最小的mini2440初始化代码（三）

;====================================================================; File Name : MiniBoot.s; Function : 初始化Mini2440开发板，使得JTAG可以调试ROM/RAM中的代码; 关闭看门狗，屏蔽中断和子中断，配置存储器; Revision: V1.0 2009-03-20 dddkkf; Revision: V1.1 2009-03-30 dddkkf 增加异常跳转、栈初始化;====================================================================; 参考代码<2440mini.s> <2440add.inc> <memcfg.inc>; 编译器：ADS1.2; 芯片类型：S32440A(ARM920T); 链接选项：-entry 0 -ro-base 0 -first MiniBoot.o(boot); 烧录到NAND Flash 地址0x0000_0000;====================================================================; File Name : 2440addr.a; Function : S3C2440 Define Address Register (Assembly); Date : March 27, 2002; Revision: Programming start (February 18,2002) -> SOP; Revision: 03.11.2003 ver 0.0Attatched for 2440;====================================================================;=================; Memory control;=================BWSCON EQU 0x48000000 ;Bus width & wait statusBANKCON0EQU 0x48000004 ;Boot ROM controlBANKCON1EQU 0x48000008 ;BANK1 controlBANKCON2EQU 0x4800000c ;BANK2 controlBANKCON3EQU 0x48000010 ;BANK3 controlBANKCON4EQU 0x48000014 ;BANK4 controlBANKCON5EQU 0x48000018 ;BANK5 controlBANKCON6EQU 0x4800001c ;BANK6 controlBANKCON7EQU 0x48000020 ;BANK7 controlREFRESH EQU 0x48000024 ;DRAM/SDRAM refreshBANKSIZEEQU 0x48000028 ;Flexible Bank SizeMRSRB6 EQU 0x4800002c ;Mode register set for SDRAM Bank6MRSRB7 EQU 0x48000030 ;Mode register set for SDRAM Bank7;=================; INTERRUPT;=================INTMSK EQU 0x4a000008 ;Interrupt mask controlINTSUBMSKEQU 0x4a00001c ;Interrupt sub mask;=================; WATCH DOG TIMER;=================WTCON EQU 0x53000000 ;Watch-dog timer mode;************************************************; NAME : MEMCFG.A; DESC : Memory bank configuration file; Revision: 02.28.2002 ver 0.0; Revision: 03.11.2003 ver 0.0Attatched for 2440;************************************************; SDRAM位于GCS6片选，地址为0x3000_0000-0x33ff_ffff; 总线宽度枚举值;BWSCONDW16EQU(0x1)DW32EQU(0x2); 评估板的内存组总线宽度; 不定义B0_BWSCON，是因为BANK0作为启动ROM，在访问前必须确定总线宽度，由OM[0:1]决定B1_BWSCONEQU (DW32); Intel Strata(28F128), 32-bit, for nCS1 when NOR Flash booting.B2_BWSCONEQU (DW16); PCMCIA(PD6710), 16-bitB3_BWSCONEQU (0xd); Ethernet(CS8900), 16-bitB4_BWSCONEQU (DW16); NOR flash(AM29LV800B), 16-bit, for nCS4 when NAND booting.B5_BWSCONEQU (DW16); A400/A410 Ext, 16-bitB6_BWSCONEQU (DW32); SDRAM(K4S561632C) 32MBx2, 32-bitB7_BWSCONEQU (DW32); N.C.; Mini2440，NOR或NAND启动; Tacs 地址有效后，等待CS; Tcos CS有效后，等待OE; Tacc 访问时间; Tcoh OE无效后，保持CS; Tah CS无效后，保持地址; Tacp Page模式下的访问时间; TPMC Page模式访问; MT 内存类型：0=SROM/3=SDRAM,; Trcd RAS到CAS的延时（地址建立时间）; SCAN 列地址位数（8/9/10bit）; Trp RAS预充电时间; Tsrc 半行周期时间; Trc=Tsrc+Trp 行周期时间;BANK0CONB0_TacsEQU0x0;0clkB0_TcosEQU0x0;0clkB0_TaccEQU0x7;14clkB0_TcohEQU0x0;0clkB0_TahEQU0x0;0clkB0_TacpEQU0x0B0_PMCEQU0x0;normal;BANK1CONB1_TacsEQU0x0;0clkB1_TcosEQU0x0;0clkB1_TaccEQU0x7;14clkB1_TcohEQU0x0;0clkB1_TahEQU0x0;0clkB1_TacpEQU0x0B1_PMCEQU0x0;normal;Bank 2 parameterB2_TacsEQU0x0;0clkB2_TcosEQU0x0;0clkB2_TaccEQU0x7;14clkB2_TcohEQU0x0;0clkB2_TahEQU0x0;0clkB2_TacpEQU0x0B2_PMCEQU0x0;normal; Mini2440，LAN;Bank 3 parameterB3_TacsEQU0x1;0clkB3_TcosEQU0x3;0clkB3_TaccEQU0x7;14clkB3_TcohEQU0x2;0clkB3_TahEQU0x1;0clkB3_TacpEQU0x3B3_PMCEQU0x0;normal;Bank 4 parameterB4_TacsEQU0x0;0clkB4_TcosEQU0x0;0clkB4_TaccEQU0x7;14clkB4_TcohEQU0x0;0clkB4_TahEQU0x0;0clkB4_TacpEQU0x0B4_PMCEQU0x0;normal;Bank 5 parameterB5_TacsEQU0x0;0clkB5_TcosEQU0x0;0clkB5_TaccEQU0x7;14clkB5_TcohEQU0x0;0clkB5_TahEQU0x0;0clkB5_TacpEQU0x0B5_PMCEQU0x0;normal; HY57V561620 (32MB=4Banks x 4M x 16Bit); Data mask function by UDQM and LDQM; Auto refresh and self refresh, 8192 refresh cycles / 64ms; Programmable CAS Latency ; 2, 3 Clocks; Row Address : RA0~12, Column Address: CA0~8;Bank 6 parameterB6_MTEQU0x3;SDRAMB6_TrcdEQU0x2;4clkB6_SCANEQU0x1;9bit;Bank 7 parameterB7_MTEQU0x3;SDRAMB7_TrcdEQU0x2;4clkB7_SCANEQU0x1;9bit;REFRESH parameterREFENEQU0x1;Refresh enableTREFMDEQU0x0;CBR(CAS before RAS)/Auto refreshTrpEQU0x2;4clkTrcEQU0x2;6clkTchrEQU0x2;3clkREFCNTEQU1269;period=7.8us, HCLK=100Mhz, (2048+1-7.8*100);===========================================; NAME: OPTION.A; DESC: Configuration options for .S files; HISTORY:; 02.28.2002: ver 0.0; 03.11.2003: ver 0.0attached for 2440.; jan E, 2004: ver0.03 modified for 2440A01.;===========================================_STACK_BASEADDRESSEQU 0x33ff8000; 堆栈起址_ISR_STARTADDRESSEQU 0x33ffff00; ISR起址;------------------------------------------------------------------------------; 代码入口;------------------------------------------------------------------------------AREA boot, CODE, READONLYENTRYCODE32_BootEntrybResetHandlerbHandlerUndef;handler for Undefined modebHandlerSWI ;handler for SWI interruptbHandlerPabort;handler for PAbortbHandlerDabort;handler for DAbortb. ;reservedbHandlerIRQ;handler for IRQ interruptbHandlerFIQ;handler for FIQ interruptResetHandler; 关闭看门狗（默认是使用看门狗复位功能，调试模式时禁止）; [WTCON]=0x0ldrr0,=WTCON ;watch dog disableldrr1,=0x0strr1,[r0]; 屏蔽所有32个中断（默认允许中断）; [INTMSK]=0xffffffffldrr0,=INTMSKldrr1,=0xffffffff ;all interrupt disablestrr1,[r0]; 屏蔽所有15个子中断（默认允许子中断）; [INTSUBMSK]=0x7fffldrr0,=INTSUBMSKldrr1,=0x7fff;all sub interrupt disablestrr1,[r0]; 把SMRDATA内存配置信息写入BWSCON开始的13个存储器控制寄存器; memcpy(BWSCON, SMRDATA, 52) adrr0,SMRDATAldrr1,=BWSCON;BWSCON Addressaddr2, r0, #52;End address of SMRDATA0ldrr3, [r0], #4strr3, [r1], #4cmpr2, r0bne%B0; 初始化各种工作模式的堆栈bl InitStacks; 完成初始化b .; 存储器配置信息SMRDATA DATA; 各Bank总线宽度DCD (0+(B1_BWSCON<<4)+(B2_BWSCON<<8)+(B3_BWSCON<<12)+(B4_BWSCON<<16)+(B5_BWSCON<<20)+(B6_BWSCON<<24)+(B7_BWSCON<<28)); SROM访问时序DCD ((B0_Tacs<<13)+(B0_Tcos<<11)+(B0_Tacc<<8)+(B0_Tcoh<<6)+(B0_Tah<<4)+(B0_Tacp<<2)+(B0_PMC)) ;GCS0DCD ((B1_Tacs<<13)+(B1_Tcos<<11)+(B1_Tacc<<8)+(B1_Tcoh<<6)+(B1_Tah<<4)+(B1_Tacp<<2)+(B1_PMC)) ;GCS1DCD ((B2_Tacs<<13)+(B2_Tcos<<11)+(B2_Tacc<<8)+(B2_Tcoh<<6)+(B2_Tah<<4)+(B2_Tacp<<2)+(B2_PMC)) ;GCS2DCD ((B3_Tacs<<13)+(B3_Tcos<<11)+(B3_Tacc<<8)+(B3_Tcoh<<6)+(B3_Tah<<4)+(B3_Tacp<<2)+(B3_PMC)) ;GCS3DCD ((B4_Tacs<<13)+(B4_Tcos<<11)+(B4_Tacc<<8)+(B4_Tcoh<<6)+(B4_Tah<<4)+(B4_Tacp<<2)+(B4_PMC)) ;GCS4DCD ((B5_Tacs<<13)+(B5_Tcos<<11)+(B5_Tacc<<8)+(B5_Tcoh<<6)+(B5_Tah<<4)+(B5_Tacp<<2)+(B5_PMC)) ;GCS5; SDRAM设置DCD ((B6_MT<<15)+(B6_Trcd<<2)+(B6_SCAN)) ;GCS6DCD ((B7_MT<<15)+(B7_Trcd<<2)+(B7_SCAN)) ;GCS7DCD ((REFEN<<23)+(TREFMD<<22)+(Trp<<20)+(Trc<<18)+(Tchr<<16)+REFCNT)DCD 0x32 ;SCLK power saving mode, BANKSIZE 128M/128MDCD 0x30 ;MRSR6 CL=3clkDCD 0x30 ;MRSR7 CL=3clk;------------------------------------------------------------------------------; 栈初始化;------------------------------------------------------------------------------; ARM工作模式，与PSR定义相同;Pre-defined constantsUSERMODE EQU 0x10FIQMODE EQU 0x11IRQMODE EQU 0x12SVCMODE EQU 0x13ABORTMODE EQU 0x17UNDEFMODE EQU 0x1bMODEMASK EQU 0x1fNOINT EQU 0xc0; 各种工作模式的堆栈起址，_STACK_BASEADDRESS在option.inc种定义;The location of stacksUserStackEQU(_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 ~; 初始化各种工作模式的堆栈 void InitStacks();;function initializing stacksInitStacks;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'mrsr0,cpsrbicr0,r0,#MODEMASK; 切换到undef模式，SPund=UndefStackorrr1,r0,#UNDEFMODE|NOINTmsrcpsr_cxsf,r1;UndefModeldrsp,=UndefStack; UndefStack=0x33FF_5C00; 切换到abt模式，SPabt=AbortStackorrr1,r0,#ABORTMODE|NOINTmsrcpsr_cxsf,r1;AbortModeldrsp,=AbortStack; AbortStack=0x33FF_6000; 切换到irq模式，SPirq=IRQStackorrr1,r0,#IRQMODE|NOINTmsrcpsr_cxsf,r1;IRQModeldrsp,=IRQStack; IRQStack=0x33FF_7000; 切换到fiq模式，SPfiq=FIQStackorrr1,r0,#FIQMODE|NOINTmsrcpsr_cxsf,r1;FIQModeldrsp,=FIQStack; FIQStack=0x33FF_8000; 切换到svc模式，SPsvc=SVCStackbicr0,r0,#MODEMASK|NOINTorrr1,r0,#SVCMODEmsrcpsr_cxsf,r1;SVCModeldrsp,=SVCStack; SVCStack=0x33FF_5800; usr模式没有被初始化，一般有C语言设置;USER mode has not be initialized.movpc,lr;The LR register won''t be valid if the current mode is not SVC mode.;------------------------------------------------------------------------------; 处理异常;------------------------------------------------------------------------------; 定义处理异常向量的例程，实现远程跳转; 宏使用了r0寄存器，并采用满递减堆栈保存r0寄存器的初始值，并在使用后恢复。; 在使用ldmfd语句跳转之前，堆栈如下所示; sp+0 -> [IsrEntry]; sp+4 -> r0; sp+8 -> 原始的堆栈 MACRO$HandlerLabel HANDLER $pISR$HandlerLabelsubsp,sp,#4;decrement sp(to store jump address)stmfdsp!,{r0};PUSH the work register to stack(lr does''t push because it return to original address)ldr r0,=$pISR;load the address of HandleXXX to r0ldr r0,[r0] ;load the contents(service routine start address) of HandleXXXstr r0,[sp,#4] ;store the contents(ISR) of HandleXXX to stackldmfd sp!,{r0,pc} ;POP the work register and pc(jump to ISR)MEND; 异常处理例程LTORGHandlerFIQ HANDLER ISR_FIQHandlerIRQ HANDLER ISR_IRQHandlerUndef HANDLER ISR_UndefHandlerSWI HANDLER ISR_SWIHandlerDabort HANDLER ISR_DabortHandlerPabort HANDLER ISR_Pabort; 异常向量表ALIGNAREA ISRTable, DATA, READWRITEMAP _ISR_STARTADDRESS; 向量表起始地址ISR_Reset # 4ISR_Undef # 4ISR_SWI# 4ISR_Pabort # 4ISR_Dabort # 4ISR_Reserved # 4ISR_IRQ# 4ISR_FIQ# 4END