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 (!can_assume(VALID_INPUT)) {
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 ((err = fdt_sw_probe_(fdt)) != 0) \
32 /* 'memrsv' state: Initial state after fdt_create()
35 * fdt_add_reservemap_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 (!can_assume(VALID_INPUT) && fdt_off_dt_strings(fdt) != 0)
45 return -FDT_ERR_BADSTATE;
49 #define FDT_SW_PROBE_MEMRSV(fdt) \
52 if ((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)
66 int err = fdt_sw_probe_(fdt);
70 if (!can_assume(VALID_INPUT) &&
71 fdt_off_dt_strings(fdt) != fdt_totalsize(fdt))
72 return -FDT_ERR_BADSTATE;
76 #define FDT_SW_PROBE_STRUCT(fdt) \
79 if ((err = fdt_sw_probe_struct_(fdt)) != 0) \
83 static inline uint32_t sw_flags(void *fdt)
85 /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */
86 return fdt_last_comp_version(fdt);
89 /* 'complete' state: Enter this state after fdt_finish()
91 * Allowed functions: none
94 static void *fdt_grab_space_(void *fdt, size_t len)
96 int offset = fdt_size_dt_struct(fdt);
99 spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
100 - fdt_size_dt_strings(fdt);
102 if ((offset + len < offset) || (offset + len > spaceleft))
105 fdt_set_size_dt_struct(fdt, offset + len);
106 return fdt_offset_ptr_w_(fdt, offset);
109 int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags)
111 const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header),
112 sizeof(struct fdt_reserve_entry));
115 if (bufsize < hdrsize)
116 return -FDT_ERR_NOSPACE;
118 if (flags & ~FDT_CREATE_FLAGS_ALL)
119 return -FDT_ERR_BADFLAGS;
121 memset(buf, 0, bufsize);
124 * magic and last_comp_version keep intermediate state during the fdt
125 * creation process, which is replaced with the proper FDT format by
128 * flags should be accessed with sw_flags().
130 fdt_set_magic(fdt, FDT_SW_MAGIC);
131 fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
132 fdt_set_last_comp_version(fdt, flags);
134 fdt_set_totalsize(fdt, bufsize);
136 fdt_set_off_mem_rsvmap(fdt, hdrsize);
137 fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
138 fdt_set_off_dt_strings(fdt, 0);
143 int fdt_create(void *buf, int bufsize)
145 return fdt_create_with_flags(buf, bufsize, 0);
148 int fdt_resize(void *fdt, void *buf, int bufsize)
150 size_t headsize, tailsize;
151 char *oldtail, *newtail;
155 headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
156 tailsize = fdt_size_dt_strings(fdt);
158 if (!can_assume(VALID_DTB) &&
159 headsize + tailsize > fdt_totalsize(fdt))
160 return -FDT_ERR_INTERNAL;
162 if ((headsize + tailsize) > bufsize)
163 return -FDT_ERR_NOSPACE;
165 oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
166 newtail = (char *)buf + bufsize - tailsize;
168 /* Two cases to avoid clobbering data if the old and new
169 * buffers partially overlap */
171 memmove(buf, fdt, headsize);
172 memmove(newtail, oldtail, tailsize);
174 memmove(newtail, oldtail, tailsize);
175 memmove(buf, fdt, headsize);
178 fdt_set_totalsize(buf, bufsize);
179 if (fdt_off_dt_strings(buf))
180 fdt_set_off_dt_strings(buf, bufsize);
185 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
187 struct fdt_reserve_entry *re;
190 FDT_SW_PROBE_MEMRSV(fdt);
192 offset = fdt_off_dt_struct(fdt);
193 if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
194 return -FDT_ERR_NOSPACE;
196 re = (struct fdt_reserve_entry *)((char *)fdt + offset);
197 re->address = cpu_to_fdt64(addr);
198 re->size = cpu_to_fdt64(size);
200 fdt_set_off_dt_struct(fdt, offset + sizeof(*re));
205 int fdt_finish_reservemap(void *fdt)
207 int err = fdt_add_reservemap_entry(fdt, 0, 0);
212 fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
216 int fdt_begin_node(void *fdt, const char *name)
218 struct fdt_node_header *nh;
221 FDT_SW_PROBE_STRUCT(fdt);
223 namelen = strlen(name) + 1;
224 nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
226 return -FDT_ERR_NOSPACE;
228 nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
229 memcpy(nh->name, name, namelen);
233 int fdt_end_node(void *fdt)
237 FDT_SW_PROBE_STRUCT(fdt);
239 en = fdt_grab_space_(fdt, FDT_TAGSIZE);
241 return -FDT_ERR_NOSPACE;
243 *en = cpu_to_fdt32(FDT_END_NODE);
247 static int fdt_add_string_(void *fdt, const char *s)
249 char *strtab = (char *)fdt + fdt_totalsize(fdt);
250 int strtabsize = fdt_size_dt_strings(fdt);
251 int len = strlen(s) + 1;
252 int struct_top, offset;
254 offset = -strtabsize - len;
255 struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
256 if (fdt_totalsize(fdt) + offset < struct_top)
257 return 0; /* no more room :( */
259 memcpy(strtab + offset, s, len);
260 fdt_set_size_dt_strings(fdt, strtabsize + len);
264 /* Must only be used to roll back in case of error */
265 static void fdt_del_last_string_(void *fdt, const char *s)
267 int strtabsize = fdt_size_dt_strings(fdt);
268 int len = strlen(s) + 1;
270 fdt_set_size_dt_strings(fdt, strtabsize - len);
273 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
275 char *strtab = (char *)fdt + fdt_totalsize(fdt);
276 int strtabsize = fdt_size_dt_strings(fdt);
281 p = fdt_find_string_(strtab - strtabsize, strtabsize, s);
287 return fdt_add_string_(fdt, s);
290 int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
292 struct fdt_property *prop;
296 FDT_SW_PROBE_STRUCT(fdt);
298 /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */
299 if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) {
301 nameoff = fdt_add_string_(fdt, name);
303 nameoff = fdt_find_add_string_(fdt, name, &allocated);
306 return -FDT_ERR_NOSPACE;
308 prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
311 fdt_del_last_string_(fdt, name);
312 return -FDT_ERR_NOSPACE;
315 prop->tag = cpu_to_fdt32(FDT_PROP);
316 prop->nameoff = cpu_to_fdt32(nameoff);
317 prop->len = cpu_to_fdt32(len);
322 int fdt_property(void *fdt, const char *name, const void *val, int len)
327 ret = fdt_property_placeholder(fdt, name, len, &ptr);
330 memcpy(ptr, val, len);
334 int fdt_finish(void *fdt)
336 char *p = (char *)fdt;
338 int oldstroffset, newstroffset;
340 int offset, nextoffset;
342 FDT_SW_PROBE_STRUCT(fdt);
345 end = fdt_grab_space_(fdt, sizeof(*end));
347 return -FDT_ERR_NOSPACE;
348 *end = cpu_to_fdt32(FDT_END);
350 /* Relocate the string table */
351 oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
352 newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
353 memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
354 fdt_set_off_dt_strings(fdt, newstroffset);
356 /* Walk the structure, correcting string offsets */
358 while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
359 if (tag == FDT_PROP) {
360 struct fdt_property *prop =
361 fdt_offset_ptr_w_(fdt, offset);
364 nameoff = fdt32_to_cpu(prop->nameoff);
365 nameoff += fdt_size_dt_strings(fdt);
366 prop->nameoff = cpu_to_fdt32(nameoff);
373 /* Finally, adjust the header */
374 fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
376 /* And fix up fields that were keeping intermediate state. */
377 fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
378 fdt_set_magic(fdt, FDT_MAGIC);