[Xen-changelog] [xen staging] xen/arm: extend device tree based multiboot protocol

[p***@xen.org]

commit f205db8a41af88f193d1e25f6e06397a95190db8
Author: Stefano Stabellini <***@kernel.org>
AuthorDate: Tue Nov 13 08:45:49 2018 -0800
Commit: Julien Grall <***@arm.com>
CommitDate: Wed Nov 14 19:25:10 2018 +0000

xen/arm: extend device tree based multiboot protocol

Extend the existing device tree based multiboot protocol to include
information regarding multiple domains to boot.

Signed-off-by: Stefano Stabellini <***@xilinx.com>
Reviewed-by: Julien Grall <***@arm.com>
---
docs/misc/arm/device-tree/booting.txt | 107 ++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)

diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt
index ce2d0dccdf..317a9e962a 100644
--- a/docs/misc/arm/device-tree/booting.txt
+++ b/docs/misc/arm/device-tree/booting.txt
@@ -119,3 +119,110 @@ For those you would hardcode the Xen commandline in the DTB under
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.
+
+
+Creating Multiple Domains directly from Xen
+===========================================
+
+It is possible to have Xen create other domains, in addition to dom0,
+out of the information provided via device tree. A kernel and initrd
+(optional) need to be specified for each guest.
+
+For each domain to be created there needs to be one node under /chosen
+with the following properties:
+
+- compatible
+
+ For domUs: "xen,domain"
+
+- memory
+
+ A 64-bit integer specifying the amount of kilobytes of RAM to
+ allocate to the guest.
+
+- cpus
+
+ An integer specifying the number of vcpus to allocate to the guest.
+
+- vpl011
+
+ An empty property to enable/disable a virtual pl011 for the guest to use.
+
+- #address-cells and #size-cells
+
+ Both #address-cells and #size-cells need to be specified because
+ both sub-nodes (described shortly) have reg properties.
+
+Under the "xen,domain" compatible node, one or more sub-nodes are present
+for the DomU kernel and ramdisk.
+
+The kernel sub-node has the following properties:
+
+- compatible
+
+ "multiboot,kernel"
+
+- reg
+
+ Specifies the physical address of the kernel in RAM and its
+ length.
+
+- bootargs (optional)
+
+ Command line parameters for the guest kernel.
+
+The ramdisk sub-node has the following properties:
+
+- compatible
+
+ "multiboot,ramdisk"
+
+- reg
+
+ Specifies the physical address of the ramdisk in RAM and its
+ length.
+
+
+Example
+=======
+
+chosen {
+ domU1 {
+ compatible = "xen,domain";
+ #address-cells = <0x2>;
+ #size-cells = <0x1>;
+ memory = <0 131072>;
+ cpus = <2>;
+ vpl011;
+
+ ***@0x4a000000 {
+ compatible = "multiboot,kernel";
+ reg = <0x0 0x4a000000 0xffffff>;
+ bootargs = "console=ttyAMA0 init=/bin/sh";
+ };
+
+ ***@0x4b000000 {
+ compatible = "multiboot,ramdisk";
+ reg = <0x0 0x4b000000 0xffffff>;
+ };
+ };
+
+ domU2 {
+ compatible = "xen,domain";
+ #address-cells = <0x2>;
+ #size-cells = <0x1>;
+ memory = <0 65536>;
+ cpus = <1>;
+
+ ***@0x4c000000 {
+ compatible = "multiboot,kernel";
+ reg = <0x0 0x4c000000 0xffffff>;
+ bootargs = "console=ttyAMA0 init=/bin/sh";
+ };
+
+ ***@0x4d000000 {
+ compatible = "multiboot,ramdisk";
+ reg = <0x0 0x4d000000 0xffffff>;
+ };
+ };
+};
--
generated by git-patchbot for /home/xen/git/xen.git#staging