原来环境变量存储在nor flash里, 前面mtdparts分区第二个分区就是params
现在修改环境变量到nand里,
搜索default environment
在Env_common.c函数里面:
default_environment结构体
default_environment结构体定义在env_common.c里面
其中有:
#ifdef CONFIG_BOOTARGS "bootargs=" CONFIG_BOOTARGS "\0" #endif
这里CONFIG_BOOTARGS没有定义,bootargs是传给内核的环境变量,在smdk2440.h里面定义CONFIG_BOOTARGS
#define CONFIG_BOOTARGS "console=ttySAC0 root=/dev/mtdblock3"
此外设置bootcmd参数:
#define CONFIG_BOOTCOMMAND "nand read 30000000 0x30008000 0x400000;bootm 30000000"
假设从0x30008000读2M到30000000
设置ip
#define CONFIG_NETMASK 255.255.255.0 #define CONFIG_IPADDR 192.168.1.1110 #define CONFIG_SERVERIP 192.168.1.113 #define CONFIG_ETHADDR 00:0c:29:45:c4:c3
修改默认分区:
0x00000000-0x00040000 : "bootloader" //256k 0x00040000-0x00060000 : "params" //128K 0x00060000-0x00460000 : "kernel" //4M 0x00460000-0x10000000 : "root"
原来的环境变量的配置:
#define CONFIG_ENV_ADDR (CONFIG_SYS_FLASH_BASE + 0x070000) #define CONFIG_ENV_IS_IN_FLASH #define CONFIG_ENV_SIZE 0x10000 /* allow to overwrite serial and ethaddr */ #define CONFIG_ENV_OVERWRITE
当输入save时:
SMDK2440 # save Saving Environment to Flash... Un-Protected 1 sectors Erasing Flash... . done Erased 1 sectors Writing to Flash... 9....8....7....6....5....4....3....2....1....done Protected 1 sectors
上面说过不要用save命令保存环境变量设置,目的是防止flash被破坏:
查看save命令帮助信息,知道saveenv,搜索saveenv
或者在SI里面搜索可得,在common目录下看Makefile,知道依赖上面宏
Env_nand.c (common):int saveenv(void)
makefile里面有:
COBJS-$(CONFIG_ENV_IS_IN_NAND) += env_nand.o
可知需要CONFIG_ENV_IS_IN_NAND
不光如此,还需要知道起始地址和大小
打开env_nand.c,里面有CONFIG_ENV_SIZE和CONFIG_ENV_OFFSET
上面的还不够,还需要擦除长度
nand_erase_options.length = CONFIG_ENV_RANGE;
即需要定义CONFIG_ENV_RANGE,设为CONFIG_ENV_SIZE
综上所知设置为:
#if 0 #define CONFIG_ENV_ADDR (CONFIG_SYS_FLASH_BASE + 0x070000) #define CONFIG_ENV_IS_IN_FLASH #define CONFIG_ENV_SIZE 0x10000 /* allow to overwrite serial and ethaddr */ #define CONFIG_ENV_OVERWRITE #endif #define CONFIG_ENV_IS_IN_NAND #define CONFIG_ENV_OFFSET 0x00040000 #define CONFIG_ENV_SIZE 0x20000 #define CONFIG_ENV_RANGE CONFIG_ENV_SIZE
改成nand后,输入save:
SMDK2440 # save Saving Environment to NAND... Erasing NAND... Erasing at 0x40000 -- 100% complete. Writing to NAND... OK
原文地址:https://www.cnblogs.com/hulig7/p/9902155.html