s3c2440时钟+nandflash拷贝至SDRAM+开启mmu

原创 于 2016-02-13 15:50:28 发布 · 1.1k 阅读 · 0 ·
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本文介绍了一种基于ARM架构的裸机程序设计方法，包括内存配置、时钟初始化、NAND闪存读取及MMU配置等内容。通过具体实例展示了如何进行硬件寄存器操作以实现LED控制和定时器中断处理。

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涉及6个文件
head.S,init.c,main.c,makefile,nand.c,out.lds

head.S
.text
.global _start
_start:
    b   Reset
HandleUndef:
    b   HandleUndef 
HandleSWI:				
    b   HandleSWI
HandlePrefetchAbort:
    b   HandlePrefetchAbort
HandleDataAbort:
    b   HandleDataAbort
HandleNotUsed:
    b   HandleNotUsed
    b   HandleIRQ
HandleFIQ:
    b   HandleFIQ
Reset:
	ldr r0, =0x53000000					
	mov r1, #0x0
	str r1, [r0]					@disable watchdog
	msr cpsr_c, #0xd2				@IRQ mode,ARM mode,IRQ disable
	ldr sp, =3072 
	msr cpsr_c, #0xd3				@Supervisor mode,ARM mode,IRQ disable
	ldr sp, =1024*4				@set up stack,4K
	msr cpsr_c, #0x53				@Supervisor mode,ARM mode,IRQ enable
	ldr sp, =4096
	bl clock_init
	bl memsetup
	bl nand_init
       ldr r0, =0x30000000			@target address(sdram),nand_read 1parameter
       mov r1, #4096				@start address,nand_read 2parameter
       mov r2, #2048*2				@size copy to sdram,nand_read 3parameter
	bl nand_read
	bl  create_page_table
	bl  mmu_init 
	ldr sp, =0xB4000000			@pstack go to sdram
	ldr lr, =halt_loop
	ldr pc, =main
halt_loop:
	b halt_loop

HandleIRQ:
	sub lr, lr, #4
	stmdb sp!, {r0-r12,lr}   
	ldr lr, =int_return             
	ldr pc, =TIMER_Handle            
int_return:
	ldmia sp!, { r0-r12,pc }^

init.c
#define	BWSCON		(*(volatile unsigned long *)0x48000000)  
#define	BANKCON0	(*(volatile unsigned long *)0x48000004)
#define	BANKCON1	(*(volatile unsigned long *)0x48000008)
#define	BANKCON2	(*(volatile unsigned long *)0x4800000C)
#define	BANKCON3	(*(volatile unsigned long *)0x48000010)
#define	BANKCON4	(*(volatile unsigned long *)0x48000014)
#define	BANKCON5    (*(volatile unsigned long *)0x48000018)
#define	BANKCON6    (*(volatile unsigned long *)0x4800001C)
#define	BANKCON7    (*(volatile unsigned long *)0x48000020)
#define	REFRESH       (*(volatile unsigned long *)0x48000024)
#define	BANKSIZE     (*(volatile unsigned long *)0x48000028)
#define	MRSRB6		(*(volatile unsigned long *)0x4800002C)
#define	MRSRB7		(*(volatile unsigned long *)0x48000030)
#define	CLKDIVN		(*(volatile unsigned long *)0x4C000014)
#define	MPLLCON	(*(volatile unsigned long *)0x4C000004)
#define S3C2440_MPLL_400MHZ 0x5C011

void memsetup()
{
	BWSCON=0x22011110;
	BANKCON0=0x00000700;//sram
	BANKCON1=0x00000700;//rom
	BANKCON2=0x00000700;
	BANKCON3=0x00000700;
	BANKCON4=0x00000700;
	BANKCON5=0x00000700;
	BANKCON6=0x00018005;//sdram
	BANKCON7=0x00018005;
	REFRESH=0x008C04F4;
	BANKSIZE=0x000000B1;
	MRSRB6=0x00000030;
	MRSRB7=0x00000030;
}

void clock_init()
{
	CLKDIVN=0x05;
__asm__(
    		"mrc    p15, 0, r1, c1, c0, 0\n"
   		 "orr    r1, r1, #0xc0000000\n"
   		 "mcr    p15, 0, r1, c1, c0, 0\n" 
   		);
      MPLLCON=S3C2440_MPLL_400MHZ;
}

void create_page_table(void)
{

#define MMU_FULL_ACCESS     (3 << 10) 
#define MMU_DOMAIN          (0 << 5)
#define MMU_SPECIAL         (1 << 4)  
#define MMU_CACHEABLE       (1 << 3) 
#define MMU_BUFFERABLE      (1 << 2) 
#define MMU_SECTION         (2)     
#define MMU_SECDESC         (MMU_FULL_ACCESS | MMU_DOMAIN | MMU_SPECIAL | MMU_SECTION)
#define MMU_SECDESC_WB      (MMU_FULL_ACCESS | MMU_DOMAIN | MMU_SPECIAL | \
                             MMU_CACHEABLE | MMU_BUFFERABLE | MMU_SECTION)
#define MMU_SECTION_SIZE    0x00100000
    unsigned long virtuladdr, physicaladdr;
    unsigned long *mmu_tlb_base = (unsigned long *)0x30000000;
    virtuladdr = 0;
    physicaladdr = 0;
    *(mmu_tlb_base + (virtuladdr >> 20)) = (physicaladdr & 0xFFF00000) | MMU_SECDESC_WB;//0~4096 the same
    
    virtuladdr = 0x56000000;
    physicaladdr = 0x56000000;
    *(mmu_tlb_base + (virtuladdr >> 20)) = (physicaladdr & 0xFFF00000) | MMU_SECDESC;
    virtuladdr = 0x4A000000;
    physicaladdr = 0x4A000000;
    *(mmu_tlb_base + (virtuladdr >> 20)) = (physicaladdr & 0xFFF00000) | MMU_SECDESC;
    virtuladdr = 0x51000000;
    physicaladdr = 0x51000000;
    *(mmu_tlb_base + (virtuladdr >> 20)) = (physicaladdr & 0xFFF00000) | MMU_SECDESC;
	
    /*SDRAM to 0xB0000000~0xB4000000*/
    virtuladdr = 0xB0000000;
    physicaladdr = 0x30000000;
    while (virtuladdr < 0xB4000000)
    {
        *(mmu_tlb_base + (virtuladdr >> 20)) = (physicaladdr & 0xFFF00000) | MMU_SECDESC_WB;
        virtuladdr += 0x100000;
        physicaladdr += 0x100000;
    }
}

/*
 * 启动MMU
 */
void mmu_init(void)
{
    unsigned long ttb = 0x30000000;
__asm__(
    "mov    r0, #0\n"
    "mcr    p15, 0, r0, c7, c7, 0\n"  
    "mcr    p15, 0, r0, c7, c10, 4\n"
    "mcr    p15, 0, r0, c8, c7, 0\n"  
    "mov    r4, %0\n"              
    "mcr    p15, 0, r4, c2, c0, 0\n"  
    "mvn    r0, #0\n"                   
    "mcr    p15, 0, r0, c3, c0, 0\n"   
    "mrc    p15, 0, r0, c1, c0, 0\n" 
    "bic    r0, r0, #0x3000\n"   
    "bic    r0, r0, #0x0300\n"  
    "bic    r0, r0, #0x0087\n" 
    "orr    r0, r0, #0x0002\n" 
    "orr    r0, r0, #0x0004\n"
    "orr    r0, r0, #0x1000\n" 
    "orr    r0, r0, #0x0001\n" 
    "mcr    p15, 0, r0, c1, c0, 0\n"  
    :
    : "r" (ttb) );
}

main.c
/*
led1 f4,led2 f5,led3 f6,int0 f0
*/
#define	GPFCON	(*(volatile unsigned long *)0x56000050)
#define	GPFDAT	(*(volatile unsigned long *)0x56000054)
#define	GPF4_OUT	(1<<(4*2))
#define	GPF5_OUT	(1<<(5*2))
#define	GPF6_OUT	(1<<(6*2))
#define	GPF4_CON_MSK	(3<<(4*2))
#define	GPF5_CON_MSK	(3<<(5*2))
#define	GPF6_CON_MSK	(3<<(6*2))
#define	GPF4_DAT_MSK	(1<<(4))
#define	GPF5_DAT_MSK	(1<<(5))
#define	GPF6_DAT_MSK	(1<<(6))
#define 	TIMER0_MSK		(1<<(10))

#define	TCFG0	(*(volatile unsigned long *)0x51000000)
#define	TCON	(*(volatile unsigned long *)0x51000008)
#define	TCNTB0	(*(volatile unsigned long *)0x5100000C)
#define INTOFFSET	(*(volatile unsigned long *)0x4A000014)
#define SRCPND	(*(volatile unsigned long *)0X4A000000)
#define INTMSK	(*(volatile unsigned long *)0X4A000008)
#define PRIORITY	(*(volatile unsigned long *)0x4A00000C)
#define INTPND	(*(volatile unsigned long *)0X4A000010)

void init_timer0()
{
	SRCPND=0x0;
	INTMSK=~TIMER0_MSK;
	TCFG0=0xff;
	TCNTB0=0xffff;
	TCON=0xa;
	TCON=0x9;
}


void led_set_out()
{
	GPFCON&=~(GPF4_CON_MSK|GPF5_CON_MSK|GPF6_CON_MSK);
    GPFCON|=GPF4_OUT|GPF5_OUT|GPF6_OUT;
	GPFDAT&=~(GPF4_DAT_MSK);
	GPFDAT&=~(GPF5_DAT_MSK);
	GPFDAT&=~(GPF6_DAT_MSK);
	GPFDAT|=(1<<4);
	GPFDAT|=(1<<5);
	GPFDAT|=(1<<6);
}

void led_reset(int ledn)
{
	if(ledn==1)
	{
		GPFDAT|=(1<<4);
	}
	else if(ledn==2)
	{
		GPFDAT|=(1<<5);
	}
	else
	{
		GPFDAT|=(1<<6);
	}
}

void led_set(int ledn)
{
	if(ledn==1)
	{
		GPFDAT&=~(GPF4_DAT_MSK);
	}
	else if(ledn==2)
	{
		GPFDAT&=~(GPF5_DAT_MSK);
	}
	else
	{
		GPFDAT&=~(GPF6_DAT_MSK);
	}
}

void TIMER_Handle()
{
	int i;
	led_set(1);
	for(i=0;i<1000000;i++);
	led_reset(1);
	SRCPND=1<<INTOFFSET;
	INTPND=1<<INTOFFSET;
}

int main()
{
	int i;
	led_set_out();
	init_timer0();
	while(1)
	{
		led_reset(2);
		for(i=0;i<10000000;i++);
		led_set(2);
		for(i=0;i<10000000;i++);
	}
	return 0;
}

makefile
out.bin : head.S  main.c nand.c init.c
	arm-linux-gcc -c -o head.o head.S
	arm-linux-gcc -c -o main.o main.c
	arm-linux-gcc -c -o nand.o nand.c
	arm-linux-gcc -c -o init.o init.c
	arm-linux-ld -Tout.lds head.o main.o nand.o init.o -o out_elf
	arm-linux-objcopy -O binary -S out_elf out.bin
	arm-linux-objdump -D -m arm  out_elf > out.dis
	#rm -f out.dis out_elf *.o
clean:
	rm -f out.dis out.bin out_elf *.o

nand.c
#define LARGER_NAND_PAGE

#define GSTATUS1        (*(volatile unsigned int *)0x560000B0)
#define BUSY            1

#define NAND_SECTOR_SIZE    512
#define NAND_BLOCK_MASK     (NAND_SECTOR_SIZE - 1)

#define NAND_SECTOR_SIZE_LP    2048
#define NAND_BLOCK_MASK_LP     (NAND_SECTOR_SIZE_LP - 1)

typedef unsigned int S3C24X0_REG32;


/* NAND FLASH (see S3C2410 manual chapter 6) */
typedef struct {
    S3C24X0_REG32   NFCONF;
    S3C24X0_REG32   NFCMD;
    S3C24X0_REG32   NFADDR;
    S3C24X0_REG32   NFDATA;
    S3C24X0_REG32   NFSTAT;
    S3C24X0_REG32   NFECC;
} S3C2410_NAND;

/* NAND FLASH (see S3C2440 manual chapter 6, www.100ask.net) */
typedef struct {
    S3C24X0_REG32   NFCONF;
    S3C24X0_REG32   NFCONT;
    S3C24X0_REG32   NFCMD;
    S3C24X0_REG32   NFADDR;
    S3C24X0_REG32   NFDATA;
    S3C24X0_REG32   NFMECCD0;
    S3C24X0_REG32   NFMECCD1;
    S3C24X0_REG32   NFSECCD;
    S3C24X0_REG32   NFSTAT;
    S3C24X0_REG32   NFESTAT0;
    S3C24X0_REG32   NFESTAT1;
    S3C24X0_REG32   NFMECC0;
    S3C24X0_REG32   NFMECC1;
    S3C24X0_REG32   NFSECC;
    S3C24X0_REG32   NFSBLK;
    S3C24X0_REG32   NFEBLK;
} S3C2440_NAND;


typedef struct {
    void (*nand_reset)(void);
    void (*wait_idle)(void);
    void (*nand_select_chip)(void);
    void (*nand_deselect_chip)(void);
    void (*write_cmd)(int cmd);
    void (*write_addr)(unsigned int addr);
    unsigned char (*read_data)(void);
}t_nand_chip;

static S3C2410_NAND * s3c2410nand = (S3C2410_NAND *)0x4e000000;
static S3C2440_NAND * s3c2440nand = (S3C2440_NAND *)0x4e000000;

static t_nand_chip nand_chip;

/* 供外部调用的函数 */
void nand_init(void);
void nand_read(unsigned char *buf, unsigned long start_addr, int size);

/* NAND Flash操作的总入口, 它们将调用S3C2410或S3C2440的相应函数 */
static void nand_reset(void);
static void wait_idle(void);
static void nand_select_chip(void);
static void nand_deselect_chip(void);
static void write_cmd(int cmd);
static void write_addr(unsigned int addr);
static unsigned char read_data(void);

/* S3C2410的NAND Flash处理函数 */
static void s3c2410_nand_reset(void);
static void s3c2410_wait_idle(void);
static void s3c2410_nand_select_chip(void);
static void s3c2410_nand_deselect_chip(void);
static void s3c2410_write_cmd(int cmd);
static void s3c2410_write_addr(unsigned int addr);
static unsigned char s3c2410_read_data();

/* S3C2440的NAND Flash处理函数 */
static void s3c2440_nand_reset(void);
static void s3c2440_wait_idle(void);
static void s3c2440_nand_select_chip(void);
static void s3c2440_nand_deselect_chip(void);
static void s3c2440_write_cmd(int cmd);
static void s3c2440_write_addr(unsigned int addr);
static unsigned char s3c2440_read_data(void);

/* S3C2410的NAND Flash操作函数 */

/* 复位 */
static void s3c2410_nand_reset(void)
{
    s3c2410_nand_select_chip();
    s3c2410_write_cmd(0xff);  // 复位命令
    s3c2410_wait_idle();
    s3c2410_nand_deselect_chip();
}

/* 等待NAND Flash就绪 */
static void s3c2410_wait_idle(void)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFSTAT;
    while(!(*p & BUSY))
        for(i=0; i<10; i++);
}

/* 发出片选信号 */
static void s3c2410_nand_select_chip(void)
{
    int i;
    s3c2410nand->NFCONF &= ~(1<<11);
    for(i=0; i<10; i++);    
}

/* 取消片选信号 */
static void s3c2410_nand_deselect_chip(void)
{
    s3c2410nand->NFCONF |= (1<<11);
}

/* 发出命令 */
static void s3c2410_write_cmd(int cmd)
{
    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFCMD;
    *p = cmd;
}

/* 发出地址 */
static void s3c2410_write_addr(unsigned int addr)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFADDR;
    
    *p = addr & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 9) & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 17) & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 25) & 0xff;
    for(i=0; i<10; i++);
}

/* 读取数据 */
static unsigned char s3c2410_read_data(void)
{
    volatile unsigned char *p = (volatile unsigned char *)&s3c2410nand->NFDATA;
    return *p;
}

/* S3C2440的NAND Flash操作函数 */

/* 复位 */
static void s3c2440_nand_reset(void)
{
    s3c2440_nand_select_chip();
    s3c2440_write_cmd(0xff);  // 复位命令
    s3c2440_wait_idle();
    s3c2440_nand_deselect_chip();
}

/* 等待NAND Flash就绪 */
static void s3c2440_wait_idle(void)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFSTAT;
    while(!(*p & BUSY))
        for(i=0; i<10; i++);
}

/* 发出片选信号 */
static void s3c2440_nand_select_chip(void)
{
    int i;
    s3c2440nand->NFCONT &= ~(1<<1);
    for(i=0; i<10; i++);    
}

/* 取消片选信号 */
static void s3c2440_nand_deselect_chip(void)
{
    s3c2440nand->NFCONT |= (1<<1);
}

/* 发出命令 */
static void s3c2440_write_cmd(int cmd)
{
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFCMD;
    *p = cmd;
}

/* 发出地址 */
static void s3c2440_write_addr(unsigned int addr)
{
    int i;
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;
    
    *p = addr & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 9) & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 17) & 0xff;
    for(i=0; i<10; i++);
    *p = (addr >> 25) & 0xff;
    for(i=0; i<10; i++);
}


static void s3c2440_write_addr_lp(unsigned int addr)
{
	int i;
	volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR;
	int col, page;

	col = addr & NAND_BLOCK_MASK_LP;
	page = addr / NAND_SECTOR_SIZE_LP;
	
	*p = col & 0xff;			/* Column Address A0~A7 */
	for(i=0; i<10; i++);		
	*p = (col >> 8) & 0x0f; 	/* Column Address A8~A11 */
	for(i=0; i<10; i++);
	*p = page & 0xff;			/* Row Address A12~A19 */
	for(i=0; i<10; i++);
	*p = (page >> 8) & 0xff;	/* Row Address A20~A27 */
	for(i=0; i<10; i++);
	*p = (page >> 16) & 0x03;	/* Row Address A28~A29 */
	for(i=0; i<10; i++);
}


/* 读取数据 */
static unsigned char s3c2440_read_data(void)
{
    volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFDATA;
    return *p;
}


/* 在第一次使用NAND Flash前，复位一下NAND Flash */
static void nand_reset(void)
{
    nand_chip.nand_reset();
}

static void wait_idle(void)
{
    nand_chip.wait_idle();
}

static void nand_select_chip(void)
{
    int i;
    nand_chip.nand_select_chip();
    for(i=0; i<10; i++);
}

static void nand_deselect_chip(void)
{
    nand_chip.nand_deselect_chip();
}

static void write_cmd(int cmd)
{
    nand_chip.write_cmd(cmd);
}
static void write_addr(unsigned int addr)
{
    nand_chip.write_addr(addr);
}

static unsigned char read_data(void)
{
    return nand_chip.read_data();
}


/* 初始化NAND Flash */
void nand_init(void)
{
#define TACLS   0
#define TWRPH0  3
#define TWRPH1  0

    /* 判断是S3C2410还是S3C2440 */
    if ((GSTATUS1 == 0x32410000) || (GSTATUS1 == 0x32410002))
    {
        nand_chip.nand_reset         = s3c2410_nand_reset;
        nand_chip.wait_idle          = s3c2410_wait_idle;
        nand_chip.nand_select_chip   = s3c2410_nand_select_chip;
        nand_chip.nand_deselect_chip = s3c2410_nand_deselect_chip;
        nand_chip.write_cmd          = s3c2410_write_cmd;
        nand_chip.write_addr         = s3c2410_write_addr;
        nand_chip.read_data          = s3c2410_read_data;

		/* 使能NAND Flash控制器, 初始化ECC, 禁止片选, 设置时序 */
        s3c2410nand->NFCONF = (1<<15)|(1<<12)|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0);
    }
    else
    {
        nand_chip.nand_reset         = s3c2440_nand_reset;
        nand_chip.wait_idle          = s3c2440_wait_idle;
        nand_chip.nand_select_chip   = s3c2440_nand_select_chip;
        nand_chip.nand_deselect_chip = s3c2440_nand_deselect_chip;
        nand_chip.write_cmd          = s3c2440_write_cmd;
#ifdef LARGER_NAND_PAGE
        nand_chip.write_addr         = s3c2440_write_addr_lp;
#else
		nand_chip.write_addr		 = s3c2440_write_addr;
#endif
        nand_chip.read_data          = s3c2440_read_data;

		/* 设置时序 */
        s3c2440nand->NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);
        /* 使能NAND Flash控制器, 初始化ECC, 禁止片选 */
        s3c2440nand->NFCONT = (1<<4)|(1<<1)|(1<<0);
    }
    
    /* 复位NAND Flash */
    nand_reset();
}


/* 读函数 */
void nand_read(unsigned char *buf, unsigned long start_addr, int size)
{
    int i, j;

#ifdef LARGER_NAND_PAGE
    if ((start_addr & NAND_BLOCK_MASK_LP) || (size & NAND_BLOCK_MASK_LP)) {
        return ;    /* 地址或长度不对齐 */
    }
#else
    if ((start_addr & NAND_BLOCK_MASK) || (size & NAND_BLOCK_MASK)) {
        return ;    /* 地址或长度不对齐 */
    }
#endif	

    /* 选中芯片 */
    nand_select_chip();

    for(i=start_addr; i < (start_addr + size);) {
      /* 发出READ0命令 */
      write_cmd(0);

      /* Write Address */
      write_addr(i);
#ifdef LARGER_NAND_PAGE
      write_cmd(0x30);		
#endif
      wait_idle();

#ifdef LARGER_NAND_PAGE
      for(j=0; j < NAND_SECTOR_SIZE_LP; j++, i++) {
#else
	  for(j=0; j < NAND_SECTOR_SIZE; j++, i++) {
#endif
          *buf = read_data();
          buf++;
      }
    }

    /* 取消片选信号 */
    nand_deselect_chip();
    
    return ;
}

out.lds
SECTIONS { 
  firtst  	0x00000000 : { head.o nand.o init.o}
  second 	0xB0000000 : AT(4096) { main.o }
}



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