1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Start Thread Multitasking |
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5 | * @ingroup ScoreThread |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-2006. |
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10 | * On-Line Applications Research Corporation (OAR). |
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11 | * |
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12 | * The license and distribution terms for this file may be |
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13 | * found in the file LICENSE in this distribution or at |
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14 | * http://www.rtems.org/license/LICENSE. |
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15 | */ |
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16 | |
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17 | #if HAVE_CONFIG_H |
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18 | #include "config.h" |
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19 | #endif |
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20 | |
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21 | #include <rtems/score/threadimpl.h> |
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22 | #include <rtems/score/assert.h> |
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23 | |
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24 | void _Thread_Start_multitasking( void ) |
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25 | { |
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26 | Per_CPU_Control *cpu_self = _Per_CPU_Get(); |
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27 | Thread_Control *heir; |
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28 | |
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29 | #if defined(RTEMS_SMP) |
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30 | _Per_CPU_State_change( cpu_self, PER_CPU_STATE_UP ); |
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31 | |
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32 | /* |
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33 | * Threads begin execution in the _Thread_Handler() function. This |
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34 | * function will set the thread dispatch disable level to zero. |
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35 | */ |
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36 | cpu_self->thread_dispatch_disable_level = 1; |
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37 | #endif |
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38 | |
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39 | heir = _Thread_Get_heir_and_make_it_executing( cpu_self ); |
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40 | |
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41 | _Profiling_Thread_dispatch_disable( cpu_self, 0 ); |
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42 | |
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43 | #if defined(RTEMS_SMP) |
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44 | _CPU_SMP_Prepare_start_multitasking(); |
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45 | #endif |
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46 | |
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47 | #if defined(_CPU_Start_multitasking) |
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48 | _CPU_Start_multitasking( &heir->Registers ); |
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49 | #elif defined(RTEMS_SMP) |
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50 | { |
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51 | Context_Control trash; |
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52 | |
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53 | /* |
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54 | * Mark the trash context as executing to not confuse the |
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55 | * _CPU_Context_switch(). On SMP configurations the context switch |
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56 | * contains a special hand over section to atomically switch from the |
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57 | * executing to the currently selected heir thread. |
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58 | */ |
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59 | _CPU_Context_Set_is_executing( &trash, true ); |
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60 | _CPU_Context_switch( &trash, &heir->Registers ); |
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61 | RTEMS_UNREACHABLE(); |
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62 | } |
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63 | #else |
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64 | _CPU_Context_Restart_self( &heir->Registers ); |
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65 | #endif |
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66 | } |
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