init.s

这是三星评估板ws310(CPU为S3c4510B)用的Bootloader.开发环境是SDT。

;************************************************************************************************
;Beijing instittue of technology
;File Name:		Init.s
;Description:		Init.
;Author:			chaisc
;Date:			200312-1
;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         	
	NOP        
        	NOP       
        	NOP       
	NOP 
        	NOP       
        	NOP       

Reset_Handler	
;******************************************************	
;mask all interrupt
;******************************************************
	LDR	R1,=0x3ff0000
	LDR	R0,=0xE7ffff90
         STR	R0,[R1]

	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, =0x00003002  
	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}
         LDR    	R1,=0x3ff5000
         LDR	R0,=0x0
         STR	R0,[R1]
         LDR    	R0,=0x3ff5008        
         LDR    	R1,[R0]
         AND    	R1,R1,#0x08
         CMP    	R1,#0x08
         BNE    	Next
         LDR    	R0,=0x10000
         MOV    	PC,R0
Next
	
;********************************************************
;Initialise system stack for different processor modes
;Change to Interrupt Mode (IRQ)
;********************************************************
	mov	r0, #0x12
	MSR	cpsr_c, r0
	mov 	sp,#0x70000
;********************************************************
;Change to Fast Interrupt Mode (FIQ)
;********************************************************
	mov	r0,#0x11
	MSR	cpsr_c, r0				
	mov 	sp,#0x7f000
;********************************************************
;Change to Supervisor Mode (SVC)
;********************************************************
         mov	r0,#0x13
	MSR	cpsr_c, r0				
	mov 	sp,#0x80000
	
         LDR	R1,=0x3FF4000
	LDR	R0,=0x0
         STR	R0,[R1]
 
*********************************************************
	IMPORT  	C_Entry
    	BL      	C_Entry
	B  	.	   

	END