PSA_CRYPTO_DRIVER_TEST_ALL is incompatible with MBEDTLS_PSA_CRYPTO_CONFIG
Explain how PSA_CRYPTO_DRIVER_TEST_ALL works and why we have it. Note that
it is incompatible with MBEDTLS_PSA_CRYPTO_CONFIG. As a consequence, disable
that option in component_test_psa_crypto_drivers.
MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS is in the full config, so there's no need to
add it explicitly.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/configs/user-config-for-test.h b/tests/configs/user-config-for-test.h
index 8c2680d..9151532 100644
--- a/tests/configs/user-config-for-test.h
+++ b/tests/configs/user-config-for-test.h
@@ -23,11 +23,31 @@
*/
#if defined(PSA_CRYPTO_DRIVER_TEST_ALL)
+/* PSA_CRYPTO_DRIVER_TEST_ALL activates test drivers while keeping the
+ * built-in implementations active. Normally setting MBEDTLS_PSA_ACCEL_xxx
+ * would disable MBEDTLS_PSA_BUILTIN_xxx unless fallback is activated, but
+ * here we arrange to have both active so that psa_crypto_*.c includes
+ * the built-in implementations and the driver code can call the built-in
+ * implementations.
+ *
+ * The point of this test mode is to verify that the
+ * driver entry points are called when they should be in a lightweight
+ * way, without requiring an actual driver. This is different from builds
+ * with libtestdriver1, where we make a copy of the library source code
+ * and use that as an external driver.
+ */
/* Enable the use of the test driver in the library, and build the generic
* part of the test driver. */
#define PSA_CRYPTO_DRIVER_TEST
+/* With MBEDTLS_PSA_CRYPTO_CONFIG, if we set up the acceleration, the
+ * built-in implementations won't be enabled. */
+#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
+#error \
+ "PSA_CRYPTO_DRIVER_TEST_ALL sets up a nonstandard configuration that is incompatible with MBEDTLS_PSA_CRYPTO_CONFIG"
+#endif
+
/* Use the accelerator driver for all cryptographic mechanisms for which
* the test driver implemented. */
#define MBEDTLS_PSA_ACCEL_KEY_TYPE_AES