efi shell 命令中如何返回上级目录和根目录？

efi shell 命令中如何返回上级目录和根目录？

返回上级：cd ..
返回目录：cd /

cd .. #上级
cd /    #根
#没用过efi，上面的命令应该通用的吧追问试过不行。追答下面是efi shell的帮助信息。你对比看看吧（我看了下，这里的根是 \ 符号）。
This command cd changes the current working directory that is used by the EFI Shell environment.
Convention Description
. Refers to the current directory.
.. Refers to the directory's parent.
\ Refers to the root of the current driver mapping.

Examples:
* To change the current filesystem to the mapped fs0 filesystem:
Shell> fs0:
* To change the current directory to the parent directory (fs0:\):
fs0:\efi\> cd ..
* To change the current directory to 'fs0:\efi\tools':
fs0:\> cd efi\tools
* To change the current directory to the root of the current fs
(fs0):
fs0:\efi\tools\> cd \
fs0:\>

* To change volumes with cd will not work!! For example:
fs0:\efi\tools\> cd fs1:\ !!!! will not work !!!!
must first type fs1: then cd to desired directory