2440init.s

s3c2440的初始化代码,对外围设备的一些初始化操作

;=========================================
; NAME: 2440INIT.S
; DESC: C start up codes
;       Configure memory, ISR ,stacks
;	Initialize C-variables
; HISTORY:
; 2002.02.25:kwtark: ver 0.0
; 2002.03.20:purnnamu: Add some functions for testing STOP,Sleep mode
; 2003.03.14:DonGo: Modified for 2440.
;=========================================

	GET option.inc
	GET memcfg.inc
	GET 2440addr.inc

BIT_SELFREFRESH EQU	(1<<22)

;Pre-defined constants
USERMODE    EQU 	0x10
FIQMODE     EQU 	0x11
IRQMODE     EQU 	0x12
SVCMODE     EQU 	0x13
ABORTMODE   EQU 	0x17
UNDEFMODE   EQU 	0x1b
MODEMASK    EQU 	0x1f
NOINT       EQU 	0xc0

;The location of stacks
UserStack	EQU	(_STACK_BASEADDRESS-0x3800)	;0x33ff4800 ~
SVCStack	EQU	(_STACK_BASEADDRESS-0x2800)	;0x33ff5800 ~
UndefStack	EQU	(_STACK_BASEADDRESS-0x2400)	;0x33ff5c00 ~
AbortStack	EQU	(_STACK_BASEADDRESS-0x2000)	;0x33ff6000 ~
IRQStack	EQU	(_STACK_BASEADDRESS-0x1000)	;0x33ff7000 ~
FIQStack	EQU	(_STACK_BASEADDRESS-0x0)	;0x33ff8000 ~

;Check if tasm.exe(armasm -16 ...@ADS 1.0) is used.
	GBLL    THUMBCODE
	[ {CONFIG} = 16
THUMBCODE SETL  {TRUE}
	    CODE32
 		|
THUMBCODE SETL  {FALSE}
    ]

 		MACRO
	MOV_PC_LR
 		[ THUMBCODE
	    bx lr
 		|
	    mov	pc,lr
 		]
	MEND

 		MACRO
	MOVEQ_PC_LR
 		[ THUMBCODE
        bxeq lr
 		|
	    moveq pc,lr
 		]
	MEND

 		MACRO
$HandlerLabel HANDLER $HandleLabel

$HandlerLabel
	sub	sp,sp,#4	;decrement sp(to store jump address)
	stmfd	sp!,{r0}	;PUSH the work register to stack(lr does not push because it return to original address)
	ldr     r0,=$HandleLabel;load the address of HandleXXX to r0
	ldr     r0,[r0]	 ;load the contents(service routine start address) of HandleXXX
	str     r0,[sp,#4]      ;store the contents(ISR) of HandleXXX to stack
	ldmfd   sp!,{r0,pc}     ;POP the work register and pc(jump to ISR)
	MEND

	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

	IMPORT	MMU_SetAsyncBusMode
	IMPORT	MMU_SetFastBusMode	;hzh

	IMPORT  Main    ; The main entry of mon program

	AREA    Init,CODE,READONLY

	ENTRY
	
	EXPORT	__ENTRY
__ENTRY
ResetEntry
	;1)The code, which converts to Big-endian, should be in little endian code.
	;2)The following little endian code will be compiled in Big-Endian mode.
	;  The code byte order should be changed as the memory bus width.
	;3)The pseudo instruction,DCD can not be used here because the linker generates error.
	ASSERT	:DEF:ENDIAN_CHANGE
	[ ENDIAN_CHANGE
	    ASSERT  :DEF:ENTRY_BUS_WIDTH
	    [ ENTRY_BUS_WIDTH=32
		b	ChangeBigEndian	    ;DCD 0xea000007
	    ]

	    [ ENTRY_BUS_WIDTH=16
		andeq	r14,r7,r0,lsl #20   ;DCD 0x0007ea00
	    ]

	    [ ENTRY_BUS_WIDTH=8
		streq	r0,[r0,-r10,ror #1] ;DCD 0x070000ea
	    ]
	|
	    b	ResetHandler
    ]
	b	HandlerUndef	;handler for Undefined mode
	b	HandlerSWI	;handler for SWI interrupt
	b	HandlerPabort	;handler for PAbort
	b	HandlerDabort	;handler for DAbort
	b	.		;reserved
	b	HandlerIRQ	;handler for IRQ interrupt
	b	HandlerFIQ	;handler for FIQ interrupt

;@0x20
	b	EnterPWDN	; Must be @0x20.
ChangeBigEndian
;@0x24
	[ ENTRY_BUS_WIDTH=32
	    DCD	0xee110f10	;0xee110f10 => mrc p15,0,r0,c1,c0,0
	    DCD	0xe3800080	;0xe3800080 => orr r0,r0,#0x80;  //Big-endian
	    DCD	0xee010f10	;0xee010f10 => mcr p15,0,r0,c1,c0,0
	]
	[ ENTRY_BUS_WIDTH=16
	    DCD 0x0f10ee11
	    DCD 0x0080e380
	    DCD 0x0f10ee01
	]
	[ ENTRY_BUS_WIDTH=8
	    DCD 0x100f11ee
	    DCD 0x800080e3
	    DCD 0x100f01ee
    ]
	DCD 0xffffffff  ;swinv 0xffffff is similar with NOP and run well in both endian mode.
	DCD 0xffffffff
	DCD 0xffffffff
	DCD 0xffffffff
	DCD 0xffffffff
	b ResetHandler
	
HandlerFIQ      HANDLER HandleFIQ
HandlerIRQ      HANDLER HandleIRQ
HandlerUndef    HANDLER HandleUndef
HandlerSWI      HANDLER HandleSWI
HandlerDabort   HANDLER HandleDabort
HandlerPabort   HANDLER HandlePabort

IsrIRQ
	sub	sp,sp,#4       ;reserved for PC
	stmfd	sp!,{r8-r9}

	ldr	r9,=INTOFFSET
	ldr	r9,[r9]
	ldr	r8,=HandleEINT0
	add	r8,r8,r9,lsl #2
	ldr	r8,[r8]
	str	r8,[sp,#8]
	ldmfd	sp!,{r8-r9,pc}


	LTORG

;=======
; ENTRY
;=======
ResetHandler
	ldr	r0,=WTCON       ;watch dog disable
	ldr	r1,=0x0
	str	r1,[r0]

	ldr	r0,=INTMSK
	ldr	r1,=0xffffffff  ;all interrupt disable
	str	r1,[r0]

	ldr	r0,=INTSUBMSK
	ldr	r1,=0x7fff		;all sub interrupt disable
	str	r1,[r0]

	[ {FALSE}
	;rGPFDAT = (rGPFDAT & ~(0xf<<4)) | ((~data & 0xf)<<4);
	; Led_Display
	ldr	r0,=GPFCON
	ldr	r1,=0x5500
	str	r1,[r0]
	ldr	r0,=GPFDAT
	ldr	r1,=0x10
	str	r1,[r0]
	]

	;To reduce PLL lock time, adjust the LOCKTIME register.
	ldr	r0,=LOCKTIME
	ldr	r1,=0xffffff
	str	r1,[r0]

    [ PLL_ON_START
	; Added for confirm clock divide. for 2440.
	; Setting value Fclk:Hclk:Pclk
	ldr	r0,=CLKDIVN
	ldr	r1,=CLKDIV_VAL		; 0=1:1:1, 1=1:1:2, 2=1:2:2, 3=1:2:4, 4=1:4:4, 5=1:4:8, 6=1:3:3, 7=1:3:6.
	str	r1,[r0]
;	MMU_SetAsyncBusMode and MMU_SetFastBusMode over 4K, so do not call here
;	call it after copy, hzh
;	[ CLKDIV_VAL>1 		; means Fclk:Hclk is not 1:1.
;	bl MMU_SetAsyncBusMode
;	|
;	bl MMU_SetFastBusMode	; default value.
;	]
	;program has not been copied, so use these directly, hzh
	[ CLKDIV_VAL>1 		; means Fclk:Hclk is not 1:1.
	mrc p15,0,r0,c1,c0,0
	orr r0,r0,#0xc0000000;R1_nF:OR:R1_iA
	mcr p15,0,r0,c1,c0,0
	|
	mrc p15,0,r0,c1,c0,0
	bic r0,r0,#0xc0000000;R1_iA:OR:R1_nF
	mcr p15,0,r0,c1,c0,0
	]
	
	;Configure UPLL
	ldr	r0,=UPLLCON
	ldr	r1,=((U_MDIV<<12)+(U_PDIV<<4)+U_SDIV)  
	str	r1,[r0]
	nop	; Caution: After UPLL setting, at least 7-clocks delay must be inserted for setting hardware be completed.
	nop
	nop
	nop
	nop
	nop
	nop
	;Configure MPLL
	ldr	r0,=MPLLCON
	ldr	r1,=((M_MDIV<<12)+(M_PDIV<<4)+M_SDIV)  ;Fin=16.9344MHz
	str	r1,[r0]
    ]

	;Check if the boot is caused by the wake-up from SLEEP mode.
	ldr	r1,=GSTATUS2
	ldr	r0,[r1]
	tst	r0,#0x2
	;In case of the wake-up from SLEEP mode, go to SLEEP_WAKEUP handler.
	bne	WAKEUP_SLEEP

	EXPORT StartPointAfterSleepWakeUp
StartPointAfterSleepWakeUp

	;Set memory control registers
 	;ldr	r0,=SMRDATA
 	adrl	r0, SMRDATA	;be careful!, hzh
	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

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;       When EINT0 is pressed,  Clear SDRAM 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; check if EIN0 button is pressed

       ldr	r0,=GPFCON
	ldr	r1,=0x0
	str	r1,[r0]
	ldr	r0,=GPFUP
	ldr	r1,=0xff
	str	r1,[r0]

	ldr	r1,=GPFDAT
	ldr	r0,[r1]
       bic	r0,r0,#(0x1e<<1)  ; bit clear
	tst	r0,#0x1
	bne %F1
	
	

; Clear SDRAM Start
  
	ldr	r0,=GPFCON
	ldr	r1,=0x55aa
	str	r1,[r0]
;	ldr	r0,=GPFUP
;	ldr	r1,=0xff
;	str	r1,[r0]
	ldr	r0,=GPFDAT
	ldr	r1,=0x0
	str	r1,[r0]	;LED=****

	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,=0x4000000   ;64MB
	ldr	r0,=0x30000000
0	
	stmia	r0!,{r1-r8}
	subs	r9,r9,#32 
	bne	%B0

;Clear SDRAM End

1

 		;Initialize stacks
	bl	InitStacks

;===========================================================
	;bl	Led_Test
	
	ldr	r0, =BWSCON
	ldr	r0, [r0]
	ands	r0, r0, #6		;OM[1:0] != 0, NOR FLash boot
	bne	copy_proc_beg		;do not read nand flash
	adr	r0, ResetEntry		;OM[1:0] == 0, NAND FLash boot
	cmp	r0, #0				;if use Multi-ice, 
	bne	copy_proc_beg		;do not read nand flash for boot
	;nop
;===========================================================
nand_boot_beg
	mov	r5, #NFCONF
	;set timing value
	ldr	r0,	=(7<<12)|(7<<8)|(7<<4)
	str	r0,	[r5]
	;enable control
	ldr	r0, =(0<<13)|(0<<12)|(0<<10)|(0<<9)|(0<<8)|(1<<6)|(1<<5)|(1<<4)|(1<<1)|(1<<0)
	str	r0, [r5, #4]
	
	bl	ReadNandID
	mov	r6, #0
	ldr	r0, =0xec73
	cmp	r5,	r0
	beq	%F1
	ldr	r0, =0xec75
	cmp	r5, r0
	beq	%F1
	mov	r6, #1
1	
	bl	ReadNandStatus
	
	mov	r8, #0
	ldr	r9, =ResetEntry
2	
	ands	r0, r8, #0x1f
	bne		%F3
	mov		r0, r8
	bl		CheckBadBlk
	cmp		r0, #0
	addne	r8, r8, #32
	bne		%F4
3	
	mov	r0, r8
	mov	r1, r9
	bl	ReadNandPage
	add	r9, r9, #512
	add	r8, r8, #1
4	
	cmp	r8, #256
	bcc	%B2
	
	mov	r5, #NFCONF			;DsNandFlash
	ldr	r0, [r5, #4]
	bic r0, r0, #1
	str	r0, [r5, #4]
	ldr	pc, =copy_proc_beg
;===========================================================
copy_proc_beg
	adr	r0, ResetEntry
	ldr	r2, BaseOfROM
	cmp	r0, r2
	ldreq	r0, TopOfROM
	beq	InitRam	
	ldr r3, TopOfROM
0	
	ldmia	r0!, {r4-r7}
	stmia	r2!, {r4-r7}
	cmp	r2, r3
	bcc	%B0
	
	sub	r2, r2, r3
	sub	r0, r0, r2				
		
InitRam	
	ldr	r2, BaseOfBSS
	ldr	r3, BaseOfZero	
0
	cmp	r2, r3
	ldrcc	r1, [r0], #4
	strcc	r1, [r2], #4
	bcc	%B0	

	mov	r0,	#0
	ldr	r3,	EndOfBSS
1	
	cmp	r2,	r3
	strcc	r0, [r2], #4
	bcc	%B1
	
	ldr	pc, =%F2		;goto compiler address
2
	
;	[ CLKDIV_VAL>1 		; means Fclk:Hclk is not 1:1.
;	bl	MMU_SetAsyncBusMode
;	|
;	bl MMU_SetFastBusMode	; default value.
;	]
	
	;bl	Led_Test

;===========================================================
  	; Setup IRQ handler
	ldr	r0,=HandleIRQ       ;This routine is needed
	ldr	r1,=IsrIRQ	  ;if there is not 'subs pc,lr,#4' at 0x18, 0x1c
	str	r1,[r0]

;	;Copy and paste RW data/zero initialized data
;	ldr	r0, =|Image$$RO$$Limit| ; Get pointer to ROM data
;	ldr	r1, =|Image$$RW$$Base|  ; and RAM copy
;	ldr	r3, =|Image$$ZI$$Base|
;
;	;Zero init base => top of initialised data
;	cmp	r0, r1      ; Check that they are different
;	beq	%F2
;1
;	cmp	r1, r3      ; Copy init data
;	ldrcc	r2, [r0], #4    ;--> LDRCC r2, [r0] + ADD r0, r0, #4
;	strcc	r2, [r1], #4    ;--> STRCC r2, [r1] + ADD r1, r1, #4
;	bcc	%B1
;2
;	ldr	r1, =|Image$$ZI$$Limit| ; Top of zero init segment
;	mov	r2, #0
;3
;	cmp	r3, r1      ; Zero init
;	strcc	r2, [r3], #4
;	bcc	%B3