U-boot-2014.04移植到MINI2440（10） 移植nand flash保存环境变

一.保存环境变量到nand flash

第一步：修改mini2440.h

由于我们执行saveenv这个命令，然后保存环境变量，u-boot的命令都是在common下实现的，切进去执行gerp “saveenv” –nr ./*.c,查找出如下结果：

这里出现了很多，打开Makefile：

# environment

obj-y += env_attr.o

obj-y += env_callback.o

obj-y += env_flags.o

obj-$(CONFIG_ENV_IS_IN_DATAFLASH) +=env_dataflash.o

obj-$(CONFIG_ENV_IS_IN_EEPROM) +=env_eeprom.o

extra-$(CONFIG_ENV_IS_EMBEDDED) +=env_embedded.o

obj-$(CONFIG_ENV_IS_IN_EEPROM) +=env_embedded.o

extra-$(CONFIG_ENV_IS_IN_FLASH) +=env_embedded.o

obj-$(CONFIG_ENV_IS_IN_NVRAM) +=env_embedded.o

obj-$(CONFIG_ENV_IS_IN_FLASH) +=env_flash.o

obj-$(CONFIG_ENV_IS_IN_MMC) += env_mmc.o

obj-$(CONFIG_ENV_IS_IN_FAT) += env_fat.o

obj-$(CONFIG_ENV_IS_IN_NAND) +=env_nand.o

obj-$(CONFIG_ENV_IS_IN_NVRAM) +=env_nvram.o

obj-$(CONFIG_ENV_IS_IN_ONENAND) +=env_onenand.o

obj-$(CONFIG_ENV_IS_IN_SPI_FLASH) +=env_sf.o

obj-$(CONFIG_ENV_IS_IN_REMOTE) +=env_remote.o

obj-$(CONFIG_ENV_IS_IN_UBI) += env_ubi.o

obj-$(CONFIG_ENV_IS_NOWHERE) +=env_nowhere.o

查找会发现，env_flash.c和env_nand.c是分别保存nor和nand的命令函数。

? 打开/include/configs/mini2440.h，第172行，注释掉为nor保存环境变量的宏，定义保存到nand，修改如下：

#if 0

#define CONFIG_ENV_ADDR???????????????? (CONFIG_SYS_FLASH_BASE +0x070000)

#define CONFIG_ENV_IS_IN_FLASH

#define CONFIG_ENV_SIZE??????????????????? 0x10000

#endif

#define CONFIG_ENV_IS_IN_NAND

#define CONFIG_ENV_OFFSET0X40000//256k for u-boot

#define CONFIG_ENV_SIZE 0x20000//128k for env

/* allow to overwrite serial and ethaddr */

#define CONFIG_ENV_OVERWRITE

??????

第二步：编译测试

从nor 启动，下载到nand，再从nand启动，输入saveenv，出现如下信息：

MINI2440 Deep_l_zh # saveenv

Saving Environment to NAND...

Erasing NAND...

Erasing at 0x40000 -- 100% complete.

Writing to NAND... OK

MINI2440 Deep_l_zh #

?????? 说明我们的环境变量保存进去了。。。

?

?????? 二.添加mtd分区

?????? 修改mini2440.h

?????? 主要是打开被注释掉的配置，第222行添加：

#define CONFIG_CMD_MTDPARTS

#define CONFIG_MTD_DEVICE

#define MTDIDS_DEFAULT"nand0=mini2440-0"

#define MTDPARTS_DEFAULT"mtdparts=mini2440-0:1m(u-boot),"

??????????????????????????????????????????????????????????????????????????????????? ?"1m(params),"

??????????????????????????????????????????????????????????????????????????????????? ?"3m(kernel),"

??????????????????????????????????????????????????????????????????????????????????? ?"-(rootfs)"

?????? 再修改下默认的环境变量，根据自己的开发板和虚拟机做设置，我这里修改如下：

#define CONFIG_NETMASK???????????? 255.255.255.0

#define CONFIG_IPADDR????????? 192.168.1.226

#define CONFIG_SERVERIP???????????? 192.168.1.122

#define CONFIG_ETHADDR????? 08:08:11:18:12:27

#define CONFIG_BOOTARGS"console=ttySAC0 root=/dev/nfs nfsroot=192.168.1.122:/opt/rootfsip=192.168.1.111:192.168.1.122:192.168.1.122:255.255.255.0:SMDK2440A.arm9.net:eth0:off"

#define CONFIG_BOOTCOMMAND"nand read 0x30008000 kernel;bootm 0x30008000"

?

?????? 编译下载，从nor 启动:

?????? nand erase 0 0x40000

?????? tftp 0x30008000 u-boot.bin

?????? nand write 0x30008000 0 0x40000

?????? 然后关闭开发板，从nand启动，输入：

?????? mtdparts default

?????? save

?????? mtdparts

?????? 这时候输出如下信息：

MINI2440 Deep_l_zh # mtdparts default

MINI2440 Deep_l_zh # save

Saving Environment to NAND...

Erasing NAND...

Erasing at 0x40000 -- 100% complete.

Writing to NAND... OK

MINI2440 Deep_l_zh # mtdparts

?

device nand0 <mini2440-0>,# parts =4

?#:name??????????????? size??????????? offset????????? mask_flags

?0:u-boot????????????? 0x00100000????? 0x00000000????? 0

?1:params????????????? 0x00100000????? 0x00100000????? 0

?2:kernel????????????? 0x00300000????? 0x00200000????? 0

?3:rootfs????????????? 0x0fb00000????? 0x00500000????? 0

?

active partition: nand0,0 - (u-boot)0x00100000 @ 0x00000000

?

defaults:

mtdids?: nand0=mini2440-0

mtdparts: mtdparts=mini2440-0:1m(u-boot),1m(params),3m(kernel),-(rootfs)

MINI2440 Deep_l_zh #

?????? 说明我们的分区已经成功了，这时候打印环境变量：printenv，输出如下信息：

baudrate=115200

bootargs=console=tty0 console=ttySAC0root=/dev/nfs nfsroot=192.168.1.122:/opt/rootfsip=192.168.1.111:192.168.1.122:192.168.1.122:255.255.255.0:SMDK2440A.arm9.net:eth0:off

bootcmd=nand read 0x30008000 60000500000;bootm 0x30008000

bootdelay=3

embedclub=bmp d 70000

ethact=dm9000

ethaddr=08:08:11:18:12:27

gatewayip=192.168.1.1

ipaddr=192.168.1.226

lcdtype=w

mtddevname=u-boot

mtddevnum=0

mtdids=nand0=mini2440-0

mtdparts=mtdparts=mini2440-0:1m(u-boot),-(rootfs)

netmask=255.255.255.0

partition=nand0,0

serverip=192.168.1.122

stderr=serial

stdin=serial

stdout=serial

?????? 说明刚才更改的环境变量也已经生效了。。。

?????? 这里我们并没有定义很多环境变量，却出现了，我猜测是因为我之前的u-boot保存的环境变量，这里我我们执行nand scrub，将nand清理一下。然后再把u-boot烧写进去。看看：

?????? nand scrub

?????? nand erase 0 0x4000

?????? tftp 0x30008000 u-boot.bin

?????? nand write 0x30008000 0 0x40000

?????? 从nand启动：

?????? saveenv

?????? printenv

MINI2440 Deep_l_zh # printenv

baudrate=115200

bootargs=console=ttySAC0 root=/dev/nfsnfsroot=192.168.1.122:/opt/rootfsip=192.168.1.111:192.168.1.122:192.168.1.122:255.255.255.0:SMDK2440A.arm9.net:eth0:off

bootcmd=nand read 0x30008000 kernel;bootm0x30008000

bootdelay=5

ethact=dm9000

ethaddr=08:08:11:18:12:27

ipaddr=192.168.1.226

netmask=255.255.255.0

serverip=192.168.1.122

stderr=serial

stdin=serial

stdout=serial

?

Environment size: 413/131068 bytes

MINI2440 Deep_l_zh #

?????? 这里就是我们的环境变凉了，自己添加进去的。再看看分区：

?????? mtdparts default

?????? save

?????? mtdparts

?????? 输出信息正常，移植结束。