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 } 109 110 int fdt_resize(void *fdt, void *buf, int bufsize) 111 { 112 size_t headsize, tailsize; 113 char *oldtail, *newtail; 114 115 FDT_SW_CHECK_HEADER(fdt); 116 117 headsize = fdt_off_dt_struct(fdt); 118 tailsize = fdt_size_dt_strings(fdt); 119 120 if ((headsize + tailsize) > bufsize) 121 return -FDT_ERR_NOSPACE; 122 123 oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; 124 newtail = (char *)buf + bufsize - tailsize; 125 126 /* Two cases to avoid clobbering data if the old and new 127 * buffers partially overlap */ 128 if (buf <= fdt) { 129 memmove(buf, fdt, headsize); 130 memmove(newtail, oldtail, tailsize); 131 } else { 132 memmove(newtail, oldtail, tailsize); 133 memmove(buf, fdt, headsize); 134 } 135 136 fdt_set_off_dt_strings(buf, bufsize); 137 fdt_set_totalsize(buf, bufsize); 138 139 return 0; 140 } 141 142 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size) 143 { 144 struct fdt_reserve_entry *re; 145 int offset; 146 147 FDT_SW_CHECK_HEADER(fdt); 148 149 if (fdt_size_dt_struct(fdt)) 150 return -FDT_ERR_BADSTATE; 151 152 offset = fdt_off_dt_struct(fdt); 153 if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) 154 return -FDT_ERR_NOSPACE; 155 156 re = (struct fdt_reserve_entry *)((char *)fdt + offset); 157 re->address = cpu_to_fdt64(addr); 158 re->size = cpu_to_fdt64(size); 159 160 fdt_set_off_dt_struct(fdt, offset + sizeof(*re)); 161 162 return 0; 163 } 164 165 int fdt_finish_reservemap(void *fdt) 166 { 167 return fdt_add_reservemap_entry(fdt, 0, 0); 168 } 169 170 int fdt_begin_node(void *fdt, const char *name) 171 { 172 struct fdt_node_header *nh; 173 int namelen = strlen(name) + 1; 174 175 FDT_SW_CHECK_HEADER(fdt); 176 177 nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen)); 178 if (! nh) 179 return -FDT_ERR_NOSPACE; 180 181 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); 182 memcpy(nh->name, name, namelen); 183 return 0; 184 } 185 186 int fdt_end_node(void *fdt) 187 { 188 fdt32_t *en; 189 190 FDT_SW_CHECK_HEADER(fdt); 191 192 en = _fdt_grab_space(fdt, FDT_TAGSIZE); 193 if (! en) 194 return -FDT_ERR_NOSPACE; 195 196 *en = cpu_to_fdt32(FDT_END_NODE); 197 return 0; 198 } 199 200 static int _fdt_find_add_string(void *fdt, const char *s) 201 { 202 char *strtab = (char *)fdt + fdt_totalsize(fdt); 203 const char *p; 204 int strtabsize = fdt_size_dt_strings(fdt); 205 int len = strlen(s) + 1; 206 int struct_top, offset; 207 208 p = _fdt_find_string(strtab - strtabsize, strtabsize, s); 209 if (p) 210 return p - strtab; 211 212 /* Add it */ 213 offset = -strtabsize - len; 214 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 215 if (fdt_totalsize(fdt) + offset < struct_top) 216 return 0; /* no more room :( */ 217 218 memcpy(strtab + offset, s, len); 219 fdt_set_size_dt_strings(fdt, strtabsize + len); 220 return offset; 221 } 222 223 int fdt_property(void *fdt, const char *name, const void *val, int len) 224 { 225 struct fdt_property *prop; 226 int nameoff; 227 228 FDT_SW_CHECK_HEADER(fdt); 229 230 nameoff = _fdt_find_add_string(fdt, name); 231 if (nameoff == 0) 232 return -FDT_ERR_NOSPACE; 233 234 prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len)); 235 if (! prop) 236 return -FDT_ERR_NOSPACE; 237 238 prop->tag = cpu_to_fdt32(FDT_PROP); 239 prop->nameoff = cpu_to_fdt32(nameoff); 240 prop->len = cpu_to_fdt32(len); 241 memcpy(prop->data, val, len); 242 return 0; 243 } 244 245 int fdt_finish(void *fdt) 246 { 247 char *p = (char *)fdt; 248 fdt32_t *end; 249 int oldstroffset, newstroffset; 250 uint32_t tag; 251 int offset, nextoffset; 252 253 FDT_SW_CHECK_HEADER(fdt); 254 255 /* Add terminator */ 256 end = _fdt_grab_space(fdt, sizeof(*end)); 257 if (! end) 258 return -FDT_ERR_NOSPACE; 259 *end = cpu_to_fdt32(FDT_END); 260 261 /* Relocate the string table */ 262 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt); 263 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); 264 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt)); 265 fdt_set_off_dt_strings(fdt, newstroffset); 266 267 /* Walk the structure, correcting string offsets */ 268 offset = 0; 269 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) { 270 if (tag == FDT_PROP) { 271 struct fdt_property *prop = 272 _fdt_offset_ptr_w(fdt, offset); 273 int nameoff; 274 275 nameoff = fdt32_to_cpu(prop->nameoff); 276 nameoff += fdt_size_dt_strings(fdt); 277 prop->nameoff = cpu_to_fdt32(nameoff); 278 } 279 offset = nextoffset; 280 } 281 if (nextoffset < 0) 282 return nextoffset; 283 284 /* Finally, adjust the header */ 285 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt)); 286 fdt_set_magic(fdt, FDT_MAGIC); 287 return 0; 288 } 289