2440init.s

驱动程序,aaa aaa aa

0
	ldr	r3, [r0], #4
	str	r3, [r1], #4
	cmp	r2, r0
	bne	%B0
	
	;===delay, hzh
	;等待SDRAM自刷新有效
	mov	r0, #&1000
1
	subs	r0, r0, #1
	bne	%B1
	;===

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;       When EINT0 is pressed,  Clear SDRAM 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; check if EIN0 button is pressed
	;设置GPF[7:0]为输入且拉高
	ldr	r0,=GPFCON
	ldr	r1,=0x0
	str	r1,[r0]
	ldr	r0,=GPFUP
	ldr	r1,=0xff
	str	r1,[r0]
	;读取GPF[7:0]引脚值,GPF[0]为高时不清SDRAM
	ldr	r1,=GPFDAT
	ldr	r0,[r1]
	bic	r0,r0,#(0x1e<<1)  ; bit clear
	tst	r0,#0x1
	bne %F1

; Clear SDRAM Start
  	;设置GPF[7:4]输出，GPF[3:0]为EINT[3:0]
	ldr	r0,=GPFCON
	ldr	r1,=0x55aa
	str	r1,[r0]
	;设置输入口为拉高
;	ldr	r0,=GPFUP
;	ldr	r1,=0xff
;	str	r1,[r0]
	;输出口输出0 GPF[7:4]接LED
	ldr	r0,=GPFDAT
	ldr	r1,=0x0
	str	r1,[r0]	;LED=****

	;清楚SDRAM
	mov r1,#0
	mov r2,#0
	mov r3,#0
	mov r4,#0
	mov r5,#0
	mov r6,#0
	mov r7,#0
	mov r8,#0
	
	ldr	r9,=0x2000000   ;64MB
	ldr	r0,=0x30000000
0	
	stmia	r0!,{r1-r8}
	subs	r9,r9,#32 
	bne	%B0

;Clear SDRAM End

1
	; b 和bl是相对寻址的
	;Initialize stacks
	bl	InitStacks

;===========================================================
	
	ldr		r0, TopOfROM	;相同则直接初始化ram即可
		
InitRam	
	;初始化有初值的RAM(RW区)
	ldr	r2, BaseOfBSS
	ldr	r3, BaseOfZero	
0
	cmp	r2, r3
	ldrcc	r1, [r0], #4
	strcc	r1, [r2], #4
	bcc	%B0	

	;清零需要清零的RAM区(ZI区)
	mov	r0,	#0
	ldr	r3,	EndOfBSS
1	
	cmp	r2,	r3
	strcc	r0, [r2], #4
	bcc	%B1
	
	;程序将跳转到执行域中的程序的相同位置继续执行
	ldr	pc, =%F2		;goto compiler address
2
	
	
	;设置IRQ服务程序
;===========================================================
  	; Setup IRQ handler
	ldr	r0,=HandleIRQ       ;This routine is needed
	ldr	r1,=IsrIRQ	  ;if there isn't 'subs pc,lr,#4' at 0x18, 0x1c
	str	r1,[r0]

	IMPORT	Bios_Main
	
    [ :LNOT:THUMBCODE
 		bl	Bios_Main	;Don't use main() because ......
 		;ldr	pc, =Main	;hzh
 		b	.
    ]

    [ THUMBCODE	 ;for start-up code for Thumb mode
 		orr	lr,pc,#1
 		bx	lr
 		CODE16
 		bl	Bios_Main	;Don't use main() because ......
 		b	.
		CODE32
    ]


;function initializing stacks
InitStacks
	;Don't use DRAM,such as stmfd,ldmfd......
	;SVCstack is initialized before
	;Under toolkit ver 2.5, 'msr cpsr,r1' can be used instead of 'msr cpsr_cxsf,r1'
	mrs	r0,cpsr
	bic	r0,r0,#MODEMASK
	orr	r1,r0,#UNDEFMODE|NOINT
	msr	cpsr_cxsf,r1		;UndefMode
	ldr	sp,=UndefStack		; UndefStack=0x33FF_5C00

	orr	r1,r0,#ABORTMODE|NOINT
	msr	cpsr_cxsf,r1		;AbortMode
	ldr	sp,=AbortStack		; AbortStack=0x33FF_6000

	orr	r1,r0,#IRQMODE|NOINT
	msr	cpsr_cxsf,r1		;IRQMode
	ldr	sp,=IRQStack		; IRQStack=0x33FF_7000

	orr	r1,r0,#FIQMODE|NOINT
	msr	cpsr_cxsf,r1		;FIQMode
	ldr	sp,=FIQStack		; FIQStack=0x33FF_8000

	bic	r0,r0,#MODEMASK|NOINT
	orr	r1,r0,#SVCMODE
	msr	cpsr_cxsf,r1		;SVCMode
	ldr	sp,=SVCStack		; SVCStack=0x33FF_5800

	;USER mode has not be initialized.

	mov	pc,lr
	;The LR register won't be valid if the current mode is not SVC mode.
	

;--------------------LED test
	EXPORT	Led_Test
Led_Test
	mov	r0, #0x56000000
	mov	r1, #0x5500
	str	r1, [r0, #0x50]
0	
	mov	r1, #0x50
	str	r1, [r0, #0x54]
	mov	r2, #0x100000
1
	subs	r2, r2, #1
	bne	%B1
	
	mov	r1, #0xa0
	str	r1, [r0, #0x54]
	mov	r2, #0x100000
2
	subs	r2, r2, #1
	bne	%B2
	b	%B0
	mov	pc, lr

;===========================================================

	LTORG

;GCS0->SST39VF1601
;GCS1->16c550
;GCS2->IDE
;GCS3->CS8900
;GCS4->DM9000
;GCS5->CF Card
;GCS6->SDRAM
;GCS7->unused

SMRDATA DATA
; Memory configuration should be optimized for best performance
; The following parameter is not optimized.
; Memory access cycle parameter strategy
; 1) The memory settings is  safe parameters even at HCLK=75Mhz.
; 2) SDRAM refresh period is for HCLK<=75Mhz.

	DCD (0+(B1_BWSCON<<4)+(B2_BWSCON<<8)+(B3_BWSCON<<12)+(B4_BWSCON<<16)+(B5_BWSCON<<20)+(B6_BWSCON<<24)+(B7_BWSCON<<28))
	DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC))   ;GCS0
	DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC))   ;GCS1
	DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC))   ;GCS2
	DCD ((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC))   ;GCS3
	DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC))   ;GCS4
	DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC))   ;GCS5
	DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN))    ;GCS6
	DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN))    ;GCS7
	DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Tsrc<<18)+(Tchr<<16)+REFCNT)

	DCD 0x30	    ;SCLK power saving mode, BANKSIZE 128M/128M
	;DCD 0x32	    ;SCLK power saving mode, BANKSIZE 128M/128M
	;DCD 0x02	    ;SCLK power saving disable, BANKSIZE 128M/128M

	DCD 0x30	    ;MRSR6 CL=3clk
	DCD 0x30	    ;MRSR7 CL=3clk
	
	IMPORT  |Image$$RO$$Base|	; Base of ROM code
	IMPORT  |Image$$RO$$Limit|  ; End of ROM code (=start of ROM data)
	IMPORT  |Image$$RW$$Base|   ; Base of RAM to initialise
	IMPORT  |Image$$ZI$$Base|   ; Base and limit of area
	IMPORT  |Image$$ZI$$Limit|  ; to zero initialise

	
BaseOfROM	DCD	|Image$$RO$$Base|
TopOfROM	DCD	|Image$$RO$$Limit|
BaseOfBSS	DCD	|Image$$RW$$Base|
BaseOfZero	DCD	|Image$$ZI$$Base|
EndOfBSS	DCD	|Image$$ZI$$Limit|


	ALIGN
	

	
;=====================================================================
; Clock division test
; Assemble code, because VSYNC time is very short
;=====================================================================
	EXPORT CLKDIV124
	EXPORT CLKDIV144
	
CLKDIV124
	
	ldr     r0, = CLKDIVN
	ldr     r1, = 0x3		; 0x3 = 1:2:4
	str     r1, [r0]
;	wait until clock is stable
	nop
	nop
	nop
	nop
	nop

	ldr     r0, = REFRESH
	ldr     r1, [r0]
	bic		r1, r1, #0xff
	bic		r1, r1, #(0x7<<8)
	orr		r1, r1, #0x470	; REFCNT135
	str     r1, [r0]
	nop
	nop
	nop
	nop
	nop
	mov     pc, lr

CLKDIV144
	ldr     r0, = CLKDIVN
	ldr     r1, = 0x4		; 0x4 = 1:4:4
	str     r1, [r0]
;	wait until clock is stable
	nop
	nop
	nop
	nop
	nop

	ldr     r0, = REFRESH
	ldr     r1, [r0]
	bic		r1, r1, #0xff
	bic		r1, r1, #(0x7<<8)
	orr		r1, r1, #0x630	; REFCNT675 - 1520
	str     r1, [r0]
	nop
	nop
	nop
	nop
	nop
	mov     pc, lr


	ALIGN

	AREA RamData, DATA, READWRITE

	^   _ISR_STARTADDRESS		; _ISR_STARTADDRESS=0x33FF_FF00
HandleReset 	#   4
HandleUndef 	#   4
HandleSWI		#   4
HandlePabort    #   4
HandleDabort    #   4
HandleReserved  #   4
HandleIRQ		#   4
HandleFIQ		#   4

;Don't use the label 'IntVectorTable',
;The value of IntVectorTable is different with the address you think it may be.
;IntVectorTable
;@0x33FF_FF20
HandleEINT0		#   4
HandleEINT1		#   4
HandleEINT2		#   4
HandleEINT3		#   4
HandleEINT4_7	#   4
HandleEINT8_23	#   4
HandleCAM		#   4		; Added for 2440.
HandleBATFLT	#   4
HandleTICK		#   4
HandleWDT		#   4
HandleTIMER0 	#   4
HandleTIMER1 	#   4
HandleTIMER2 	#   4
HandleTIMER3 	#   4
HandleTIMER4 	#   4
HandleUART2  	#   4
;@0x33FF_FF60
HandleLCD 		#   4
HandleDMA0		#   4
HandleDMA1		#   4
HandleDMA2		#   4
HandleDMA3		#   4
HandleMMC		#   4
HandleSPI0		#   4
HandleUART1		#   4
HandleNFCON		#   4		; Added for 2440.
HandleUSBD		#   4
HandleUSBH		#   4
HandleIIC		#   4
HandleUART0 	#   4
HandleSPI1 		#   4
HandleRTC 		#   4
HandleADC 		#   4
;@0x33FF_FFA0
	END