;=========================================<br />; NAME: 2440INIT.S<br />; DESC: C start up codes<br />; Configure memory, ISR ,stacks<br />; Initialize C-variables<br />; HISTORY:<br />; 2002.02.25:kwtark: ver 0.0<br />; 2002.03.20:purnnamu: Add some functions for testing STOP,Sleep mode<br />; 2003.03.14:DonGo: Modified for 2440.<br />;=========================================<br /><br /> GET option.inc<br /> GET memcfg.inc<br /> GET 2440addr.inc<br /><br />BIT_SELFREFRESH EQU (1<<22) ;bit[22]=1,others=0<br /><br />;Pre-defined constants ;系统的工作模式设定<br />USERMODE EQU 0x10<br />FIQMODE EQU 0x11<br />IRQMODE EQU 0x12<br />SVCMODE EQU 0x13<br />ABORTMODE EQU 0x17<br />UNDEFMODE EQU 0x1b<br />MODEMASK EQU 0x1f<br />NOINT EQU 0xc0<br /><br />;The location of stacks ;系统的堆栈空间设定<br />UserStack EQU (_STACK_BASEADDRESS-0x3800) ;0x33ff4800 ~<br />SVCStack EQU (_STACK_BASEADDRESS-0x2800) ;0x33ff5800 ~<br />UndefStack EQU (_STACK_BASEADDRESS-0x2400) ;0x33ff5c00 ~<br />AbortStack EQU (_STACK_BASEADDRESS-0x2000) ;0x33ff6000 ~<br />IRQStack EQU (_STACK_BASEADDRESS-0x1000) ;0x33ff7000 ~<br />FIQStack EQU (_STACK_BASEADDRESS-0x0) ;0x33ff8000 ~<br /><br />;arm处理器有两种工作状态 1.arm:32位 这种工作状态下执行字对准的arm指令 2.Thumb:16位 这种工作状<br />;态执行半字对准的Thumb指令 <br />;因为处理器分为16位 32位两种工作状态 程序的编译器也是分16位和32两种编译方式 所以下面的程序用<br />;于根据处理器工作状态确定编译器编译方式 <br />;code16伪指令指示汇编编译器后面的指令为16位的thumb指令 <br />;code32伪指令指示汇编编译器后面的指令为32位的arm指令 <br />;这段是为了统一目前的处理器工作状态和软件编译方式(16位编译环境使用tasm.exe编译<br />;Check if tasm.exe(armasm -16 ...@ADS 1.0) is used.<br /><br /> GBLL THUMBCODE ;定义一个全局变量<br /> [ {CONFIG} = 16 ;if config==16 这里表示你的目前处于领先地16位编译方式<br />THUMBCODE SETL {TRUE} ;设置THUMBCODE 为 true表示告诉系统当前想用thumb,但实际启动时不行,只能启动后再跳<br /> ; ][|]表示if else endif <br /> CODE32 ;启动时强制使用32位编译模式<br /> |<br />THUMBCODE SETL {FALSE} ;如果系统要求是ARM指令,则直接设置THUMBCODE 为 false 说明当前的是32位编译模式<br /> ]<br /><br /> MACRO ;宏定义<br /> MOV_PC_LR<br /> [ THUMBCODE<br /> bx lr<br /> |<br /> mov pc,lr<br /> ]<br /> MEND<br /><br /> MACRO<br /> MOVEQ_PC_LR<br /> [ THUMBCODE<br /> bxeq lr ;相等Z=1,则跳转<br /> |<br /> moveq pc,lr<br /> ]<br /> MEND<br /><br />;注意下面这段程序是个宏定义 很多人对这段程序不理解 我再次强调这是一个宏定义 所以大家要注意了<br />;下面包含的HandlerXXX HANDLER HandleXXX将都被下面这段程序展开 <br />;这段程序用于把中断服务程序的首地址装载到pc中,有人称之为“加载程序”。 <br />;本初始化程序定义了一个数据区(在文件最后),34个字空间,存放相应中断服务程序的首地址。每个字<br />;空间都有一个标号,以Handle***命名。 <br />;在向量中断模式下使用“加载程序”来执行中断服务程序。 <br />;这里就必须讲一下向量中断模式和非向量中断模式的概念 <br />;向量中断模式是当cpu读取位于0x18处的IRQ中断指令的时候,系统自动读取对应于该中断源确定地址上的;<br />;指令取代0x18处的指令,通过跳转指令系统就直接跳转到对应地址 <br />;函数中 节省了中断处理时间提高了中断处理速度标 例如 ADC中断的向量地址为0xC0,则在0xC0处放如下<br />;代码:ldr PC,=HandlerADC 当ADC中断产生的时候系统会 <br />;自动跳转到HandlerADC函数中 <br />;非向量中断模式处理方式是一种传统的中断处理方法,当系统产生中断的时候,系统将interrupt <br />;pending寄存器中对应标志位置位 然后跳转到位于0x18处的统一中断 <br />;函数中 该函数通过读取interrupt pending寄存器中对应标志位 来判断中断源 并根据优先级关系再跳到<br />;对应中断源的处理代码中<br /><br /> MACRO <br />$HandlerLabel HANDLER $HandleLabel<br /><br />$HandlerLabel<br /> sub sp,sp,#4 ;decrement sp(to store jump address)<br /> stmfd sp!,{r0} ;PUSH the work register to stack(lr does't push because it return to original address)<br /> ldr r0,=$HandleLabel;load the address of HandleXXX to r0<br /> ldr r0,[r0] ;load the contents(service routine start address) of HandleXXX<br /> str r0,[sp,#4] ;store the contents(ISR) of HandleXXX to stack<br /> ldmfd sp!,{r0,pc} ;POP the work register and pc(jump to ISR)<br /> MEND<br />;将$HandleLabel地址空间中的数据给PC,中断服务程序的入口<br /><br /><br /> IMPORT |Image$$RO$$Limit| ; End of ROM code (=start of ROM data)<br /> IMPORT |Image$$RW$$Base| ; Base of RAM to initialise<br /> IMPORT |Image$$ZI$$Base| ; Base and limit of area<br /> IMPORT |Image$$ZI$$Limit| ; to zero initialise<br /><br /> IMPORT Main<br />;导入要用到的字符常量<br /><br /> AREA Init,CODE,READONLY<br /><br />;异常中断矢量表(每个表项占4个字节) 下面是中断向量表 一旦系统运行时有中断发生 即使移植了操作<br />;系统 如linux 处理器已经把控制权交给了操作系统 一旦发生中断 处理器还是会跳转到从0x0开始 <br />;中断向量表中某个中断表项(依据中断类型)开始执行 <br />;具体中断向量布局请参考s3c44b0 spec 例如 adc中断向量为 0x000000c0下面对应表中第49项位置 向量地址0x0+4*(49-1)=0x000000c0 <br /><br /> ENTRY<br />;板子上电和复位后 程序开始从位于0x0处开始执行硬件刚刚上电复位后 程序从这里开始执行跳转到标<br />;为ResetHandler处执行<br /><br /> ;1)The code, which converts to Big-endian, should be in little endian code.<br /> ;2)The following little endian code will be compiled in Big-Endian mode.<br /> ; The code byte order should be changed as the memory bus width.<br /> ;3)The pseudo instruction,DCD can't be used here because the linker generates error.<br /> <br /> ;条件编译,在编译成机器码前就设定好<br /> ASSERT :DEF:ENDIAN_CHANGE ;判断ENDIAN_CHANGE是否已定义<br /> [ ENDIAN_CHANGE ;如果已经定义了ENDIAN_CHANGE,则判断,here is FALSE<br /> ASSERT :DEF:ENTRY_BUS_WIDTH ;判断ENTRY_BUS_WIDTH是否已定义<br /> ][ ENTRY_BUS_WIDTH=32 ;如果已经定义了ENTRY_BUS_WIDTH,则判断是不是为32<br /> b ChangeBigEndian ;DCD 0xea000007<br /> ]<br /> ;在bigendian中,地址为A的字单元包括字节单元A,A+1,A+2,A+3,字节单元由高位到低位为A,A+1,A+2,A+3<br /> ; 地址为A的字单元包括半字单元A,A+2,半字单元由高位到低位为A,A+2<br /> [ ENTRY_BUS_WIDTH=16<br /> andeq r14,r7,r0,lsl #20 ;DCD 0x0007ea00 也是b ChangeBigEndian指令,只是由于总线不一样而取机器码的顺序不一样<br /> ] ;先取低位->高位 上述指令是通过机器码装换而来的<br /><br /> [ ENTRY_BUS_WIDTH=8<br /> streq r0,][r0,-r10,ror #1] ;DCD 0x070000ea 也是b ChangeBigEndian指令,只是由于总线不一样而取机器码的顺序不一样<br /> ]<br /> |<br /> b ResetHandler ;//here is the first instrument 0x00<br /> ]<br /> b HandlerUndef ;handler for Undefined mode ;0x04<br /> b HandlerSWI ;handler for SWI interrupt ;0x08<br /> b HandlerPabort ;handler for PAbort ;0x0c<br /> b HandlerDabort ;handler for DAbort ;0x10<br /> b . ;reserved ;0x14<br /> b HandlerIRQ ;handler for IRQ interrupt ;0x18<br /> b HandlerFIQ ;handler for FIQ interrupt ;0x1c<br /><br />;@0x20<br /> b EnterPWDN ; Must be @0x20.<br /><br /><br />;通过设置CP15的C1的位7,设置存储格式为Bigendian,三种总线方式<br />ChangeBigEndian ;//here ENTRY_BUS_WIDTH=16<br />;@0x24<br /> [ ENTRY_BUS_WIDTH=32<br /> DCD 0xee110f10 ;0xee110f10 => mrc p15,0,r0,c1,c0,0<br /> DCD 0xe3800080 ;0xe3800080 => orr r0,r0,#0x80; //Big-endian<br /> DCD 0xee010f10 ;0xee010f10 => mcr p15,0,r0,c1,c0,0<br /> ;对存储器控制寄存器操作,指定内存模式为Big-endian<br /> ;因为刚开始CPU都是按照32位总线的指令格式运行的,如果采用其他的话,CPU别不了,必须转化<br /> ;但当系统初始化好以后,则CPU能自动识别<br /> ]<br /> [ ENTRY_BUS_WIDTH=16<br /> DCD 0x0f10ee11<br /> DCD 0x0080e380<br /> DCD 0x0f10ee01<br /> ;因为采用Big-endian模式,采用16位总线时,物理地址的高位和数据的地位对应<br /> ;所以指令的机器码也相应的高低对调<br /> ]<br /> [ ENTRY_BUS_WIDTH=8<br /> DCD 0x100f11ee<br /> DCD 0x800080e3<br /> DCD 0x100f01ee<br /> ]<br /> DCD 0xffffffff ;swinv 0xffffff is similar with NOP and run well in both endian mode.<br /> DCD 0xffffffff<br /> DCD 0xffffffff<br /> DCD 0xffffffff<br /> DCD 0xffffffff<br /> b ResetHandler<br /><br />;Function for entering power down mode<br />; 1. SDRAM should be in self-refresh mode.<br />; 2. All interrupt should be maksked for SDRAM/DRAM self-refresh.<br />; 3. LCD controller should be disabled for SDRAM/DRAM self-refresh.<br />; 4. The I-cache may have to be turned on.<br />; 5. The location of the following code may have not to be changed.<br /><br />;void EnterPWDN(int CLKCON);<br />EnterPWDN<br /> mov r2,r0 ;r2=rCLKCON 保存原始数据 0x4c00000c 使能各模块的时钟输入<br /> tst r0,#0x8 ;测试bit[3] SLEEP mode? 1=>sleep<br /> bne ENTER_SLEEP ;C=0,即TST结果非0,bit[3]=1<br /><br />;//进入PWDN后如果不是sleep则进入stop<br /><br />;//进入Stop mode<br />ENTER_STOP<br /> ldr r0,=REFRESH ;0x48000024 DRAM/SDRAM refresh config<br /> ldr r3,[r0] ;r3=rREFRESH<br /> mov r1, r3<br /> orr r1, r1, #BIT_SELFREFRESH ;Enable SDRAM self-refresh<br /> str r1, [r0] ;Enable SDRAM self-refresh<br />;//Enable SDRAM self-refresh<br /> mov r1,#16 ;wait until self-refresh is issued. may not be needed.<br />0 subs r1,r1,#1<br /> bne %B0<br />;//wait 16 fclks for self-refresh<br /> ldr r0,=CLKCON ;enter STOP mode.<br /> str r2,[r0]<br />;//??????????????<br /><br /> mov r1,#32<br />0 subs r1,r1,#1 ;1) wait until the STOP mode is in effect.<br /> bne %B0 ;2) Or wait here until the CPU&Peripherals will be turned-off<br /> ;Entering SLEEP mode, only the reset by wake-up is available.<br /><br /> ldr r0,=REFRESH ;exit from SDRAM self refresh mode.<br /> str r3,[r0]<br /><br /> MOV_PC_LR ;back to main process<br /> <br /><br />ENTER_SLEEP<br /> ;NOTE.<br /> ;1) rGSTATUS3 should have the return address after wake-up from SLEEP mode.<br /><br /> ldr r0,=REFRESH<br /> ldr r1,[r0] ;r1=rREFRESH<br /> orr r1, r1, #BIT_SELFREFRESH<br /> str r1, [r0] ;Enable SDRAM self-refresh<br />;//Enable SDRAM self-refresh<br /><br /> mov r1,#16 ;Wait until self-refresh is issued,which may not be needed.<br />0 subs r1,r1,#1<br /> bne %B0<br />;//Wait until self-refresh is issued,which may not be needed<br /><br /> ldr r1,=MISCCR ;IO register <br /> ldr r0,[r1]<br /> orr r0,r0,#(7<<17) ;Set SCLK0=1, SCLK1=1, SCKE=1.<br /> str r0,[r1]<br /><br /> ldr r0,=CLKCON ; Enter sleep mode<br /> str r2,[r0]<br /><br /> b . ;CPU will die here.<br />;//进入Sleep Mode,1)设置SDRAM为self-refresh<br />;// 2)设置MISCCR bit[17] 1:sclk0=sclk 0:sclk0=0<br />;// bit[18] 1:sclk1=sclk 0:sclk1=0<br />;// bit[19] 1:Self refresh retain enable<br />;// 0:Self refresh retain disable <br />;// When 1, After wake-up from sleep, The self-refresh will be retained.<br /><br />WAKEUP_SLEEP<br /> ;Release SCLKn after wake-up from the SLEEP mode.<br /> ldr r1,=MISCCR<br /> ldr r0,[r1]<br /> bic r0,r0,#(7<<17) ;SCLK0:0->SCLK, SCLK1:0->SCLK, SCKE:0->=SCKE.<br /> str r0,[r1]<br />;//设置MISCCR<br /><br /> ;Set memory control registers<br /> ldr r0,=SMRDATA<br /> ldr r1,=BWSCON ;BWSCON Address ;//总线宽度和等待控制寄存器<br /> add r2, r0, #52 ;End address of SMRDATA<br />0<br /> ldr r3, [r0], #4 ;数据处理后R0自加4,[R0]->R3,R0+4->R0<br /> str r3, [r1], #4<br /> cmp r2, r0<br /> bne %B0<br />;//设置所有的memory control register,他的初始地址为BWSCON,初始化<br />;//数据在以SMRDATA为起始的存储区<br /><br /> mov r1,#256<br />0 subs r1,r1,#1 ;1) wait until the SelfRefresh is released.<br /> bne %B0<br />;//1) wait until the SelfRefresh is released.<br /><br /> ldr r1,=GSTATUS3 ;GSTATUS3 has the start address just after SLEEP wake-up<br /> ldr r0,[r1]<br /><br /> mov pc,r0<br />;//跳出Sleep Mode,进入Sleep状态前的PC<br /><br /><br /><br />;//异常中断宏调用<br /> LTORG<br />HandlerFIQ HANDLER HandleFIQ<br />HandlerIRQ HANDLER HandleIRQ<br />HandlerUndef HANDLER HandleUndef<br />HandlerSWI HANDLER HandleSWI<br />HandlerDabort HANDLER HandleDabort<br />HandlerPabort HANDLER HandlePabort<br /><br />IsrIRQ<br /> sub sp,sp,#4 ;reserved for PC<br /> stmfd sp!,{r8-r9}<br /><br /> ldr r9,=INTOFFSET ;地址为0x4a000014的空间存着中断的偏移<br /> ldr r9,[r9] ;I_ISR<br /> ldr r8,=HandleEINT0<br /> add r8,r8,r9,lsl #2<br /> ldr r8,[r8]<br /> str r8,[sp,#8]<br /> ldmfd sp!,{r8-r9,pc}<br />;//外部中断号判断,通过中断服务程序入口地址存储器的地址偏移确定<br />;//PC=[HandleEINT0+][INTOFFSET]]<br /><br />;=======<br />; ENTRY<br />;扳子上电和复位后 程序开始从位于0x0执行b ResetHandler 程序从跳转到这里执行 <br />;板子上电复位后 执行几个步骤这里通过标号在注释中加1,2,3....标示 标号表示执行顺序 <br />;1.禁止看门狗 屏蔽所有中断<br />;=======<br />ResetHandler<br /><br />;//1.禁止看门狗 屏蔽所有中断<br /> ldr r0,=WTCON ;watch dog disable<br /> ldr r1,=0x0<br /> str r1,[r0]<br /><br /> ldr r0,=INTMSK<br /> ldr r1,=0xffffffff ;all interrupt disable<br /> str r1,[r0]<br /><br /> ldr r0,=INTSUBMSK<br /> ldr r1,=0x3ff ;all sub interrupt disable<br /> str r1,[r0]<br /><br /> [ {FALSE}<br /> ;//rGPFDAT = (rGPFDAT & ~(0xf<<4)) | ((~data & 0xf)<<4);<br /> ;//Led_Display<br /> ldr r0,=GPFCON ;//F-IO In/Out config 10 10 10 10 00 00 00 00<br /> ldr r1,=0x5500 ;//00 = Input 01 = Output<br /> str r1,][r0] ;//10 = EINT[0] 11 = Reserved <br /> ldr r0,=GPFDAT ;//F-IO data register<br /> ldr r1,=0x10<br /> str r1,[r0]<br /> ]<br /><br />;//2.根据工作频率设置pll <br />;这里介绍一下计算公式 <br />;//Fpllo=(m*Fin)/(p*2^s) <br />;//m=MDIV+8,p=PDIV+2,s=SDIV <br />;The proper range of P and M: 1<=P<=62, 1<=M<=248<br /><br />;Fpllo必须大于20Mhz小于66Mhz <br />;Fpllo*2^s必须小于170Mhz <br />;如下面的PLLCON设定中的M_DIV P_DIV S_DIV是取自option.h中 <br />;#elif (MCLK==40000000) <br />;#define PLL_M (0x48) <br />;#define PLL_P (0x3) <br />;#define PLL_S (0x2) <br />;所以m=MDIV+8=80,p=PDIV+2=5,s=SDIV=2 <br />;硬件使用晶振为10Mhz,即Fin=10Mhz <br />;Fpllo=80*10/5*2^2=40Mhz<br /><br /> ;To reduce PLL lock time, adjust the LOCKTIME register.<br /> ldr r0,=LOCKTIME<br /> ldr r1,=0xffffff<br /> str r1,[r0]<br />;//设置PLL的重置延迟<br /><br /> [ PLL_ON_START<br /> ; Added for confirm clock divide. for 2440.<br /> ; Setting value Fclk:Hclk:Pclk<br /> ldr r0,=CLKDIVN <br /> 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.<br /> str r1,][r0] ;//数据表示分频数<br /><br /> ;//Configure UPLL Fin=12.0MHz UFout=48MHz<br /> ldr r0,=UPLLCON<br /> ldr r1,=((U_MDIV<<12)+(U_PDIV<<4)+U_SDIV) ;//USB PLL CONFIG<br /> str r1,[r0]<br /> <br /> nop ;// Caution: After UPLL setting, at least 7-clocks delay must be inserted for setting hardware be completed.<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /> ;//Configure MPLL Fin=12.0MHz MFout=304.8MHz<br /> ldr r0,=MPLLCON<br /> ldr r1,=((M_MDIV<<12)+(M_PDIV<<4)+M_SDIV) <br /> str r1,[r0]<br /> ]<br /> <br />;//Check if the boot is caused by the wake-up from SLEEP mode.<br /> ldr r1,=GSTATUS2<br /> ldr r0,[r1]<br /> tst r0,#0x2 ;test if bit[1] is 1 or 0 0->C=1<br /> ; 1->C=0<br /> ;In case of the wake-up from SLEEP mode, go to SLEEP_WAKEUP handler.<br /> bne WAKEUP_SLEEP ;C=0,jump<br /><br /> EXPORT StartPointAfterSleepWakeUp<br />StartPointAfterSleepWakeUp<br /><br />;//3.置存储相关寄存器的程序 <br />;这是设置SDRAM,flash ROM 存储器连接和工作时序的程序,片选定义的程序 <br />;SMRDATA map在下面的程序中定义 <br />;SMRDATA中涉及的值请参考memcfg.s程序 <br />;具体寄存器各位含义请参考s3c44b0 spec <br /> ;Set memory control registers<br /> ldr r0,=SMRDATA<br /> ldr r1,=BWSCON ;BWSCON Address<br /> add r2, r0, #52 ;End address of SMRDATA<br /><br /> <br />0<br /> ldr r3, [r0], #4<br /> str r3, [r1], #4<br /> cmp r2, r0<br /> bne %B0<br />;//set memory registers<br /><br /><br />;//4.初始化各模式下的栈指针<br /> ;Initialize stacks<br /> bl InitStacks<br /> <br /> <br /><br />;//5.设置缺省中断处理函数 <br /> ; Setup IRQ handler<br /> ldr r0,=HandleIRQ ;This routine is needed<br /> ldr r1,=IsrIRQ ;if there isn't 'subs pc,lr,#4' at 0x18, 0x1c<br /> str r1,[r0]<br /> ;//initialize the IRQ 将普通中断判断程序的入口地址给HandleIRQ<br /> <br /> <br /><br />;//6.将数据段拷贝到ram中 将零初始化数据段清零 跳入C语言的main函数执行 到这步结束bootloader初步引导结束<br /> ;If main() is used, the variable initialization will be done in __main().<br /> <br /> [ :LNOT:USE_MAIN ;initialized {FALSE}<br /> ;Copy and paste RW data/zero initialized data<br /> <br /> LDR r0, =|Image$$RO$$Limit| ; Get pointer to ROM data<br /> LDR r1, =|Image$$RW$$Base| ; and RAM copy<br /> LDR r3, =|Image$$ZI$$Base| <br /> <br /> ;Zero init base => top of initialised data<br /> CMP r0, r1 ; Check that they are different just for debug??????????????????????????<br /> BEQ %F2<br />1 <br /> CMP r1, r3 ; Copy init data<br /> LDRCC r2, ][r0], #4 ;--> LDRCC r2, [r0] + ADD r0, r0, #4 <br /> STRCC r2, [r1], #4 ;--> STRCC r2, [r1] + ADD r1, r1, #4<br /> BCC %B1<br />2 <br /> LDR r1, =|Image$$ZI$$Limit| ; Top of zero init segment<br /> MOV r2, #0<br />3 <br /> CMP r3, r1 ; Zero init<br /> STRCC r2, [r3], #4<br /> BCC %B3<br /> ]<br /><br /><br /> <br /> [ :LNOT:THUMBCODE ;if thumbcode={false} bl main<br /> bl Main ;Don't use main() because ......<br /> b . <br /> ]<br /><br /><br />;//if thumbcod={ture}<br /> [ THUMBCODE ;for start-up code for Thumb mode<br /> orr lr,pc,#1<br /> bx lr<br /> CODE16<br /> bl Main ;Don't use main() because ......<br /> b .<br /> CODE32<br /> ]<br /><br /><br />;function initializing stacks<br />InitStacks<br /> ;Don't use DRAM,such as stmfd,ldmfd......<br /> ;SVCstack is initialized before<br /> ;Under toolkit ver 2.5, 'msr cpsr,r1' can be used instead of 'msr cpsr_cxsf,r1'<br /> <br /> mrs r0,cpsr<br /> bic r0,r0,#MODEMASK<br /> orr r1,r0,#UNDEFMODE|NOINT<br /> msr cpsr_cxsf,r1 ;UndefMode<br /> ldr sp,=UndefStack ; UndefStack=0x33FF_5C00<br /><br /> orr r1,r0,#ABORTMODE|NOINT<br /> msr cpsr_cxsf,r1 ;AbortMode<br /> ldr sp,=AbortStack ; AbortStack=0x33FF_6000<br /><br /> orr r1,r0,#IRQMODE|NOINT<br /> msr cpsr_cxsf,r1 ;IRQMode<br /> ldr sp,=IRQStack ; IRQStack=0x33FF_7000<br /><br /> orr r1,r0,#FIQMODE|NOINT<br /> msr cpsr_cxsf,r1 ;FIQMode<br /> ldr sp,=FIQStack ; FIQStack=0x33FF_8000<br /><br /> bic r0,r0,#MODEMASK|NOINT<br /> orr r1,r0,#SVCMODE<br /> msr cpsr_cxsf,r1 ;SVCMode<br /> ldr sp,=SVCStack ; SVCStack=0x33FF_5800<br /><br /> ;USER mode has not be initialized.<br /> ;//为什么不用初始化user的stacks,系统刚启动的时候运行在哪个模式下???????????????????<br /> mov pc,lr<br /> ;The LR register won't be valid if the current mode is not SVC mode.?????????????<br />;//系统一开始运行就是SVCmode????????????????????????????????????????<br /> <br />;=====================================================================<br />; Clock division test<br />; Assemble code, because VSYNC time is very short<br />;=====================================================================<br /> EXPORT CLKDIV124<br /> EXPORT CLKDIV144<br /> <br />CLKDIV124<br /> <br /> ldr r0, = CLKDIVN<br /> ldr r1, = 0x3 ; 0x3 = 1:2:4<br /> str r1, [r0]<br />; wait until clock is stable<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /><br /> ldr r0, = REFRESH<br /> ldr r1, [r0]<br /> bic r1, r1, #0xff<br /> bic r1, r1, #(0x7<<8)<br /> orr r1, r1, #0x470 ; REFCNT135<br /> str r1, [r0]<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /> mov pc, lr<br /><br />CLKDIV144<br /> ldr r0, = CLKDIVN<br /> ldr r1, = 0x4 ; 0x4 = 1:4:4<br /> str r1, [r0]<br />; wait until clock is stable<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /><br /> ldr r0, = REFRESH<br /> ldr r1, [r0]<br /> bic r1, r1, #0xff<br /> bic r1, r1, #(0x7<<8)<br /> orr r1, r1, #0x630 ; REFCNT675 - 1520<br /> str r1, [r0]<br /> nop<br /> nop<br /> nop<br /> nop<br /> nop<br /> mov pc, lr<br /><br /><br />;存储器控制寄存器的定义区<br /> LTORG<br /><br />SMRDATA DATA<br />; Memory configuration should be optimized for best performance<br />; The following parameter is not optimized.<br />; Memory access cycle parameter strategy<br />; 1) The memory settings is safe parameters even at HCLK=75Mhz.<br />; 2) SDRAM refresh period is for HCLK<=75Mhz.<br /><br /> DCD (0+(B1_BWSCON<<4)+(B2_BWSCON<<8)+(B3_BWSCON<<12)+(B4_BWSCON<<16)+(B5_BWSCON<<20)+(B6_BWSCON<<24)+(B7_BWSCON<<28))<br /> DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC)) ;GCS0<br /> DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC)) ;GCS1<br /> DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC)) ;GCS2<br /> DCD ((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC)) ;GCS3<br /> DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC)) ;GCS4<br /> DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC)) ;GCS5<br /> DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN)) ;GCS6<br /> DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN)) ;GCS7<br /> DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT)<br /><br /> DCD 0x32 ;SCLK power saving mode, BANKSIZE 128M/128M<br /><br /> DCD 0x30 ;MRSR6 CL=3clk<br /> DCD 0x30 ;MRSR7 CL=3clk<br /><br /><br /> ALIGN<br /><br /> AREA RamData, DATA, READWRITE<br /><br /> ^ _ISR_STARTADDRESS ; _ISR_STARTADDRESS=0x33FF_FF00<br />HandleReset # 4<br />HandleUndef # 4<br />HandleSWI # 4<br />HandlePabort # 4<br />HandleDabort # 4<br />HandleReserved # 4<br />HandleIRQ # 4<br />HandleFIQ # 4<br /><br />;Don't use the label 'IntVectorTable',<br />;The value of IntVectorTable is different with the address you think it may be.<br />;IntVectorTable<br />;@0x33FF_FF20<br />HandleEINT0 # 4<br />HandleEINT1 # 4<br />HandleEINT2 # 4<br />HandleEINT3 # 4<br />HandleEINT4_7 # 4<br />HandleEINT8_23 # 4<br />HandleCAM # 4 ; Added for 2440.<br />HandleBATFLT # 4<br />HandleTICK # 4<br />HandleWDT # 4<br />HandleTIMER0 # 4<br />HandleTIMER1 # 4<br />HandleTIMER2 # 4<br />HandleTIMER3 # 4<br />HandleTIMER4 # 4<br />HandleUART2 # 4<br />;@0x33FF_FF60<br />HandleLCD # 4<br />HandleDMA0 # 4<br />HandleDMA1 # 4<br />HandleDMA2 # 4<br />HandleDMA3 # 4<br />HandleMMC # 4<br />HandleSPI0 # 4<br />HandleUART1 # 4<br />HandleNFCON # 4 ; Added for 2440.<br />HandleUSBD # 4<br />HandleUSBH # 4<br />HandleIIC # 4<br />HandleUART0 # 4<br />HandleSPI1 # 4<br />HandleRTC # 4<br />HandleADC # 4<br />;@0x33FF_FFA0<br /> END<br /> |
|