allwinner: H616: Add reserved-memory node to DT
When the BL31 for the Allwinner H616 runs in DRAM, we need to make sure
we tell the non-secure world about the memory region it uses.
Add a reserved-memory node to the DT, which covers the area that BL31
could occupy. The "no-map" property will prevent OSes from mapping
the area, so there would be no speculative accesses.
Change-Id: I808f3e1a8089da53bbe4fc6435a808e9159831e1
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/allwinner/sun50i_h616/prepare_dtb.c b/plat/allwinner/sun50i_h616/prepare_dtb.c
new file mode 100644
index 0000000..e94b0b4
--- /dev/null
+++ b/plat/allwinner/sun50i_h616/prepare_dtb.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2021, ARM Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <libfdt.h>
+
+#include <common/debug.h>
+#include <common/fdt_fixup.h>
+#include <common/fdt_wrappers.h>
+
+#include <sunxi_private.h>
+
+void sunxi_prepare_dtb(void *fdt)
+{
+ int ret;
+
+ if (fdt == NULL || fdt_check_header(fdt) != 0) {
+ return;
+ }
+ ret = fdt_open_into(fdt, fdt, 0x100000);
+ if (ret < 0) {
+ ERROR("Preparing devicetree at %p: error %d\n", fdt, ret);
+ return;
+ }
+
+ /* Reserve memory used by Trusted Firmware. */
+ if (fdt_add_reserved_memory(fdt, "tf-a@40000000", BL31_BASE,
+ BL31_LIMIT - BL31_BASE)) {
+ WARN("Failed to add reserved memory nodes to DT.\n");
+ return;
+ }
+
+ ret = fdt_pack(fdt);
+ if (ret < 0) {
+ ERROR("Failed to pack devicetree at %p: error %d\n",
+ fdt, ret);
+ } else {
+ clean_dcache_range((uintptr_t)fdt, fdt_blob_size(fdt));
+ INFO("Changed devicetree to reserve BL31 memory.\n");
+ }
+}