blob: 65da5aec7552c70162b6646ded99a32c72797b9d [file] [log] [blame]
Grant Likelye169cfb2009-11-23 14:53:09 -07001/*
2 * Functions for working with the Flattened Device Tree data format
3 *
4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5 * benh@kernel.crashing.org
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 */
11
Grant Likely41f88002009-11-23 20:07:01 -070012#include <linux/kernel.h>
Grant Likelyf7b3a832009-11-24 03:26:58 -070013#include <linux/initrd.h>
Grant Likelye169cfb2009-11-23 14:53:09 -070014#include <linux/of.h>
15#include <linux/of_fdt.h>
Jeremy Kerr4ef7b372010-02-14 07:13:47 -070016#include <linux/string.h>
17#include <linux/errno.h>
Grant Likely51975db2010-02-01 21:34:14 -070018
Grant Likely86e03222009-12-10 23:42:21 -070019#ifdef CONFIG_PPC
20#include <asm/machdep.h>
21#endif /* CONFIG_PPC */
22
Jeremy Kerr4ef7b372010-02-14 07:13:47 -070023#include <asm/page.h>
24
Grant Likelyf00abd92009-11-24 03:27:10 -070025int __initdata dt_root_addr_cells;
26int __initdata dt_root_size_cells;
27
Grant Likelye169cfb2009-11-23 14:53:09 -070028struct boot_param_header *initial_boot_params;
29
30char *find_flat_dt_string(u32 offset)
31{
32 return ((char *)initial_boot_params) +
Jeremy Kerr087f79c2010-01-30 04:14:19 -070033 be32_to_cpu(initial_boot_params->off_dt_strings) + offset;
Grant Likelye169cfb2009-11-23 14:53:09 -070034}
Grant Likelyc8cb7a52009-11-23 18:54:23 -070035
36/**
37 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
38 * @it: callback function
39 * @data: context data pointer
40 *
41 * This function is used to scan the flattened device-tree, it is
42 * used to extract the memory information at boot before we can
43 * unflatten the tree
44 */
45int __init of_scan_flat_dt(int (*it)(unsigned long node,
46 const char *uname, int depth,
47 void *data),
48 void *data)
49{
50 unsigned long p = ((unsigned long)initial_boot_params) +
Jeremy Kerr087f79c2010-01-30 04:14:19 -070051 be32_to_cpu(initial_boot_params->off_dt_struct);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070052 int rc = 0;
53 int depth = -1;
54
55 do {
Jeremy Kerr33714882010-01-30 01:45:26 -070056 u32 tag = be32_to_cpup((__be32 *)p);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070057 char *pathp;
58
59 p += 4;
60 if (tag == OF_DT_END_NODE) {
61 depth--;
62 continue;
63 }
64 if (tag == OF_DT_NOP)
65 continue;
66 if (tag == OF_DT_END)
67 break;
68 if (tag == OF_DT_PROP) {
Jeremy Kerr33714882010-01-30 01:45:26 -070069 u32 sz = be32_to_cpup((__be32 *)p);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070070 p += 8;
Jeremy Kerr087f79c2010-01-30 04:14:19 -070071 if (be32_to_cpu(initial_boot_params->version) < 0x10)
Grant Likelyf1d4c3a2010-06-25 12:16:52 -060072 p = ALIGN(p, sz >= 8 ? 8 : 4);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070073 p += sz;
Grant Likelyf1d4c3a2010-06-25 12:16:52 -060074 p = ALIGN(p, 4);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070075 continue;
76 }
77 if (tag != OF_DT_BEGIN_NODE) {
78 pr_err("Invalid tag %x in flat device tree!\n", tag);
79 return -EINVAL;
80 }
81 depth++;
82 pathp = (char *)p;
Grant Likelyf1d4c3a2010-06-25 12:16:52 -060083 p = ALIGN(p + strlen(pathp) + 1, 4);
Grant Likelyc8cb7a52009-11-23 18:54:23 -070084 if ((*pathp) == '/') {
85 char *lp, *np;
86 for (lp = NULL, np = pathp; *np; np++)
87 if ((*np) == '/')
88 lp = np+1;
89 if (lp != NULL)
90 pathp = lp;
91 }
92 rc = it(p, pathp, depth, data);
93 if (rc != 0)
94 break;
95 } while (1);
96
97 return rc;
98}
Grant Likely819d2812009-11-23 19:44:23 -070099
100/**
101 * of_get_flat_dt_root - find the root node in the flat blob
102 */
103unsigned long __init of_get_flat_dt_root(void)
104{
105 unsigned long p = ((unsigned long)initial_boot_params) +
Jeremy Kerr087f79c2010-01-30 04:14:19 -0700106 be32_to_cpu(initial_boot_params->off_dt_struct);
Grant Likely819d2812009-11-23 19:44:23 -0700107
Jeremy Kerr33714882010-01-30 01:45:26 -0700108 while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
Grant Likely819d2812009-11-23 19:44:23 -0700109 p += 4;
Jeremy Kerr33714882010-01-30 01:45:26 -0700110 BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
Grant Likely819d2812009-11-23 19:44:23 -0700111 p += 4;
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600112 return ALIGN(p + strlen((char *)p) + 1, 4);
Grant Likely819d2812009-11-23 19:44:23 -0700113}
114
Grant Likelyca900cf2009-11-23 20:06:59 -0700115/**
116 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
117 *
118 * This function can be used within scan_flattened_dt callback to get
119 * access to properties
120 */
121void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
122 unsigned long *size)
123{
124 unsigned long p = node;
125
126 do {
Jeremy Kerr33714882010-01-30 01:45:26 -0700127 u32 tag = be32_to_cpup((__be32 *)p);
Grant Likelyca900cf2009-11-23 20:06:59 -0700128 u32 sz, noff;
129 const char *nstr;
130
131 p += 4;
132 if (tag == OF_DT_NOP)
133 continue;
134 if (tag != OF_DT_PROP)
135 return NULL;
136
Jeremy Kerr33714882010-01-30 01:45:26 -0700137 sz = be32_to_cpup((__be32 *)p);
138 noff = be32_to_cpup((__be32 *)(p + 4));
Grant Likelyca900cf2009-11-23 20:06:59 -0700139 p += 8;
Jeremy Kerr087f79c2010-01-30 04:14:19 -0700140 if (be32_to_cpu(initial_boot_params->version) < 0x10)
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600141 p = ALIGN(p, sz >= 8 ? 8 : 4);
Grant Likelyca900cf2009-11-23 20:06:59 -0700142
143 nstr = find_flat_dt_string(noff);
144 if (nstr == NULL) {
145 pr_warning("Can't find property index name !\n");
146 return NULL;
147 }
148 if (strcmp(name, nstr) == 0) {
149 if (size)
150 *size = sz;
151 return (void *)p;
152 }
153 p += sz;
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600154 p = ALIGN(p, 4);
Grant Likelyca900cf2009-11-23 20:06:59 -0700155 } while (1);
156}
157
Grant Likely00e38ef2009-11-23 20:07:00 -0700158/**
159 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
160 * @node: node to test
161 * @compat: compatible string to compare with compatible list.
162 */
163int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
164{
165 const char *cp;
166 unsigned long cplen, l;
167
168 cp = of_get_flat_dt_prop(node, "compatible", &cplen);
169 if (cp == NULL)
170 return 0;
171 while (cplen > 0) {
Stuart Yoder883c2cf2010-07-23 13:42:44 -0500172 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
Grant Likely00e38ef2009-11-23 20:07:00 -0700173 return 1;
174 l = strlen(cp) + 1;
175 cp += l;
176 cplen -= l;
177 }
178
179 return 0;
180}
181
Grant Likelybbd33932009-11-23 20:07:00 -0700182static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
183 unsigned long align)
184{
185 void *res;
186
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600187 *mem = ALIGN(*mem, align);
Grant Likelybbd33932009-11-23 20:07:00 -0700188 res = (void *)*mem;
189 *mem += size;
190
191 return res;
192}
193
194/**
195 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
196 * @p: pointer to node in flat tree
197 * @dad: Parent struct device_node
198 * @allnextpp: pointer to ->allnext from last allocated device_node
199 * @fpsize: Size of the node path up at the current depth.
200 */
201unsigned long __init unflatten_dt_node(unsigned long mem,
202 unsigned long *p,
203 struct device_node *dad,
204 struct device_node ***allnextpp,
205 unsigned long fpsize)
206{
207 struct device_node *np;
208 struct property *pp, **prev_pp = NULL;
209 char *pathp;
210 u32 tag;
211 unsigned int l, allocl;
212 int has_name = 0;
213 int new_format = 0;
214
Jeremy Kerr33714882010-01-30 01:45:26 -0700215 tag = be32_to_cpup((__be32 *)(*p));
Grant Likelybbd33932009-11-23 20:07:00 -0700216 if (tag != OF_DT_BEGIN_NODE) {
217 pr_err("Weird tag at start of node: %x\n", tag);
218 return mem;
219 }
220 *p += 4;
221 pathp = (char *)*p;
222 l = allocl = strlen(pathp) + 1;
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600223 *p = ALIGN(*p + l, 4);
Grant Likelybbd33932009-11-23 20:07:00 -0700224
225 /* version 0x10 has a more compact unit name here instead of the full
226 * path. we accumulate the full path size using "fpsize", we'll rebuild
227 * it later. We detect this because the first character of the name is
228 * not '/'.
229 */
230 if ((*pathp) != '/') {
231 new_format = 1;
232 if (fpsize == 0) {
233 /* root node: special case. fpsize accounts for path
234 * plus terminating zero. root node only has '/', so
235 * fpsize should be 2, but we want to avoid the first
236 * level nodes to have two '/' so we use fpsize 1 here
237 */
238 fpsize = 1;
239 allocl = 2;
240 } else {
241 /* account for '/' and path size minus terminal 0
242 * already in 'l'
243 */
244 fpsize += l;
245 allocl = fpsize;
246 }
247 }
248
249 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
250 __alignof__(struct device_node));
251 if (allnextpp) {
252 memset(np, 0, sizeof(*np));
253 np->full_name = ((char *)np) + sizeof(struct device_node);
254 if (new_format) {
255 char *fn = np->full_name;
256 /* rebuild full path for new format */
257 if (dad && dad->parent) {
258 strcpy(fn, dad->full_name);
259#ifdef DEBUG
260 if ((strlen(fn) + l + 1) != allocl) {
261 pr_debug("%s: p: %d, l: %d, a: %d\n",
262 pathp, (int)strlen(fn),
263 l, allocl);
264 }
265#endif
266 fn += strlen(fn);
267 }
268 *(fn++) = '/';
269 memcpy(fn, pathp, l);
270 } else
271 memcpy(np->full_name, pathp, l);
272 prev_pp = &np->properties;
273 **allnextpp = np;
274 *allnextpp = &np->allnext;
275 if (dad != NULL) {
276 np->parent = dad;
277 /* we temporarily use the next field as `last_child'*/
278 if (dad->next == NULL)
279 dad->child = np;
280 else
281 dad->next->sibling = np;
282 dad->next = np;
283 }
284 kref_init(&np->kref);
285 }
286 while (1) {
287 u32 sz, noff;
288 char *pname;
289
Jeremy Kerr33714882010-01-30 01:45:26 -0700290 tag = be32_to_cpup((__be32 *)(*p));
Grant Likelybbd33932009-11-23 20:07:00 -0700291 if (tag == OF_DT_NOP) {
292 *p += 4;
293 continue;
294 }
295 if (tag != OF_DT_PROP)
296 break;
297 *p += 4;
Jeremy Kerr33714882010-01-30 01:45:26 -0700298 sz = be32_to_cpup((__be32 *)(*p));
299 noff = be32_to_cpup((__be32 *)((*p) + 4));
Grant Likelybbd33932009-11-23 20:07:00 -0700300 *p += 8;
Jeremy Kerr087f79c2010-01-30 04:14:19 -0700301 if (be32_to_cpu(initial_boot_params->version) < 0x10)
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600302 *p = ALIGN(*p, sz >= 8 ? 8 : 4);
Grant Likelybbd33932009-11-23 20:07:00 -0700303
304 pname = find_flat_dt_string(noff);
305 if (pname == NULL) {
306 pr_info("Can't find property name in list !\n");
307 break;
308 }
309 if (strcmp(pname, "name") == 0)
310 has_name = 1;
311 l = strlen(pname) + 1;
312 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
313 __alignof__(struct property));
314 if (allnextpp) {
David Gibson04b954a2010-02-01 21:34:15 -0700315 /* We accept flattened tree phandles either in
316 * ePAPR-style "phandle" properties, or the
317 * legacy "linux,phandle" properties. If both
318 * appear and have different values, things
319 * will get weird. Don't do that. */
320 if ((strcmp(pname, "phandle") == 0) ||
321 (strcmp(pname, "linux,phandle") == 0)) {
Grant Likely6016a362010-01-28 14:06:53 -0700322 if (np->phandle == 0)
Grant Likely9a6b2e52010-07-23 01:48:25 -0600323 np->phandle = be32_to_cpup((__be32*)*p);
Grant Likelybbd33932009-11-23 20:07:00 -0700324 }
David Gibson04b954a2010-02-01 21:34:15 -0700325 /* And we process the "ibm,phandle" property
326 * used in pSeries dynamic device tree
327 * stuff */
Grant Likelybbd33932009-11-23 20:07:00 -0700328 if (strcmp(pname, "ibm,phandle") == 0)
Grant Likely9a6b2e52010-07-23 01:48:25 -0600329 np->phandle = be32_to_cpup((__be32 *)*p);
Grant Likelybbd33932009-11-23 20:07:00 -0700330 pp->name = pname;
331 pp->length = sz;
332 pp->value = (void *)*p;
333 *prev_pp = pp;
334 prev_pp = &pp->next;
335 }
Grant Likelyf1d4c3a2010-06-25 12:16:52 -0600336 *p = ALIGN((*p) + sz, 4);
Grant Likelybbd33932009-11-23 20:07:00 -0700337 }
338 /* with version 0x10 we may not have the name property, recreate
339 * it here from the unit name if absent
340 */
341 if (!has_name) {
342 char *p1 = pathp, *ps = pathp, *pa = NULL;
343 int sz;
344
345 while (*p1) {
346 if ((*p1) == '@')
347 pa = p1;
348 if ((*p1) == '/')
349 ps = p1 + 1;
350 p1++;
351 }
352 if (pa < ps)
353 pa = p1;
354 sz = (pa - ps) + 1;
355 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
356 __alignof__(struct property));
357 if (allnextpp) {
358 pp->name = "name";
359 pp->length = sz;
360 pp->value = pp + 1;
361 *prev_pp = pp;
362 prev_pp = &pp->next;
363 memcpy(pp->value, ps, sz - 1);
364 ((char *)pp->value)[sz - 1] = 0;
365 pr_debug("fixed up name for %s -> %s\n", pathp,
366 (char *)pp->value);
367 }
368 }
369 if (allnextpp) {
370 *prev_pp = NULL;
371 np->name = of_get_property(np, "name", NULL);
372 np->type = of_get_property(np, "device_type", NULL);
373
374 if (!np->name)
375 np->name = "<NULL>";
376 if (!np->type)
377 np->type = "<NULL>";
378 }
Jason Gunthorpe7f809e12010-03-26 22:09:56 -0600379 while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
380 if (tag == OF_DT_NOP)
381 *p += 4;
382 else
383 mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
Jeremy Kerr33714882010-01-30 01:45:26 -0700384 tag = be32_to_cpup((__be32 *)(*p));
Grant Likelybbd33932009-11-23 20:07:00 -0700385 }
386 if (tag != OF_DT_END_NODE) {
387 pr_err("Weird tag at end of node: %x\n", tag);
388 return mem;
389 }
390 *p += 4;
391 return mem;
392}
Grant Likely41f88002009-11-23 20:07:01 -0700393
Grant Likelyf7b3a832009-11-24 03:26:58 -0700394#ifdef CONFIG_BLK_DEV_INITRD
395/**
396 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
397 * @node: reference to node containing initrd location ('chosen')
398 */
399void __init early_init_dt_check_for_initrd(unsigned long node)
400{
Jeremy Kerr1406bc22010-01-30 01:31:21 -0700401 unsigned long start, end, len;
Jeremy Kerr33714882010-01-30 01:45:26 -0700402 __be32 *prop;
Grant Likelyf7b3a832009-11-24 03:26:58 -0700403
404 pr_debug("Looking for initrd properties... ");
405
406 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
Jeremy Kerr1406bc22010-01-30 01:31:21 -0700407 if (!prop)
408 return;
409 start = of_read_ulong(prop, len/4);
Grant Likelyf7b3a832009-11-24 03:26:58 -0700410
Jeremy Kerr1406bc22010-01-30 01:31:21 -0700411 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
412 if (!prop)
413 return;
414 end = of_read_ulong(prop, len/4);
Grant Likelyf7b3a832009-11-24 03:26:58 -0700415
Jeremy Kerr1406bc22010-01-30 01:31:21 -0700416 early_init_dt_setup_initrd_arch(start, end);
417 pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start, end);
Grant Likelyf7b3a832009-11-24 03:26:58 -0700418}
419#else
420inline void early_init_dt_check_for_initrd(unsigned long node)
421{
422}
423#endif /* CONFIG_BLK_DEV_INITRD */
424
Grant Likely41f88002009-11-23 20:07:01 -0700425/**
Grant Likelyf00abd92009-11-24 03:27:10 -0700426 * early_init_dt_scan_root - fetch the top level address and size cells
427 */
428int __init early_init_dt_scan_root(unsigned long node, const char *uname,
429 int depth, void *data)
430{
Jeremy Kerr33714882010-01-30 01:45:26 -0700431 __be32 *prop;
Grant Likelyf00abd92009-11-24 03:27:10 -0700432
433 if (depth != 0)
434 return 0;
435
Jeremy Kerr33714882010-01-30 01:45:26 -0700436 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
437 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
438
Grant Likelyf00abd92009-11-24 03:27:10 -0700439 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
Jeremy Kerr33714882010-01-30 01:45:26 -0700440 if (prop)
441 dt_root_size_cells = be32_to_cpup(prop);
Grant Likelyf00abd92009-11-24 03:27:10 -0700442 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
443
444 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
Jeremy Kerr33714882010-01-30 01:45:26 -0700445 if (prop)
446 dt_root_addr_cells = be32_to_cpup(prop);
Grant Likelyf00abd92009-11-24 03:27:10 -0700447 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
448
449 /* break now */
450 return 1;
451}
452
Jeremy Kerr2e89e682010-01-30 01:41:49 -0700453u64 __init dt_mem_next_cell(int s, __be32 **cellp)
Grant Likely83f7a062009-11-24 03:37:56 -0700454{
Jeremy Kerr2e89e682010-01-30 01:41:49 -0700455 __be32 *p = *cellp;
Grant Likely83f7a062009-11-24 03:37:56 -0700456
457 *cellp = p + s;
458 return of_read_number(p, s);
459}
460
Grant Likely51975db2010-02-01 21:34:14 -0700461/**
462 * early_init_dt_scan_memory - Look for an parse memory nodes
463 */
464int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
465 int depth, void *data)
466{
467 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
468 __be32 *reg, *endp;
469 unsigned long l;
470
471 /* We are scanning "memory" nodes only */
472 if (type == NULL) {
473 /*
474 * The longtrail doesn't have a device_type on the
475 * /memory node, so look for the node called /memory@0.
476 */
477 if (depth != 1 || strcmp(uname, "memory@0") != 0)
478 return 0;
479 } else if (strcmp(type, "memory") != 0)
480 return 0;
481
482 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
483 if (reg == NULL)
484 reg = of_get_flat_dt_prop(node, "reg", &l);
485 if (reg == NULL)
486 return 0;
487
488 endp = reg + (l / sizeof(__be32));
489
490 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
491 uname, l, reg[0], reg[1], reg[2], reg[3]);
492
493 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
494 u64 base, size;
495
496 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
497 size = dt_mem_next_cell(dt_root_size_cells, &reg);
498
499 if (size == 0)
500 continue;
501 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
502 (unsigned long long)size);
503
504 early_init_dt_add_memory_arch(base, size);
505 }
506
507 return 0;
508}
509
Grant Likely86e03222009-12-10 23:42:21 -0700510int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
511 int depth, void *data)
512{
513 unsigned long l;
514 char *p;
515
516 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
517
518 if (depth != 1 ||
519 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
520 return 0;
521
522 early_init_dt_check_for_initrd(node);
523
524 /* Retreive command line */
525 p = of_get_flat_dt_prop(node, "bootargs", &l);
526 if (p != NULL && l > 0)
527 strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
528
529#ifdef CONFIG_CMDLINE
530#ifndef CONFIG_CMDLINE_FORCE
531 if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
532#endif
533 strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
534#endif /* CONFIG_CMDLINE */
535
536 early_init_dt_scan_chosen_arch(node);
537
538 pr_debug("Command line is: %s\n", cmd_line);
539
540 /* break now */
541 return 1;
542}
543
Grant Likelyf00abd92009-11-24 03:27:10 -0700544/**
Grant Likely41f88002009-11-23 20:07:01 -0700545 * unflatten_device_tree - create tree of device_nodes from flat blob
546 *
547 * unflattens the device-tree passed by the firmware, creating the
548 * tree of struct device_node. It also fills the "name" and "type"
549 * pointers of the nodes so the normal device-tree walking functions
550 * can be used.
551 */
552void __init unflatten_device_tree(void)
553{
554 unsigned long start, mem, size;
555 struct device_node **allnextp = &allnodes;
556
557 pr_debug(" -> unflatten_device_tree()\n");
558
Grant Likely8bfe9b52010-04-13 16:12:26 -0700559 if (!initial_boot_params) {
560 pr_debug("No device tree pointer\n");
561 return;
562 }
563
564 pr_debug("Unflattening device tree:\n");
565 pr_debug("magic: %08x\n", be32_to_cpu(initial_boot_params->magic));
566 pr_debug("size: %08x\n", be32_to_cpu(initial_boot_params->totalsize));
567 pr_debug("version: %08x\n", be32_to_cpu(initial_boot_params->version));
568
569 if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
570 pr_err("Invalid device tree blob header\n");
571 return;
572 }
573
Grant Likely41f88002009-11-23 20:07:01 -0700574 /* First pass, scan for size */
575 start = ((unsigned long)initial_boot_params) +
Jeremy Kerr087f79c2010-01-30 04:14:19 -0700576 be32_to_cpu(initial_boot_params->off_dt_struct);
Grant Likely41f88002009-11-23 20:07:01 -0700577 size = unflatten_dt_node(0, &start, NULL, NULL, 0);
578 size = (size | 3) + 1;
579
580 pr_debug(" size is %lx, allocating...\n", size);
581
582 /* Allocate memory for the expanded device tree */
Jeremy Kerr4ef7b372010-02-14 07:13:47 -0700583 mem = early_init_dt_alloc_memory_arch(size + 4,
584 __alignof__(struct device_node));
Grant Likely41f88002009-11-23 20:07:01 -0700585 mem = (unsigned long) __va(mem);
586
Jeremy Kerr33714882010-01-30 01:45:26 -0700587 ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
Grant Likely41f88002009-11-23 20:07:01 -0700588
589 pr_debug(" unflattening %lx...\n", mem);
590
591 /* Second pass, do actual unflattening */
592 start = ((unsigned long)initial_boot_params) +
Jeremy Kerr087f79c2010-01-30 04:14:19 -0700593 be32_to_cpu(initial_boot_params->off_dt_struct);
Grant Likely41f88002009-11-23 20:07:01 -0700594 unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
Jeremy Kerr33714882010-01-30 01:45:26 -0700595 if (be32_to_cpup((__be32 *)start) != OF_DT_END)
Grant Likely41f88002009-11-23 20:07:01 -0700596 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
Jeremy Kerr33714882010-01-30 01:45:26 -0700597 if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
Grant Likely41f88002009-11-23 20:07:01 -0700598 pr_warning("End of tree marker overwritten: %08x\n",
Jeremy Kerr33714882010-01-30 01:45:26 -0700599 be32_to_cpu(((__be32 *)mem)[size / 4]));
Grant Likely41f88002009-11-23 20:07:01 -0700600 *allnextp = NULL;
601
602 /* Get pointer to OF "/chosen" node for use everywhere */
603 of_chosen = of_find_node_by_path("/chosen");
604 if (of_chosen == NULL)
605 of_chosen = of_find_node_by_path("/chosen@0");
606
607 pr_debug(" <- unflatten_device_tree()\n");
608}