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 }