2440init.s

2440的bootloader

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

$HandlerLabel
	sub	sp,sp,#4	;decrement sp(to store jump address)
	stmfd	sp!,{r0}	;PUSH the work register to stack(lr does't push because it return to original address)
	ldr     r0,=$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$$RO$$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  Main    ; The main entry of mon program

	AREA    Init,CODE,READONLY

	ENTRY

	;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't 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

;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
	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 r1,=0x30024000
	ldr r0,[r1]

	mov pc,r0

	LTORG
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}

;=======
; 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,=0x3ff		;all sub interrupt disable
	str	r1,[r0]


       ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	;;;;;;;;;;;;;;;;        Max1718 1.35V Setting          ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	; rGPBDAT=(rGPBDAT&0x77f)|(0<<7);	//D4
	; rGPFDAT=(rGPFDAT&0x0f)|(1<<7)|(0<<6)|(0<<5)|(0<<4);	//D3~0
	; rGPBCON=(rGPBCON&0x3f3fff)|(1<<14);	// GPB7: Output
	; rGPFCON=(rGPFCON&0x00ff)|(0x5500);  // GPF4~7: Output 
	; rGPBDAT&=~(1<<8);   //Latch enable
	; rGPBCON=(rGPBCON&0x3cffff)|(1<<16);	// GPB8: Output
	; rGPBDAT|=(1<<10);   //Output enable
	; rGPBCON=(rGPBCON&0x0fffff)|(1<<20);	// GPB10: Output
	;  rGPBDAT|=(1<<8);	//Latch disable
	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; 

	
	; rGPBDAT=(rGPBDAT&0x77f)|(0<<7);	//D4
;	ldr	r0,=GPBDAT
;	ldr	r1, =(0<<7)
;	str	r1,[r0]
	
       ; rGPFDAT=(rGPFDAT&0x0f)|(1<<7)|(0<<6)|(0<<5)|(0<<4);	//D3~0 
;	ldr	r0,=GPFDAT
;	ldr	r1,=(1<<7)|(0<<6)|(0<<5)|(0<<4)
;	str	r1,[r0]

	; rGPBCON=(rGPBCON&0x3f3fff)|(1<<14);	// GPB7: Output
;	ldr	r0,=GPBCON
;	ldr	r1,=(1<<14)
;	str	r1,[r0]

	; rGPFCON=(rGPFCON&0x00ff)|(0x5500);  // GPF4~7: Output 
;	ldr	r0,=GPFCON
;	ldr	r1,=(0x5500)
;	str	r1,[r0]

	; rGPBDAT&=~(1<<8);   //Latch enable
;	ldr	r0,=GPBDAT
;	ldr	r1, [r0]
;	bic   r1, r1, #(1<<8)
;	str	r1,[r0]

	; rGPBCON=(rGPBCON&0x3cffff)|(1<<16);	// GPB8: Output
;	ldr	r0,=GPBCON
;	ldr	r1, [r0]
;	bic   r1, r1, #(1<<16)
;	orr   r1, r1, #(1<<16)
;	str	r1,[r0]
	
	; rGPBDAT|=(1<<10);   //Output enable
;	ldr	r0,=GPBDAT
;	ldr   r1, [r0]
;	orr	r1, r1, #(1<<10)
;	str	r1,[r0]