2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
4 * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause
6 #include "libfdt_env.h"
11 #include "libfdt_internal.h"
13 static int _fdt_sw_check_header(void *fdt)
15 if (fdt_magic(fdt) != FDT_SW_MAGIC)
16 return -FDT_ERR_BADMAGIC;
17 /* FIXME: should check more details about the header state */
21 #define FDT_SW_CHECK_HEADER(fdt) \
24 if ((err = _fdt_sw_check_header(fdt)) != 0) \
28 static void *_fdt_grab_space(void *fdt, size_t len)
30 int offset = fdt_size_dt_struct(fdt);
33 spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
34 - fdt_size_dt_strings(fdt);
36 if ((offset + len < offset) || (offset + len > spaceleft))
39 fdt_set_size_dt_struct(fdt, offset + len);
40 return _fdt_offset_ptr_w(fdt, offset);
43 int fdt_create(void *buf, int bufsize)
47 if (bufsize < sizeof(struct fdt_header))
48 return -FDT_ERR_NOSPACE;
50 memset(buf, 0, bufsize);
52 fdt_set_magic(fdt, FDT_SW_MAGIC);
53 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
54 fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
55 fdt_set_totalsize(fdt, bufsize);
57 fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
58 sizeof(struct fdt_reserve_entry)));
59 fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
60 fdt_set_off_dt_strings(fdt, bufsize);
65 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
67 struct fdt_reserve_entry *re;
70 FDT_SW_CHECK_HEADER(fdt);
72 if (fdt_size_dt_struct(fdt))
73 return -FDT_ERR_BADSTATE;
75 offset = fdt_off_dt_struct(fdt);
76 if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
77 return -FDT_ERR_NOSPACE;
79 re = (struct fdt_reserve_entry *)((char *)fdt + offset);
80 re->address = cpu_to_fdt64(addr);
81 re->size = cpu_to_fdt64(size);
83 fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
88 int fdt_finish_reservemap(void *fdt)
90 return fdt_add_reservemap_entry(fdt, 0, 0);
93 int fdt_begin_node(void *fdt, const char *name)
95 struct fdt_node_header *nh;
96 int namelen = strlen(name) + 1;
98 FDT_SW_CHECK_HEADER(fdt);
100 nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
102 return -FDT_ERR_NOSPACE;
104 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
105 memcpy(nh->name, name, namelen);
109 int fdt_end_node(void *fdt)
113 FDT_SW_CHECK_HEADER(fdt);
115 en = _fdt_grab_space(fdt, FDT_TAGSIZE);
117 return -FDT_ERR_NOSPACE;
119 *en = cpu_to_fdt32(FDT_END_NODE);
123 static int _fdt_find_add_string(void *fdt, const char *s)
125 char *strtab = (char *)fdt + fdt_totalsize(fdt);
127 int strtabsize = fdt_size_dt_strings(fdt);
128 int len = strlen(s) + 1;
129 int struct_top, offset;
131 p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
136 offset = -strtabsize - len;
137 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
138 if (fdt_totalsize(fdt) + offset < struct_top)
139 return 0; /* no more room :( */
141 memcpy(strtab + offset, s, len);
142 fdt_set_size_dt_strings(fdt, strtabsize + len);
146 int fdt_property(void *fdt, const char *name, const void *val, int len)
148 struct fdt_property *prop;
151 FDT_SW_CHECK_HEADER(fdt);
153 nameoff = _fdt_find_add_string(fdt, name);
155 return -FDT_ERR_NOSPACE;
157 prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
159 return -FDT_ERR_NOSPACE;
161 prop->tag = cpu_to_fdt32(FDT_PROP);
162 prop->nameoff = cpu_to_fdt32(nameoff);
163 prop->len = cpu_to_fdt32(len);
164 memcpy(prop->data, val, len);
168 int fdt_finish(void *fdt)
170 char *p = (char *)fdt;
172 int oldstroffset, newstroffset;
174 int offset, nextoffset;
176 FDT_SW_CHECK_HEADER(fdt);
179 end = _fdt_grab_space(fdt, sizeof(*end));
181 return -FDT_ERR_NOSPACE;
182 *end = cpu_to_fdt32(FDT_END);
184 /* Relocate the string table */
185 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
186 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
187 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
188 fdt_set_off_dt_strings(fdt, newstroffset);
190 /* Walk the structure, correcting string offsets */
192 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
193 if (tag == FDT_PROP) {
194 struct fdt_property *prop =
195 _fdt_offset_ptr_w(fdt, offset);
198 nameoff = fdt32_to_cpu(prop->nameoff);
199 nameoff += fdt_size_dt_strings(fdt);
200 prop->nameoff = cpu_to_fdt32(nameoff);
207 /* Finally, adjust the header */
208 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
209 fdt_set_magic(fdt, FDT_MAGIC);