Julien Grall writes ("Re: [PATCH v2] docs/arm64: update the documention for loading XSM support"):
The new version looks good to me: Acked-by: Julien Grall julien.grall@arm.com
Can a native speaker (Ian, Konrad, George) double-check the wording)?
I found it rather difficult to read. See updated version, attached.
I dropped your ack because I want to be sure that the new version still describes the actual behaviour. I kept Wei's release-ack.
Thanks, Ian.
From bd8f24667d353a4c90203d51c1fdb42a66b79973 Mon Sep 17 00:00:00 2001
From: Fu Wei fu.wei@linaro.org Date: Thu, 21 Apr 2016 19:07:09 +0800 Subject: [PATCH] docs/arm64: update the documention for loading XSM support
This patch updates the documentation for allowing detection of an XSM module that lacks a specific compatible string.
(This mechanism was added in commit ca32012341f3, "xen/arm64: check XSM Magic from the second unknown module.")
Signed-off-by: Fu Wei fu.wei@linaro.org Signed-off-by: Ian Jackson ian.jackson@eu.citrix.com Release-acked-by: Wei Liu wei.liu2@citrix.com --- docs/misc/arm/device-tree/booting.txt | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-)
diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt index ad98bf3..f3179d6 100644 --- a/docs/misc/arm/device-tree/booting.txt +++ b/docs/misc/arm/device-tree/booting.txt @@ -24,10 +24,29 @@ Each node contains the following properties: string (which must always be present).
Xen will assume that the first module which lacks a more - specific compatible string is a "multiboot,kernel" and that - the second such is a "multiboot,ramdisk". Any subsequent - modules which lack a specific compatiblity string will not - receive any special treatment. + specific compatible string is a "multiboot,kernel". + + Xen will examine each module, starting from the second + module that lacks a specific compatible string. Xen will + check each such module for the XSM Magic number: + + - For a module which has the XSM Magic number: it will be + treated by Xen as if its compatible string was + "xen,xsm-policy"; + + - For a module which does not have the XSM Magic: the second + module lacking a compatible string will be treated by Xen as + if its compatible string was "multiboot,ramdisk"; for the + third and subsequent modules which lack a specific + compatible string, Xen will not apply any special treatment. + + This means if the ramdisk module is present and does not have the + compatible string "multiboot,ramdisk", then it must always be the + second module. + + Note: This XSM Magic detection behavior was introduced by Xen 4.7. + Xen 4.6 (and downwards) still requires the XSM module to have the + compatible string "xen,xsm-policy".
Xen 4.4 supported a different set of legacy compatible strings which remain supported such that systems supporting both 4.4