How does debian enter single-user mode?

How to enter the single-user mode of debian-Debian information of the Linux release-details are as follows. Use grub to edit single to enter

Enter the root password, which is different from Debian and other release versions. init calls sulogin to request the root password. the program sulogin does not use PAM, so the destroyed PAM setting will not destroy this program.

In fact, you don't need to enter any mode, as long as you get the root bash.

Add init =/bin/bash to the line of the kernel in the grub startup Item.

Note: In this status, the/is read-only and cannot be modified. The modification can only be remounted to read/write (mount-o remount, rw /).