.EXTERN main
	.EXTERN portSWI
	.TEXT
	.GLOBAL _start
	.set __stack_end__, 0x589000
	.set  SVC_STACK_SIZE, 0x00000400
	.set  MODE_SVC, 0x13            /* Supervisor Mode */
	.set  MODE_USR, 0x10            /* User Mode */
	.set  MODE_SYS, 0x1F			/*System Mode */
	
	.equ  I_BIT, 0x80               /* when I bit is set, IRQ is disabled */
    .equ  F_BIT, 0x40               /* when F bit is set, FIQ is disabled */
	
_start:
	b	_reset
	b	_ud_h
	b	_SWI_h
	b	_pre_h
	b	_abort_h
	nop
	b	_irq
	b	_fiq

_reset:
	ldr r0, = __stack_end__
	msr   CPSR_c, #MODE_SVC /* Supervisor Mode */
	mov   sp, r0 /*update stack pointer supervisor mode*/
	sub   r0, r0, #SVC_STACK_SIZE /*stack end for user mode*/
	msr   CPSR_c, #MODE_USR /* System Mode */
	mov	  sp,r0  /*update stack pointer user mode*/
	/*mov		ip,sp */
	
	bl		main
	b		_exit
_exit:
	b		_exit

_ud_h:
	b	_ud_h
_SWI_h:
	/*STMFD SP!, {r0-r13} 
	MRS r2, SPSR
	STMFD SP!, {r2} 
	STMFD SP!, {lr} 
	MOV r1, sp */
	STMFD SP!, {ip}
	
	b	portSWI /*_SWI_h*/
_pre_h:
	b	_pre_h
_abort_h:
	b	_abort_h
_irq:
	b	_irq
_fiq:
	b	_fiq