libfdt/fdt_sw.c

   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 check_header_sw(void *fdt)
  59 {
  60         if (fdt_magic(fdt) != SW_MAGIC)
  61                 return -FDT_ERR_BADMAGIC;
  62         return 0;
  63 }
  64
  65 static void *grab_space(void *fdt, int len)
  66 {
  67         int offset = fdt_size_dt_struct(fdt);
  68         int spaceleft;
  69
  70         spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
  71                 - fdt_size_dt_strings(fdt);
  72
  73         if ((offset + len < offset) || (offset + len > spaceleft))
  74                 return NULL;
  75
  76         fdt_set_size_dt_struct(fdt, offset + len);
  77         return fdt_offset_ptr_w(fdt, offset, len);
  78 }
  79
  80 int fdt_create(void *buf, int bufsize)
  81 {
  82         void *fdt = buf;
  83
  84         if (bufsize < sizeof(struct fdt_header))
  85                 return -FDT_ERR_NOSPACE;
  86
  87         memset(buf, 0, bufsize);
  88
  89         fdt_set_magic(fdt, SW_MAGIC);
  90         fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
  91         fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
  92         fdt_set_totalsize(fdt,  bufsize);
  93
  94         fdt_set_off_mem_rsvmap(fdt, ALIGN(sizeof(struct fdt_header),
  95                                           sizeof(struct fdt_reserve_entry)));
  96         fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
  97         fdt_set_off_dt_strings(fdt, bufsize);
  98
  99         return 0;
 100 }
 101
 102 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 103 {
 104         struct fdt_reserve_entry *re;
 105         int err = check_header_sw(fdt);
 106         int offset;
 107
 108         if (err)
 109                 return err;
 110         if (fdt_size_dt_struct(fdt))
 111                 return -FDT_ERR_BADSTATE;
 112
 113         offset = fdt_off_dt_struct(fdt);
 114         if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
 115                 return -FDT_ERR_NOSPACE;
 116
 117         re = (struct fdt_reserve_entry *)(fdt + offset);
 118         re->address = cpu_to_fdt64(addr);
 119         re->size = cpu_to_fdt64(size);
 120
 121         fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
 122
 123         return 0;
 124 }
 125
 126 int fdt_finish_reservemap(void *fdt)
 127 {
 128         return fdt_add_reservemap_entry(fdt, 0, 0);
 129 }
 130
 131 int fdt_begin_node(void *fdt, const char *name)
 132 {
 133         struct fdt_node_header *nh;
 134         int err = check_header_sw(fdt);
 135         int namelen = strlen(name) + 1;
 136
 137         if (err)
 138                 return err;
 139
 140         nh = grab_space(fdt, sizeof(*nh) + ALIGN(namelen, FDT_TAGSIZE));
 141         if (! nh)
 142                 return -FDT_ERR_NOSPACE;
 143
 144         nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
 145         memcpy(nh->name, name, namelen);
 146         return 0;
 147 }
 148
 149 int fdt_end_node(void *fdt)
 150 {
 151         uint32_t *en;
 152         int err = check_header_sw(fdt);
 153
 154         if (err)
 155                 return err;
 156
 157         en = grab_space(fdt, FDT_TAGSIZE);
 158         if (! en)
 159                 return -FDT_ERR_NOSPACE;
 160
 161         *en = cpu_to_fdt32(FDT_END_NODE);
 162         return 0;
 163 }
 164
 165 static int find_add_string(void *fdt, const char *s)
 166 {
 167         char *strtab = (char *)fdt + fdt_totalsize(fdt);
 168         const char *p;
 169         int strtabsize = fdt_size_dt_strings(fdt);
 170         int len = strlen(s) + 1;
 171         int struct_top, offset;
 172
 173         p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
 174         if (p)
 175                 return p - strtab;
 176
 177         /* Add it */
 178         offset = -strtabsize - len;
 179         struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
 180         if (fdt_totalsize(fdt) + offset < struct_top)
 181                 return 0; /* no more room :( */
 182
 183         memcpy(strtab + offset, s, len);
 184         fdt_set_size_dt_strings(fdt, strtabsize + len);
 185         return offset;
 186 }
 187
 188 int fdt_property(void *fdt, const char *name, const void *val, int len)
 189 {
 190         struct fdt_property *prop;
 191         int err = check_header_sw(fdt);
 192         int nameoff;
 193
 194         if (err)
 195                 return err;
 196
 197         nameoff = find_add_string(fdt, name);
 198         if (nameoff == 0)
 199                 return -FDT_ERR_NOSPACE;
 200
 201         prop = grab_space(fdt, sizeof(*prop) + ALIGN(len, FDT_TAGSIZE));
 202         if (! prop)
 203                 return -FDT_ERR_NOSPACE;
 204
 205         prop->tag = cpu_to_fdt32(FDT_PROP);
 206         prop->nameoff = cpu_to_fdt32(nameoff);
 207         prop->len = cpu_to_fdt32(len);
 208         memcpy(prop->data, val, len);
 209         return 0;
 210 }
 211
 212 int fdt_finish(void *fdt)
 213 {
 214         int err = check_header_sw(fdt);
 215         char *p = (char *)fdt;
 216         uint32_t *end;
 217         int oldstroffset, newstroffset;
 218         uint32_t tag;
 219         int offset, nextoffset;
 220
 221         if (err)
 222                 return err;
 223
 224         /* Add terminator */
 225         end = grab_space(fdt, sizeof(*end));
 226         if (! end)
 227                 return -FDT_ERR_NOSPACE;
 228         *end = cpu_to_fdt32(FDT_END);
 229
 230         /* Relocate the string table */
 231         oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
 232         newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
 233         memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
 234         fdt_set_off_dt_strings(fdt, newstroffset);
 235
 236         /* Walk the structure, correcting string offsets */
 237         offset = 0;
 238         while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
 239                 if (tag == FDT_PROP) {
 240                         struct fdt_property *prop =
 241                                 fdt_offset_ptr_w(fdt, offset, sizeof(*prop));
 242                         int nameoff;
 243
 244                         if (! prop)
 245                                 return -FDT_ERR_BADSTRUCTURE;
 246
 247                         nameoff = fdt32_to_cpu(prop->nameoff);
 248                         nameoff += fdt_size_dt_strings(fdt);
 249                         prop->nameoff = cpu_to_fdt32(nameoff);
 250                 }
 251                 offset = nextoffset;
 252         }
 253
 254         /* Finally, adjust the header */
 255         fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
 256         fdt_set_magic(fdt, FDT_MAGIC);
 257         return 0;
 258 }