1 // SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
6 #include "libfdt_env.h"
11 #include "libfdt_internal.h"
13 static int fdt_sw_probe_(void *fdt)
15 if (fdt_chk_basic()) {
16 if (fdt_magic(fdt) == FDT_MAGIC)
17 return -FDT_ERR_BADSTATE;
18 else if (fdt_magic(fdt) != FDT_SW_MAGIC)
19 return -FDT_ERR_BADMAGIC;
25 #define FDT_SW_PROBE(fdt) \
28 if (fdt_chk_basic() && (err = fdt_sw_probe_(fdt)) != 0) \
32 /* 'memrsv' state: Initial state after fdt_create()
35 * fdt_add_reservmap_entry()
36 * fdt_finish_reservemap() [moves to 'struct' state]
38 static int fdt_sw_probe_memrsv_(void *fdt)
40 int err = fdt_sw_probe_(fdt);
44 if (fdt_chk_extra() && fdt_off_dt_strings(fdt) != 0)
45 return -FDT_ERR_BADSTATE;
49 #define FDT_SW_PROBE_MEMRSV(fdt) \
52 if (fdt_chk_extra() && (err = fdt_sw_probe_memrsv_(fdt)) != 0) \
56 /* 'struct' state: Enter this state after fdt_finish_reservemap()
62 * fdt_finish() [moves to 'complete' state]
64 static int fdt_sw_probe_struct_(void *fdt)
70 err = fdt_sw_probe_(fdt);
74 if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt))
75 return -FDT_ERR_BADSTATE;
79 #define FDT_SW_PROBE_STRUCT(fdt) \
82 if (fdt_chk_extra() && (err = fdt_sw_probe_struct_(fdt)) != 0) \
86 static inline uint32_t sw_flags(void *fdt)
88 /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */
89 return fdt_last_comp_version(fdt);
92 /* 'complete' state: Enter this state after fdt_finish()
94 * Allowed functions: none
97 static void *fdt_grab_space_(void *fdt, size_t len)
99 int offset = fdt_size_dt_struct(fdt);
102 spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
103 - fdt_size_dt_strings(fdt);
105 if ((offset + len < offset) || (offset + len > spaceleft))
108 fdt_set_size_dt_struct(fdt, offset + len);
109 return fdt_offset_ptr_w_(fdt, offset);
112 int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags)
114 const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header),
115 sizeof(struct fdt_reserve_entry));
118 if (bufsize < hdrsize)
119 return -FDT_ERR_NOSPACE;
121 if (flags & ~FDT_CREATE_FLAGS_ALL)
122 return -FDT_ERR_BADFLAGS;
124 memset(buf, 0, bufsize);
127 * magic and last_comp_version keep intermediate state during the fdt
128 * creation process, which is replaced with the proper FDT format by
131 * flags should be accessed with sw_flags().
133 fdt_set_magic(fdt, FDT_SW_MAGIC);
134 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
135 fdt_set_last_comp_version(fdt, flags);
137 fdt_set_totalsize(fdt, bufsize);
139 fdt_set_off_mem_rsvmap(fdt, hdrsize);
140 fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
141 fdt_set_off_dt_strings(fdt, 0);
146 int fdt_create(void *buf, int bufsize)
148 return fdt_create_with_flags(buf, bufsize, 0);
151 int fdt_resize(void *fdt, void *buf, int bufsize)
153 size_t headsize, tailsize;
154 char *oldtail, *newtail;
158 headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
159 tailsize = fdt_size_dt_strings(fdt);
161 if (fdt_chk_extra() && (headsize + tailsize) > fdt_totalsize(fdt))
162 return -FDT_ERR_INTERNAL;
164 if ((headsize + tailsize) > bufsize)
165 return -FDT_ERR_NOSPACE;
167 oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
168 newtail = (char *)buf + bufsize - tailsize;
170 /* Two cases to avoid clobbering data if the old and new
171 * buffers partially overlap */
173 memmove(buf, fdt, headsize);
174 memmove(newtail, oldtail, tailsize);
176 memmove(newtail, oldtail, tailsize);
177 memmove(buf, fdt, headsize);
180 fdt_set_totalsize(buf, bufsize);
181 if (fdt_off_dt_strings(buf))
182 fdt_set_off_dt_strings(buf, bufsize);
187 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
189 struct fdt_reserve_entry *re;
192 FDT_SW_PROBE_MEMRSV(fdt);
194 offset = fdt_off_dt_struct(fdt);
195 if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
196 return -FDT_ERR_NOSPACE;
198 re = (struct fdt_reserve_entry *)((char *)fdt + offset);
199 re->address = cpu_to_fdt64(addr);
200 re->size = cpu_to_fdt64(size);
202 fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
207 int fdt_finish_reservemap(void *fdt)
209 int err = fdt_add_reservemap_entry(fdt, 0, 0);
214 fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
218 int fdt_begin_node(void *fdt, const char *name)
220 struct fdt_node_header *nh;
223 FDT_SW_PROBE_STRUCT(fdt);
225 namelen = strlen(name) + 1;
226 nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
228 return -FDT_ERR_NOSPACE;
230 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
231 memcpy(nh->name, name, namelen);
235 int fdt_end_node(void *fdt)
239 FDT_SW_PROBE_STRUCT(fdt);
241 en = fdt_grab_space_(fdt, FDT_TAGSIZE);
243 return -FDT_ERR_NOSPACE;
245 *en = cpu_to_fdt32(FDT_END_NODE);
249 static int fdt_add_string_(void *fdt, const char *s)
251 char *strtab = (char *)fdt + fdt_totalsize(fdt);
252 int strtabsize = fdt_size_dt_strings(fdt);
253 int len = strlen(s) + 1;
254 int struct_top, offset;
256 offset = -strtabsize - len;
257 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
258 if (fdt_totalsize(fdt) + offset < struct_top)
259 return 0; /* no more room :( */
261 memcpy(strtab + offset, s, len);
262 fdt_set_size_dt_strings(fdt, strtabsize + len);
266 /* Must only be used to roll back in case of error */
267 static void fdt_del_last_string_(void *fdt, const char *s)
269 int strtabsize = fdt_size_dt_strings(fdt);
270 int len = strlen(s) + 1;
272 fdt_set_size_dt_strings(fdt, strtabsize - len);
275 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
277 char *strtab = (char *)fdt + fdt_totalsize(fdt);
278 int strtabsize = fdt_size_dt_strings(fdt);
283 p = fdt_find_string_(strtab - strtabsize, strtabsize, s);
289 return fdt_add_string_(fdt, s);
292 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
294 struct fdt_property *prop;
298 FDT_SW_PROBE_STRUCT(fdt);
300 /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */
301 if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) {
303 nameoff = fdt_add_string_(fdt, name);
305 nameoff = fdt_find_add_string_(fdt, name, &allocated);
308 return -FDT_ERR_NOSPACE;
310 prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
313 fdt_del_last_string_(fdt, name);
314 return -FDT_ERR_NOSPACE;
317 prop->tag = cpu_to_fdt32(FDT_PROP);
318 prop->nameoff = cpu_to_fdt32(nameoff);
319 prop->len = cpu_to_fdt32(len);
324 int fdt_property(void *fdt, const char *name, const void *val, int len)
329 ret = fdt_property_placeholder(fdt, name, len, &ptr);
332 memcpy(ptr, val, len);
336 int fdt_finish(void *fdt)
338 char *p = (char *)fdt;
340 int oldstroffset, newstroffset;
342 int offset, nextoffset;
344 FDT_SW_PROBE_STRUCT(fdt);
347 end = fdt_grab_space_(fdt, sizeof(*end));
349 return -FDT_ERR_NOSPACE;
350 *end = cpu_to_fdt32(FDT_END);
352 /* Relocate the string table */
353 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
354 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
355 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
356 fdt_set_off_dt_strings(fdt, newstroffset);
358 /* Walk the structure, correcting string offsets */
360 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
361 if (tag == FDT_PROP) {
362 struct fdt_property *prop =
363 fdt_offset_ptr_w_(fdt, offset);
366 nameoff = fdt32_to_cpu(prop->nameoff);
367 nameoff += fdt_size_dt_strings(fdt);
368 prop->nameoff = cpu_to_fdt32(nameoff);
375 /* Finally, adjust the header */
376 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
378 /* And fix up fields that were keeping intermediate state. */
379 fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
380 fdt_set_magic(fdt, FDT_MAGIC);