1;/**************************************************************************/ 2;/* */ 3;/* Copyright (c) Microsoft Corporation. All rights reserved. */ 4;/* */ 5;/* This software is licensed under the Microsoft Software License */ 6;/* Terms for Microsoft Azure RTOS. Full text of the license can be */ 7;/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ 8;/* and in the root directory of this software. */ 9;/* */ 10;/**************************************************************************/ 11; 12; 13;/**************************************************************************/ 14;/**************************************************************************/ 15;/** */ 16;/** ThreadX Component */ 17;/** */ 18;/** Thread */ 19;/** */ 20;/**************************************************************************/ 21;/**************************************************************************/ 22; 23; 24;#define TX_SOURCE_CODE 25; 26; 27;/* Include necessary system files. */ 28; 29;#include "tx_api.h" 30;#include "tx_thread.h" 31;#include "tx_timer.h" 32; 33; 34 .global __tx_thread_execute_ptr 35 .global __tx_thread_current_ptr 36 .global __tx_timer_time_slice 37#if (TX_LOW_POWER == 1) 38 .global _tx_low_power_enter 39 .global _tx_low_power_exit 40 .global __tx_thread_preempt_disable 41#endif 42; 43 .text 44 45;/**************************************************************************/ 46;/* */ 47;/* FUNCTION RELEASE */ 48;/* */ 49;/* _tx_thread_schedule RXv2/GNURX */ 50;/* 6.1.11 */ 51;/* AUTHOR */ 52;/* */ 53;/* William E. Lamie, Microsoft Corporation */ 54;/* */ 55;/* DESCRIPTION */ 56;/* */ 57;/* This function waits for a thread control block pointer to appear in */ 58;/* the _tx_thread_execute_ptr variable. Once a thread pointer appears */ 59;/* in the variable, the corresponding thread is resumed. */ 60;/* */ 61;/* INPUT */ 62;/* */ 63;/* None */ 64;/* */ 65;/* OUTPUT */ 66;/* */ 67;/* None */ 68;/* */ 69;/* CALLS */ 70;/* */ 71;/* None */ 72;/* */ 73;/* CALLED BY */ 74;/* */ 75;/* _tx_initialize_kernel_enter ThreadX entry function */ 76;/* _tx_thread_system_return Return to system from thread */ 77;/* _tx_thread_context_restore Restore thread's context */ 78;/* */ 79;/* RELEASE HISTORY */ 80;/* */ 81;/* DATE NAME DESCRIPTION */ 82;/* */ 83;/* 12-30-2020 William E. Lamie Initial Version 6.1.3 */ 84;/* 10-15-2021 William E. Lamie Modified comment(s), and */ 85;/* removed unnecessary stack */ 86;/* type checking, */ 87;/* resulting in version 6.1.9 */ 88;/* 01-31-2022 William E. Lamie Modified comment(s), */ 89;/* resulting in version 6.1.10 */ 90;/* 04-25-2022 William E. Lamie Modified comment(s), and */ 91;/* added low power support, */ 92;/* resulting in version 6.1.11 */ 93;/* */ 94;/**************************************************************************/ 95;VOID _tx_thread_schedule(VOID) 96;{ 97 .global __tx_thread_schedule 98__tx_thread_schedule: 99; 100; 101; /* Wait for a thread to execute. */ 102; do 103; { 104 MOV.L #__tx_thread_execute_ptr, R1 ; Address of thread to executer ptr 105__tx_thread_schedule_loop: 106 SETPSW I ; Enable interrupts 107 CLRPSW I ; Disable interrupts 108 MOV.L [R1],R2 ; Pickup next thread to execute 109 CMP #0,R2 ; Is it NULL? 110 BNE __tx_thread_thread_ready ; Not NULL, schedule the thread 111 ; Idle system - no thread is ready 112#if (TX_LOW_POWER == 1) 113 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 114 MOV.L [R1], R2 115 ADD #1, R2 ; Disable preemption while enter/exit 116 MOV.L R2, [R1] 117 BSR _tx_low_power_enter ; Possibly enter low power mode 118#endif 119 120#if (TX_ENABLE_WAIT == 1) 121 WAIT ; Wait for interrupt 122#endif 123 124#if (TX_LOW_POWER == 1) 125 CLRPSW I ; Disable interrupts (because WAIT enables interrupts) 126 BSR _tx_low_power_exit ; Possibly exit low power mode 127 MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag. 128 MOV.L [R1], R2 129 SUB #1, R2 ; Enable preemption 130 MOV.L R2, [R1] 131 MOV.L #__tx_thread_execute_ptr, R1 ; Address of thread to executer ptr 132#endif 133 134 BRA __tx_thread_schedule_loop ; Idle system, keep checking 135 136__tx_thread_thread_ready: 137; 138; } 139; while(_tx_thread_execute_ptr == TX_NULL); 140; 141; /* Yes! We have a thread to execute. Note that interrupts are locked out at this point. */ 142; 143; /* Setup the current thread pointer. */ 144; _tx_thread_current_ptr = _tx_thread_execute_ptr; 145; 146 MOV.L #__tx_thread_current_ptr, R3 147 MOV.L R2,[R3] ; Setup current thread pointer 148; 149; /* Increment the run count for this thread. */ 150; _tx_thread_current_ptr -> tx_thread_run_count++; 151; 152 MOV.L 4[R2],R3 ; Pickup run count 153 ADD #1,R3 ; Increment run counter 154 MOV.L R3,4[R2] ; Store it back in control block 155; 156; /* Setup time-slice, if present. */ 157; _tx_timer_time_slice = _tx_thread_current_ptr -> tx_thread_time_slice; 158; 159 MOV.L 24[R2],R3 ; Pickup thread time-slice 160 MOV.L #__tx_timer_time_slice,R4 ; Pickup pointer to time-slice 161 MOV.L R3, [R4] ; Setup time-slice 162; 163; /* Switch to the thread's stack. */ 164; SP = _tx_thread_execute_ptr -> tx_thread_stack_ptr; 165 SETPSW U ; User stack mode 166 MOV.L 8[R2],R0 ; Pickup stack pointer 167 168 POPM R1-R3 ; Restore accumulators. 169 MVTACLO R3, A0 170 MVTACHI R2, A0 171 MVTACGU R1, A0 172 POPM R1-R3 173 MVTACLO R3, A1 174 MVTACHI R2, A1 175 MVTACGU R1, A1 176 177 POPM R6-R13 ; Recover interrupt stack frame 178 POPC FPSW 179 POPM R14-R15 180 POPM R3-R5 181 POPM R1-R2 182 RTE ; Return to point of interrupt, this restores PC and PSW 183 184;} 185 186 187.global __tx_thread_context_save 188.global __tx_thread_context_restore 189 190 191; Software triggered interrupt used to perform context switches. 192; The priority of this interrupt is set to the lowest priority within 193; tx_initialize_low_level() and triggered by ThreadX when calling 194; _tx_thread_system_return(). 195.global $tableentry$27$.rvectors 196$tableentry$27$.rvectors: 197 198 PUSHM R1-R2 199 200 BSR __tx_thread_context_save 201 202 BRA __tx_thread_context_restore 203 204 .end 205
