U-boot中的网络命令 ---- nfs命令

[u-boot: v2013.01-rc1]

[Author: Bo Shen ]

Source code:

CONFIG_CMD_NFS被include/config_cmd_default.h包含，所以在板子相关的配置文件中包含"include "并且没有#undef CONFIG_CMD_NFS, nfs命令就会被默认加入进来。

1. nfs命令帮助信息

--------------------------------------------------------

U-Boot> help nfs
nfs - boot image via network using NFS protocol

Usage:
nfs [loadAddress] [[hostIPaddr:]bootfilename]

--------------------------------------------------------

2. nfs使用方法

假设nfs服务器目录为/nfsroot.

U-Boot> nfs 0x22000000 /nfsroot/uImage

这样，u-boot就会自动挂载nfs然后下载uImage，当uImage被成功下载后，即可运行bootm 0x22000000去启动Linux内核了。

3. FAQ

3.1 *** ERROR: Cannot umount

解决方法：README

-------------------------------------------------------

CONFIG_NFS_TIMEOUT

Timeout in milliseconds used in NFS protocol.
If you encounter "ERROR: Cannot umount" in nfs command,
try longer timeout such as
#define CONFIG_NFS_TIMEOUT 10000UL
-------------------------------------------------------