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fdt_sw.c

/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "libfdt_env.h"

#include <fdt.h>
#include <libfdt.h>

#include "libfdt_internal.h"

static int _fdt_sw_check_header(void *fdt)
{
      if (fdt_magic(fdt) != FDT_SW_MAGIC)
            return -FDT_ERR_BADMAGIC;
      /* FIXME: should check more details about the header state */
      return 0;
}

#define FDT_SW_CHECK_HEADER(fdt) \
      { \
            int err; \
            if ((err = _fdt_sw_check_header(fdt)) != 0) \
                  return err; \
      }

static void *_fdt_grab_space(void *fdt, int len)
{
      int offset = fdt_size_dt_struct(fdt);
      int spaceleft;

      spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
            - fdt_size_dt_strings(fdt);

      if ((offset + len < offset) || (offset + len > spaceleft))
            return NULL;

      fdt_set_size_dt_struct(fdt, offset + len);
      return fdt_offset_ptr_w(fdt, offset, len);
}

int fdt_create(void *buf, int bufsize)
{
      void *fdt = buf;

      if (bufsize < sizeof(struct fdt_header))
            return -FDT_ERR_NOSPACE;

      memset(buf, 0, bufsize);

      fdt_set_magic(fdt, FDT_SW_MAGIC);
      fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
      fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
      fdt_set_totalsize(fdt,  bufsize);

      fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
                                    sizeof(struct fdt_reserve_entry)));
      fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
      fdt_set_off_dt_strings(fdt, bufsize);

      return 0;
}

int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
{
      struct fdt_reserve_entry *re;
      int offset;

      FDT_SW_CHECK_HEADER(fdt);

      if (fdt_size_dt_struct(fdt))
            return -FDT_ERR_BADSTATE;

      offset = fdt_off_dt_struct(fdt);
      if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
            return -FDT_ERR_NOSPACE;

      re = (struct fdt_reserve_entry *)((char *)fdt + offset);
      re->address = cpu_to_fdt64(addr);
      re->size = cpu_to_fdt64(size);

      fdt_set_off_dt_struct(fdt, offset + sizeof(*re));

      return 0;
}

int fdt_finish_reservemap(void *fdt)
{
      return fdt_add_reservemap_entry(fdt, 0, 0);
}

int fdt_begin_node(void *fdt, const char *name)
{
      struct fdt_node_header *nh;
      int namelen = strlen(name) + 1;

      FDT_SW_CHECK_HEADER(fdt);

      nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
      if (! nh)
            return -FDT_ERR_NOSPACE;

      nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
      memcpy(nh->name, name, namelen);
      return 0;
}

int fdt_end_node(void *fdt)
{
      uint32_t *en;

      FDT_SW_CHECK_HEADER(fdt);

      en = _fdt_grab_space(fdt, FDT_TAGSIZE);
      if (! en)
            return -FDT_ERR_NOSPACE;

      *en = cpu_to_fdt32(FDT_END_NODE);
      return 0;
}

static int _fdt_find_add_string(void *fdt, const char *s)
{
      char *strtab = (char *)fdt + fdt_totalsize(fdt);
      const char *p;
      int strtabsize = fdt_size_dt_strings(fdt);
      int len = strlen(s) + 1;
      int struct_top, offset;

      p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
      if (p)
            return p - strtab;

      /* Add it */
      offset = -strtabsize - len;
      struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
      if (fdt_totalsize(fdt) + offset < struct_top)
            return 0; /* no more room :( */

      memcpy(strtab + offset, s, len);
      fdt_set_size_dt_strings(fdt, strtabsize + len);
      return offset;
}

int fdt_property(void *fdt, const char *name, const void *val, int len)
{
      struct fdt_property *prop;
      int nameoff;

      FDT_SW_CHECK_HEADER(fdt);

      nameoff = _fdt_find_add_string(fdt, name);
      if (nameoff == 0)
            return -FDT_ERR_NOSPACE;

      prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
      if (! prop)
            return -FDT_ERR_NOSPACE;

      prop->tag = cpu_to_fdt32(FDT_PROP);
      prop->nameoff = cpu_to_fdt32(nameoff);
      prop->len = cpu_to_fdt32(len);
      memcpy(prop->data, val, len);
      return 0;
}

int fdt_finish(void *fdt)
{
      char *p = (char *)fdt;
      uint32_t *end;
      int oldstroffset, newstroffset;
      uint32_t tag;
      int offset, nextoffset;

      FDT_SW_CHECK_HEADER(fdt);

      /* Add terminator */
      end = _fdt_grab_space(fdt, sizeof(*end));
      if (! end)
            return -FDT_ERR_NOSPACE;
      *end = cpu_to_fdt32(FDT_END);

      /* Relocate the string table */
      oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
      newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
      memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
      fdt_set_off_dt_strings(fdt, newstroffset);

      /* Walk the structure, correcting string offsets */
      offset = 0;
      while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
            if (tag == FDT_PROP) {
                  struct fdt_property *prop =
                        fdt_offset_ptr_w(fdt, offset, sizeof(*prop));
                  int nameoff;

                  if (! prop)
                        return -FDT_ERR_BADSTRUCTURE;

                  nameoff = fdt32_to_cpu(prop->nameoff);
                  nameoff += fdt_size_dt_strings(fdt);
                  prop->nameoff = cpu_to_fdt32(nameoff);
            }
            offset = nextoffset;
      }

      /* Finally, adjust the header */
      fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
      fdt_set_magic(fdt, FDT_MAGIC);
      return 0;
}

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