请教，关于OK6410 NAND Flash 裸机调试

[visitedgood]

开发板是256MB/2G Nand flash。Nand flash型号：K9GAG08U0D 。我是看 “伟东山ok6410（裸机调试部分）”的视频。前面的还算没多大问题，但到NAND Flash这部分就出问题,nand.c文件代码修改多次和参照别的代码还是不行,到copy2ddr获取的数据有问题，不知道是Nand flash初始化参数出错还是什么问题。用linux编译，j-link烧写，nand启动。请教大神要怎么修改

代码：
nand.c

#define MEM_SYS_CFG     (*((volatile unsigned long *)0x7E00F120))
#define NFCONF          (*((volatile unsigned long *)0x70200000))
#define NFCONT          (*((volatile unsigned long *)0x70200004))
#define NFCMMD          (*((volatile unsigned long *)0x70200008))
#define NFADDR          (*((volatile unsigned long *)0x7020000C))
#define NFDATA          (*((volatile unsigned char *)0x70200010))
#define NFSTAT          (*((volatile unsigned long *)0x70200028))

void nand_select(void)
{
    NFCONT &= ~(1<<1);
}

void nand_deselect(void)
{
    NFCONT |= (1<<1);
}


void nand_cmd(unsigned char cmd)
{
    NFCMMD = cmd;
}

void nand_addr(unsigned char addr)
{
    NFADDR = addr;
}

unsigned char nand_get_data(void)
{
    return NFDATA;
}

void nand_send_data(unsigned char data)
{
    NFDATA = data;
}

void wait_ready(void)
{
    while ((NFSTAT & 0x1) == 0);
}

void nand_reset(void)
{
    /* 选中 */
    nand_select();
   
    /* 发出0xff命令 */
    nand_cmd(0xff);

    /* 等待就绪 */
    wait_ready();
   
    /* 取消选中 */
    nand_deselect();
}

void nand_init(void)
{
    /* 让xm0csn2用作nand flash cs0 片选引脚 */
    MEM_SYS_CFG &= ~(1<<1);

    /* 设置时间参数 */
#define TACLS     0
#define TWRPH0    1
#define TWRPH1    0
    NFCONF &= ~((1<<30) | (7<<12) | (7<<8) | (7<<4));
    NFCONF |= ((TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4));

    /* 使能nand flash controller */
    NFCONT |= 1;
    NFCONT &= ~(1<<16); /* 森止soft lock */

    nand_reset();
}

void nand_send_addr(unsigned int addr)
{
#if 0   
    unsigned int page = addr / 2048;

    /* 这两个地址表示从页内哪里开始 */
    nand_addr(addr & 0xff);
    nand_addr((addr >> 8) & 0xff);

    /* 下面三个地址表示哪一页 */
    nand_addr(page & 0xff);
    nand_addr((page >> 8) & 0xff);
    nand_addr((page >> 16) & 0xff);
#else
    nand_addr(addr & 0xff);         /* a0~a7 */
    nand_addr((addr >> 8) & 0x1f);   /* 程序的角度: a8~a12 */

    nand_addr((addr >> 13) & 0xff); /* 程序的角度: a13~a20 */
    nand_addr((addr >> 21) & 0xff); /* 程序的角度: a21~a28 */
    nand_addr((addr >> 29) & 0x7); /* 程序的角度: a29~    */
   
#endif
}

int nand_read(unsigned int nand_start, unsigned int ddr_start, unsigned int len)
{
    unsigned int addr = nand_start;
    int i = nand_start % 4096;//nand_start % 2048;
    int count = 0;
    unsigned char *dest = (unsigned char *)ddr_start;
   
    /* 选中芯片 */
    nand_select();

    while (count < len)
    {
        /* 发出命令0x00 */
        nand_cmd(0x00);

        /* 发出地址 */
        nand_send_addr(addr);

        /* 发出命令0x30 */
        nand_cmd(0x30);

        /* 等待就绪 */
        wait_ready();

        /* 读数据 */
        for (; i < 4096 && count < len; i++)
        {
            dest[count++] = nand_get_data();
            addr++;            
        }

        i = 0;        
    }

    /* 取消片选 */
    nand_deselect();
    return 0;
}

int copy2ddr(unsigned int nand_start, unsigned int ddr_start, unsigned int len)
{
    int ret;
   
    /* 初始化nand flash controller */
    nand_init();
   
    /* 读nand flash */
    ret = nand_read(nand_start, ddr_start, len);
   
    return ret;
}

start.S

.globl _start
_start:

/* 硬件相关的设置 */
    /* Peri port setup */
    ldr r0, =0x70000000
    orr r0, r0, #0x13
    mcr p15,0,r0,c15,c2,4       @ 256M(0x70000000-0x7fffffff)
   
/* 关看门狗 */
/* 往WTCON(0x7E004000)写0 */
   
    ldr r0, =0x7E004000
    mov r1, #0
    str r1, [r0]
   
    /* 设置栈 */
    ldr sp, =8*1024

    /* 设置时钟 */
    /*bl clock_init*/

    /* 设置DDR */
    bl ddr_init
   
    /* 重定位 */
/* 把程序的代码段、数据段复制到它的链接地址去 */   
    adr r0, _start   /* 获得_start指令当前所在的地址 : 0*/
    ldr r1, =_start  /* _start的链接地址 0x51000000 */
   
    ldr r2, =bss_start      /* bss段的起始链接地址 */
   
    sub r2, r2, r1
   
    cmp r0,r1
    beq clean_bss
   
    bl copy2ddr
    cmp r0, #0
    bne halt
        
    /* 清BSS */
/* 把BSS段对应的内存清零 */
clean_bss:
    ldr r0, =bss_start
    ldr r1, =bss_end
    mov r3, #0
    cmp r0, r1
    beq on_ddr
clean_loop:
    str r3, [r0], #4
    cmp r0, r1   
    bne clean_loop        

on_ddr:
    ldr pc, =main
halt:
    b halt    

uart.lds

SECTIONS {
    . = 0x51000000;
    .text : {
            start.o
            sdram.o
            nand.o
            * (.text)
    }

    .rodata : {
            * (.rodata)
    }

.data : {
            * (.data)
    }

    bss_start = .;
    .bss ALIGN(4)  : { *(.bss)  *(COMMON) }

   bss_end = .;
}

[小潘盼盼]

s3c6410启动时自动拷贝nand flash前4页的内容到片内内存执行，而且拷贝时只拷每页中的前2KByte好像是为了兼容2k页的 所有copy2ddr函数中不要把所有数据全部照搬过去，只搬每页的前2k到ddr连接起来 这个问题也困扰我好长时间刚刚解决