83 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			83 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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|  * 2011-08-14     weety    copy from mini2440
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|  * 2015-04-15     ArdaFu     convert from context_gcc.s
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|  */
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| 
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| #define NOINT            0xc0
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| 
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|     SECTION    .text:CODE(6)
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| /*
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|  * rt_base_t rt_hw_interrupt_disable();
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|  */
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|     PUBLIC rt_hw_interrupt_disable
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| rt_hw_interrupt_disable:
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|     MRS     R0, CPSR
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|     ORR     R1, R0, #NOINT
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|     MSR     CPSR_C, R1
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|     MOV     PC, LR
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| 
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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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|     PUBLIC rt_hw_interrupt_enable
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| rt_hw_interrupt_enable:
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|     MSR     CPSR_CXSF, R0
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|     MOV     PC, LR
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| 
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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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|     PUBLIC 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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|     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 spsr
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|     MSR     SPSR_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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| /*
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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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|     PUBLIC 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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|     LDMFD   SP!, {R0-R12, LR, PC}^   ; pop new task r0-r12, lr & pc
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| 
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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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|     IMPORT rt_thread_switch_interrupt_flag
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|     IMPORT rt_interrupt_from_thread
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|     IMPORT rt_interrupt_to_thread
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|     PUBLIC 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 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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|     MOV     PC, LR
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|     END
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|     
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