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|
;/***************************************************************************
; * Copyright (c) 2024 Microsoft Corporation
; *
; * This program and the accompanying materials are made available under the
; * terms of the MIT License which is available at
; * https://opensource.org/licenses/MIT.
; *
; * SPDX-License-Identifier: MIT
; **************************************************************************/
;
;
;/**************************************************************************/
;/**************************************************************************/
;/** */
;/** ThreadX Component */
;/** */
;/** Thread */
;/** */
;/**************************************************************************/
;/**************************************************************************/
SWI0 EQU 0x872E0
extern __tx_timer_expiration_process
extern __tx_timer_system_clock
extern __tx_timer_expired_time_slice
extern __tx_timer_current_ptr
extern __tx_timer_expired
extern __tx_timer_list_start
extern __tx_timer_time_slice
extern __tx_timer_list_end
extern __tx_thread_time_slice
extern __tx_thread_preempt_disable
extern __tx_thread_execute_ptr
extern __tx_thread_current_ptr
section .text:CODE:ROOT
;/**************************************************************************/
;/* */
;/* FUNCTION RELEASE */
;/* */
;/* _tx_timer_interrupt RXv3/IAR */
;/* 6.1.11 */
;/* AUTHOR */
;/* */
;/* William E. Lamie, Microsoft Corporation */
;/* */
;/* DESCRIPTION */
;/* */
;/* This function processes the hardware timer interrupt. This */
;/* processing includes incrementing the system clock and checking for */
;/* time slice and/or timer expiration. If either is found, the */
;/* interrupt context save/restore functions are called along with the */
;/* expiration functions. */
;/* */
;/* INPUT */
;/* */
;/* None */
;/* */
;/* OUTPUT */
;/* */
;/* None */
;/* */
;/* CALLS */
;/* */
;/* _tx_thread_context_save Save interrupted context */
;/* _tx_timer_expiration_process Timer expiration processing */
;/* _tx_thread_time_slice Time slice interrupted thread */
;/* _tx_thread_context_restore Restore interrupted context */
;/* */
;/* CALLED BY */
;/* */
;/* interrupt vector */
;/* */
;/**************************************************************************/
public __tx_timer_interrupt
__tx_timer_interrupt:
;
; /* Upon entry to this routine, it is assumed that all interrupts are locked
; out and the stack looks like the following:
; SP+4 -> Interrupted PC
; SP+8-> Interrupted SR
; */
;
; /* Increment the system clock. */
; _tx_timer_system_clock++;
;
PUSHM R14-R15
PUSHM R1-R5
MOV.L #__tx_timer_system_clock, R1 ; Pickup address of system clock
MOV.L [R1], R2 ; Pickup system clock
ADD #1, R2 ; Increment system clock
MOV.L R2,[R1] ; Store new system clock
;
; /* Test for time-slice expiration. */
; if (_tx_timer_time_slice)
; {
;
MOV.L #__tx_timer_time_slice, R1 ; Pickup address of time slice
MOV.L [R1], R2 ; Pickup the current time slice
CMP #0, R2 ; Is a time slice active?
BEQ __tx_timer_no_time_slice ; No, skip timer slice processing
;
; /* Decrement the time_slice. */
; _tx_timer_time_slice--;
;
SUB #1, R2 ; Decrement the time-slice
MOV.L R2, [R1] ; Store time-slice
;
; /* Check for expiration. */
; if (__tx_timer_time_slice == 0)
;
CMP #0, R2 ; Has it expired?
BNE __tx_timer_no_time_slice ; No, time-slice has not expired
;
; /* Set the time-slice expired flag. */
; _tx_timer_expired_time_slice = TX_TRUE;
;
MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup address of expired time-slice
MOV.L #1, R2 ; Build expired value
MOV.L R2, [R1] ; Set expired time slice variable
; }
;
__tx_timer_no_time_slice:
;
; /* Test for timer expiration. */
; if (*_tx_timer_current_ptr)
; {
;
MOV.L #__tx_timer_current_ptr, R1 ; Pickup address of current timer ptr
MOV.L [R1], R2 ; Pickup current pointer
MOV.L [R2+], R1 ; pickup timer list entry, _tx_timer_current_ptr++
CMP #0, R1 ; Is timer pointer NULL?
BEQ __tx_timer_no_timer ; Yes, no timer has expired
;
; /* Set expiration flag. */
; _tx_timer_expired = TX_TRUE;
;
MOV.L #__tx_timer_expired,R2 ; Build address of expired flag
MOV.L #1, R1 ; Build expired value
MOV.L R1, [R2]
BRA __tx_timer_done ; Finished with timer processing
;
; }
; else
; {
__tx_timer_no_timer:
;
; /* No timer expired, increment the timer pointer. */
; _tx_timer_current_ptr++;
;
; /* R2 already contains __tx_timer_current_ptr++ */
;
; /* Check for wrap-around. */
; if (_tx_timer_current_ptr == _tx_timer_list_end)
;
MOV.L #__tx_timer_list_end, R1 ; Pickup the timer list end ptr
MOV.L [R1], R1 ; Pickup actual timer list end
CMP R1, R2 ; Are we at list end?
BNE __tx_timer_skip_wrap ; No, don't move pointer to the
; top of the list
;
; /* Wrap to beginning of list. */
; _tx_timer_current_ptr = _tx_timer_list_start;
;
MOV.L #__tx_timer_list_start, R2 ; Pickup the timer list start ptr
MOV.L [R2], R2 ; Pickup the start of the list
; }
;
__tx_timer_skip_wrap:
MOV.L #__tx_timer_current_ptr,R1
MOV.L R2, [R1] ; Store in updated pointer in _tx_timer_current_ptr
__tx_timer_done:
;
; /* See if anything has expired. */
; if ((_tx_timer_expired_time_slice) || (_tx_timer_expired))
; {
;
MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup expired time slice addr
MOV.L [R1], R1 ; Pickup expired time slice
MOV.L #__tx_timer_expired, R2 ; Pickup expired timer flag address
MOV.L [R2], R2 ; Pickup actual flag
OR R1, R2 ; Or flags together
BEQ __tx_timer_nothing_expired ; If Z set, nothing has expired
__tx_something_expired:
; /* Did a timer expire? */
; if (_tx_timer_expired)
; {
MOV.L #__tx_timer_expired,R1 ; Pickup expired flag address
MOV.L [R1], R1 ; Pickup expired flag
CMP #0,R1 ; Is the expired timer flag set?
BEQ __tx_timer_dont_activate ; No, skip timer activation
;
; /* Process timer expiration. */
; _tx_timer_expiration_process();
;
BSR __tx_timer_expiration_process ; Call the timer expiration handling routine
;
; }
__tx_timer_dont_activate:
;
; /* Did time slice expire? */
; if (_tx_timer_expired_time_slice)
; {
;
MOV.L #__tx_timer_expired_time_slice, R1 ; Pickup time-slice expired flag addr
MOV.L [R1], R1 ; Pickup actual flag
CMP #0,R1 ; Has time-slice expired?
BEQ __tx_timer_not_ts_expiration ; No, skip time-slice expiration
;
; /* Time slice interrupted thread. */
; _tx_thread_time_slice();
BSR __tx_thread_time_slice ; Call time-slice processing
; /* Check if we must trigger a context switch. */
MOV.L #__tx_thread_preempt_disable, R1 ; Load prempt disable flag.
MOV.L [R1], R1
CMP #0, R1
BNE __tx_timer_not_ts_expiration ; Skip if prempt disabled.
MOV.L #__tx_thread_execute_ptr, R1
MOV.L [R1], R1
MOV.L #__tx_thread_current_ptr, R2
MOV.L [R2], R2
CMP R1, R2
BEQ __tx_timer_not_ts_expiration
MOV.L #SWI0, R1
MOV.L #1, [R1]
; }
;
__tx_timer_not_ts_expiration:
__tx_timer_nothing_expired:
POPM R1-R5
POPM R14-R15
;
RTS ; Return to point of interrupt
;
;}
END
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