1、vyos@vyos:~$ cat /proc/cmdline
BOOT_IMAGE=/boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 console=ttyS0,115200 console=tty0
vyos@vyos:~$ 

2、vyos@vyos:~$ sudo update-initramfs -u 
update-initramfs: Generating /boot/initrd.img-4.19.148-amd64-vyos
live-boot: core filesystems devices utils udev wget blockdev.

3、vyos@vyos:~$ cat /boot/grub/grub.cfg
# Generated by /opt/vyatta/sbin/vyatta-grub-setup at Fri 04 Dec 2020 09:58:45 AM UTC
set default=0
set timeout=5
serial --unit=0 --speed=115200
terminal_output --append serial
terminal_input serial console

menuentry "VyOS 1.3-rolling-202010110146 linux (KVM console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146  console=ttyS0,115200 console=tty0
	initrd /boot/1.3-rolling-202010110146/initrd.img
	notsc clocksource=acpi_pm quite
}

menuentry "VyOS 1.3-rolling-202010110146 linux (Serial console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 console=tty0 console=ttyS0,115200
	initrd /boot/1.3-rolling-202010110146/initrd.img
}

menuentry "VyOS 1.3-rolling-202010110146 linux (USB console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 console=tty0 console=ttyUSB0,115200
	initrd /boot/1.3-rolling-202010110146/initrd.img
}

menuentry "Lost password change 1.3-rolling-202010110146 (KVM console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 selinux=0 console=ttyS0,115200 console=tty0 init=/opt/vyatta/sbin/standalone_root_pw_reset
	initrd /boot/1.3-rolling-202010110146/initrd.img
}

menuentry "Lost password change 1.3-rolling-202010110146 (Serial console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 selinux=0 console=tty0 console=ttyS0,115200 init=/opt/vyatta/sbin/standalone_root_pw_reset
	initrd /boot/1.3-rolling-202010110146/initrd.img
}

menuentry "Lost password change 1.3-rolling-202010110146 (USB console)" {
	linux /boot/1.3-rolling-202010110146/vmlinuz boot=live rootdelay=5 noautologin net.ifnames=0 biosdevname=0 vyos-union=/boot/1.3-rolling-202010110146 selinux=0 console=tty0 console=ttyUSB0,115200 init=/opt/vyatta/sbin/standalone_root_pw_reset
	initrd /boot/1.3-rolling-202010110146/initrd.img
}