279 lines
		
	
	
		
			7.6 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			279 lines
		
	
	
		
			7.6 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      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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| 
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| #include "rt_low_level_init.h"
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| 
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| #define S_FRAME_SIZE    (18*4)   ;72
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| 
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| ;#define S_SPSR          (17*4)   ;SPSR
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| ;#define S_CPSR          (16*4)   ;CPSR
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| #define S_PC            (15*4)   ;R15
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| ;#define S_LR            (14*4)   ;R14
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| ;#define S_SP            (13*4)   ;R13
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| 
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| ;#define S_IP            (12*4)   ;R12
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| ;#define S_FP            (11*4)   ;R11
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| ;#define S_R10           (10*4)
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| ;#define S_R9            (9*4)
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| ;#define S_R8            (8*4)
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| ;#define S_R7            (7*4)
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| ;#define S_R6            (6*4)
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| ;#define S_R5            (5*4)
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| ;#define S_R4            (4*4)
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| ;#define S_R3            (3*4)
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| ;#define S_R2            (2*4)
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| ;#define S_R1            (1*4)
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| ;#define S_R0            (0*4)
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| 
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| #define MODE_SYS        0x1F
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| #define MODE_FIQ        0x11
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| #define MODE_IRQ        0x12
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| #define MODE_SVC        0x13
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| #define MODE_ABT        0x17
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| #define MODE_UND        0x1B
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| #define MODEMASK        0x1F
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| 
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| #define NOINT           0xC0
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| 
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| ;----------------------- Stack and Heap Definitions ----------------------------
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|     MODULE ?cstartup
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|     SECTION .noinit:DATA:NOROOT(3)
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|     DATA
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| 
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|     ALIGNRAM 3
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|     DS8 UND_STK_SIZE
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|     PUBLIC UND_STACK_START
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| UND_STACK_START:
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| 
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|     ALIGNRAM 3
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|     DS8 ABT_STK_SIZE
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|     PUBLIC ABT_STACK_START
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| ABT_STACK_START:
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| 
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|     ALIGNRAM 3
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|     DS8 FIQ_STK_SIZE
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|     PUBLIC FIQ_STACK_START
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| FIQ_STACK_START:
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| 
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|     ALIGNRAM 3
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|     DS8 IRQ_STK_SIZE
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|     PUBLIC IRQ_STACK_START
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| IRQ_STACK_START:
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| 
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|     ALIGNRAM 3
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|     DS8 SYS_STK_SIZE
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|     PUBLIC SYS_STACK_START
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| SYS_STACK_START:
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| 
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|     ALIGNRAM 3
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|     DS8 SVC_STK_SIZE
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|     PUBLIC SVC_STACK_START
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| SVC_STACK_START:
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| 
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| ;--------------Jump vector table------------------------------------------------
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|     SECTION .intvec:CODE:ROOT(2)
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|     ARM
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|     PUBLIC Entry_Point
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| Entry_Point:
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| __iar_init$$done:               ; The interrupt vector is not needed
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|                                 ; until after copy initialization is done
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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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| 
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| vector_reset:
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|     DC32 Reset_Handler
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| vector_undef:
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|     DC32 Undef_Handler
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| vector_swi:
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|     DC32 SWI_Handler
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| vector_pabt:
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|     DC32 PAbt_Handler
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| vector_dabt:
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|     DC32 DAbt_Handler
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| vector_resv:
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|     DC32 Resv_Handler
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| vector_irq:
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|     DC32 IRQ_Handler
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| vector_fiq:
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|     DC32 FIQ_Handler
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| 
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| ;----------------- Reset Handler -----------------------------------------------
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|     EXTERN rt_low_level_init
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|     EXTERN ?main
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|     PUBLIC __iar_program_start
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| __iar_program_start:
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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|NOINT
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|     MSR     CPSR_cxsf, R0
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|     
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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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| 
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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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| 
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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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| 
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|     ORR     R1, R0, #MODE_UND|NOINT
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|     MSR     CPSR_cxsf, R1            ; Undef mode
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|     LDR     SP, =UND_STACK_START
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| 
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|     ORR     R1,R0,#MODE_ABT|NOINT
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|     MSR     CPSR_cxsf,R1             ; Abort mode
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|     LDR     SP, =ABT_STACK_START
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| 
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|     ORR     R1,R0,#MODE_IRQ|NOINT
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|     MSR     CPSR_cxsf,R1             ; IRQ mode
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|     LDR     SP, =IRQ_STACK_START
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| 
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|     ORR     R1,R0,#MODE_FIQ|NOINT
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|     MSR     CPSR_cxsf,R1             ; FIQ mode
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|     LDR     SP, =FIQ_STACK_START
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| 
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|     ORR     R1,R0,#MODE_SYS|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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| 
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|     ORR     R1,R0,#MODE_SVC|NOINT
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|     MSR     CPSR_cxsf,R1             ; SVC mode
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|     LDR     SP, =SVC_STACK_START
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|     
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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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| 
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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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| 
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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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| 
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|     SECTION .text:CODE:ROOT(2)
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|     ARM
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| Undef_Handler:
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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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| 
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| SWI_Handler:
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|     BL      rt_hw_trap_swi
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| 
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| PAbt_Handler:
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|     BL      rt_hw_trap_pabt
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| 
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| DAbt_Handler:
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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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| 
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| Resv_Handler:
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|     BL      rt_hw_trap_resv
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| 
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| IRQ_Handler:
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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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| 
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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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| 
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|     LDMFD   SP!, {R0-R12,LR}
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|     SUBS    PC, LR, #4
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| 
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| FIQ_Handler:
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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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| 
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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:
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|     MOV     R1,  #0                 ; Clear flag
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|     STR     R1,  [R0]               ; Save to flag variable
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| 
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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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| 
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|     MRS     R0,  SPSR               ; Get CPSR of interrupt thread
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| 
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|     MSR     CPSR_c, #MODE_SVC|NOINT ; Switch to SVC mode and no interrupt
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| 
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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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| 
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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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| 
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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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| 
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|     LDMFD   SP!, {R4}               ; Pop new task's SPSR
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|     MSR     SPSR_cxsf, R4
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| 
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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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|     END
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