init.s

ARM开发的源码

#*********************************************************************************************
# File：	init.s
# Author:	embest
# Desc:		C start up codes.Configure memory, Initialize ISR ,stacks,initialize C-variables
#			Fill zeros into zero-initialized C-variables
# History:
#*********************************************************************************************

/*------------------------------------------------------------------------------------------*/
/*	 								global symbol define						 			*/
/*------------------------------------------------------------------------------------------*/
	.global _start
	
/*------------------------------------------------------------------------------------------*/
/*	 								code								 				    */
/*------------------------------------------------------------------------------------------*/	
	.text
_start:
# Set  interrupt / exception vectors
	b       Reset_Handler
Undefined_Handler:
	b       Undefined_Handler
SWI_Handler:
	b       SWI_Handler
Prefetch_Handler:
	b       Prefetch_Handler
Abort_Handler:
	b       Abort_Handler                                                                    
	nop						                     /* Reserved vector */
IRQ_Handler:
	b       IRQ_Handler
FIQ_Handler:
	b       FIQ_Handler	    
Reset_Handler:
	ldr	sp, =0x00002000

# *********************************************************
# Branch on C code Main function (with interworking)      *					               	
# Branch must be performed by an interworking call as     *
# either an ARM or Thumb.main C function must be          *
# supported. This makes the code not position-independant.*
# A Branch with link would generate errors                *
# *********************************************************
	.extern     __main

	ldr         r0, = __main
	mov         lr, pc
	
    # jump to __main()
	bx          r0
	
# *********************************************************
# * Loop for ever					                      * 	
# * End of application. Normally, never occur.        	  *
# * Could jump on Software Reset ( B 0x0 ).           	  *
# *********************************************************
End:
	b           End

    .end