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fdt_sw.c
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1 /*
2  * libfdt - Flat Device Tree manipulation
3  * Copyright (C) 2006 David Gibson, IBM Corporation.
4  *
5  * libfdt is dual licensed: you can use it either under the terms of
6  * the GPL, or the BSD license, at your option.
7  *
8  * a) This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public
19  * License along with this library; if not, write to the Free
20  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21  * MA 02110-1301 USA
22  *
23  * Alternatively,
24  *
25  * b) Redistribution and use in source and binary forms, with or
26  * without modification, are permitted provided that the following
27  * conditions are met:
28  *
29  * 1. Redistributions of source code must retain the above
30  * copyright notice, this list of conditions and the following
31  * disclaimer.
32  * 2. Redistributions in binary form must reproduce the above
33  * copyright notice, this list of conditions and the following
34  * disclaimer in the documentation and/or other materials
35  * provided with the distribution.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50  */
51 #include "libfdt_env.h"
52 
53 #include <fdt.h>
54 #include <libfdt.h>
55 
56 #include "libfdt_internal.h"
57 
58 static int _fdt_sw_check_header(void *fdt)
59 {
60  if (fdt_magic(fdt) != FDT_SW_MAGIC)
61  return -FDT_ERR_BADMAGIC;
62  /* FIXME: should check more details about the header state */
63  return 0;
64 }
65 
66 #define FDT_SW_CHECK_HEADER(fdt) \
67  { \
68  int err; \
69  if ((err = _fdt_sw_check_header(fdt)) != 0) \
70  return err; \
71  }
72 
73 static void *_fdt_grab_space(void *fdt, size_t len)
74 {
75  int offset = fdt_size_dt_struct(fdt);
76  int spaceleft;
77 
78  spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
79  - fdt_size_dt_strings(fdt);
80 
81  if ((offset + len < offset) || (offset + len > spaceleft))
82  return NULL;
83 
84  fdt_set_size_dt_struct(fdt, offset + len);
85  return _fdt_offset_ptr_w(fdt, offset);
86 }
87 
88 int fdt_create(void *buf, int bufsize)
89 {
90  void *fdt = buf;
91 
92  if (bufsize < sizeof(struct fdt_header))
93  return -FDT_ERR_NOSPACE;
94 
95  memset(buf, 0, bufsize);
96 
97  fdt_set_magic(fdt, FDT_SW_MAGIC);
98  fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
99  fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
100  fdt_set_totalsize(fdt, bufsize);
101 
102  fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
103  sizeof(struct fdt_reserve_entry)));
104  fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
105  fdt_set_off_dt_strings(fdt, bufsize);
106 
107  return 0;
108 }
109 
111 {
112  struct fdt_reserve_entry *re;
113  int offset;
114 
115  FDT_SW_CHECK_HEADER(fdt);
116 
117  if (fdt_size_dt_struct(fdt))
118  return -FDT_ERR_BADSTATE;
119 
120  offset = fdt_off_dt_struct(fdt);
121  if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
122  return -FDT_ERR_NOSPACE;
123 
124  re = (struct fdt_reserve_entry *)((char *)fdt + offset);
125  re->address = cpu_to_fdt64(addr);
126  re->size = cpu_to_fdt64(size);
127 
128  fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
129 
130  return 0;
131 }
132 
133 int fdt_finish_reservemap(void *fdt)
134 {
135  return fdt_add_reservemap_entry(fdt, 0, 0);
136 }
137 
138 int fdt_begin_node(void *fdt, const char *name)
139 {
140  struct fdt_node_header *nh;
141  int namelen = strlen(name) + 1;
142 
143  FDT_SW_CHECK_HEADER(fdt);
144 
145  nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
146  if (! nh)
147  return -FDT_ERR_NOSPACE;
148 
150  memcpy(nh->name, name, namelen);
151  return 0;
152 }
153 
154 int fdt_end_node(void *fdt)
155 {
156  uint32_t *en;
157 
158  FDT_SW_CHECK_HEADER(fdt);
159 
160  en = _fdt_grab_space(fdt, FDT_TAGSIZE);
161  if (! en)
162  return -FDT_ERR_NOSPACE;
163 
164  *en = cpu_to_fdt32(FDT_END_NODE);
165  return 0;
166 }
167 
168 static int _fdt_find_add_string(void *fdt, const char *s)
169 {
170  char *strtab = (char *)fdt + fdt_totalsize(fdt);
171  const char *p;
172  int strtabsize = fdt_size_dt_strings(fdt);
173  int len = strlen(s) + 1;
174  int struct_top, offset;
175 
176  p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
177  if (p)
178  return p - strtab;
179 
180  /* Add it */
181  offset = -strtabsize - len;
182  struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
183  if (fdt_totalsize(fdt) + offset < struct_top)
184  return 0; /* no more room :( */
185 
186  memcpy(strtab + offset, s, len);
187  fdt_set_size_dt_strings(fdt, strtabsize + len);
188  return offset;
189 }
190 
191 int fdt_property(void *fdt, const char *name, const void *val, int len)
192 {
193  struct fdt_property *prop;
194  int nameoff;
195 
196  FDT_SW_CHECK_HEADER(fdt);
197 
198  nameoff = _fdt_find_add_string(fdt, name);
199  if (nameoff == 0)
200  return -FDT_ERR_NOSPACE;
201 
202  prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
203  if (! prop)
204  return -FDT_ERR_NOSPACE;
205 
206  prop->tag = cpu_to_fdt32(FDT_PROP);
207  prop->nameoff = cpu_to_fdt32(nameoff);
208  prop->len = cpu_to_fdt32(len);
209  memcpy(prop->data, val, len);
210  return 0;
211 }
212 
213 int fdt_finish(void *fdt)
214 {
215  char *p = (char *)fdt;
216  uint32_t *end;
217  int oldstroffset, newstroffset;
218  uint32_t tag;
219  int offset, nextoffset;
220 
221  FDT_SW_CHECK_HEADER(fdt);
222 
223  /* Add terminator */
224  end = _fdt_grab_space(fdt, sizeof(*end));
225  if (! end)
226  return -FDT_ERR_NOSPACE;
227  *end = cpu_to_fdt32(FDT_END);
228 
229  /* Relocate the string table */
230  oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
231  newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
232  memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
233  fdt_set_off_dt_strings(fdt, newstroffset);
234 
235  /* Walk the structure, correcting string offsets */
236  offset = 0;
237  while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
238  if (tag == FDT_PROP) {
239  struct fdt_property *prop =
240  _fdt_offset_ptr_w(fdt, offset);
241  int nameoff;
242 
243  nameoff = fdt32_to_cpu(prop->nameoff);
244  nameoff += fdt_size_dt_strings(fdt);
245  prop->nameoff = cpu_to_fdt32(nameoff);
246  }
247  offset = nextoffset;
248  }
249  if (nextoffset < 0)
250  return nextoffset;
251 
252  /* Finally, adjust the header */
253  fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
254  fdt_set_magic(fdt, FDT_MAGIC);
255  return 0;
256 }