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, int 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, len);

    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_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)

   111 {

   112 	struct fdt_reserve_entry *re;

   113 	int offset;

   114 

   115 	FDT_SW_CHECK_HEADER(fdt);

   116 

   117 	if (fdt_size_dt_struct(fdt))

   118 		return -FDT_ERR_BADSTATE;

   119 

   120 	offset = fdt_off_dt_struct(fdt);

   121 	if ((offset + sizeof(*re)) > fdt_totalsize(fdt))

   122 		return -FDT_ERR_NOSPACE;

   123 

   124 	re = (struct fdt_reserve_entry *)((char *)fdt + offset);

   125 	re->address = cpu_to_fdt64(addr);

   126 	re->size = cpu_to_fdt64(size);

   127 

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

   129 

   130 	return 0;

   131 }

   132 

   133 int fdt_finish_reservemap(void *fdt)

   134 {

   135 	return fdt_add_reservemap_entry(fdt, 0, 0);

   136 }

   137 

   138 int fdt_begin_node(void *fdt, const char *name)

   139 {

   140 	struct fdt_node_header *nh;

   141 	int namelen = strlen(name) + 1;

   142 

   143 	FDT_SW_CHECK_HEADER(fdt);

   144 

   145 	nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));

   146 	if (! nh)

   147 		return -FDT_ERR_NOSPACE;

   148 

   149 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);

   150 	memcpy(nh->name, name, namelen);

   151 	return 0;

   152 }

   153 

   154 int fdt_end_node(void *fdt)

   155 {

   156 	uint32_t *en;

   157 

   158 	FDT_SW_CHECK_HEADER(fdt);

   159 

   160 	en = _fdt_grab_space(fdt, FDT_TAGSIZE);

   161 	if (! en)

   162 		return -FDT_ERR_NOSPACE;

   163 

   164 	*en = cpu_to_fdt32(FDT_END_NODE);

   165 	return 0;

   166 }

   167 

   168 static int _fdt_find_add_string(void *fdt, const char *s)

   169 {

   170 	char *strtab = (char *)fdt + fdt_totalsize(fdt);

   171 	const char *p;

   172 	int strtabsize = fdt_size_dt_strings(fdt);

   173 	int len = strlen(s) + 1;

   174 	int struct_top, offset;

   175 

   176 	p = _fdt_find_string(strtab - strtabsize, strtabsize, s);

   177 	if (p)

   178 		return p - strtab;

   179 

   180 	/* Add it */

   181 	offset = -strtabsize - len;

   182 	struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);

   183 	if (fdt_totalsize(fdt) + offset < struct_top)

   184 		return 0; /* no more room :( */

   185 

   186 	memcpy(strtab + offset, s, len);

   187 	fdt_set_size_dt_strings(fdt, strtabsize + len);

   188 	return offset;

   189 }

   190 

   191 int fdt_property(void *fdt, const char *name, const void *val, int len)

   192 {

   193 	struct fdt_property *prop;

   194 	int nameoff;

   195 

   196 	FDT_SW_CHECK_HEADER(fdt);

   197 

   198 	nameoff = _fdt_find_add_string(fdt, name);

   199 	if (nameoff == 0)

   200 		return -FDT_ERR_NOSPACE;

   201 

   202 	prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));

   203 	if (! prop)

   204 		return -FDT_ERR_NOSPACE;

   205 

   206 	prop->tag = cpu_to_fdt32(FDT_PROP);

   207 	prop->nameoff = cpu_to_fdt32(nameoff);

   208 	prop->len = cpu_to_fdt32(len);

   209 	memcpy(prop->data, val, len);

   210 	return 0;

   211 }

   212 

   213 int fdt_finish(void *fdt)

   214 {

   215 	char *p = (char *)fdt;

   216 	uint32_t *end;

   217 	int oldstroffset, newstroffset;

   218 	uint32_t tag;

   219 	int offset, nextoffset;

   220 

   221 	FDT_SW_CHECK_HEADER(fdt);

   222 

   223 	/* Add terminator */

   224 	end = _fdt_grab_space(fdt, sizeof(*end));

   225 	if (! end)

   226 		return -FDT_ERR_NOSPACE;

   227 	*end = cpu_to_fdt32(FDT_END);

   228 

   229 	/* Relocate the string table */

   230 	oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);

   231 	newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);

   232 	memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));

   233 	fdt_set_off_dt_strings(fdt, newstroffset);

   234 

   235 	/* Walk the structure, correcting string offsets */

   236 	offset = 0;

   237 	while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {

   238 		if (tag == FDT_PROP) {

   239 			struct fdt_property *prop =

   240 				fdt_offset_ptr_w(fdt, offset, sizeof(*prop));

   241 			int nameoff;

   242 

   243 			if (! prop)

   244 				return -FDT_ERR_BADSTRUCTURE;

   245 

   246 			nameoff = fdt32_to_cpu(prop->nameoff);

   247 			nameoff += fdt_size_dt_strings(fdt);

   248 			prop->nameoff = cpu_to_fdt32(nameoff);

   249 		}

   250 		offset = nextoffset;

   251 	}

   252 

   253 	/* Finally, adjust the header */

   254 	fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));

   255 	fdt_set_magic(fdt, FDT_MAGIC);

   256 	return 0;

   257 }