xref: /openbmc/u-boot/lib/libfdt/fdt_sw.c (revision 797d1b9de118d4d3f6d918e7412c3ff9b7883bf0)
1  /*
2   * libfdt - Flat Device Tree manipulation
3   * Copyright (C) 2006 David Gibson, IBM Corporation.
4   * SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
5   */
6  #include <libfdt_env.h>
7  #include <fdt.h>
8  #include <libfdt.h>
9  
10  #include "libfdt_internal.h"
11  
12  static int _fdt_sw_check_header(void *fdt)
13  {
14  	if (fdt_magic(fdt) != FDT_SW_MAGIC)
15  		return -FDT_ERR_BADMAGIC;
16  	/* FIXME: should check more details about the header state */
17  	return 0;
18  }
19  
20  #define FDT_SW_CHECK_HEADER(fdt) \
21  	{ \
22  		int err; \
23  		if ((err = _fdt_sw_check_header(fdt)) != 0) \
24  			return err; \
25  	}
26  
27  static void *_fdt_grab_space(void *fdt, size_t len)
28  {
29  	int offset = fdt_size_dt_struct(fdt);
30  	int spaceleft;
31  
32  	spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
33  		- fdt_size_dt_strings(fdt);
34  
35  	if ((offset + len < offset) || (offset + len > spaceleft))
36  		return NULL;
37  
38  	fdt_set_size_dt_struct(fdt, offset + len);
39  	return _fdt_offset_ptr_w(fdt, offset);
40  }
41  
42  int fdt_create(void *buf, int bufsize)
43  {
44  	void *fdt = buf;
45  
46  	if (bufsize < sizeof(struct fdt_header))
47  		return -FDT_ERR_NOSPACE;
48  
49  	memset(buf, 0, bufsize);
50  
51  	fdt_set_magic(fdt, FDT_SW_MAGIC);
52  	fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
53  	fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
54  	fdt_set_totalsize(fdt,  bufsize);
55  
56  	fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
57  					      sizeof(struct fdt_reserve_entry)));
58  	fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
59  	fdt_set_off_dt_strings(fdt, bufsize);
60  
61  	return 0;
62  }
63  
64  int fdt_resize(void *fdt, void *buf, int bufsize)
65  {
66  	size_t headsize, tailsize;
67  	char *oldtail, *newtail;
68  
69  	FDT_SW_CHECK_HEADER(fdt);
70  
71  	headsize = fdt_off_dt_struct(fdt);
72  	tailsize = fdt_size_dt_strings(fdt);
73  
74  	if ((headsize + tailsize) > bufsize)
75  		return -FDT_ERR_NOSPACE;
76  
77  	oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
78  	newtail = (char *)buf + bufsize - tailsize;
79  
80  	/* Two cases to avoid clobbering data if the old and new
81  	 * buffers partially overlap */
82  	if (buf <= fdt) {
83  		memmove(buf, fdt, headsize);
84  		memmove(newtail, oldtail, tailsize);
85  	} else {
86  		memmove(newtail, oldtail, tailsize);
87  		memmove(buf, fdt, headsize);
88  	}
89  
90  	fdt_set_off_dt_strings(buf, bufsize);
91  	fdt_set_totalsize(buf, bufsize);
92  
93  	return 0;
94  }
95  
96  int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
97  {
98  	struct fdt_reserve_entry *re;
99  	int offset;
100  
101  	FDT_SW_CHECK_HEADER(fdt);
102  
103  	if (fdt_size_dt_struct(fdt))
104  		return -FDT_ERR_BADSTATE;
105  
106  	offset = fdt_off_dt_struct(fdt);
107  	if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
108  		return -FDT_ERR_NOSPACE;
109  
110  	re = (struct fdt_reserve_entry *)((char *)fdt + offset);
111  	re->address = cpu_to_fdt64(addr);
112  	re->size = cpu_to_fdt64(size);
113  
114  	fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
115  
116  	return 0;
117  }
118  
119  int fdt_finish_reservemap(void *fdt)
120  {
121  	return fdt_add_reservemap_entry(fdt, 0, 0);
122  }
123  
124  int fdt_begin_node(void *fdt, const char *name)
125  {
126  	struct fdt_node_header *nh;
127  	int namelen = strlen(name) + 1;
128  
129  	FDT_SW_CHECK_HEADER(fdt);
130  
131  	nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
132  	if (! nh)
133  		return -FDT_ERR_NOSPACE;
134  
135  	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
136  	memcpy(nh->name, name, namelen);
137  	return 0;
138  }
139  
140  int fdt_end_node(void *fdt)
141  {
142  	fdt32_t *en;
143  
144  	FDT_SW_CHECK_HEADER(fdt);
145  
146  	en = _fdt_grab_space(fdt, FDT_TAGSIZE);
147  	if (! en)
148  		return -FDT_ERR_NOSPACE;
149  
150  	*en = cpu_to_fdt32(FDT_END_NODE);
151  	return 0;
152  }
153  
154  static int _fdt_find_add_string(void *fdt, const char *s)
155  {
156  	char *strtab = (char *)fdt + fdt_totalsize(fdt);
157  	const char *p;
158  	int strtabsize = fdt_size_dt_strings(fdt);
159  	int len = strlen(s) + 1;
160  	int struct_top, offset;
161  
162  	p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
163  	if (p)
164  		return p - strtab;
165  
166  	/* Add it */
167  	offset = -strtabsize - len;
168  	struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
169  	if (fdt_totalsize(fdt) + offset < struct_top)
170  		return 0; /* no more room :( */
171  
172  	memcpy(strtab + offset, s, len);
173  	fdt_set_size_dt_strings(fdt, strtabsize + len);
174  	return offset;
175  }
176  
177  int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
178  {
179  	struct fdt_property *prop;
180  	int nameoff;
181  
182  	FDT_SW_CHECK_HEADER(fdt);
183  
184  	nameoff = _fdt_find_add_string(fdt, name);
185  	if (nameoff == 0)
186  		return -FDT_ERR_NOSPACE;
187  
188  	prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
189  	if (! prop)
190  		return -FDT_ERR_NOSPACE;
191  
192  	prop->tag = cpu_to_fdt32(FDT_PROP);
193  	prop->nameoff = cpu_to_fdt32(nameoff);
194  	prop->len = cpu_to_fdt32(len);
195  	*valp = prop->data;
196  	return 0;
197  }
198  
199  int fdt_property(void *fdt, const char *name, const void *val, int len)
200  {
201  	void *ptr;
202  	int ret;
203  
204  	ret = fdt_property_placeholder(fdt, name, len, &ptr);
205  	if (ret)
206  		return ret;
207  	memcpy(ptr, val, len);
208  	return 0;
209  }
210  
211  int fdt_finish(void *fdt)
212  {
213  	char *p = (char *)fdt;
214  	fdt32_t *end;
215  	int oldstroffset, newstroffset;
216  	uint32_t tag;
217  	int offset, nextoffset;
218  
219  	FDT_SW_CHECK_HEADER(fdt);
220  
221  	/* Add terminator */
222  	end = _fdt_grab_space(fdt, sizeof(*end));
223  	if (! end)
224  		return -FDT_ERR_NOSPACE;
225  	*end = cpu_to_fdt32(FDT_END);
226  
227  	/* Relocate the string table */
228  	oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
229  	newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
230  	memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
231  	fdt_set_off_dt_strings(fdt, newstroffset);
232  
233  	/* Walk the structure, correcting string offsets */
234  	offset = 0;
235  	while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
236  		if (tag == FDT_PROP) {
237  			struct fdt_property *prop =
238  				_fdt_offset_ptr_w(fdt, offset);
239  			int nameoff;
240  
241  			nameoff = fdt32_to_cpu(prop->nameoff);
242  			nameoff += fdt_size_dt_strings(fdt);
243  			prop->nameoff = cpu_to_fdt32(nameoff);
244  		}
245  		offset = nextoffset;
246  	}
247  	if (nextoffset < 0)
248  		return nextoffset;
249  
250  	/* Finally, adjust the header */
251  	fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
252  	fdt_set_magic(fdt, FDT_MAGIC);
253  	return 0;
254  }
255