u-boot/arch/arm/mach-stm32mp/boot_params.c

// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
 * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
 */

#define LOG_CATEGORY LOGC_ARCH

#include <common.h>
#include <log.h>
#include <linux/libfdt.h>
#include <asm/arch/sys_proto.h>
#include <asm/sections.h>
#include <asm/system.h>

/*
 * Use the saved FDT address provided by TF-A at boot time (NT_FW_CONFIG =
 * Non Trusted Firmware configuration file) when the pointer is valid
 */
void *board_fdt_blob_setup(int *err)
{
	unsigned long nt_fw_dtb = get_stm32mp_bl2_dtb();

	log_debug("%s: nt_fw_dtb=%lx\n", __func__, nt_fw_dtb);

	*err = 0;
	/* use external device tree only if address is valid */
	if (nt_fw_dtb >= STM32_DDR_BASE) {
		if (fdt_magic(nt_fw_dtb) == FDT_MAGIC)
			return (void *)nt_fw_dtb;
		log_debug("%s: DTB not found.\n", __func__);
	}
	log_debug("%s: fall back to builtin DTB, %p\n", __func__, _end);

	return (void *)_end;
}