symbian-qemu-0.9.1-12/dtc-trunk/libfdt/fdt.c
changeset 1 2fb8b9db1c86
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0:ffa851df0825 1:2fb8b9db1c86
       
     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 int fdt_check_header(const void *fdt)
       
    59 {
       
    60 	if (fdt_magic(fdt) == FDT_MAGIC) {
       
    61 		/* Complete tree */
       
    62 		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
       
    63 			return -FDT_ERR_BADVERSION;
       
    64 		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
       
    65 			return -FDT_ERR_BADVERSION;
       
    66 	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
       
    67 		/* Unfinished sequential-write blob */
       
    68 		if (fdt_size_dt_struct(fdt) == 0)
       
    69 			return -FDT_ERR_BADSTATE;
       
    70 	} else {
       
    71 		return -FDT_ERR_BADMAGIC;
       
    72 	}
       
    73 
       
    74 	return 0;
       
    75 }
       
    76 
       
    77 const void *fdt_offset_ptr(const void *fdt, int offset, int len)
       
    78 {
       
    79 	const char *p;
       
    80 
       
    81 	if (fdt_version(fdt) >= 0x11)
       
    82 		if (((offset + len) < offset)
       
    83 		    || ((offset + len) > fdt_size_dt_struct(fdt)))
       
    84 			return NULL;
       
    85 
       
    86 	p = _fdt_offset_ptr(fdt, offset);
       
    87 
       
    88 	if (p + len < p)
       
    89 		return NULL;
       
    90 	return p;
       
    91 }
       
    92 
       
    93 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
       
    94 {
       
    95 	const uint32_t *tagp, *lenp;
       
    96 	uint32_t tag;
       
    97 	const char *p;
       
    98 
       
    99 	if (offset % FDT_TAGSIZE)
       
   100 		return -1;
       
   101 
       
   102 	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
       
   103 	if (! tagp)
       
   104 		return FDT_END; /* premature end */
       
   105 	tag = fdt32_to_cpu(*tagp);
       
   106 	offset += FDT_TAGSIZE;
       
   107 
       
   108 	switch (tag) {
       
   109 	case FDT_BEGIN_NODE:
       
   110 		/* skip name */
       
   111 		do {
       
   112 			p = fdt_offset_ptr(fdt, offset++, 1);
       
   113 		} while (p && (*p != '\0'));
       
   114 		if (! p)
       
   115 			return FDT_END;
       
   116 		break;
       
   117 	case FDT_PROP:
       
   118 		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
       
   119 		if (! lenp)
       
   120 			return FDT_END;
       
   121 		/* skip name offset, length and value */
       
   122 		offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
       
   123 		break;
       
   124 	}
       
   125 
       
   126 	if (nextoffset)
       
   127 		*nextoffset = FDT_TAGALIGN(offset);
       
   128 
       
   129 	return tag;
       
   130 }
       
   131 
       
   132 int _fdt_check_node_offset(const void *fdt, int offset)
       
   133 {
       
   134 	if ((offset < 0) || (offset % FDT_TAGSIZE)
       
   135 	    || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
       
   136 		return -FDT_ERR_BADOFFSET;
       
   137 
       
   138 	return offset;
       
   139 }
       
   140 
       
   141 int fdt_next_node(const void *fdt, int offset, int *depth)
       
   142 {
       
   143 	int nextoffset = 0;
       
   144 	uint32_t tag;
       
   145 
       
   146 	if (offset >= 0)
       
   147 		if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
       
   148 			return nextoffset;
       
   149 
       
   150 	do {
       
   151 		offset = nextoffset;
       
   152 		tag = fdt_next_tag(fdt, offset, &nextoffset);
       
   153 
       
   154 		switch (tag) {
       
   155 		case FDT_PROP:
       
   156 		case FDT_NOP:
       
   157 			break;
       
   158 
       
   159 		case FDT_BEGIN_NODE:
       
   160 			if (depth)
       
   161 				(*depth)++;
       
   162 			break;
       
   163 
       
   164 		case FDT_END_NODE:
       
   165 			if (depth)
       
   166 				(*depth)--;
       
   167 			break;
       
   168 
       
   169 		case FDT_END:
       
   170 			return -FDT_ERR_NOTFOUND;
       
   171 
       
   172 		default:
       
   173 			return -FDT_ERR_BADSTRUCTURE;
       
   174 		}
       
   175 	} while (tag != FDT_BEGIN_NODE);
       
   176 
       
   177 	return offset;
       
   178 }
       
   179 
       
   180 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
       
   181 {
       
   182 	int len = strlen(s) + 1;
       
   183 	const char *last = strtab + tabsize - len;
       
   184 	const char *p;
       
   185 
       
   186 	for (p = strtab; p <= last; p++)
       
   187 		if (memcmp(p, s, len) == 0)
       
   188 			return p;
       
   189 	return NULL;
       
   190 }
       
   191 
       
   192 int fdt_move(const void *fdt, void *buf, int bufsize)
       
   193 {
       
   194 	FDT_CHECK_HEADER(fdt);
       
   195 
       
   196 	if (fdt_totalsize(fdt) > bufsize)
       
   197 		return -FDT_ERR_NOSPACE;
       
   198 
       
   199 	memmove(buf, fdt, fdt_totalsize(fdt));
       
   200 	return 0;
       
   201 }