[20091116]u-boot-mdt-nand

u-boot提供了MTD层支持，可以使用Linux下的nand驱动，如果Linux下nand驱动开发完成了，移植到u-boot下可以让你的工作方便很多。

1 copy linux driver to /u-boot-1.3.3/cpu/sep0718/nand_flash.c

2 修改 /u-boot-1.3.3/cpu/sep0718/Makefile

OBJS = serial.o interrupts.o cpu.o nand_flash.o

3 修改 /include/configs/SEP4020.c

add 

#define CONFIG_CMD_NAND

#define NAND_MAX_CHIPS 1

#define CFG_NAND_BASE 0x11000200

#define CFG_MAX_NAND_DEVICE 1 // Max number of NAND devices

#define SECTORSIZE 512

#define ADDR_COLUMN 1

#define ADDR_PAGE 2

#define ADDR_COLUMN_PAGE 3

#define NAND_ChipID_UNKNOWN 0x00

#define NAND_MAX_FLOORS 1

4 修改nand_flash.c

注意没有虚拟地址，只有实地址

5 修改 /drivers/mtd/nand_base.c

line2322

#ifdef CONFIG_MTD_NAND_SEP0718

/* Read manufacturer and device IDs for sep4020  */

nand_maf_id = this->read_byte(mtd);

  nand_dev_id = (*(volatile unsigned long*)NAND_ID1)>>8;

nand_dev_id &= 0xff;

//printf("read id! id is 0x%x\n",nand_dev_id);

#else

nand_maf_id = this->read_byte(mtd);

    nand_dev_id = this->read_byte(mtd);

#endif

line 2406

//this will change if the chip is sep0718 

#ifndef CONFIG_MTD_NAND_SEP0718

if (this->options & NAND_4PAGE_ARRAY)

this->erase_cmd = multi_erase_cmd;

else

this->erase_cmd = single_erase_cmd;

#endif