Export KEY_ALG as a user build option
The `KEY_ALG` variable is used to select the algorithm for key
generation by `cert_create` tool for signing the certificates. This
variable was previously undocumented and did not have a global default
value. This patch corrects this and also adds changes to derive the
value of `TF_MBEDTLS_KEY_ALG` based on `KEY_ALG` if it not set by the
platform. The corresponding assignment of these variables are also now
removed from the `arm_common.mk` makefile.
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: I78e2d6f4fc04ed5ad35ce2266118afb63127a5a4
diff --git a/docs/user-guide.rst b/docs/user-guide.rst
index 043af63..1502c8c 100644
--- a/docs/user-guide.rst
+++ b/docs/user-guide.rst
@@ -405,6 +405,11 @@
AArch64 and facilitates the loading of ``SP_MIN`` and BL33 as AArch32 executable
images.
+- ``KEY_ALG``: This build flag enables the user to select the algorithm to be
+ used for generating the PKCS keys and subsequent signing of the certificate.
+ It accepts 2 values viz ``rsa``, ``ecdsa``. The default value of this flag
+ is ``rsa``.
+
- ``LDFLAGS``: Extra user options appended to the linkers' command line in
addition to the one set by the build system.