ADSArm2440启动代码分析文档格式.docx

ADSArm2440启动代码分析文档格式.docx

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importheadfile

GEToption.inc

GETmemcfg.inc

GET2440addr.inc

BIT_SELFREFRESHEQU（1<

<

22

配置模式

Pre-definedconstants

USERMODEEQU0x10

FIQMODEEQU0x11

IRQMODEEQU0x12

系统监控模式

SVCMODEEQU0x13

ABORTMODEEQU0x17

UNDEFMODEEQU0x1b

模式屏蔽寄存器

MODEMASKEQU0x1f

NOINTEQU0xc0

堆栈的定义大小及地址

Thelocationofstacks

UserStackEQU（_STACK_BASEADDRESS-0x3800;

0x33ff4800~

SVCStackEQU（_STACK_BASEADDRESS-0x2800;

0x33ff5800~

UndefStackEQU（_STACK_BASEADDRESS-0x2400;

0x33ff5c00~

AbortStackEQU（_STACK_BASEADDRESS-0x2000;

0x33ff6000~

IRQStackEQU（_STACK_BASEADDRESS-0x1000;

0x33ff7000~

FIQStackEQU（_STACK_BASEADDRESS-0x0;

0x33ff8000~

检测是工作在thumb状态下还是arm状态下;

Checkiftasm.exe（armasm-16...@ADS1.0isused.

GBLLTHUMBCODE

[{CONFIG}=16

THUMBCODESETL{TRUE}

CODE32

|

THUMBCODESETL{FALSE}

]

MACRO

MOV_PC_LR

[THUMBCODE

bxlr

movpc,lr

MEND

MOVEQ_PC_LR

bxeqlr

moveqpc,lr

$HandlerLabelHANDLER$HandleLabel;

宏定义的调用方式

$HandlerLabel

subsp,sp,#4;

decrementsp（tostorejumpaddress

stmfdsp!

{r0};

PUSHtheworkregistertostack（lrdoes'

tpushbecauseitreturntooriginaladdress

ldrr0,=$HandleLabel;

loadtheaddressofHandleXXXtor0

ldrr0,[r0];

loadthecontents（serviceroutinestartaddressofHandleXXX

strr0,[sp,#4];

storethecontents（ISRofHandleXXXtostackldmfdsp!

{r0,pc};

POPtheworkregisterandpc（jumptoISR

MEND;

宏定义的结束

------------------------------------------------------------------;

外部定义的函数和变量的声明

IMPORT|Image$$RO$$Limit|;

EndofROMcode（=startofROMdataIMPORT|Image$$RW$$Base|;

BaseofRAMtoinitialise

IMPORT|Image$$ZI$$Base|;

Baseandlimitofarea

IMPORT|Image$$ZI$$Limit|;

tozeroinitialise

IMPORTMain

代码段的入口

AREAInit,CODE,READONLY

ENTRY

1Thecode,whichconvertstoBig-endian,shouldbeinlittleendiancode.;

2ThefollowinglittleendiancodewillbecompiledinBig-Endianmode.;

Thecodebyteordershouldbechangedasthememorybuswidth.

3Thepseudoinstruction,DCDcan'

tbeusedherebecausethelinkergenerateserror.

ASSERT:

DEF:

ENDIAN_CHANGE

[ENDIAN_CHANGE

ENTRY_BUS_WIDTH

[ENTRY_BUS_WIDTH=32

bChangeBigEndian;

DCD0xea000007

[ENTRY_BUS_WIDTH=16

andeqr14,r7,r0,lsl#20;

DCD0x0007ea00

[ENTRY_BUS_WIDTH=8

streqr0,[r0,-r10,ror#1];

DCD0x070000ea

bResetHandler

bHandlerUndef;

handlerforUndefinedmode

bHandlerSWI;

handlerforSWIinterrupt

bHandlerPabort;

handlerforPAbort

bHandlerDabort;

handlerforDAbort

b.;

reserved

bHandlerIRQ;

handlerforIRQinterrupt

bHandlerFIQ;

handlerforFIQinterrupt

@0x20

bEnterPWDN;

Mustbe@0x20.

ChangeBigEndian

@0x24

DCD0xee110f10;

0xee110f10=>

mrcp15,0,r0,c1,c0,0

DCD0xe3800080;

0xe3800080=>

orrr0,r0,#0x80;

//Big-endian

DCD0xee010f10;

0xee010f10=>

mcrp15,0,r0,c1,c0,0

DCD0x0f10ee11

DCD0x0080e380

DCD0x0f10ee01

DCD0x100f11ee

DCD0x800080e3

DCD0x100f01ee

DCD0xffffffff;

swinv0xffffffissimilarwithNOPandrunwellinbothendianmode.

DCD0xffffffff

Functionforenteringpowerdownmode

1.SDRAMshouldbeinself-refreshmode.

2.AllinterruptshouldbemakskedforSDRAM/DRAMself-refresh.;

3.LCDcontrollershouldbedisabledforSDRAM/DRAMself-refresh.;

4.TheI-cachemayhavetobeturnedon.

5.Thelocationofthefollowingcodemayhavenottobechanged.;

voidEnterPWDN（intCLKCON;

EnterPWDN

movr2,r0;

r2=rCLKCON

tstr0,#0x8;

SLEEPmode?

bneENTER_SLEEP

ENTER_STOP

ldrr0,=REFRESH

ldrr3,[r0];

r3=rREFRESH

movr1,r3

orrr1,r1,#BIT_SELFREFRESH

strr1,[r0];

EnableSDRAMself-refresh

movr1,#16;

waituntilself-refreshisissued.maynotbeneeded.0subsr1,r1,#1

bne%B0

ldrr0,=CLKCON;

enterSTOPmode.

strr2,[r0]

movr1,#32

0subsr1,r1,#1;

1waituntiltheSTOPmodeisineffect.

bne%B0;

2OrwaithereuntiltheCPU&

Peripheralswillbeturned-off;

EnteringSLEEPmode,onlytheresetbywake-upisavailable.ldrr0,=REFRESH;

exitfromSDRAMselfrefreshmode.

strr3,[r0]

ENTER_SLEEP

NOTE.

1rGSTATUS3shouldhavethereturnaddressafterwake-upfromSLEEPmode.

ldrr1,[r0];

r1=rREFRESH

Waituntilself-refreshisissued,whichmaynotbeneeded.0subsr1,r1,#1

ldrr1,=MISCCR

ldrr0,[r1]

orrr0,r0,#（7<

17;

SetSCLK0=0,SCLK1=0,SCKE=0.

strr0,[r1]

ldr