[PATCH v4 6/8] Documentation: migration-guides: Document change in keyspec env vars

[Jonas Rebmann <jre@pengutronix.de>]

Only users providing complete keyspecs containing backslashes or spaces
via an environment variable are affected by this change in the handling
of keytoc's command line arguments.

Signed-off-by: Jonas Rebmann <jre@pengutronix.de>
---
 Documentation/migration-guides/migration-master.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/migration-guides/migration-master.rst b/Documentation/migration-guides/migration-master.rst
index 42e370d42f..9d1756bdc4 100644
--- a/Documentation/migration-guides/migration-master.rst
+++ b/Documentation/migration-guides/migration-master.rst
@@ -1,5 +1,22 @@
 :orphan:
 
+CONFIG_CRYPTO_PUBLIC_KEYS
+-------------------------
+
+The syntax of keytoc keyspecs when fully provided via an environment variable
+was slightly changed to allow any number of keyspecs to be provided via an
+environment variable. Such environment variables are now split at spaces to be
+interpreted as multiple keyspecs. Any literal spaces and backslashes contained
+in such keyspecs need to be escaped with a backslash.
+
+This only applies to the form:
+
+  CONFIG_CRYPTO_PUBLIC_KEYS="__ENV__A"
+
+While the interpretation of environment variables specifying hint or URI remains unchanged:
+
+  CONFIG_CRYPTO_PUBLIC_KEYS="keyring=kr:__ENV__B"
+
 ARM i.MX HAB
 ------------
 

-- 
2.53.0.308.g50d063e335