2440init.s

学习写了下无OS的软件,大家看看吧请认真阅读您的

;	cmp	r3, r1      ; Zero init
;	strcc	r2, [r3], #4
;	bcc	%B3


    [ :LNOT:THUMBCODE
 		bl	Main	;Do not use main() because ......
 		;ldr	pc, =Main	;
 		b	.
    ]

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


;function initializing stacks
InitStacks
	;Do not 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 will not be valid if the current mode is not SVC mode.
	
;===========================================================
ReadNandID
	mov      r7,#NFCONF
	ldr      r0,[r7,#4]		;NFChipEn();
	bic      r0,r0,#2
	str      r0,[r7,#4]
	mov      r0,#0x90		;WrNFCmd(RdIDCMD);
	strb     r0,[r7,#8]
	mov      r4,#0			;WrNFAddr(0);
	strb     r4,[r7,#0xc]
1							;while(NFIsBusy());
	ldr      r0,[r7,#0x20]
	tst      r0,#1
	beq      %B1
	ldrb     r0,[r7,#0x10]	;id  = RdNFDat()<<8;
	mov      r0,r0,lsl #8
	ldrb     r1,[r7,#0x10]	;id |= RdNFDat();
	orr      r5,r1,r0
	ldr      r0,[r7,#4]		;NFChipDs();
	orr      r0,r0,#2
	str      r0,[r7,#4]
	mov		 pc,lr	
	
ReadNandStatus
	mov		 r7,#NFCONF
	ldr      r0,[r7,#4]		;NFChipEn();
	bic      r0,r0,#2
	str      r0,[r7,#4]
	mov      r0,#0x70		;WrNFCmd(QUERYCMD);
	strb     r0,[r7,#8]	
	ldrb     r1,[r7,#0x10]	;r1 = RdNFDat();
	ldr      r0,[r7,#4]		;NFChipDs();
	orr      r0,r0,#2
	str      r0,[r7,#4]
	mov		 pc,lr

WaitNandBusy
	mov      r0,#0x70		;WrNFCmd(QUERYCMD);
	mov      r1,#NFCONF
	strb     r0,[r1,#8]
1							;while(!(RdNFDat()&0x40));	
	ldrb     r0,[r1,#0x10]
	tst      r0,#0x40
	beq		 %B1
	mov      r0,#0			;WrNFCmd(READCMD0);
	strb     r0,[r1,#8]
	mov      pc,lr

CheckBadBlk
	mov		r7, lr
	mov		r5, #NFCONF
	
	bic      r0,r0,#0x1f	;addr &= ~0x1f;
	ldr      r1,[r5,#4]		;NFChipEn()
	bic      r1,r1,#2
	str      r1,[r5,#4]

	mov      r1,#0x50		;WrNFCmd(READCMD2)
	strb     r1,[r5,#8]
	mov      r1, #5;6		;6->5
	strb     r1,[r5,#0xc]	;WrNFAddr(5);(6) 6->5
	strb     r0,[r5,#0xc]	;WrNFAddr(addr)
	mov      r1,r0,lsr #8	;WrNFAddr(addr>>8)
	strb     r1,[r5,#0xc]
	cmp      r6,#0			;if(NandAddr)		
	movne    r0,r0,lsr #16	;WrNFAddr(addr>>16)
	strneb   r0,[r5,#0xc]
	
;	bl		WaitNandBusy	;WaitNFBusy()
	;do not use WaitNandBusy, after WaitNandBusy will read part A!
	mov	r0, #100
1
	subs	r0, r0, #1
	bne	%B1
2
	ldr	r0, [r5, #0x20]
	tst	r0, #1
	beq	%B2	

	ldrb	r0, [r5,#0x10]	;RdNFDat()
	sub		r0, r0, #0xff
	
	mov      r1,#0			;WrNFCmd(READCMD0)
	strb     r1,[r5,#8]
	
	ldr      r1,[r5,#4]		;NFChipDs()
	orr      r1,r1,#2
	str      r1,[r5,#4]
	
	mov		pc, r7
	
ReadNandPage
	mov		 r7,lr
	mov      r4,r1
	mov      r5,#NFCONF

	ldr      r1,[r5,#4]		;NFChipEn()
	bic      r1,r1,#2
	str      r1,[r5,#4]	

	mov      r1,#0			;WrNFCmd(READCMD0)
	strb     r1,[r5,#8]	
	strb     r1,[r5,#0xc]	;WrNFAddr(0)
	strb     r0,[r5,#0xc]	;WrNFAddr(addr)
	mov      r1,r0,lsr #8	;WrNFAddr(addr>>8)
	strb     r1,[r5,#0xc]	
	cmp      r6,#0			;if(NandAddr)		
	movne    r0,r0,lsr #16	;WrNFAddr(addr>>16)
	strneb   r0,[r5,#0xc]
	
	ldr      r0,[r5,#4]		;InitEcc()
	orr      r0,r0,#0x10
	str      r0,[r5,#4]
	
	bl       WaitNandBusy	;WaitNFBusy()
	
	mov      r0,#0			;for(i=0; i<512; i++)
1
	ldrb     r1,[r5,#0x10]	;buf[i] = RdNFDat()
	strb     r1,[r4,r0]
	add      r0,r0,#1
	bic      r0,r0,#0x10000
	cmp      r0,#0x200
	bcc      %B1
	
	ldr      r0,[r5,#4]		;NFChipDs()
	orr      r0,r0,#2
	str      r0,[r5,#4]
		
	mov		 pc,r7

;--------------------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 0x32	    ;SCLK power saving mode, BANKSIZE 128M/128M

	DCD 0x30	    ;MRSR6 CL=3clk
	DCD 0x30	    ;MRSR7 CL=3clk
	
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
	
;Function for entering power down mode
; 1. SDRAM should be in self-refresh mode.
; 2. All interrupt should be maksked for SDRAM/DRAM self-refresh.
; 3. LCD controller should be disabled for SDRAM/DRAM self-refresh.
; 4. The I-cache may have to be turned on.
; 5. The location of the following code may have not to be changed.

;void EnterPWDN(int CLKCON);
EnterPWDN
	mov r2,r0		;r2=rCLKCON
	tst r0,#0x8		;SLEEP mode?
	bne ENTER_SLEEP

ENTER_STOP
	ldr r0,=REFRESH
	ldr r3,[r0]		;r3=rREFRESH
	mov r1, r3
	orr r1, r1, #BIT_SELFREFRESH
	str r1, [r0]		;Enable SDRAM self-refresh

	mov r1,#16			;wait until self-refresh is issued. may not be needed.
0	subs r1,r1,#1
	bne %B0

	ldr r0,=CLKCON		;enter STOP mode.
	str r2,[r0]

	mov r1,#32
0	subs r1,r1,#1	;1) wait until the STOP mode is in effect.
	bne %B0		;2) Or wait here until the CPU&Peripherals will be turned-off
			;   Entering SLEEP mode, only the reset by wake-up is available.

	ldr r0,=REFRESH ;exit from SDRAM self refresh mode.
	str r3,[r0]

	MOV_PC_LR

ENTER_SLEEP
	;NOTE.
	;1) rGSTATUS3 should have the return address after wake-up from SLEEP mode.

	ldr r0,=REFRESH
	ldr r1,[r0]		;r1=rREFRESH
	orr r1, r1, #BIT_SELFREFRESH
	str r1, [r0]		;Enable SDRAM self-refresh

	mov r1,#16			;Wait until self-refresh is issued,which may not be needed.
0	subs r1,r1,#1
	bne %B0

	ldr	r1,=MISCCR
	ldr	r0,[r1]
	orr	r0,r0,#(7<<17)  ;Set SCLK0=0, SCLK1=0, SCKE=0.
	str	r0,[r1]

	ldr r0,=CLKCON		; Enter sleep mode
	str r2,[r0]

	b .			;CPU will die here.


WAKEUP_SLEEP
	;Release SCLKn after wake-up from the SLEEP mode.
	ldr	r1,=MISCCR
	ldr	r0,[r1]
	bic	r0,r0,#(7<<17)  ;SCLK0:0->SCLK, SCLK1:0->SCLK, SCKE:0->=SCKE.
	str	r0,[r1]

	;Set memory control registers
 	ldr	r0,=SMRDATA	;be careful! 
	ldr	r1,=BWSCON	;BWSCON Address
	add	r2, r0, #52	;End address of SMRDATA
0
	ldr	r3, [r0], #4
	str	r3, [r1], #4
	cmp	r2, r0
	bne	%B0

	mov r1,#256
0	subs r1,r1,#1	;1) wait until the SelfRefresh is released.
	bne %B0

	ldr r1,=GSTATUS3 	;GSTATUS3 has the start address just after SLEEP wake-up
	ldr r0,[r1]

	mov pc,r0
	
;=====================================================================
; 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

;Do not 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