?? tx_ts.68
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/**************************************************************************/
/* */
/* Copyright (c) 1996-2000 by Express Logic Inc. */
/* */
/* This software is copyrighted by and is the sole property of Express */
/* Logic, Inc. All rights, title, ownership, or other interests */
/* in the software remain the property of Express Logic, Inc. This */
/* software may only be used in accordance with the corresponding */
/* license agreement. Any unauthorized use, duplication, transmission, */
/* distribution, or disclosure of this software is expressly forbidden. */
/* */
/* This Copyright notice may not be removed or modified without prior */
/* written consent of Express Logic, Inc. */
/* */
/* Express Logic, Inc. reserves the right to modify this software */
/* without notice. */
/* */
/* Express Logic, Inc. */
/* 11440 West Bernardo Court info@expresslogic.com */
/* Suite 366 http://www.expresslogic.com */
/* San Diego, CA 92127 */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Thread Control (THR) */
/** */
/**************************************************************************/
/**************************************************************************/
/* #define TX_SOURCE_CODE */
/* Include necessary system files. */
/* #include "tx_api.h"
#include "tx_thr.h"
#include "tx_tim.h" */
XREF _tx_thread_execute_ptr
XREF _tx_thread_current_ptr
XREF _tx_timer_time_slice
#ifdef TX_ENABLE_EVENT_LOGGING
XREF _tx_el_thread_running
#endif
SECT .text,x
ALIGN 4
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_thread_schedule 68332/Green Hills */
/* 3.0a */
/* AUTHOR */
/* */
/* William E. Lamie, Express Logic, Inc. */
/* */
/* 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 */
/* */
/* 09-07-1999 William E. Lamie Initial Version 3.0 */
/* 12-02-1999 William E. Lamie Modified comment(s), */
/* added optional thread */
/* ready event logging, and */
/* added logic for long word */
/* solicited stack alignment, */
/* resulting in version 3.0a. */
/* */
/**************************************************************************/
/* VOID _tx_thread_schedule(VOID)
{ */
XDEF _tx_thread_schedule
_tx_thread_schedule:
/* Enable interrupts. */
move.w #$2000,%SR
/* Wait for a thread to execute. */
/* do
{ */
__tx_thread_schedule_loop:
tst.l _tx_thread_execute_ptr
beq.s __tx_thread_schedule_loop
/* }
while(_tx_thread_execute_ptr == TX_NULL); */
/* Yes! We have a thread to execute. Lockout interrupts and
transfer control to it. */
movea.l _tx_thread_execute_ptr,%A0
ori.w #$2700,%SR ; Lockout interrupts
/* Setup the current thread pointer. */
/* _tx_thread_current_ptr = _tx_thread_execute_ptr; */
move.l %A0,_tx_thread_current_ptr ; Setup current thread pointer
/* Increment the run count for this thread. */
/* _tx_thread_current_ptr -> tx_run_count++; */
addq.l #1,4(%A0) ; Increment run counter
/* Setup time-slice, if present. */
/* _tx_timer_time_slice = _tx_thread_current_ptr -> tx_time_slice; */
move.l 24(%A0),%D1 ; Pickup the time-slice value
move.l %D1,_tx_timer_time_slice ; Set up time slice
/* Switch to the thread's stack. */
/* SP = _tx_thread_execute_ptr -> tx_stack_ptr; */
movea.l 8(%A0),%A7 ; Pickup stack pointer
/* Determine if an interrupt frame or a synchronous task suspension frame
is present. */
move.w (%A7)+,%D0 ; Pickup stack type
beq __tx_thread_synch_return ; If 0, a synchronous return frame is present
movem.l (%A7)+,%D0-%D7/%A0-%A6 ; Otherwise, recover all registers because this
/* ; is an interrupt stack frame! */
add.l #6,%A7 ; Skip past reserved space for ISR processing
rte ; Return to point of interrupt in thread
__tx_thread_synch_return:
movem.l (%A7)+,%D2-%D7/%A2-%A6 ; Recover minimal register set
move.w (%A7)+,%SR ; Recover thread's status register
adda #2,%A7 ; Recover alignment word
rts ; Return to thread where it last returned to the
/* ; kernel */
/* } */
END
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