1/*
2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
4 *
5 *     Redistribution and use in source and binary forms, with or
6 *     without modification, are permitted provided that the following
7 *     conditions are met:
8 *
9 *     1. Redistributions of source code must retain the above
10 *        copyright notice, this list of conditions and the following
11 *        disclaimer.
12 *     2. Redistributions in binary form must reproduce the above
13 *        copyright notice, this list of conditions and the following
14 *        disclaimer in the documentation and/or other materials
15 *        provided with the distribution.
16 *
17 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
18 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
20 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
22 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
29 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31#include <fdt.h>
32#include <libfdt.h>
33
34#include "libfdt_env.h"
35#include "libfdt_internal.h"
36
37static int _fdt_sw_check_header(void *fdt)
38{
39        if (fdt_magic(fdt) != FDT_SW_MAGIC)
40                return -FDT_ERR_BADMAGIC;
41        /* FIXME: should check more details about the header state */
42        return 0;
43}
44
45#define FDT_SW_CHECK_HEADER(fdt) \
46        { \
47                int err; \
48                if ((err = _fdt_sw_check_header(fdt)) != 0) \
49                        return err; \
50        }
51
52static void *_fdt_grab_space(void *fdt, size_t len)
53{
54        int offset = fdt_size_dt_struct(fdt);
55        int spaceleft;
56
57        spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
58                - fdt_size_dt_strings(fdt);
59
60        if ((offset + len < offset) || (offset + len > spaceleft))
61                return NULL;
62
63        fdt_set_size_dt_struct(fdt, offset + len);
64        return _fdt_offset_ptr_w(fdt, offset);
65}
66
67int fdt_create(void *buf, int bufsize)
68{
69        void *fdt = buf;
70
71        if (bufsize < sizeof(struct fdt_header))
72                return -FDT_ERR_NOSPACE;
73
74        memset(buf, 0, bufsize);
75
76        fdt_set_magic(fdt, FDT_SW_MAGIC);
77        fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
78        fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
79        fdt_set_totalsize(fdt,  bufsize);
80
81        fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
82                                              sizeof(struct fdt_reserve_entry)));
83        fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
84        fdt_set_off_dt_strings(fdt, bufsize);
85
86        return 0;
87}
88
89int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
90{
91        struct fdt_reserve_entry *re;
92        int offset;
93
94        FDT_SW_CHECK_HEADER(fdt);
95
96        if (fdt_size_dt_struct(fdt))
97                return -FDT_ERR_BADSTATE;
98
99        offset = fdt_off_dt_struct(fdt);
100        if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
101                return -FDT_ERR_NOSPACE;
102
103        re = (struct fdt_reserve_entry *)((char *)fdt + offset);
104        re->address = cpu_to_fdt64(addr);
105        re->size = cpu_to_fdt64(size);
106
107        fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
108
109        return 0;
110}
111
112int fdt_finish_reservemap(void *fdt)
113{
114        return fdt_add_reservemap_entry(fdt, 0, 0);
115}
116
117int fdt_begin_node(void *fdt, const char *name)
118{
119        struct fdt_node_header *nh;
120        int namelen = strlen(name) + 1;
121
122        FDT_SW_CHECK_HEADER(fdt);
123
124        nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
125        if (! nh)
126                return -FDT_ERR_NOSPACE;
127
128        nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
129        memcpy(nh->name, name, namelen);
130        return 0;
131}
132
133int fdt_end_node(void *fdt)
134{
135        fdt32_t *en;
136
137        FDT_SW_CHECK_HEADER(fdt);
138
139        en = _fdt_grab_space(fdt, FDT_TAGSIZE);
140        if (! en)
141                return -FDT_ERR_NOSPACE;
142
143        *en = cpu_to_fdt32(FDT_END_NODE);
144        return 0;
145}
146
147static int _fdt_find_add_string(void *fdt, const char *s)
148{
149        char *strtab = (char *)fdt + fdt_totalsize(fdt);
150        const char *p;
151        int strtabsize = fdt_size_dt_strings(fdt);
152        int len = strlen(s) + 1;
153        int struct_top, offset;
154
155        p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
156        if (p)
157                return p - strtab;
158
159        /* Add it */
160        offset = -strtabsize - len;
161        struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
162        if (fdt_totalsize(fdt) + offset < struct_top)
163                return 0; /* no more room :( */
164
165        memcpy(strtab + offset, s, len);
166        fdt_set_size_dt_strings(fdt, strtabsize + len);
167        return offset;
168}
169
170int fdt_property(void *fdt, const char *name, const void *val, int len)
171{
172        struct fdt_property *prop;
173        int nameoff;
174
175        FDT_SW_CHECK_HEADER(fdt);
176
177        nameoff = _fdt_find_add_string(fdt, name);
178        if (nameoff == 0)
179                return -FDT_ERR_NOSPACE;
180
181        prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
182        if (! prop)
183                return -FDT_ERR_NOSPACE;
184
185        prop->tag = cpu_to_fdt32(FDT_PROP);
186        prop->nameoff = cpu_to_fdt32(nameoff);
187        prop->len = cpu_to_fdt32(len);
188        memcpy(prop->data, val, len);
189        return 0;
190}
191
192int fdt_finish(void *fdt)
193{
194        char *p = (char *)fdt;
195        fdt32_t *end;
196        int oldstroffset, newstroffset;
197        uint32_t tag;
198        int offset, nextoffset;
199
200        FDT_SW_CHECK_HEADER(fdt);
201
202        /* Add terminator */
203        end = _fdt_grab_space(fdt, sizeof(*end));
204        if (! end)
205                return -FDT_ERR_NOSPACE;
206        *end = cpu_to_fdt32(FDT_END);
207
208        /* Relocate the string table */
209        oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
210        newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
211        memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
212        fdt_set_off_dt_strings(fdt, newstroffset);
213
214        /* Walk the structure, correcting string offsets */
215        offset = 0;
216        while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
217                if (tag == FDT_PROP) {
218                        struct fdt_property *prop =
219                                _fdt_offset_ptr_w(fdt, offset);
220                        int nameoff;
221
222                        nameoff = fdt32_to_cpu(prop->nameoff);
223                        nameoff += fdt_size_dt_strings(fdt);
224                        prop->nameoff = cpu_to_fdt32(nameoff);
225                }
226                offset = nextoffset;
227        }
228        if (nextoffset < 0)
229                return nextoffset;
230
231        /* Finally, adjust the header */
232        fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
233        fdt_set_magic(fdt, FDT_MAGIC);
234        return 0;
235}
236