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/*
* File : context.S
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rt-thread.org/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2006-03-13 Bernard first version
*/
#define NOINT 0xc0
/*
* rt_base_t rt_hw_interrupt_disable()/*
*/
.globl rt_hw_interrupt_disable
rt_hw_interrupt_disable:
mrs r0, cpsr
orr r1, r0, #NOINT
msr cpsr_c, r1
mov pc, lr
/*
* void rt_hw_interrupt_enable(rt_base_t level)/*
*/
.globl rt_hw_interrupt_enable
rt_hw_interrupt_enable:
msr cpsr, r0
mov pc, lr
/*
* void rt_hw_context_switch(rt_uint32 from, rt_uint32 to)/*
* r0 --> from
* r1 --> to
*/
.globl rt_hw_context_switch
rt_hw_context_switch:
stmfd sp!, {lr} /* push pc (lr should be pushed in place of PC) */
stmfd sp!, {r0-r12, lr} /* push lr & register file */
mrs r4, cpsr
stmfd sp!, {r4} /* push cpsr */
mrs r4, spsr
stmfd sp!, {r4} /* push spsr */
str sp, [r0] /* store sp in preempted tasks TCB */
ldr sp, [r1] /* get new task stack pointer */
ldmfd sp!, {r4} /* pop new task spsr */
msr spsr_cxsf, r4
ldmfd sp!, {r4} /* pop new task cpsr */
msr cpsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc} /* pop new task r0-r12, lr & pc */
/*
* void rt_hw_context_switch_to(rt_uint32 to)/*
* r0 --> to
*/
.globl rt_hw_context_switch_to
rt_hw_context_switch_to:
ldr sp, [r0] /* get new task stack pointer */
ldmfd sp!, {r4} /* pop new task spsr */
msr spsr_cxsf, r4
ldmfd sp!, {r4} /* pop new task cpsr */
msr cpsr_cxsf, r4
ldmfd sp!, {r0-r12, lr, pc} /* pop new task r0-r12, lr & pc */
/*
* 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:
ldr r2, =rt_thread_switch_interrupt_flag
ldr r3, [r2]
cmp r3, #1
beq _reswitch
mov r3, #1 /* set rt_thread_switch_interrupt_flag to 1 */
str r3, [r2]
ldr r2, =rt_interrupt_from_thread /* set rt_interrupt_from_thread */
str r0, [r2]
_reswitch:
ldr r2, =rt_interrupt_to_thread /* set rt_interrupt_to_thread */
str r1, [r2]
mov pc, lr
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