[PATCH] liveupdate: document liveupdate=on

[Pratyush Yadav]

From: "Pratyush Yadav (Google)" <pratyush at kernel.org>

While the liveupdate= parameter is documented in kernel-parameters.txt,
it is not listed in LUO's user facing documentation. This can make it
hard for users to figure out how to enable the subsystem, since enabling
just the config isn't enough.

Note the need for the kernel parameter in LUO core documentation, which
gets exported to Documentation/core-api/liveupdate.rst.

Suggested-by: Luca Boccassi <luca.boccassi at gmail.com>
Signed-off-by: Pratyush Yadav (Google) <pratyush at kernel.org>
---

Notes:
    I think we should take this patch through the liveupdate/fixes branch.

 kernel/liveupdate/luo_core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c
index 803f51c84275..5d5827ced73c 100644
--- a/kernel/liveupdate/luo_core.c
+++ b/kernel/liveupdate/luo_core.c
@@ -36,6 +36,10 @@
  *
  * LUO uses Kexec Handover to transfer memory state from the current kernel to
  * the next kernel. For more details see Documentation/core-api/kho/index.rst.
+ *
+ * .. note::
+ *     To enable LUO, boot the kernel with the ``liveupdate=on`` command line
+ *     parameter.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

base-commit: b1378127003b61930ce30064328640503ad3ef6d
-- 
2.54.0.563.g4f69b47b94-goog