diff mbox

[v3] xen: arm: doc: Add firmware requirements

Message ID 1461598974-5165-1-git-send-email-dirk.behme@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dirk Behme April 25, 2016, 3:42 p.m. UTC
From: Dirk Behme <dirk.behme@de.bosch.com>

Add a section about what the firmware should do in EL3 before starting Xen.

E.g guest will use HVC instruction to issue hypercall. As this can be set only
at EL3, i.e. outside Xen, document this boot requirement.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
---
 docs/misc/arm/booting.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Stefano Stabellini April 26, 2016, 9:37 a.m. UTC | #1
On Mon, 25 Apr 2016, Dirk Behme wrote:
> From: Dirk Behme <dirk.behme@de.bosch.com>
> 
> Add a section about what the firmware should do in EL3 before starting Xen.
> 
> E.g guest will use HVC instruction to issue hypercall. As this can be set only
> at EL3, i.e. outside Xen, document this boot requirement.
> 
> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

Added to me queue


>  docs/misc/arm/booting.txt | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt
> index 9802e5e..c7c1d7e 100644
> --- a/docs/misc/arm/booting.txt
> +++ b/docs/misc/arm/booting.txt
> @@ -23,6 +23,17 @@ The exceptions to this on 32-bit ARM are as follows:
>  
>  There are no exception on 64-bit ARM.
>  
> +
> +Firmware/bootloader requirements
> +--------------------------------
> +
> +Xen relies on some settings the firmware has to configure in EL3 before starting Xen.
> +
> +* Xen must be entered in NS EL2 mode
> +
> +* The bit SCR_EL3.HCR (resp. SCR.HCE for 32-bit ARM) must be set to 1.
> +
> +
>  [1] linux/Documentation/arm/Booting
>  Latest version: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm/Booting
>  
> -- 
> 2.8.1
>
diff mbox

Patch

diff --git a/docs/misc/arm/booting.txt b/docs/misc/arm/booting.txt
index 9802e5e..c7c1d7e 100644
--- a/docs/misc/arm/booting.txt
+++ b/docs/misc/arm/booting.txt
@@ -23,6 +23,17 @@  The exceptions to this on 32-bit ARM are as follows:
 
 There are no exception on 64-bit ARM.
 
+
+Firmware/bootloader requirements
+--------------------------------
+
+Xen relies on some settings the firmware has to configure in EL3 before starting Xen.
+
+* Xen must be entered in NS EL2 mode
+
+* The bit SCR_EL3.HCR (resp. SCR.HCE for 32-bit ARM) must be set to 1.
+
+
 [1] linux/Documentation/arm/Booting
 Latest version: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm/Booting