triple-dash on linux kernel command line switches
===

I'm trying to add a switch to send linux kernel log to the serial console on XenServer6.

The kernel command options can be edited on the EXTLinux config file ( `/boot/extlinux.conf` ).

Here is an excerpt:

    serial 1 115200
    default xe
    prompt 1
    timeout 50
    
    label xe
      # XenServer
      kernel mboot.c32
      append /boot/xen.gz mem=1024G dom0_max_vcpus=4 dom0_mem=752M lowmem_emergency_pool=1M crashkernel=64M@32M console= vga=mode-0x0311 --- /boot/vmlinuz-2.6-xen root=LABEL=root-tfnnfzfp ro xencons=hvc com2=115200,8n1 console=com2 console=hvc0 console=tty0 quiet vga=785 splash --- /boot/initrd-2.6-xen.img
    
    label xe-serial
      # XenServer (Serial)
      kernel mboot.c32
      append /boot/xen.gz com1=115200,8n1 console=com1,vga mem=1024G dom0_max_vcpus=4 dom0_mem=752M lowmem_emergency_pool=1M crashkernel=64M@32M --- /boot/vmlinuz-2.6-xen root=LABEL=root-tfnnfzfp ro console=tty0 xencons=hvc console=hvc0 --- /boot/initrd-2.6-xen.img


What is the meaning of the triple dashes ( `---` )on the command line?
