/*
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/*
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* Thread Handler
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* Thread Handler
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*
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*
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*
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*
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* COPYRIGHT (c) 1989-1999.
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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* On-Line Applications Research Corporation (OAR).
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*
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*
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* The license and distribution terms for this file may be
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* The license and distribution terms for this file may be
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* found in found in the file LICENSE in this distribution or at
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* found in found in the file LICENSE in this distribution or at
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* http://www.OARcorp.com/rtems/license.html.
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* http://www.OARcorp.com/rtems/license.html.
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*
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*
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* $Id: threadstartmultitasking.c,v 1.2 2001-09-27 11:59:34 chris Exp $
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* $Id: threadstartmultitasking.c,v 1.2 2001-09-27 11:59:34 chris Exp $
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*/
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*/
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#include <rtems/system.h>
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#include <rtems/system.h>
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#include <rtems/score/apiext.h>
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#include <rtems/score/apiext.h>
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#include <rtems/score/context.h>
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#include <rtems/score/context.h>
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#include <rtems/score/interr.h>
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#include <rtems/score/interr.h>
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#include <rtems/score/isr.h>
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#include <rtems/score/isr.h>
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#include <rtems/score/object.h>
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#include <rtems/score/object.h>
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#include <rtems/score/priority.h>
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#include <rtems/score/priority.h>
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#include <rtems/score/states.h>
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#include <rtems/score/states.h>
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#include <rtems/score/sysstate.h>
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#include <rtems/score/sysstate.h>
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#include <rtems/score/thread.h>
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#include <rtems/score/thread.h>
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#include <rtems/score/threadq.h>
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#include <rtems/score/threadq.h>
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#include <rtems/score/userext.h>
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#include <rtems/score/userext.h>
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#include <rtems/score/wkspace.h>
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#include <rtems/score/wkspace.h>
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/*PAGE
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/*PAGE
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*
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*
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* _Thread_Start_multitasking
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* _Thread_Start_multitasking
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*
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*
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* This kernel routine readies the requested thread, the thread chain
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* This kernel routine readies the requested thread, the thread chain
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* is adjusted. A new heir thread may be selected.
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* is adjusted. A new heir thread may be selected.
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*
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*
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* Input parameters:
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* Input parameters:
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* system_thread - pointer to system initialization thread control block
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* system_thread - pointer to system initialization thread control block
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* idle_thread - pointer to idle thread control block
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* idle_thread - pointer to idle thread control block
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*
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*
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* Output parameters: NONE
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* Output parameters: NONE
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*
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*
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* NOTE: This routine uses the "blocking" heir selection mechanism.
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* NOTE: This routine uses the "blocking" heir selection mechanism.
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* This insures the correct heir after a thread restart.
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* This insures the correct heir after a thread restart.
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*
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*
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* INTERRUPT LATENCY:
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* INTERRUPT LATENCY:
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* ready chain
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* ready chain
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* select heir
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* select heir
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*/
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*/
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void _Thread_Start_multitasking( void )
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void _Thread_Start_multitasking( void )
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{
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{
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/*
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/*
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* The system is now multitasking and completely initialized.
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* The system is now multitasking and completely initialized.
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* This system thread now either "goes away" in a single processor
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* This system thread now either "goes away" in a single processor
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* system or "turns into" the server thread in an MP system.
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* system or "turns into" the server thread in an MP system.
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*/
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*/
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_System_state_Set( SYSTEM_STATE_UP );
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_System_state_Set( SYSTEM_STATE_UP );
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_Context_Switch_necessary = FALSE;
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_Context_Switch_necessary = FALSE;
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_Thread_Executing = _Thread_Heir;
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_Thread_Executing = _Thread_Heir;
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/*
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/*
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* Get the init task(s) running.
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* Get the init task(s) running.
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*
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*
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* Note: Thread_Dispatch() is normally used to dispatch threads. As
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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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* part of its work, Thread_Dispatch() restores floating point
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* state for the heir task.
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* state for the heir task.
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*
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*
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* This code avoids Thread_Dispatch(), and so we have to restore
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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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* (actually initialize) the floating point state "by hand".
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*
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*
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* Ignore the CPU_USE_DEFERRED_FP_SWITCH because we must always
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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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* switch in the first thread if it is FP.
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*/
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*/
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#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
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#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
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/*
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/*
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* don't need to worry about saving BSP's floating point state
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* don't need to worry about saving BSP's floating point state
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*/
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*/
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if ( _Thread_Heir->fp_context != NULL )
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if ( _Thread_Heir->fp_context != NULL )
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_Context_Restore_fp( &_Thread_Heir->fp_context );
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_Context_Restore_fp( &_Thread_Heir->fp_context );
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#endif
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#endif
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_Context_Switch( &_Thread_BSP_context, &_Thread_Heir->Registers );
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_Context_Switch( &_Thread_BSP_context, &_Thread_Heir->Registers );
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}
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}
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