xref: /freebsd/sys/contrib/libfdt/fdt.c (revision 6780e684d49034610f82bea5d3bfb04d42e91628)
121fdc27aSRafal Jaworowski /*
221fdc27aSRafal Jaworowski  * libfdt - Flat Device Tree manipulation
321fdc27aSRafal Jaworowski  * Copyright (C) 2006 David Gibson, IBM Corporation.
421fdc27aSRafal Jaworowski  *
521fdc27aSRafal Jaworowski  * libfdt is dual licensed: you can use it either under the terms of
621fdc27aSRafal Jaworowski  * the GPL, or the BSD license, at your option.
721fdc27aSRafal Jaworowski  *
821fdc27aSRafal Jaworowski  *  a) This library is free software; you can redistribute it and/or
921fdc27aSRafal Jaworowski  *     modify it under the terms of the GNU General Public License as
1021fdc27aSRafal Jaworowski  *     published by the Free Software Foundation; either version 2 of the
1121fdc27aSRafal Jaworowski  *     License, or (at your option) any later version.
1221fdc27aSRafal Jaworowski  *
1321fdc27aSRafal Jaworowski  *     This library is distributed in the hope that it will be useful,
1421fdc27aSRafal Jaworowski  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
1521fdc27aSRafal Jaworowski  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
1621fdc27aSRafal Jaworowski  *     GNU General Public License for more details.
1721fdc27aSRafal Jaworowski  *
1821fdc27aSRafal Jaworowski  *     You should have received a copy of the GNU General Public
1921fdc27aSRafal Jaworowski  *     License along with this library; if not, write to the Free
2021fdc27aSRafal Jaworowski  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
2121fdc27aSRafal Jaworowski  *     MA 02110-1301 USA
2221fdc27aSRafal Jaworowski  *
2321fdc27aSRafal Jaworowski  * Alternatively,
2421fdc27aSRafal Jaworowski  *
2521fdc27aSRafal Jaworowski  *  b) Redistribution and use in source and binary forms, with or
2621fdc27aSRafal Jaworowski  *     without modification, are permitted provided that the following
2721fdc27aSRafal Jaworowski  *     conditions are met:
2821fdc27aSRafal Jaworowski  *
2921fdc27aSRafal Jaworowski  *     1. Redistributions of source code must retain the above
3021fdc27aSRafal Jaworowski  *        copyright notice, this list of conditions and the following
3121fdc27aSRafal Jaworowski  *        disclaimer.
3221fdc27aSRafal Jaworowski  *     2. Redistributions in binary form must reproduce the above
3321fdc27aSRafal Jaworowski  *        copyright notice, this list of conditions and the following
3421fdc27aSRafal Jaworowski  *        disclaimer in the documentation and/or other materials
3521fdc27aSRafal Jaworowski  *        provided with the distribution.
3621fdc27aSRafal Jaworowski  *
3721fdc27aSRafal Jaworowski  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
3821fdc27aSRafal Jaworowski  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
3921fdc27aSRafal Jaworowski  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
4021fdc27aSRafal Jaworowski  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
4121fdc27aSRafal Jaworowski  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
4221fdc27aSRafal Jaworowski  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
4321fdc27aSRafal Jaworowski  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
4421fdc27aSRafal Jaworowski  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
4521fdc27aSRafal Jaworowski  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
4621fdc27aSRafal Jaworowski  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
4721fdc27aSRafal Jaworowski  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
4821fdc27aSRafal Jaworowski  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
4921fdc27aSRafal Jaworowski  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5021fdc27aSRafal Jaworowski  */
5121fdc27aSRafal Jaworowski #include "libfdt_env.h"
5221fdc27aSRafal Jaworowski 
5321fdc27aSRafal Jaworowski #include <fdt.h>
5421fdc27aSRafal Jaworowski #include <libfdt.h>
5521fdc27aSRafal Jaworowski 
5621fdc27aSRafal Jaworowski #include "libfdt_internal.h"
5721fdc27aSRafal Jaworowski 
5821fdc27aSRafal Jaworowski int fdt_check_header(const void *fdt)
5921fdc27aSRafal Jaworowski {
6021fdc27aSRafal Jaworowski 	if (fdt_magic(fdt) == FDT_MAGIC) {
6121fdc27aSRafal Jaworowski 		/* Complete tree */
6221fdc27aSRafal Jaworowski 		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
6321fdc27aSRafal Jaworowski 			return -FDT_ERR_BADVERSION;
6421fdc27aSRafal Jaworowski 		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
6521fdc27aSRafal Jaworowski 			return -FDT_ERR_BADVERSION;
6621fdc27aSRafal Jaworowski 	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
6721fdc27aSRafal Jaworowski 		/* Unfinished sequential-write blob */
6821fdc27aSRafal Jaworowski 		if (fdt_size_dt_struct(fdt) == 0)
6921fdc27aSRafal Jaworowski 			return -FDT_ERR_BADSTATE;
7021fdc27aSRafal Jaworowski 	} else {
7121fdc27aSRafal Jaworowski 		return -FDT_ERR_BADMAGIC;
7221fdc27aSRafal Jaworowski 	}
7321fdc27aSRafal Jaworowski 
7421fdc27aSRafal Jaworowski 	return 0;
7521fdc27aSRafal Jaworowski }
7621fdc27aSRafal Jaworowski 
7721fdc27aSRafal Jaworowski const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
7821fdc27aSRafal Jaworowski {
79*6780e684SKyle Evans 	unsigned absoffset = offset + fdt_off_dt_struct(fdt);
80*6780e684SKyle Evans 
81*6780e684SKyle Evans 	if ((absoffset < offset)
82*6780e684SKyle Evans 	    || ((absoffset + len) < absoffset)
83*6780e684SKyle Evans 	    || (absoffset + len) > fdt_totalsize(fdt))
84*6780e684SKyle Evans 		return NULL;
8521fdc27aSRafal Jaworowski 
8621fdc27aSRafal Jaworowski 	if (fdt_version(fdt) >= 0x11)
8721fdc27aSRafal Jaworowski 		if (((offset + len) < offset)
8821fdc27aSRafal Jaworowski 		    || ((offset + len) > fdt_size_dt_struct(fdt)))
8921fdc27aSRafal Jaworowski 			return NULL;
9021fdc27aSRafal Jaworowski 
91*6780e684SKyle Evans 	return fdt_offset_ptr_(fdt, offset);
9221fdc27aSRafal Jaworowski }
9321fdc27aSRafal Jaworowski 
9421fdc27aSRafal Jaworowski uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
9521fdc27aSRafal Jaworowski {
96*6780e684SKyle Evans 	const fdt32_t *tagp, *lenp;
9721fdc27aSRafal Jaworowski 	uint32_t tag;
9821fdc27aSRafal Jaworowski 	int offset = startoffset;
9921fdc27aSRafal Jaworowski 	const char *p;
10021fdc27aSRafal Jaworowski 
10121fdc27aSRafal Jaworowski 	*nextoffset = -FDT_ERR_TRUNCATED;
10221fdc27aSRafal Jaworowski 	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
10321fdc27aSRafal Jaworowski 	if (!tagp)
10421fdc27aSRafal Jaworowski 		return FDT_END; /* premature end */
10521fdc27aSRafal Jaworowski 	tag = fdt32_to_cpu(*tagp);
10621fdc27aSRafal Jaworowski 	offset += FDT_TAGSIZE;
10721fdc27aSRafal Jaworowski 
10821fdc27aSRafal Jaworowski 	*nextoffset = -FDT_ERR_BADSTRUCTURE;
10921fdc27aSRafal Jaworowski 	switch (tag) {
11021fdc27aSRafal Jaworowski 	case FDT_BEGIN_NODE:
11121fdc27aSRafal Jaworowski 		/* skip name */
11221fdc27aSRafal Jaworowski 		do {
11321fdc27aSRafal Jaworowski 			p = fdt_offset_ptr(fdt, offset++, 1);
11421fdc27aSRafal Jaworowski 		} while (p && (*p != '\0'));
11521fdc27aSRafal Jaworowski 		if (!p)
11621fdc27aSRafal Jaworowski 			return FDT_END; /* premature end */
11721fdc27aSRafal Jaworowski 		break;
11821fdc27aSRafal Jaworowski 
11921fdc27aSRafal Jaworowski 	case FDT_PROP:
12021fdc27aSRafal Jaworowski 		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
12121fdc27aSRafal Jaworowski 		if (!lenp)
12221fdc27aSRafal Jaworowski 			return FDT_END; /* premature end */
12321fdc27aSRafal Jaworowski 		/* skip-name offset, length and value */
12421fdc27aSRafal Jaworowski 		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
12521fdc27aSRafal Jaworowski 			+ fdt32_to_cpu(*lenp);
12621fdc27aSRafal Jaworowski 		break;
12721fdc27aSRafal Jaworowski 
12821fdc27aSRafal Jaworowski 	case FDT_END:
12921fdc27aSRafal Jaworowski 	case FDT_END_NODE:
13021fdc27aSRafal Jaworowski 	case FDT_NOP:
13121fdc27aSRafal Jaworowski 		break;
13221fdc27aSRafal Jaworowski 
13321fdc27aSRafal Jaworowski 	default:
13421fdc27aSRafal Jaworowski 		return FDT_END;
13521fdc27aSRafal Jaworowski 	}
13621fdc27aSRafal Jaworowski 
13721fdc27aSRafal Jaworowski 	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
13821fdc27aSRafal Jaworowski 		return FDT_END; /* premature end */
13921fdc27aSRafal Jaworowski 
14021fdc27aSRafal Jaworowski 	*nextoffset = FDT_TAGALIGN(offset);
14121fdc27aSRafal Jaworowski 	return tag;
14221fdc27aSRafal Jaworowski }
14321fdc27aSRafal Jaworowski 
144*6780e684SKyle Evans int fdt_check_node_offset_(const void *fdt, int offset)
14521fdc27aSRafal Jaworowski {
14621fdc27aSRafal Jaworowski 	if ((offset < 0) || (offset % FDT_TAGSIZE)
14721fdc27aSRafal Jaworowski 	    || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
14821fdc27aSRafal Jaworowski 		return -FDT_ERR_BADOFFSET;
14921fdc27aSRafal Jaworowski 
15021fdc27aSRafal Jaworowski 	return offset;
15121fdc27aSRafal Jaworowski }
15221fdc27aSRafal Jaworowski 
153*6780e684SKyle Evans int fdt_check_prop_offset_(const void *fdt, int offset)
15452baf267SWarner Losh {
15552baf267SWarner Losh 	if ((offset < 0) || (offset % FDT_TAGSIZE)
15652baf267SWarner Losh 	    || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
15752baf267SWarner Losh 		return -FDT_ERR_BADOFFSET;
15852baf267SWarner Losh 
15952baf267SWarner Losh 	return offset;
16052baf267SWarner Losh }
16152baf267SWarner Losh 
16221fdc27aSRafal Jaworowski int fdt_next_node(const void *fdt, int offset, int *depth)
16321fdc27aSRafal Jaworowski {
16421fdc27aSRafal Jaworowski 	int nextoffset = 0;
16521fdc27aSRafal Jaworowski 	uint32_t tag;
16621fdc27aSRafal Jaworowski 
16721fdc27aSRafal Jaworowski 	if (offset >= 0)
168*6780e684SKyle Evans 		if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0)
16921fdc27aSRafal Jaworowski 			return nextoffset;
17021fdc27aSRafal Jaworowski 
17121fdc27aSRafal Jaworowski 	do {
17221fdc27aSRafal Jaworowski 		offset = nextoffset;
17321fdc27aSRafal Jaworowski 		tag = fdt_next_tag(fdt, offset, &nextoffset);
17421fdc27aSRafal Jaworowski 
17521fdc27aSRafal Jaworowski 		switch (tag) {
17621fdc27aSRafal Jaworowski 		case FDT_PROP:
17721fdc27aSRafal Jaworowski 		case FDT_NOP:
17821fdc27aSRafal Jaworowski 			break;
17921fdc27aSRafal Jaworowski 
18021fdc27aSRafal Jaworowski 		case FDT_BEGIN_NODE:
18121fdc27aSRafal Jaworowski 			if (depth)
18221fdc27aSRafal Jaworowski 				(*depth)++;
18321fdc27aSRafal Jaworowski 			break;
18421fdc27aSRafal Jaworowski 
18521fdc27aSRafal Jaworowski 		case FDT_END_NODE:
18621fdc27aSRafal Jaworowski 			if (depth && ((--(*depth)) < 0))
18721fdc27aSRafal Jaworowski 				return nextoffset;
18821fdc27aSRafal Jaworowski 			break;
18921fdc27aSRafal Jaworowski 
19021fdc27aSRafal Jaworowski 		case FDT_END:
19121fdc27aSRafal Jaworowski 			if ((nextoffset >= 0)
19221fdc27aSRafal Jaworowski 			    || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
19321fdc27aSRafal Jaworowski 				return -FDT_ERR_NOTFOUND;
19421fdc27aSRafal Jaworowski 			else
19521fdc27aSRafal Jaworowski 				return nextoffset;
19621fdc27aSRafal Jaworowski 		}
19721fdc27aSRafal Jaworowski 	} while (tag != FDT_BEGIN_NODE);
19821fdc27aSRafal Jaworowski 
19921fdc27aSRafal Jaworowski 	return offset;
20021fdc27aSRafal Jaworowski }
20121fdc27aSRafal Jaworowski 
202*6780e684SKyle Evans int fdt_first_subnode(const void *fdt, int offset)
203*6780e684SKyle Evans {
204*6780e684SKyle Evans 	int depth = 0;
205*6780e684SKyle Evans 
206*6780e684SKyle Evans 	offset = fdt_next_node(fdt, offset, &depth);
207*6780e684SKyle Evans 	if (offset < 0 || depth != 1)
208*6780e684SKyle Evans 		return -FDT_ERR_NOTFOUND;
209*6780e684SKyle Evans 
210*6780e684SKyle Evans 	return offset;
211*6780e684SKyle Evans }
212*6780e684SKyle Evans 
213*6780e684SKyle Evans int fdt_next_subnode(const void *fdt, int offset)
214*6780e684SKyle Evans {
215*6780e684SKyle Evans 	int depth = 1;
216*6780e684SKyle Evans 
217*6780e684SKyle Evans 	/*
218*6780e684SKyle Evans 	 * With respect to the parent, the depth of the next subnode will be
219*6780e684SKyle Evans 	 * the same as the last.
220*6780e684SKyle Evans 	 */
221*6780e684SKyle Evans 	do {
222*6780e684SKyle Evans 		offset = fdt_next_node(fdt, offset, &depth);
223*6780e684SKyle Evans 		if (offset < 0 || depth < 1)
224*6780e684SKyle Evans 			return -FDT_ERR_NOTFOUND;
225*6780e684SKyle Evans 	} while (depth > 1);
226*6780e684SKyle Evans 
227*6780e684SKyle Evans 	return offset;
228*6780e684SKyle Evans }
229*6780e684SKyle Evans 
230*6780e684SKyle Evans const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
23121fdc27aSRafal Jaworowski {
23221fdc27aSRafal Jaworowski 	int len = strlen(s) + 1;
23321fdc27aSRafal Jaworowski 	const char *last = strtab + tabsize - len;
23421fdc27aSRafal Jaworowski 	const char *p;
23521fdc27aSRafal Jaworowski 
23621fdc27aSRafal Jaworowski 	for (p = strtab; p <= last; p++)
23721fdc27aSRafal Jaworowski 		if (memcmp(p, s, len) == 0)
23821fdc27aSRafal Jaworowski 			return p;
23921fdc27aSRafal Jaworowski 	return NULL;
24021fdc27aSRafal Jaworowski }
24121fdc27aSRafal Jaworowski 
24221fdc27aSRafal Jaworowski int fdt_move(const void *fdt, void *buf, int bufsize)
24321fdc27aSRafal Jaworowski {
24421fdc27aSRafal Jaworowski 	FDT_CHECK_HEADER(fdt);
24521fdc27aSRafal Jaworowski 
24621fdc27aSRafal Jaworowski 	if (fdt_totalsize(fdt) > bufsize)
24721fdc27aSRafal Jaworowski 		return -FDT_ERR_NOSPACE;
24821fdc27aSRafal Jaworowski 
24921fdc27aSRafal Jaworowski 	memmove(buf, fdt, fdt_totalsize(fdt));
25021fdc27aSRafal Jaworowski 	return 0;
25121fdc27aSRafal Jaworowski }
252