init.s.bak

一个比较好的三星s3c4510的启动代码

;************************************************************************************************
;Beijing instittue of technology
;File Name:		Init.s
;Description:		Init.
;Author:		chaisc
;Date:			2003.8.13
;SDRAM Configuration:	Use ljg.txt,SDRAM remap to address 0x0~0x100,0000(16MB) 
;************************************************************************************************	
	GET	mem.a
	GET	casia1.a
	IMPORT main_entry

	CODE32
	AREA    Init,CODE,READONLY
	ENTRY 
	B       Reset_Handler		
        	NOP       ;IRQ_Handler
        	NOP        ;IRQ_Handler
        	NOP       ;IRQ_Handler
        	NOP       ;IRQ_Handler
	        NOP 
        	NOP       ;IRQ_Handler
        	NOP       ;IRQ_Handler


Reset_Handler	
 ;==========================================================
 ;Change Base address and dram
 ;==========================================================
 	B INITIALIZE_STACK
			;/* set the SPSR under super */ 
;*********************************	
;mask all interrupt
;*********************************
INITIALIZE_STACK
 
         LDR	R1,=0x3ff0000
	 LDR	R0,=0xE7ffff90
         STR	R0,[R1]
         LDR    R1,=0x3ff5000
         LDR	R0,=0x0
         STR	R0,[R1]
         LDR    R0,=0x3ff5008        
         LDR    R1,[R0]
         AND    R1,R1,#0x04
         CMP    R1,#0x04
         BNE    Next
         LDR    R0,=0x100000
        MOV    PC,R0
Next
	LDR	r0, =0x3FF0000 + 0x3010
	LDR	r1, =rEXTDBWTH  
	LDR	r2, =rROMCON0    
	LDR	r3, =rROMCON1
	LDR	r4, =rROMCON2
	LDR	r5, =rROMCON3
	LDR	r6, =rROMCON4
	LDR	r7, =rROMCON5
	LDR	r8, =0x14010380
	LDR	r9, =rSDRAMCON1
	LDR	r10,=rSDRAMCON2
	LDR	r11,=rSDRAMCON3
	LDR	r12,=rSREFEXTCON
	STMIA	r0, {r1-r12}
	    
	ldr	r0, =0x0
	ldr	r1, =0x200000		
	ldr	r2, =0x400000

rom2ram_copy_loop
	ldr	r3, [r0], #4
	str	r3, [r2], #4
	subs	r1, r1, #4
	bne	rom2ram_copy_loop
        

	LDR	r0, =0x3FF0000 + 0x3010
	LDR	r1, =00003002  
	LDR	r2, =0x12040060   
	LDR	r3, =rROMCON1
	LDR	r4, =rROMCON2
	LDR	r5, =rROMCON3
	LDR	r6, =rROMCON4
	LDR	r7, =rROMCON5
	LDR	r8, =0x10000380
	LDR	r9, =rSDRAMCON1
	LDR	r10,=rSDRAMCON2
	LDR	r11,=rSDRAMCON3
	LDR	r12,=rSREFEXTCON
	STMIA	r0, {r1-r12}

	
;******************************************************
;Initialise system stack for different processor modes
************************************************
	mov	r0, #0x12
	MSR	cpsr_c, r0
	mov 	sp,#0x70000
	mov	r0,#0x11
	MSR	cpsr_c, r0				;/* change to FIQ MODE */
	mov 	sp,#0x7f000
	
         mov	r0,#0x13
	MSR	cpsr_c, r0				;/* change to FIQ MODE */
	mov 	sp,#0x80000
	
         LDR	R1,=0x3FF4000
	 LDR	R0,=0x0
         STR	R0,[R1]
         
        
         

	
     
;************************************************
	

;********************************************************
;Mask off all IRQ sources
;********************************************************


**********************************************************
	    IMPORT  C_Entry
    	    BL      C_Entry
	    B  		.
	    
	    EXPORT	FIQ
	    IMPORT      ISR_FiqHandler;BDMA_Rx_isr
FIQ
	   SUB lr,lr,#4
	   STMFD sp!,{lr}
	   MRS r14,spsr
	   STMFD sp!,{r0-r12,r14}

	       
           BL ISR_FiqHandler;BDMA_Rx_isr
           LDMFD sp!,{r0-r12,r14}
           MSR spsr_cf,r14
           LDR	R1,=0x3FF4008
	   LDR	R0,=0x19ffff
	   STR	R0,[R1]
           LDMFD sp!,{pc}^ 

    

	END