start.s

S3C2410学习的基础资料 大部分实验源码及工程

;=========================================
; NAME: 2410INIT.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,POWER_OFF mode
;=========================================

	GET option.s
	GET memcfg.s
	GET 2410addr.s

BIT_SELFREFRESH EQU	(1<<22)
;ARM异常模式的定义
;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

;ARM个异常模式堆栈
;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 	;[ = IF
THUMBCODE SETL  {TRUE}
	    CODE32          ; CODE32 表明一下操作都在ARM状态
    	| 				;| = ELSE  
THUMBCODE SETL  {FALSE}
    	]				;] = ENDIF

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

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

;宏定义－进入异常流程
;HANDLER－宏的名称
;$HandleLabel－宏的参数
;这个宏的作用是把各个中断程序的地址装入当前的PC，2410有两种装断模式 一种是没有中断向量表，一种是使用中断向量表的
;使用中断向量表只能是IRQ方式，当使用中断向量表的时候，中断发生时由2410的中断控制器自动跳转到
;相应的位置。
    	MACRO
$HandlerLabel HANDLER $HandleLabel

$HandlerLabel
	sub	sp,sp,#4        	;decrement sp(to store jump address)
	stmfd	sp!,{r0}        ;PUSH the work register to stack(lr doest push because it return to original address)
	ldr     r0,=$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
;连接器生成的输出段相关的符号
;引入连接器生成的映象文件的各个部分地址。
;OR－只读区域、RW－读写区域、ZI－初始化为0的区域。	
	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	

;引入外部函数Main，进入C程序。	
	IMPORT  Main    ; The main entry of mon program
	;IMPORT  LEDTEST 
;定义ARM汇编程序段，段名为SelfBoot，程序段为只读的代码段。	
	AREA    SelfBoot, CODE, READONLY
;程序入口地址
	ENTRY
	 
ResetEntry

	;程序段执行的第一跳指令，为8个异常中断处理向量，要按顺序放置。
	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

	LTORG ;声明一个数据缓冲池的开始   
HandlerFIQ      HANDLER HandleFIQ
HandlerIRQ      HANDLER HandleIRQ
HandlerUndef    HANDLER HandleUndef
HandlerSWI      HANDLER HandleSWI
HandlerDabort   HANDLER HandleDabort
HandlerPabort   HANDLER HandlePabort

;采用INTOFFSET寄存器判定IRQ中断源
IsrIRQ  
	sub	sp,sp,#4       
	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}


;======================================================
; ENTRY  
;======================================================
;初始化程序入口指令
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,=0x3ff		;all sub interrupt disable
	str	r1,[r0]
	
	;To reduce PLL lock time, adjust the LOCKTIME register. 
	ldr	r0,=LOCKTIME
	ldr	r1,=0xffffff
	str	r1,[r0]
        
	;Configure MPLL
	ldr	r0,=MPLLCON          
	ldr	r1,=((M_MDIV<<12)+(M_PDIV<<4)+M_SDIV)  ;Fin=12MHz,Fout=50MHz
	str	r1,[r0]

	;设置存储器控制寄存器。
	;Set memory control registers
	adr	r0, SMRDATA
	ldr	r1,=BWSCON	;BWSCON Address
	add	r2, r0, #52	;End address of SMRDATA一共13个寄存器
0       
	ldr	r3, [r0], #4    
	str	r3, [r1], #4    
	cmp	r2, r0		
	bne	%B0

	;禁止Icache和Dcache，禁止MMU
	;IMPORT  MMU_DisableICache
    ;bl MMU_DisableICache ;
	;IMPORT  MMU_DisableDCache
    ;bl MMU_DisableDCache ;
    ;IMPORT  MMU_InvalidateICache
    ;bl  MMU_InvalidateICache ;
    ;IMPORT  MMU_DisableMMU
    ;bl  MMU_DisableMMU ;
	
	;初始化堆栈
    ;Initialize stacks
	bl	InitStacks
	
	;建立IRQ中断
  	; 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]
	
;===========================================================
	adr	r0, ResetEntry
	ldr	r2, BaseOfROM
	cmp	r0, r2
	ldreq	r0, TopOfROM
	beq	InitRam	
	ldr r3, TopOfROM
;将RO区域的代码copy到RW域中并且将ZI区域初始化为0。
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	;copy 初始化代码
	ldrcc	r1, [r0], #4
	strcc	r1, [r2], #4
	bcc	%B0	

	mov	r0,	#0  ;初始化ZI区域为0
	ldr	r3,	EndOfBSS
1	
	cmp	r2,	r3
	strcc	r0, [r2], #4
	bcc	%B1	

	bl	Main	;bl	Main        ;Dont use main() because ......
   	b	.                       

;堆栈初始化
;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
	
	;UndefMode堆栈
	mrs	r0,cpsr
	bic	r0,r0,#MODEMASK
	orr	r1,r0,#UNDEFMODE|NOINT
	msr	cpsr_cxsf,r1		;UndefMode
	ldr	sp,=UndefStack
	
	;AbortMode堆栈
	orr	r1,r0,#ABORTMODE|NOINT
	msr	cpsr_cxsf,r1		;AbortMode
	ldr	sp,=AbortStack
	
	;IRQMode堆栈
	orr	r1,r0,#IRQMODE|NOINT
	msr	cpsr_cxsf,r1		;IRQMode
	ldr	sp,=IRQStack
    
    ;FIQMode堆栈
	orr	r1,r0,#FIQMODE|NOINT
	msr	cpsr_cxsf,r1		;FIQMode
	ldr	sp,=FIQStack
	
	;SVCMode堆栈
	bic	r0,r0,#MODEMASK|NOINT
	orr	r1,r0,#SVCMODE
	msr	cpsr_cxsf,r1		;SVCMode
	ldr	sp,=SVCStack
	
	;USER mode has not be initialized.
	
	mov	pc,lr 
	;The LR register won't be valid if the current mode is not SVC mode.'
	

	LTORG ;声明一个数据缓冲池的开始

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));BWSCON=0x2211D110
    	DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC))   ;GCS0  BANK0CON=0x0700
    	DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC))   ;GCS1  BANK1CON=0x7FFC
    	DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC))   ;GCS2  BANKCON2=0x0700
    	DCD 0x1f7c;((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC))   ;GCS3	BANKCON3=0x0700
    	DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC))   ;GCS4  BANKCON4=0x0700
    	DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC))   ;GCS5  BANKCON5=0x0700
    	DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN))    ;GCS6  BANKCON6=0x18005
    	DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN))    ;GCS7  BANKCON7=0x18005
    	DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT)  ;REFRESH=0x008E0459   
		DCD 0x32            ;SCLK power saving mode, BANKSIZE 128M/128M       ;BANKSIZE=0x32
    	DCD 0x30            ;MRSR6 CL=3clk   ;MRSRB6=0x30
    	DCD 0x30            ;MRSR7			 ;MRSRB7=0x30


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 ;通过添加补丁字节使当前位置满足一定的对齐方式

		;可读写的数据段
    	AREA RamData, DATA, READWRITE

;^=MAP:定义一个结构化的内存表（storage map）的首地址，地址为0x33ff8000
        ^   _ISR_STARTADDRESS ;0x33ff8000
HandleReset 	#   4   ;#--Field：定义一个结构化内存表中的数据域，该域为4个字节
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'
HandleEINT0   	#   4
HandleEINT1   	#   4
HandleEINT2   	#   4
HandleEINT3   	#   4
HandleEINT4_7	#   4
HandleEINT8_23	#   4
HandleRSV6		#   4
HandleBATFLT   	#   4
HandleTICK   	#   4
HandleWDT		#   4
HandleTIMER0 	#   4
HandleTIMER1 	#   4
HandleTIMER2 	#   4
HandleTIMER3 	#   4
HandleTIMER4 	#   4
HandleUART2  	#   4
HandleLCD 		#   4
HandleDMA0		#   4
HandleDMA1		#   4
HandleDMA2		#   4
HandleDMA3		#   4
HandleMMC		#   4
HandleSPI0		#   4
HandleUART1		#   4
HandleRSV24		#   4
HandleUSBD		#   4
HandleUSBH		#   4
HandleIIC   	#   4
HandleUART0 		#   4
HandleSPI1 		#   4
HandleRTC 		#   4
HandleADC 		#   4

        END