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/*
* Copyright (c) 2006-2020, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2019-12-04 Jiaxun Yang Initial version
* 2020-07-26 lizhirui Fixed some problems
*/
#ifndef __ASSEMBLY__
#define __ASSEMBLY__
#endif
#include "mips_regs.h"
#include "stackframe.h"
.section ".text", "ax"
.set noreorder
/*
* void rt_hw_context_switch(rt_uint32 from, rt_uint32 to)
* a0 --> from
* a1 --> to
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
MTC0 ra, CP0_EPC
SAVE_ALL
REG_S sp, 0(a0) /* store sp in preempted tasks TCB */
REG_L sp, 0(a1) /* get new task stack pointer */
RESTORE_ALL_AND_RET
/*
* void rt_hw_context_switch_to(rt_uint32 to)/*
* a0 --> to
*/
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
REG_L sp, 0(a0) /* get new task stack pointer */
RESTORE_ALL_AND_RET
/*
* void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to)/*
*/
.globl rt_thread_switch_interrupt_flag
.globl rt_interrupt_from_thread
.globl rt_interrupt_to_thread
.globl rt_hw_context_switch_interrupt
rt_hw_context_switch_interrupt:
PTR_LA t0, rt_thread_switch_interrupt_flag
REG_L t1, 0(t0)
nop
bnez t1, _reswitch
nop
li t1, 0x01 /* set rt_thread_switch_interrupt_flag to 1 */
LONG_S t1, 0(t0)
PTR_LA t0, rt_interrupt_from_thread /* set rt_interrupt_from_thread */
LONG_S a0, 0(t0)
_reswitch:
PTR_LA t0, rt_interrupt_to_thread /* set rt_interrupt_to_thread */
LONG_S a1, 0(t0)
jr ra
nop
/*
* void rt_hw_context_switch_interrupt_do(rt_base_t flag)
*/
.globl rt_interrupt_enter
.globl rt_interrupt_leave
.globl rt_general_exc_dispatch
.globl mips_irq_handle
mips_irq_handle:
SAVE_ALL
/* let k0 keep the current context sp */
move k0, sp
/* switch to kernel stack */
PTR_LA sp, _system_stack
jal rt_interrupt_enter
nop
/* Get Old SP from k0 as paremeter in a0 */
move a0, k0
jal rt_general_exc_dispatch
nop
jal rt_interrupt_leave
nop
/* switch sp back to thread context */
move sp, k0
/*
* if rt_thread_switch_interrupt_flag set, jump to
* rt_hw_context_switch_interrupt_do and do not return
*/
PTR_LA k0, rt_thread_switch_interrupt_flag
LONG_L k1, 0(k0)
beqz k1, spurious_interrupt
nop
LONG_S zero, 0(k0) /* clear flag */
nop
/*
* switch to the new thread
*/
PTR_LA k0, rt_interrupt_from_thread
LONG_L k1, 0(k0)
nop
LONG_S sp, 0(k1) /* store sp in preempted task TCB */
PTR_LA k0, rt_interrupt_to_thread
LONG_L k1, 0(k0)
nop
LONG_L sp, 0(k1) /* get new task stack pointer */
j spurious_interrupt
nop
spurious_interrupt:
RESTORE_ALL_AND_RET
.set reorder
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