xref: /linux-6.15/arch/arc/kernel/devtree.c (revision 999159a5)
1 /*
2  * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * Based on reduced version of METAG
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 
12 #include <linux/init.h>
13 #include <linux/reboot.h>
14 #include <linux/memblock.h>
15 #include <linux/of.h>
16 #include <linux/of_fdt.h>
17 #include <asm/prom.h>
18 
19 /* called from unflatten_device_tree() to bootstrap devicetree itself */
20 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
21 {
22 	return __va(memblock_alloc(size, align));
23 }
24 
25 /**
26  * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
27  * @dt:		virtual address pointer to dt blob
28  *
29  * If a dtb was passed to the kernel, then use it to choose the correct
30  * machine_desc and to setup the system.
31  */
32 int __init setup_machine_fdt(void *dt)
33 {
34 	struct boot_param_header *devtree = dt;
35 	unsigned long dt_root;
36 	char *model, *compat;
37 	char manufacturer[16];
38 
39 	/* check device tree validity */
40 	if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
41 		return 1;
42 
43 	/* Search the mdescs for the 'best' compatible value match */
44 	initial_boot_params = devtree;
45 	dt_root = of_get_flat_dt_root();
46 
47 	/* compat = "<manufacturer>,<model>" */
48 	compat = of_get_flat_dt_prop(dt_root, "compatible", NULL);
49 	if (!compat)
50 		compat = "<unknown>";
51 
52 	model = strchr(compat, ',');
53 	if (model)
54 		model++;
55 
56 	strlcpy(manufacturer, compat, model ? model - compat : strlen(compat));
57 
58 	pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer);
59 
60 	/* Retrieve various information from the /chosen node */
61 	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
62 
63 	return 0;
64 }
65