嵌入式Linux开发环境的搭建之：U-Boot移植

NFADDR = (i >> NFADDR = (i >> 25) & 0xff;

wait_idle();

for (j = 0; j < NAND_SECTOR_SIZE; j++, i++)

{

*buf = (NFDATA & 0xff);

buf++;

}

}

/* chip Disable */

NFCONF |= 0x800; /* chip disable */

return 0;

}

修改board/fs2410/makefile文件，以增加nand_read()函数。

OBJS := fs2410.o flash.o nand_read.o

（7）加入Nand Flash的初始化函数（board/fs2410/fs2410.c）。

#if (CONFIG_COMMANDS & CFG_CMD_NAND)

typedef enum

{

NFCE_LOW,

NFCE_HIGH

} NFCE_STATE;

static inline void NF_Conf(u16 conf)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

nand->NFCONF = conf;

}

static inline void NF_Cmd(u8 cmd)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

nand->NFCMD = cmd;

}

static inline void NF_CmdW(u8 cmd)

{

NF_Cmd(cmd);

udelay(1);

}

static inline void NF_Addr(u8 addr)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

nand->NFADDR = addr;

}

static inline void NF_SetCE(NFCE_STATE s)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

switch (s)

{

case NFCE_LOW:

nand->NFCONF &= ~(1<<11);

break;

case NFCE_HIGH:

nand->NFCONF |= (1<<11);

break;

}

}

static inline void NF_WaitRB(void)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

while (!(nand->NFSTAT & (1<<0)));

}

static inline void NF_Write(u8 data)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

nand->NFDATA = data;

}

static inline u8 NF_Read(void)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

return(nand->NFDATA);

}

static inline void NF_Init_ECC(void)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

nand->NFCONF |= (1<<12);

}

static inline u32 NF_Read_ECC(void)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

return(nand->NFECC);

}

#endif

/*

* NAND flash initialization.

*/

#if (CONFIG_COMMANDS & CFG_CMD_NAND)

extern ulong nand_probe(ulong physadr);

static inline void NF_Reset(void)

{

int i;

NF_SetCE(NFCE_LOW);

NF_Cmd(0xFF); /* reset command */

for (i = 0; i < 10; i++); /* tWB = 100ns. */

NF_WaitRB(); /* wait 200~500us; */

NF_SetCE(NFCE_HIGH);

}

static inline void NF_Init(void)

{

#define TACLS 0

#define TWRPH0 4

#define TWRPH1 2

NF_Conf((1<<15)|(0<<14)|(0<<13)|(1<<12)

|(1<<11)|(TACLS<<8)|(TWRPH0<<4)|(TWRPH1<<0));

/* 1 1 1 1, 1 xxx, r xxx, r xxx */

/* En 512B 4step ECCR nFCE=H tACLS tWRPH0 tWRPH1 */

NF_Reset();

}

void nand_init(void)

{

S3C2410_NAND * const nand = S3C2410_GetBase_NAND();

NF_Init();

#ifdef DEBUG

printf("NAND flash probing at 0x%.8lX\n", (ulong)nand);

#endif

printf ("%4lu MB\n", nand_probe((ulong)nand) >> 20);

}

#endif

（8）修改GPIO配置（board/fs2410/fs2410.c）。

/* set up the I/O ports */

gpio->GPACON = 0x007FFFFF;

gpio->GPBCON = 0x002AAAAA;

gpio->GPBUP = 0x000002BF;

gpio->GPCCON = 0xAAAAAAAA;

gpio->GPCUP = 0x0000FFFF;

gpio->GPDCON = 0xAAAAAAAA;

gpio->GPDUP = 0x0000FFFF;

gpio->GPECON = 0xAAAAAAAA;

gpio->GPEUP = 0x000037F7;

gpio->GPFCON = 0x00000000;

gpio->GPFUP = 0x00000000;

gpio->GPGCON = 0xFFEAFF5A;

gpio->GPGUP = 0x0000F0DC;

gpio->GPHCON = 0x0018AAAA;

gpio->GPHDAT = 0x000001FF;

gpio->GPHUP = 0x00000656

（9）提供nand flash相关宏定义（include/configs/fs2410.h），具体参考源码。

（10）加入Nand Flash设备（include/linux/mtd/nand_ids.h）

static struct nand_flash_dev nand_flash_ids[] =

{

......

{"Samsung KM29N16000",NAND_MFR_SAMSUNG, 0x64,