Dom0 kernel and ramdisk modules
================================

Xen is passed the dom0 kernel and initrd via a reference in the /chosen
node of the device tree.

Each node has the form /chosen/modules/module@<N> and contains the following
properties:

- compatible

	Must be:

		"xen,<type>", "xen,multiboot-module"

	where <type> must be one of:

	- "linux-zimage" -- the dom0 kernel
	- "linux-initrd" -- the dom0 ramdisk

- reg

	Specifies the physical address of the module in RAM and the
	length of the module.

- bootargs (optional)

	Command line associated with this module. This is deprecated and should
	be replaced by the bootargs variations described below.


Command lines
=============

Xen also checks for properties directly under /chosen to find suitable command
lines for Xen and Dom0. The logic is the following:

 - If xen,xen-bootargs is present, it will be used for Xen.
 - If xen,dom0-bootargs is present, it will be used for Dom0.
 - If xen,xen-bootargs is _not_ present, but xen,dom0-bootargs is,
   bootargs will be used for Xen.
 - If no Xen specific properties are present, bootargs is for Dom0.
 - If xen,xen-bootargs is present, but xen,dom0-bootargs is missing,
   bootargs will be used for Dom0.

Most of these cases is to make booting with Xen-unaware bootloaders easier.
For those you would hardcode the Xen commandline in the DTB under
/chosen/xen,xen-bootargs and would let the bootloader set the Dom0 command
line by writing bootargs (as for native Linux).
A Xen-aware bootloader would set xen,xen-bootargs for Xen, xen,dom0-bootargs
for Dom0 and bootargs for native Linux.