text: // SPDX-License-Identifier: (BSD-2-Clause OR GPL-2.0+)
  /*
   * 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, size_t 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);
  }
  
  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_resize(void *fdt, void *buf, int bufsize)
  {
  	size_t headsize, tailsize;
  	char *oldtail, *newtail;
  
  	FDT_SW_CHECK_HEADER(fdt);
  
  	headsize = fdt_off_dt_struct(fdt);
  	tailsize = fdt_size_dt_strings(fdt);
  
  	if ((headsize + tailsize) > bufsize)
  		return -FDT_ERR_NOSPACE;
  
  	oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
  	newtail = (char *)buf + bufsize - tailsize;
  
  	/* Two cases to avoid clobbering data if the old and new
  	 * buffers partially overlap */
  	if (buf <= fdt) {
  		memmove(buf, fdt, headsize);
  		memmove(newtail, oldtail, tailsize);
  	} else {
  		memmove(newtail, oldtail, tailsize);
  		memmove(buf, fdt, headsize);
  	}
  
  	fdt_set_off_dt_strings(buf, bufsize);
  	fdt_set_totalsize(buf, 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)
  {
  	fdt32_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;
  	fdt32_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);
  			int nameoff;
  
  			nameoff = fdt32_to_cpu(prop->nameoff);
  			nameoff += fdt_size_dt_strings(fdt);
  			prop->nameoff = cpu_to_fdt32(nameoff);
  		}
  		offset = nextoffset;
  	}
  	if (nextoffset < 0)
  		return nextoffset;
  
  	/* Finally, adjust the header */
  	fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
  	fdt_set_magic(fdt, FDT_MAGIC);
  	return 0;
  }
  