feat(imx8mp): enable BL32 fdt overlay support on imx8mp

Allow OP-TEE to generate a device-tree overlay binary
that will be applied by u-boot on the regular dtb.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: Idfd268cdd8b7ba321f8e1b9b85c2bba7ffdeddf0

plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c

@@ -163,6 +163,11 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 #ifdef SPD_trusty
 	bl32_image_ep_info.args.arg0 = BL32_SIZE;
 	bl32_image_ep_info.args.arg1 = BL32_BASE;
+#else
+	/* Make sure memory is clean */
+	mmio_write_32(BL32_FDT_OVERLAY_ADDR, 0);
+	bl33_image_ep_info.args.arg3 = BL32_FDT_OVERLAY_ADDR;
+	bl32_image_ep_info.args.arg3 = BL32_FDT_OVERLAY_ADDR;
 #endif
 #endif
 

plat/imx/imx8m/imx8mp/include/platform_def.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 NXP
+ * Copyright 2020-2022 NXP
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -62,6 +62,8 @@
 #define PLAT_NS_IMAGE_OFFSET		U(0x40200000)
 #define PLAT_NS_IMAGE_SIZE		U(0x00200000)
 
+#define BL32_FDT_OVERLAY_ADDR		(PLAT_NS_IMAGE_OFFSET + 0x3000000)
+
 /* GICv3 base address */
 #define PLAT_GICD_BASE			U(0x38800000)
 #define PLAT_GICR_BASE			U(0x38880000)