97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * Copyright (c) 2006-2018, RT-Thread Development Team
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 *
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 * SPDX-License-Identifier: Apache-2.0
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 *
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 * Change Logs:
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 * Date           Author       Notes
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 * 2011-01-13     weety    copy from mini2440
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 */
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/*!
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 * \addtogroup ARMv6
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 */
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/*@{*/
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#include <rtconfig.h>
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#define NOINT          0xc0
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#define FPEXC_EN       (1 << 30) /* VFP enable bit */
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/*
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 * rt_base_t rt_hw_interrupt_disable();
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 */
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.globl rt_hw_interrupt_disable
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rt_hw_interrupt_disable:
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    mrs r0, cpsr
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    cpsid if
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    bx  lr
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/*
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 * void rt_hw_interrupt_enable(rt_base_t level);
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 */
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.globl rt_hw_interrupt_enable
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rt_hw_interrupt_enable:
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    msr cpsr_c, r0
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    bx  lr
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/*
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 * void rt_hw_context_switch(rt_uint32 from, rt_uint32 to);
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 * r0 --> from
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 * r1 --> to
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 */
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.globl rt_hw_context_switch
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rt_hw_context_switch:
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    stmfd   sp!, {lr}       @ push pc (lr should be pushed in place of PC)
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    stmfd   sp!, {r0-r12, lr}   @ push lr & register file
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    mrs r4, cpsr
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    tst lr, #0x01
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    orrne r4, r4, #0x20     @ it's thumb code
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    stmfd sp!, {r4}         @ push cpsr
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    str sp, [r0]            @ store sp in preempted tasks TCB
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    ldr sp, [r1]            @ get new task stack pointer
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    ldmfd sp!, {r4}         @ pop new task cpsr to spsr
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    msr spsr_cxsf, r4
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_do_switch:
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    ldmfd sp!, {r0-r12, lr, pc}^  @ pop new task r0-r12, lr & pc, copy spsr to cpsr
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/*
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 * void rt_hw_context_switch_to(rt_uint32 to);
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 * r0 --> to
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 */
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.globl rt_hw_context_switch_to
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rt_hw_context_switch_to:
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    ldr sp, [r0]            @ get new task stack pointer
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    ldmfd sp!, {r4}         @ pop new task spsr
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    msr spsr_cxsf, r4
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    bic r4, r4, #0x20       @ must be ARM mode
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    msr cpsr_cxsf, r4
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    ldmfd sp!, {r0-r12, lr, pc}^   @ pop new task r0-r12, lr & pc
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/*
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 * void rt_hw_context_switch_interrupt(rt_uint32 from, rt_uint32 to);
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 */
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.globl rt_thread_switch_interrupt_flag
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.globl rt_interrupt_from_thread
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.globl rt_interrupt_to_thread
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.globl rt_hw_context_switch_interrupt
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rt_hw_context_switch_interrupt:
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    ldr r2, =rt_thread_switch_interrupt_flag
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    ldr r3, [r2]
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    cmp r3, #1
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    beq _reswitch
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    mov r3, #1              @ set rt_thread_switch_interrupt_flag to 1
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    str r3, [r2]
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    ldr r2, =rt_interrupt_from_thread   @ set rt_interrupt_from_thread
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    str r0, [r2]
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_reswitch:
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    ldr r2, =rt_interrupt_to_thread     @ set rt_interrupt_to_thread
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    str r1, [r2]
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    bx  lr
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