302 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			302 lines
		
	
	
		
			8.2 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      first version
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; * 2015-04-15     ArdaFu     Split from AT91SAM9260 BSP
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; * 2015-04-21     ArdaFu     Remove remap code. Using mmu to map vector table
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; * 2015-06-04     aozima     Align stack address to 8 byte.
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; */
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UND_STK_SIZE EQU 512
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SVC_STK_SIZE EQU 4096
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ABT_STK_SIZE EQU 512
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IRQ_STK_SIZE EQU 1024
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FIQ_STK_SIZE EQU 1024
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SYS_STK_SIZE EQU 512
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Heap_Size    EQU 512
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S_FRAME_SIZE    EQU     (18*4)   ;72
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S_PC            EQU     (15*4)   ;R15
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MODE_USR        EQU     0X10
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MODE_FIQ        EQU     0X11
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MODE_IRQ        EQU     0X12
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MODE_SVC        EQU     0X13
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MODE_ABT        EQU     0X17
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MODE_UND        EQU     0X1B
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MODE_SYS        EQU     0X1F
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MODEMASK        EQU     0X1F
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NOINT           EQU     0xC0
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;----------------------- Stack and Heap Definitions ----------------------------
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    AREA    STACK, NOINIT, READWRITE, ALIGN=3
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Stack_Mem
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    SPACE   UND_STK_SIZE
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    EXPORT UND_STACK_START
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UND_STACK_START
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    ALIGN 8
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    SPACE   ABT_STK_SIZE
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    EXPORT ABT_STACK_START
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ABT_STACK_START
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    ALIGN 8
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    SPACE   FIQ_STK_SIZE
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    EXPORT FIQ_STACK_START
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FIQ_STACK_START
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    ALIGN 8
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    SPACE   IRQ_STK_SIZE
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    EXPORT IRQ_STACK_START
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IRQ_STACK_START
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    ALIGN 8
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    SPACE   SYS_STK_SIZE
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    EXPORT SYS_STACK_START
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SYS_STACK_START
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    ALIGN 8
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    SPACE   SVC_STK_SIZE
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    EXPORT SVC_STACK_START
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SVC_STACK_START
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Stack_Top
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__initial_sp
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__heap_base
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Heap_Mem        SPACE   Heap_Size
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__heap_limit
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    PRESERVE8
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;--------------Jump vector table------------------------------------------------
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    EXPORT Entry_Point
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    AREA    RESET, CODE, READONLY
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    ARM
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Entry_Point
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    LDR     PC, vector_reset
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    LDR     PC, vector_undef
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    LDR     PC, vector_swi
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    LDR     PC, vector_pabt
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    LDR     PC, vector_dabt
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    LDR     PC, vector_resv
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    LDR     PC, vector_irq
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    LDR     PC, vector_fiq
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vector_reset
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    DCD     Reset_Handler
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vector_undef
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    DCD     Undef_Handler
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vector_swi
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    DCD     SWI_Handler
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vector_pabt
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    DCD     PAbt_Handler
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vector_dabt
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    DCD     DAbt_Handler
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vector_resv
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    DCD     Resv_Handler
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vector_irq
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    DCD     IRQ_Handler
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vector_fiq
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    DCD     FIQ_Handler
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;----------------- Reset Handler -----------------------------------------------
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    IMPORT rt_low_level_init
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    IMPORT  __main
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    EXPORT  Reset_Handler
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Reset_Handler
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    ; set the cpu to SVC32 mode
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    MRS     R0,CPSR
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    BIC     R0,R0,#MODEMASK
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    ORR     R0,R0,#MODE_SVC:OR:NOINT
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    MSR     CPSR_cxsf,R0
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    ; Set CO-Processor
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    ; little-end,disbale I/D Cache MMU, vector table is 0x00000000
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    MRC     p15, 0, R0, c1, c0, 0   ; Read CP15
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    LDR     R1, =0x00003085         ; set clear bits
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    BIC     R0, R0, R1
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    MCR     p15, 0, R0, c1, c0, 0   ; Write CP15
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    ; Call low level init function,
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    ; disable and clear all IRQs, Init MMU, Init interrupt controller, etc.
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    LDR     SP, =SVC_STACK_START
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    LDR     R0, =rt_low_level_init
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    BLX     R0
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Setup_Stack
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    ; Setup Stack for each mode
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    MRS     R0, CPSR
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    BIC     R0, R0, #MODEMASK
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    ORR     R1, R0, #MODE_UND:OR:NOINT
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    MSR     CPSR_cxsf, R1            ; Undef mode
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    LDR     SP, =UND_STACK_START
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    ORR     R1,R0,#MODE_ABT:OR:NOINT
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    MSR     CPSR_cxsf,R1             ; Abort mode
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    LDR     SP, =ABT_STACK_START
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    ORR     R1,R0,#MODE_IRQ:OR:NOINT
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    MSR     CPSR_cxsf,R1             ; IRQ mode
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    LDR     SP, =IRQ_STACK_START
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    ORR     R1,R0,#MODE_FIQ:OR:NOINT
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    MSR     CPSR_cxsf,R1             ; FIQ mode
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    LDR     SP, =FIQ_STACK_START
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    ORR     R1,R0,#MODE_SYS:OR:NOINT
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    MSR     CPSR_cxsf,R1             ; SYS/User mode
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    LDR     SP, =SYS_STACK_START
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    ORR     R1,R0,#MODE_SVC:OR:NOINT
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    MSR     CPSR_cxsf,R1             ; SVC mode
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    LDR     SP, =SVC_STACK_START
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    ; Enter the C code
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    LDR     R0, =__main
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    BLX     R0
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;----------------- Exception Handler -------------------------------------------
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    IMPORT rt_hw_trap_udef
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    IMPORT rt_hw_trap_swi
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    IMPORT rt_hw_trap_pabt
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    IMPORT rt_hw_trap_dabt
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    IMPORT rt_hw_trap_resv
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    IMPORT rt_hw_trap_irq
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    IMPORT rt_hw_trap_fiq
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    IMPORT rt_interrupt_enter
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    IMPORT rt_interrupt_leave
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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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Undef_Handler PROC
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    SUB     SP, SP, #S_FRAME_SIZE
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    STMIA   SP, {R0 - R12}          ; Calling R0-R12
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    ADD     R8, SP, #S_PC
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    STMDB   R8, {SP, LR}            ; Calling SP, LR
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    STR     LR, [R8, #0]            ; Save calling PC
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    MRS     R6, SPSR
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    STR     R6, [R8, #4]            ; Save CPSR
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    STR     R0, [R8, #8]            ; Save SPSR
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    MOV     R0, SP
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    BL      rt_hw_trap_udef
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    ENDP
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SWI_Handler PROC
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    BL      rt_hw_trap_swi
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    ENDP
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PAbt_Handler PROC
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    BL      rt_hw_trap_pabt
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    ENDP
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DAbt_Handler PROC
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    SUB     SP, SP, #S_FRAME_SIZE
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    STMIA   SP, {R0 - R12}          ; Calling R0-R12
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    ADD     R8, SP, #S_PC
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    STMDB   R8, {SP, LR}            ; Calling SP, LR
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    STR     LR, [R8, #0]            ; Save calling PC
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    MRS     R6, SPSR
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    STR     R6, [R8, #4]            ; Save CPSR
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    STR     R0, [R8, #8]            ; Save SPSR
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    MOV     R0, SP
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    BL      rt_hw_trap_dabt
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    ENDP
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Resv_Handler PROC
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    BL      rt_hw_trap_resv
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    ENDP
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FIQ_Handler PROC
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    STMFD   SP!, {R0-R7,LR}
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    BL      rt_hw_trap_fiq
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    LDMFD   SP!, {R0-R7,LR}
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    SUBS    PC, LR, #4
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    ENDP
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IRQ_Handler PROC
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    STMFD   SP!, {R0-R12,LR}
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    BL      rt_interrupt_enter
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    BL      rt_hw_trap_irq
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    BL      rt_interrupt_leave
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    ; If rt_thread_switch_interrupt_flag set,
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    ; jump to rt_hw_context_switch_interrupt_do and don't return
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    LDR     R0, =rt_thread_switch_interrupt_flag
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    LDR     R1, [R0]
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    CMP     R1, #1
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    BEQ     rt_hw_context_switch_interrupt_do
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    LDMFD   SP!, {R0-R12,LR}
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    SUBS    PC, LR, #4
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    ENDP
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;------ void rt_hw_context_switch_interrupt_do(rt_base_t flag) -----------------
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rt_hw_context_switch_interrupt_do PROC
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    MOV     R1,  #0                 ; Clear flag
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    STR     R1,  [R0]               ; Save to flag variable
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    LDMFD   SP!, {R0-R12,LR}        ; Reload saved registers
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    STMFD   SP, {R0-R2}             ; Save R0-R2
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    SUB     R1,  SP, #4*3           ; Save old task's SP to R1
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    SUB     R2,  LR, #4             ; Save old task's PC to R2
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    MRS     R0,  SPSR               ; Get CPSR of interrupt thread
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    MSR     CPSR_c, #MODE_SVC:OR:NOINT  ; Switch to SVC mode and no interrupt
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    STMFD   SP!, {R2}               ; Push old task's PC
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    STMFD   SP!, {R3-R12,LR}        ; Push old task's LR,R12-R3
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    LDMFD   R1, {R1-R3}
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    STMFD   SP!, {R1-R3}            ; Push old task's R2-R0
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    STMFD   SP!, {R0}               ; Push old task's CPSR
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    LDR     R4,  =rt_interrupt_from_thread
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    LDR     R5,  [R4]               ; R5 = stack ptr in old tasks's TCB
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    STR     SP,  [R5]               ; Store SP in preempted tasks's TCB
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    LDR     R6,  =rt_interrupt_to_thread
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    LDR     R6,  [R6]               ; R6 = stack ptr in new tasks's TCB
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    LDR     SP,  [R6]               ; Get new task's stack pointer
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    LDMFD   SP!, {R4}               ; Pop new task's SPSR
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    MSR     SPSR_cxsf, R4
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    LDMFD   SP!, {R0-R12,LR,PC}^    ; pop new task's R0-R12,LR & PC SPSR to CPSR
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    ENDP
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;*******************************************************************************
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; User Stack and Heap initialization
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;*******************************************************************************
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                 IF      :DEF:__MICROLIB
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                 EXPORT  __initial_sp
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                 EXPORT  __heap_base
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                 EXPORT  __heap_limit
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                 ELSE
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                 IMPORT  __use_two_region_memory
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                 EXPORT  __user_initial_stackheap
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__user_initial_stackheap
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                 LDR     R0, = Heap_Mem                         ; heap base
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                 LDR     R1, = SVC_STACK_START                  ; stack base (top-address)
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                 LDR     R2, = (Heap_Mem +  Heap_Size)          ; heap limit
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                 LDR     R3, = (SVC_STACK_START - SVC_STK_SIZE) ; stack limit (low-address)
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                 BX      LR
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                 ALIGN
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                 ENDIF
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    END
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