prom.c

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Device tree support
 4 *
 5 * Copyright (C) 2013, 2015 Altera Corporation
 6 * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
 7 *
 8 * Based on MIPS support for CONFIG_OF device tree support
 9 *
10 * Copyright (C) 2010 Cisco Systems Inc. <dediao@cisco.com>
11 */
12
13#include <linux/init.h>
14#include <linux/types.h>
15#include <linux/memblock.h>
16#include <linux/of.h>
17#include <linux/of_fdt.h>
18#include <linux/io.h>
19
20#include <asm/sections.h>
21
22void __init early_init_devtree(void *params)
23{
24	__be32 __maybe_unused *dtb = (u32 *)__dtb_start;
25
26#if defined(CONFIG_NIOS2_DTB_AT_PHYS_ADDR)
27	if (be32_to_cpup((__be32 *)CONFIG_NIOS2_DTB_PHYS_ADDR) ==
28		 OF_DT_HEADER) {
29		params = (void *)CONFIG_NIOS2_DTB_PHYS_ADDR;
30		early_init_dt_scan(params, __pa(params));
31		return;
32	}
33#endif
34
35#ifdef CONFIG_BUILTIN_DTB
36	if (be32_to_cpu((__be32) *dtb) == OF_DT_HEADER)
37		params = (void *)__dtb_start;
38#endif
39
40	early_init_dt_scan(params, __pa(params));
41}