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;/**************************************************************************/
;/* */
;/* Copyright (c) Microsoft Corporation. All rights reserved. */
;/* */
;/* This software is licensed under the Microsoft Software License */
;/* Terms for Microsoft Azure RTOS. Full text of the license can be */
;/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
;/* and in the root directory of this software. */
;/* */
;/**************************************************************************/
;
;
;/**************************************************************************/
;/**************************************************************************/
;/** */
;/** ThreadX Component */
;/** */
;/** Thread */
;/** */
;/**************************************************************************/
;/**************************************************************************/
.global __tx_thread_execute_ptr
.global __tx_thread_current_ptr
.global __tx_timer_time_slice
;
.text
;/**************************************************************************/
;/* */
;/* FUNCTION RELEASE */
;/* */
;/* _tx_thread_schedule RXv2/GNURX */
;/* 6.1.3 */
;/* AUTHOR */
;/* */
;/* William E. Lamie, Microsoft Corporation */
;/* */
;/* DESCRIPTION */
;/* */
;/* This function waits for a thread control block pointer to appear in */
;/* the _tx_thread_execute_ptr variable. Once a thread pointer appears */
;/* in the variable, the corresponding thread is resumed. */
;/* */
;/* INPUT */
;/* */
;/* None */
;/* */
;/* OUTPUT */
;/* */
;/* None */
;/* */
;/* CALLS */
;/* */
;/* None */
;/* */
;/* CALLED BY */
;/* */
;/* _tx_initialize_kernel_enter ThreadX entry function */
;/* _tx_thread_system_return Return to system from thread */
;/* _tx_thread_context_restore Restore thread's context */
;/* */
;/* RELEASE HISTORY */
;/* */
;/* DATE NAME DESCRIPTION */
;/* */
;/* 12-31-2020 William E. Lamie Initial Version 6.1.3 */
;/* */
;/**************************************************************************/
;VOID _tx_thread_schedule(VOID)
;{
.global __tx_thread_schedule
__tx_thread_schedule:
;
; /* Enable interrupts. */
;
SETPSW I
;
; /* Wait for a thread to execute. */
; do
; {
MOV.L #__tx_thread_execute_ptr, R1 ; Address of thread to executer ptr
__tx_thread_schedule_loop:
MOV.L [R1],R2 ; Pickup next thread to execute
CMP #0,R2 ; Is it NULL?
BEQ __tx_thread_schedule_loop ; Yes, idle system, keep checking
;
; }
; while(_tx_thread_execute_ptr == TX_NULL);
;
; /* Yes! We have a thread to execute. Lockout interrupts and
; transfer control to it. */
;
CLRPSW I ; disable interrupts
;
; /* Setup the current thread pointer. */
; _tx_thread_current_ptr = _tx_thread_execute_ptr;
;
MOV.L #__tx_thread_current_ptr, R3
MOV.L R2,[R3] ; Setup current thread pointer
;
; /* Increment the run count for this thread. */
; _tx_thread_current_ptr -> tx_thread_run_count++;
;
MOV.L 4[R2],R3 ; Pickup run count
ADD #1,R3 ; Increment run counter
MOV.L R3,4[R2] ; Store it back in control block
;
; /* Setup time-slice, if present. */
; _tx_timer_time_slice = _tx_thread_current_ptr -> tx_thread_time_slice;
;
MOV.L 24[R2],R3 ; Pickup thread time-slice
MOV.L #__tx_timer_time_slice,R4 ; Pickup pointer to time-slice
MOV.L R3, [R4] ; Setup time-slice
;
; /* Switch to the thread's stack. */
; SP = _tx_thread_execute_ptr -> tx_thread_stack_ptr;
SETPSW U ; user stack mode
MOV.L 8[R2],R0 ; Pickup stack pointer
;
; /* Determine if an interrupt frame or a synchronous task suspension frame
; is present. */
;
POP R1 ; Pickup stack type
CMP #1, R1 ; Is it an interrupt stack?
BNE __tx_thread_synch_return ; No, a synchronous return frame is present.
POPM R1-R3 ; Restore accumulators.
MVTACLO R3, A0
MVTACHI R2, A0
MVTACGU R1, A0
POPM R1-R3
MVTACLO R3, A1
MVTACHI R2, A1
MVTACGU R1, A1
POPM R6-R13 ; Recover interrupt stack frame
POPC FPSW
POPM R14-R15
POPM R3-R5
POPM R1-R2
RTE ; return to point of interrupt, this restores PC and PSW
__tx_thread_synch_return:
POPC PSW
POPM R6-R13 ; Recover solicited stack frame
RTS
;
;}
.global __tx_thread_context_save
.global __tx_thread_context_restore
; Software triggered interrupt used to perform context switches.
; The priority of this interrupt is set to the lowest priority within
; tx_initialize_low_level() and triggered by ThreadX when calling
; _tx_thread_system_return().
.global $tableentry$27$.rvectors
$tableentry$27$.rvectors:
PUSHM R1-R2
BSR __tx_thread_context_save
BRA __tx_thread_context_restore
.end
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