers );
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#else
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_Context_Switch( context, &heir->Registers );
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#endif
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#if defined(RTEMS_SMP)
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} else {
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/*
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* Threads begin execution in the _Thread_Handler() function. This
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* function will set the thread dispatch disable level to zero and calls
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* _Per_CPU_Release().
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*/
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self_cpu->thread_dispatch_disable_level = 1;
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_CPU_Context_restore( &heir->Registers );
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}
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#endif
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}
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