vector1.s

ARM 4510 bootloader,完整的工程实例

	AREA	SelfBoot, CODE, READONLY
	
ModeMask 		EQU	0x1F
SVC32Mode		EQU	0x13
IRQ32Mode		EQU	0x12
FIQ32Mode		EQU	0x11
User32Mode		EQU	0x10
Abort32Mode		EQU	0x17
Undef32Mode		EQU	0x1B
IRQ_BIT			EQU	0x80
FIQ_BIT			EQU	0x40	
	
	ENTRY

	IMPORT	main
	
ResetEntry	
	mrs	r0, cpsr				;enter svc mode and disable irq,fiq
	bic	r0, r0, #ModeMask
	orr	r0, r0, #(SVC32Mode :OR: IRQ_BIT :OR: FIQ_BIT)
	msr	cpsr_c, r0	
	
	mov	r0, #0
	ldr	r2, BaseOfZero
	ldr	r3,	EndOfBSS		
0	
	str	r0, [r2], #4
	cmp	r2, r3	
	bcc	%B0	
		 	
	b	main	 		
	
;***********************************************
	IMPORT	|Image$$RO$$Base|	; ROM code start	
	IMPORT	|Image$$RO$$Limit|	; RAM data starts after ROM program
	IMPORT	|Image$$RW$$Base|	; Pre-initialised variables
	IMPORT	|Image$$ZI$$Base|	; uninitialised variables
	IMPORT	|Image$$ZI$$Limit|	; End of variable RAM space

BaseOfROM	DCD	|Image$$RO$$Base|
TopOfROM	DCD	|Image$$RO$$Limit|
BaseOfBSS	DCD	|Image$$RW$$Base|
BaseOfZero	DCD	|Image$$ZI$$Base|
EndOfBSS	DCD	|Image$$ZI$$Limit|
	
;***********************************************
	
	END