init.s

pxa255,bootloaer ,从初始化中断到GPIO口

				;GET LEVEL0_H.S
				GET register.s
				GET memory.s
				GET	gpio_config.s
			
				IMPORT	|Image$$RO$$Limit|
			    IMPORT	|Image$$RW$$Base|
			    IMPORT	|Image$$ZI$$Base|
			    IMPORT	|Image$$ZI$$Limit|
			    
		  		AREA INIT, CODE, READONLY
				CODE32
		 		ENTRY
		   		B	Reset
Undef	   		B	Undef
SWI		   		B	SWI
Pabort	   		B	Pabort	
Dabort	   		B	Dabort
Reserved   		B	Reserved
IRQ		   		B	IRQ
FIQ		   		B	FIQ 
				
				MACRO
				CPWAIT  $r0
				mrc	p15,0,r0,c2,c0,0
				mov	r0,r0
				sub	pc,pc,#4	
				MEND

Reset

				ldr	r0,=0x2001
			    mcr	p15,0,r0,c15,c1,0	;//enable access to all coprocessors if r0=0x3fff,enable all coprocessor.if r0=2001,enable CP13 and CP0.
			    CPWAIT	
			    
;			    mrc p15,0,r0,c1,c0,0
;			    bic r0,r0,#0x1f87	
				ldr r0,=0x2078			
				mcr	p15,0,r0,c1,c0,0	;//Disable MMU and I-cache&D-cache
			    CPWAIT
			    
			    ldr r0,=0x00000000		;//clean TLB,Caches and write Buffer
			    mcr	p15,0,r0,c8,c7,0
			    mcr p15,0,r0,c7,c7,0
			    mcr p15,0,r0,c7,c10,4    
			   	CPWAIT
			    
			   	mvn r0,#0x0             ;//Open system memory Access Domain visiting popedom    
				mcr p15,0,r0,c3,c0,0  
			    CPWAIT


			    LDR r0, =0x00000000		;  // Mask of all Interrupt   
			    LDR	r1,	=ICMR
			    STR r0, [r1]


			    LDR r1, =CCCR_L27|CCCR_M2|CCCR_N10 ;// Set CPU Frequency  0x0141:MEM 99M,CORE 200M
			    LDR	r0,=CCCR
			    STR r1,[r0]
						  
			  
			    LDR r1, =CKEN				 ;// Init CKEN,OSCC
			    LDR r0, =0x00000000			
			    STR r0, [ r1]
			    LDR r0, =0x00000003
			    LDR r1, =OSCC
			    STR	r0,[r1]              ;32.768KHZ is on
			  
  
			    ;Set FCS&TURBO Bit and changer CPU Frequency into TURBO Mode