rpi3: Move shared rpi3 files into common directory
To be able to share code more easily between the existing Raspberry Pi 3
and the upcoming Raspberry Pi 4 platform, move some code which is not
board specific into a "common" directory.
Change-Id: I9211ab2d754b040128fac13c2f0a30a5cc8c7f2c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/rpi/common/rpi3_stack_protector.c b/plat/rpi/common/rpi3_stack_protector.c
new file mode 100644
index 0000000..aae5fac
--- /dev/null
+++ b/plat/rpi/common/rpi3_stack_protector.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdint.h>
+
+#include <lib/utils.h>
+#include <lib/utils_def.h>
+
+#include <drivers/rpi3/rng/rpi3_rng.h>
+
+/* Get 128 bits of entropy and fuse the values together to form the canary. */
+#define TRNG_NBYTES 16U
+
+u_register_t plat_get_stack_protector_canary(void)
+{
+ size_t i;
+ u_register_t buf[TRNG_NBYTES / sizeof(u_register_t)];
+ u_register_t ret = 0U;
+
+ rpi3_rng_read(buf, sizeof(buf));
+
+ for (i = 0U; i < ARRAY_SIZE(buf); i++)
+ ret ^= buf[i];
+
+ return ret;
+}