arch/nios2/kernel/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
  22 void __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_NIOS2_DTB_SOURCE_BOOL
  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 }