参考博文：
《u-boot-2011.03在mini2440/micro2440上的移植》
移植（五）添加nand支持：
host@debian:~/soft/mini2440/u-boot-2011.03$ touch drivers/mtd/nand/s3c2440_nand.c host@debian:~/soft/mini2440/u-boot-2011.03$ vim drivers/mtd/nand/s3c2440_nand.c 添加下面内容： #include <common.h> #if 0 #define DEBUGN printf #else #define DEBUGN(x, args ...) {} #endif #include <nand.h> #include <asm/arch/s3c24x0_cpu.h> #include <asm/io.h> #define __REGb(x) (*(volatile unsigned char *)(x)) #define __REGi(x) (*(volatile unsigned int *)(x)) #define NF_BASE 0x4e000000 //Nand配置寄存器基地址 #define NFCONF __REGi(NF_BASE + 0x0) //偏移后还是得到配置寄存器基地址 #define NFCONT __REGi(NF_BASE + 0x4) //偏移后得到Nand控制寄存器基地址 #define NFCMD __REGb(NF_BASE + 0x8) //偏移后得到Nand指令寄存器基地址 #define NFADDR __REGb(NF_BASE + 0xc) //偏移后得到Nand地址寄存器基地址 #define NFDATA __REGb(NF_BASE + 0x10) //偏移后得到Nand数据寄存器基地址 #define NFMECCD0 __REGi(NF_BASE + 0x14) //偏移后得到Nand主数据区域ECC0寄存器基地址 #define NFMECCD1 __REGi(NF_BASE + 0x18) //偏移后得到Nand主数据区域ECC1寄存器基地址 #define NFSECCD __REGi(NF_BASE + 0x1C) //偏移后得到Nand空闲区域ECC寄存器基地址 #define NFSTAT __REGb(NF_BASE + 0x20) //偏移后得到Nand状态寄存器基地址 #define NFSTAT0 __REGi(NF_BASE + 0x24) //偏移后得到Nand ECC0状态寄存器基地址 #define NFSTAT1 __REGi(NF_BASE + 0x28) //偏移后得到Nand ECC1状态寄存器基地址 #define NFMECC0 __REGi(NF_BASE + 0x2C) //偏移后得到Nand主数据区域ECC0状态寄存器基地址 #define NFMECC1 __REGi(NF_BASE + 0x30) //偏移后得到Nand主数据区域ECC1状态寄存器基地址 #define NFSECC __REGi(NF_BASE + 0x34) //偏移后得到Nand空闲区域ECC状态寄存器基地址 #define NFSBLK __REGi(NF_BASE + 0x38) //偏移后得到Nand块开始地址 #define NFEBLK __REGi(NF_BASE + 0x3c) //偏移后得到Nand块结束地址 #define S3C2440_NFCONT_nCE (1<<1) #define S3C2440_ADDR_NALE 0x0c #define S3C2440_ADDR_NCLE 0x08 ulong IO_ADDR_W = NF_BASE; static void s3c2440_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl) { struct nand_chip *chip = mtd->priv; DEBUGN("hwcontrol(): 0x%02x 0x%02x/n", cmd, ctrl); if (ctrl & NAND_CTRL_CHANGE) { IO_ADDR_W = NF_BASE; if (!(ctrl & NAND_CLE)) //要写的是地址 IO_ADDR_W |= S3C2440_ADDR_NALE; if (!(ctrl & NAND_ALE)) //要写的是命令 IO_ADDR_W |= S3C2440_ADDR_NCLE; if (ctrl & NAND_NCE) NFCONT &= ~S3C2440_NFCONT_nCE; //使能nand flash else NFCONT |= S3C2440_NFCONT_nCE; //禁止nand flash } if (cmd != NAND_CMD_NONE) writeb(cmd,(void *)IO_ADDR_W); } static int s3c2440_dev_ready(struct mtd_info *mtd) { DEBUGN("dev_ready/n"); return (NFSTAT & 0x01); } int board_nand_init(struct nand_chip *nand) { u_int32_t cfg; u_int8_t tacls, twrph0, twrph1; struct s3c24x0_clock_power * const clk_power = s3c24x0_get_base_clock_power(); DEBUGN("board_nand_init()/n"); tacls = 1; twrph0 = 2; twrph1 = 1; cfg = (tacls<<12)|(twrph0<<8)|(twrph1<<4); NFCONF = cfg; cfg = (1<<6)|(1<<4)|(0<<1)|(1<<0); NFCONT = cfg; /* initialize nand_chip data structure */ nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)0x4e000010; /* read_buf and write_buf are default */ /* read_byte and write_byte are default */ /* hwcontrol always must be implemented */ nand->cmd_ctrl = s3c2440_hwcontrol; nand->dev_ready = s3c2440_dev_ready; return 0; } host@debian:~/soft/mini2440/u-boot-2011.03$ vim drivers/mtd/nand/Makefile 添加一行： COBJS-$(CONFIG_NAND_S3C2440) += s3c2440_nand.o
host@debian:~/soft/mini2440/u-boot-2011.03$ vim include/configs/mini2440.h
添加下面内容：
#define CONFIG_MTD_DEVICE
#define CONFIG_NAND_S3C2440
#define CONFIG_CMD_NAND
#if defined(CONFIG_CMD_NAND)
#define CONFIG_SYS_NAND_BASE 0x4E000000 //Nand配置寄存器基地址
#define CONFIG_SYS_MAX_NAND_DEVICE 1
#define CONFIG_MTD_NAND_VERIFY_WRITE 1
#endif
#define CONFIG_ENV_IS_IN_NAND 1
#define CONFIG_ENV_OFFSET 0x40000 //将环境变量保存到nand中的0x40000位置
#define CONFIG_ENV_SIZE 0x10000 /* Total Size of Environment Sector */
修改后，进行编译，却得到好几个编译错误：
env_nand.o: In function `env_get_char_spec': /home/host/soft/mini2440/u-boot-2011.03/common/env_nand.c:77: multiple definition of `env_get_char_spec' env_flash.o:/home/host/soft/mini2440/u-boot-2011.03/common/env_flash.c:82: first defined here env_nand.o: In function `env_init': /home/host/soft/mini2440/u-boot-2011.03/common/env_nand.c:144: multiple definition of `env_init' env_flash.o:/home/host/soft/mini2440/u-boot-2011.03/common/env_flash.c:244: first defined here env_nand.o: In function `env_relocate_spec': /home/host/soft/mini2440/u-boot-2011.03/common/env_nand.c:420: multiple definition of `env_relocate_spec' env_flash.o:/home/host/soft/mini2440/u-boot-2011.03/common/env_flash.c:379: first defined here env_nand.o: In function `saveenv': /home/host/soft/mini2440/u-boot-2011.03/common/env_nand.c:245: multiple definition of `saveenv' env_flash.o:/home/host/soft/mini2440/u-boot-2011.03/common/env_flash.c:259: first defined here env_nand.o:(.data+0x0): multiple definition of `env_name_spec' env_flash.o:(.data+0x4): first defined here env_nand.o: In function `env_get_char_spec': /home/host/soft/mini2440/u-boot-2011.03/common/env_nand.c:77: multiple definition of `env_ptr' env_flash.o:(.data+0x0): first defined here make[1]: *** [libcommon.o] 错误 1 make[1]: Leaving directory `/home/host/soft/mini2440/u-boot-2011.03/common'
这是因为include/configs/mini2440.h已经定义了CONFIG_ENV_IS_IN_FLASH，新加入的定义CONFIG_ENV_IS_IN_NAND与之冲突，可以将
CONFIG_ENV_IS_IN_FLASH宏定义屏蔽掉即可。
修改好后重新编译，按照《mini2440移植uboot 2011.03（上）》中的步骤将其加载到mini2440 内存，然后启动uboot，得到下面的输出信息：
U-Boot 2011.03-00000-g18dedc3-dirty (Jun 04 2014 - 10:25:38) DRAM: 64 MiB Flash: 512 KiB NAND: NAND_ECC_NONE selected by board driver. This is not recommended !! 128 MiB *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: dm9000 MINI2440 # nand nand - NAND sub-system Usage: nand info - show available NAND devices nand device [dev] - show or set current device nand read - addr off|partition size nand write - addr off|partition size read/write 'size' bytes starting at offset 'off' to/from memory address 'addr', skipping bad blocks. nand erase[.spread] [clean] [off [size]] - erase 'size' bytes from offset 'off' With '.spread', erase enough for given file size, otherwise, 'size' includes skipped bad blocks. nand erase.part [clean] partition - erase entire mtd partition' nand erase.chip [clean] - erase entire chip' nand bad - show bad blocks nand dump[.oob] off - dump page nand scrub off size | scrub.part partition | scrub.chip really clean NAND erasing bad blocks (UNSAFE) nand markbad off [...] - mark bad block(s) at offset (UNSAFE) nand biterr off - make a bit error at offset (UNSAFE)
移植（六）：添加nfs,命令补全的支持.
host@debian:~/soft/mini2440/u-boot-2011.03$ vim include/configs/mini2440.h
添加下面内容：
#define CONFIG_CMDLINE_EDITING
#ifdef CONFIG_CMDLINE_EDITING
#undef CONFIG_AUTO_COMPLETE
#else
#define CONFIG_AUTO_COMPLETE
#endif
#define CONFIG_CMD_NFS
修改完后，重新进行编译并加载到mini2440内存中执行，得到下面的输出：
U-Boot 2011.03-00000-g0e6506b-dirty (Jun 04 2014 - 10:49:01) DRAM: 64 MiB Flash: 512 KiB NAND: NAND_ECC_NONE selected by board driver. This is not recommended !! 128 MiB *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: dm9000 MINI2440 # nfs 30007fc0 /home/host/nfs/mini2440/uImage dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:00:3e:26:0a:5b operating at unknown: 0 mode Using dm9000 device File transfer via NFS from server 192.168.211.2; our IP address is 192.168.211.25 Filename '/home/host/nfs/mini2440/uImage'. Load address: 0x30007fc0 Loading: * Abort MINI2440 # nfs 30007fc0 /home/host/nfs/mini2440/uImage dm9000 i/o: 0x20000300, id: 0x90000a46 DM9000: running in 16 bit mode MAC: 08:00:3e:26:0a:5b operating at unknown: 0 mode Using dm9000 device File transfer via NFS from server 192.168.211.2; our IP address is 192.168.211.25 Filename '/home/host/nfs/mini2440/uImage'. Load address: 0x30007fc0 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ##################################################### done Bytes transferred = 2266684 (22963c hex)
第一次调用nfs有可能不成功(跟前面的ping命令执行情况类似)。
后续移植过程我没有再继续下去了，因为我对yaffs兴趣不大，我希望能让它支持ubifs并且自己重新移植一遍。
整个代码（包含git历史记录）下载地址：http://pan.baidu.com/s/1dDipCqt