1 /*
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
12 #include <linux/kernel.h>
13 #include <linux/initrd.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_fdt.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20
21 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
22 #ifdef CONFIG_PPC
23 #include <asm/machdep.h>
24 #endif /* CONFIG_PPC */
25
26 #include <asm/page.h>
27
of_fdt_get_string(struct boot_param_header * blob,u32 offset)28 char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
29 {
30 return ((char *)blob) +
31 be32_to_cpu(blob->off_dt_strings) + offset;
32 }
33
34 /**
35 * of_fdt_get_property - Given a node in the given flat blob, return
36 * the property ptr
37 */
of_fdt_get_property(struct boot_param_header * blob,unsigned long node,const char * name,unsigned long * size)38 void *of_fdt_get_property(struct boot_param_header *blob,
39 unsigned long node, const char *name,
40 unsigned long *size)
41 {
42 unsigned long p = node;
43
44 do {
45 u32 tag = be32_to_cpup((__be32 *)p);
46 u32 sz, noff;
47 const char *nstr;
48
49 p += 4;
50 if (tag == OF_DT_NOP)
51 continue;
52 if (tag != OF_DT_PROP)
53 return NULL;
54
55 sz = be32_to_cpup((__be32 *)p);
56 noff = be32_to_cpup((__be32 *)(p + 4));
57 p += 8;
58 if (be32_to_cpu(blob->version) < 0x10)
59 p = ALIGN(p, sz >= 8 ? 8 : 4);
60
61 nstr = of_fdt_get_string(blob, noff);
62 if (nstr == NULL) {
63 pr_warning("Can't find property index name !\n");
64 return NULL;
65 }
66 if (strcmp(name, nstr) == 0) {
67 if (size)
68 *size = sz;
69 return (void *)p;
70 }
71 p += sz;
72 p = ALIGN(p, 4);
73 } while (1);
74 }
75
76 /**
77 * of_fdt_is_compatible - Return true if given node from the given blob has
78 * compat in its compatible list
79 * @blob: A device tree blob
80 * @node: node to test
81 * @compat: compatible string to compare with compatible list.
82 *
83 * On match, returns a non-zero value with smaller values returned for more
84 * specific compatible values.
85 */
of_fdt_is_compatible(struct boot_param_header * blob,unsigned long node,const char * compat)86 int of_fdt_is_compatible(struct boot_param_header *blob,
87 unsigned long node, const char *compat)
88 {
89 const char *cp;
90 unsigned long cplen, l, score = 0;
91
92 cp = of_fdt_get_property(blob, node, "compatible", &cplen);
93 if (cp == NULL)
94 return 0;
95 while (cplen > 0) {
96 score++;
97 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
98 return score;
99 l = strlen(cp) + 1;
100 cp += l;
101 cplen -= l;
102 }
103
104 return 0;
105 }
106
107 /**
108 * of_fdt_match - Return true if node matches a list of compatible values
109 */
of_fdt_match(struct boot_param_header * blob,unsigned long node,const char * const * compat)110 int of_fdt_match(struct boot_param_header *blob, unsigned long node,
111 const char *const *compat)
112 {
113 unsigned int tmp, score = 0;
114
115 if (!compat)
116 return 0;
117
118 while (*compat) {
119 tmp = of_fdt_is_compatible(blob, node, *compat);
120 if (tmp && (score == 0 || (tmp < score)))
121 score = tmp;
122 compat++;
123 }
124
125 return score;
126 }
127
unflatten_dt_alloc(unsigned long * mem,unsigned long size,unsigned long align)128 static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
129 unsigned long align)
130 {
131 void *res;
132
133 *mem = ALIGN(*mem, align);
134 res = (void *)*mem;
135 *mem += size;
136
137 return res;
138 }
139
140 /**
141 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
142 * @blob: The parent device tree blob
143 * @mem: Memory chunk to use for allocating device nodes and properties
144 * @p: pointer to node in flat tree
145 * @dad: Parent struct device_node
146 * @allnextpp: pointer to ->allnext from last allocated device_node
147 * @fpsize: Size of the node path up at the current depth.
148 */
unflatten_dt_node(struct boot_param_header * blob,unsigned long mem,unsigned long * p,struct device_node * dad,struct device_node *** allnextpp,unsigned long fpsize)149 static unsigned long unflatten_dt_node(struct boot_param_header *blob,
150 unsigned long mem,
151 unsigned long *p,
152 struct device_node *dad,
153 struct device_node ***allnextpp,
154 unsigned long fpsize)
155 {
156 struct device_node *np;
157 struct property *pp, **prev_pp = NULL;
158 char *pathp;
159 u32 tag;
160 unsigned int l, allocl;
161 int has_name = 0;
162 int new_format = 0;
163
164 tag = be32_to_cpup((__be32 *)(*p));
165 if (tag != OF_DT_BEGIN_NODE) {
166 pr_err("Weird tag at start of node: %x\n", tag);
167 return mem;
168 }
169 *p += 4;
170 pathp = (char *)*p;
171 l = allocl = strlen(pathp) + 1;
172 *p = ALIGN(*p + l, 4);
173
174 /* version 0x10 has a more compact unit name here instead of the full
175 * path. we accumulate the full path size using "fpsize", we'll rebuild
176 * it later. We detect this because the first character of the name is
177 * not '/'.
178 */
179 if ((*pathp) != '/') {
180 new_format = 1;
181 if (fpsize == 0) {
182 /* root node: special case. fpsize accounts for path
183 * plus terminating zero. root node only has '/', so
184 * fpsize should be 2, but we want to avoid the first
185 * level nodes to have two '/' so we use fpsize 1 here
186 */
187 fpsize = 1;
188 allocl = 2;
189 l = 1;
190 *pathp = '\0';
191 } else {
192 /* account for '/' and path size minus terminal 0
193 * already in 'l'
194 */
195 fpsize += l;
196 allocl = fpsize;
197 }
198 }
199
200 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
201 __alignof__(struct device_node));
202 if (allnextpp) {
203 char *fn;
204 memset(np, 0, sizeof(*np));
205 np->full_name = fn = ((char *)np) + sizeof(*np);
206 if (new_format) {
207 /* rebuild full path for new format */
208 if (dad && dad->parent) {
209 strcpy(fn, dad->full_name);
210 #ifdef DEBUG
211 if ((strlen(fn) + l + 1) != allocl) {
212 pr_debug("%s: p: %d, l: %d, a: %d\n",
213 pathp, (int)strlen(fn),
214 l, allocl);
215 }
216 #endif
217 fn += strlen(fn);
218 }
219 *(fn++) = '/';
220 }
221 memcpy(fn, pathp, l);
222
223 prev_pp = &np->properties;
224 **allnextpp = np;
225 *allnextpp = &np->allnext;
226 if (dad != NULL) {
227 np->parent = dad;
228 /* we temporarily use the next field as `last_child'*/
229 if (dad->next == NULL)
230 dad->child = np;
231 else
232 dad->next->sibling = np;
233 dad->next = np;
234 }
235 kref_init(&np->kref);
236 }
237 /* process properties */
238 while (1) {
239 u32 sz, noff;
240 char *pname;
241
242 tag = be32_to_cpup((__be32 *)(*p));
243 if (tag == OF_DT_NOP) {
244 *p += 4;
245 continue;
246 }
247 if (tag != OF_DT_PROP)
248 break;
249 *p += 4;
250 sz = be32_to_cpup((__be32 *)(*p));
251 noff = be32_to_cpup((__be32 *)((*p) + 4));
252 *p += 8;
253 if (be32_to_cpu(blob->version) < 0x10)
254 *p = ALIGN(*p, sz >= 8 ? 8 : 4);
255
256 pname = of_fdt_get_string(blob, noff);
257 if (pname == NULL) {
258 pr_info("Can't find property name in list !\n");
259 break;
260 }
261 if (strcmp(pname, "name") == 0)
262 has_name = 1;
263 l = strlen(pname) + 1;
264 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
265 __alignof__(struct property));
266 if (allnextpp) {
267 /* We accept flattened tree phandles either in
268 * ePAPR-style "phandle" properties, or the
269 * legacy "linux,phandle" properties. If both
270 * appear and have different values, things
271 * will get weird. Don't do that. */
272 if ((strcmp(pname, "phandle") == 0) ||
273 (strcmp(pname, "linux,phandle") == 0)) {
274 if (np->phandle == 0)
275 np->phandle = be32_to_cpup((__be32*)*p);
276 }
277 /* And we process the "ibm,phandle" property
278 * used in pSeries dynamic device tree
279 * stuff */
280 if (strcmp(pname, "ibm,phandle") == 0)
281 np->phandle = be32_to_cpup((__be32 *)*p);
282 pp->name = pname;
283 pp->length = sz;
284 pp->value = (void *)*p;
285 *prev_pp = pp;
286 prev_pp = &pp->next;
287 }
288 *p = ALIGN((*p) + sz, 4);
289 }
290 /* with version 0x10 we may not have the name property, recreate
291 * it here from the unit name if absent
292 */
293 if (!has_name) {
294 char *p1 = pathp, *ps = pathp, *pa = NULL;
295 int sz;
296
297 while (*p1) {
298 if ((*p1) == '@')
299 pa = p1;
300 if ((*p1) == '/')
301 ps = p1 + 1;
302 p1++;
303 }
304 if (pa < ps)
305 pa = p1;
306 sz = (pa - ps) + 1;
307 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
308 __alignof__(struct property));
309 if (allnextpp) {
310 pp->name = "name";
311 pp->length = sz;
312 pp->value = pp + 1;
313 *prev_pp = pp;
314 prev_pp = &pp->next;
315 memcpy(pp->value, ps, sz - 1);
316 ((char *)pp->value)[sz - 1] = 0;
317 pr_debug("fixed up name for %s -> %s\n", pathp,
318 (char *)pp->value);
319 }
320 }
321 if (allnextpp) {
322 *prev_pp = NULL;
323 np->name = of_get_property(np, "name", NULL);
324 np->type = of_get_property(np, "device_type", NULL);
325
326 if (!np->name)
327 np->name = "<NULL>";
328 if (!np->type)
329 np->type = "<NULL>";
330 }
331 while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
332 if (tag == OF_DT_NOP)
333 *p += 4;
334 else
335 mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
336 fpsize);
337 tag = be32_to_cpup((__be32 *)(*p));
338 }
339 if (tag != OF_DT_END_NODE) {
340 pr_err("Weird tag at end of node: %x\n", tag);
341 return mem;
342 }
343 *p += 4;
344 return mem;
345 }
346
347 /**
348 * __unflatten_device_tree - create tree of device_nodes from flat blob
349 *
350 * unflattens a device-tree, creating the
351 * tree of struct device_node. It also fills the "name" and "type"
352 * pointers of the nodes so the normal device-tree walking functions
353 * can be used.
354 * @blob: The blob to expand
355 * @mynodes: The device_node tree created by the call
356 * @dt_alloc: An allocator that provides a virtual address to memory
357 * for the resulting tree
358 */
__unflatten_device_tree(struct boot_param_header * blob,struct device_node ** mynodes,void * (* dt_alloc)(u64 size,u64 align))359 static void __unflatten_device_tree(struct boot_param_header *blob,
360 struct device_node **mynodes,
361 void * (*dt_alloc)(u64 size, u64 align))
362 {
363 unsigned long start, mem, size;
364 struct device_node **allnextp = mynodes;
365
366 pr_debug(" -> unflatten_device_tree()\n");
367
368 if (!blob) {
369 pr_debug("No device tree pointer\n");
370 return;
371 }
372
373 pr_debug("Unflattening device tree:\n");
374 pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
375 pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
376 pr_debug("version: %08x\n", be32_to_cpu(blob->version));
377
378 if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
379 pr_err("Invalid device tree blob header\n");
380 return;
381 }
382
383 /* First pass, scan for size */
384 start = ((unsigned long)blob) +
385 be32_to_cpu(blob->off_dt_struct);
386 size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
387 size = (size | 3) + 1;
388
389 pr_debug(" size is %lx, allocating...\n", size);
390
391 /* Allocate memory for the expanded device tree */
392 mem = (unsigned long)
393 dt_alloc(size + 4, __alignof__(struct device_node));
394
395 ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
396
397 pr_debug(" unflattening %lx...\n", mem);
398
399 /* Second pass, do actual unflattening */
400 start = ((unsigned long)blob) +
401 be32_to_cpu(blob->off_dt_struct);
402 unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
403 if (be32_to_cpup((__be32 *)start) != OF_DT_END)
404 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
405 if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
406 pr_warning("End of tree marker overwritten: %08x\n",
407 be32_to_cpu(((__be32 *)mem)[size / 4]));
408 *allnextp = NULL;
409
410 pr_debug(" <- unflatten_device_tree()\n");
411 }
412
kernel_tree_alloc(u64 size,u64 align)413 static void *kernel_tree_alloc(u64 size, u64 align)
414 {
415 return kzalloc(size, GFP_KERNEL);
416 }
417
418 /**
419 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
420 *
421 * unflattens the device-tree passed by the firmware, creating the
422 * tree of struct device_node. It also fills the "name" and "type"
423 * pointers of the nodes so the normal device-tree walking functions
424 * can be used.
425 */
of_fdt_unflatten_tree(unsigned long * blob,struct device_node ** mynodes)426 void of_fdt_unflatten_tree(unsigned long *blob,
427 struct device_node **mynodes)
428 {
429 struct boot_param_header *device_tree =
430 (struct boot_param_header *)blob;
431 __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
432 }
433 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
434
435 /* Everything below here references initial_boot_params directly. */
436 int __initdata dt_root_addr_cells;
437 int __initdata dt_root_size_cells;
438
439 struct boot_param_header *initial_boot_params;
440
441 #ifdef CONFIG_OF_EARLY_FLATTREE
442
443 /**
444 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
445 * @it: callback function
446 * @data: context data pointer
447 *
448 * This function is used to scan the flattened device-tree, it is
449 * used to extract the memory information at boot before we can
450 * unflatten the tree
451 */
of_scan_flat_dt(int (* it)(unsigned long node,const char * uname,int depth,void * data),void * data)452 int __init of_scan_flat_dt(int (*it)(unsigned long node,
453 const char *uname, int depth,
454 void *data),
455 void *data)
456 {
457 unsigned long p = ((unsigned long)initial_boot_params) +
458 be32_to_cpu(initial_boot_params->off_dt_struct);
459 int rc = 0;
460 int depth = -1;
461
462 do {
463 u32 tag = be32_to_cpup((__be32 *)p);
464 const char *pathp;
465
466 p += 4;
467 if (tag == OF_DT_END_NODE) {
468 depth--;
469 continue;
470 }
471 if (tag == OF_DT_NOP)
472 continue;
473 if (tag == OF_DT_END)
474 break;
475 if (tag == OF_DT_PROP) {
476 u32 sz = be32_to_cpup((__be32 *)p);
477 p += 8;
478 if (be32_to_cpu(initial_boot_params->version) < 0x10)
479 p = ALIGN(p, sz >= 8 ? 8 : 4);
480 p += sz;
481 p = ALIGN(p, 4);
482 continue;
483 }
484 if (tag != OF_DT_BEGIN_NODE) {
485 pr_err("Invalid tag %x in flat device tree!\n", tag);
486 return -EINVAL;
487 }
488 depth++;
489 pathp = (char *)p;
490 p = ALIGN(p + strlen(pathp) + 1, 4);
491 if (*pathp == '/')
492 pathp = kbasename(pathp);
493 rc = it(p, pathp, depth, data);
494 if (rc != 0)
495 break;
496 } while (1);
497
498 return rc;
499 }
500
501 /**
502 * of_get_flat_dt_root - find the root node in the flat blob
503 */
of_get_flat_dt_root(void)504 unsigned long __init of_get_flat_dt_root(void)
505 {
506 unsigned long p = ((unsigned long)initial_boot_params) +
507 be32_to_cpu(initial_boot_params->off_dt_struct);
508
509 while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
510 p += 4;
511 BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
512 p += 4;
513 return ALIGN(p + strlen((char *)p) + 1, 4);
514 }
515
516 /**
517 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
518 *
519 * This function can be used within scan_flattened_dt callback to get
520 * access to properties
521 */
of_get_flat_dt_prop(unsigned long node,const char * name,unsigned long * size)522 void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
523 unsigned long *size)
524 {
525 return of_fdt_get_property(initial_boot_params, node, name, size);
526 }
527
528 /**
529 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
530 * @node: node to test
531 * @compat: compatible string to compare with compatible list.
532 */
of_flat_dt_is_compatible(unsigned long node,const char * compat)533 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
534 {
535 return of_fdt_is_compatible(initial_boot_params, node, compat);
536 }
537
538 /**
539 * of_flat_dt_match - Return true if node matches a list of compatible values
540 */
of_flat_dt_match(unsigned long node,const char * const * compat)541 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
542 {
543 return of_fdt_match(initial_boot_params, node, compat);
544 }
545
546 #ifdef CONFIG_BLK_DEV_INITRD
547 /**
548 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
549 * @node: reference to node containing initrd location ('chosen')
550 */
early_init_dt_check_for_initrd(unsigned long node)551 void __init early_init_dt_check_for_initrd(unsigned long node)
552 {
553 u64 start, end;
554 unsigned long len;
555 __be32 *prop;
556
557 pr_debug("Looking for initrd properties... ");
558
559 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
560 if (!prop)
561 return;
562 start = of_read_number(prop, len/4);
563
564 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
565 if (!prop)
566 return;
567 end = of_read_number(prop, len/4);
568
569 early_init_dt_setup_initrd_arch(start, end);
570 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
571 (unsigned long long)start, (unsigned long long)end);
572 }
573 #else
early_init_dt_check_for_initrd(unsigned long node)574 inline void early_init_dt_check_for_initrd(unsigned long node)
575 {
576 }
577 #endif /* CONFIG_BLK_DEV_INITRD */
578
579 /**
580 * early_init_dt_scan_root - fetch the top level address and size cells
581 */
early_init_dt_scan_root(unsigned long node,const char * uname,int depth,void * data)582 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
583 int depth, void *data)
584 {
585 __be32 *prop;
586
587 if (depth != 0)
588 return 0;
589
590 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
591 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
592
593 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
594 if (prop)
595 dt_root_size_cells = be32_to_cpup(prop);
596 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
597
598 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
599 if (prop)
600 dt_root_addr_cells = be32_to_cpup(prop);
601 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
602
603 /* break now */
604 return 1;
605 }
606
dt_mem_next_cell(int s,__be32 ** cellp)607 u64 __init dt_mem_next_cell(int s, __be32 **cellp)
608 {
609 __be32 *p = *cellp;
610
611 *cellp = p + s;
612 return of_read_number(p, s);
613 }
614
615 /**
616 * early_init_dt_scan_memory - Look for an parse memory nodes
617 */
early_init_dt_scan_memory(unsigned long node,const char * uname,int depth,void * data)618 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
619 int depth, void *data)
620 {
621 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
622 __be32 *reg, *endp;
623 unsigned long l;
624
625 /* We are scanning "memory" nodes only */
626 if (type == NULL) {
627 /*
628 * The longtrail doesn't have a device_type on the
629 * /memory node, so look for the node called /memory@0.
630 */
631 if (depth != 1 || strcmp(uname, "memory@0") != 0)
632 return 0;
633 } else if (strcmp(type, "memory") != 0)
634 return 0;
635
636 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
637 if (reg == NULL)
638 reg = of_get_flat_dt_prop(node, "reg", &l);
639 if (reg == NULL)
640 return 0;
641
642 endp = reg + (l / sizeof(__be32));
643
644 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
645 uname, l, reg[0], reg[1], reg[2], reg[3]);
646
647 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
648 u64 base, size;
649
650 base = dt_mem_next_cell(dt_root_addr_cells, ®);
651 size = dt_mem_next_cell(dt_root_size_cells, ®);
652
653 if (size == 0)
654 continue;
655 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
656 (unsigned long long)size);
657
658 early_init_dt_add_memory_arch(base, size);
659 }
660
661 return 0;
662 }
663
664 /*
665 * Convert configs to something easy to use in C code
666 */
667 #if defined(CONFIG_CMDLINE_FORCE)
668 static const int overwrite_incoming_cmdline = 1;
669 static const int read_dt_cmdline;
670 static const int concat_cmdline;
671 #elif defined(CONFIG_CMDLINE_EXTEND)
672 static const int overwrite_incoming_cmdline;
673 static const int read_dt_cmdline = 1;
674 static const int concat_cmdline = 1;
675 #else /* CMDLINE_FROM_BOOTLOADER */
676 static const int overwrite_incoming_cmdline;
677 static const int read_dt_cmdline = 1;
678 static const int concat_cmdline;
679 #endif
680
681 #ifdef CONFIG_CMDLINE
682 static const char *config_cmdline = CONFIG_CMDLINE;
683 #else
684 static const char *config_cmdline = "";
685 #endif
686
early_init_dt_scan_chosen(unsigned long node,const char * uname,int depth,void * data)687 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
688 int depth, void *data)
689 {
690 unsigned long l = 0;
691 char *p = NULL;
692 char *cmdline = data;
693
694 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
695
696 if (depth != 1 || !cmdline ||
697 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
698 return 0;
699
700 early_init_dt_check_for_initrd(node);
701
702 /* Put CONFIG_CMDLINE in if forced or if data had nothing in it to start */
703 if (overwrite_incoming_cmdline || !cmdline[0])
704 strlcpy(cmdline, config_cmdline, COMMAND_LINE_SIZE);
705
706 /* Retrieve command line unless forcing */
707 if (read_dt_cmdline)
708 p = of_get_flat_dt_prop(node, "bootargs", &l);
709
710 if (p != NULL && l > 0) {
711 if (concat_cmdline) {
712 int cmdline_len;
713 int copy_len;
714 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
715 cmdline_len = strlen(cmdline);
716 copy_len = COMMAND_LINE_SIZE - cmdline_len - 1;
717 copy_len = min((int)l, copy_len);
718 strncpy(cmdline + cmdline_len, p, copy_len);
719 cmdline[cmdline_len + copy_len] = '\0';
720 } else {
721 strlcpy(cmdline, p, min((int)l, COMMAND_LINE_SIZE));
722 }
723 }
724
725 pr_debug("Command line is: %s\n", (char*)data);
726
727 /* break now */
728 return 1;
729 }
730
731 /**
732 * unflatten_device_tree - create tree of device_nodes from flat blob
733 *
734 * unflattens the device-tree passed by the firmware, creating the
735 * tree of struct device_node. It also fills the "name" and "type"
736 * pointers of the nodes so the normal device-tree walking functions
737 * can be used.
738 */
unflatten_device_tree(void)739 void __init unflatten_device_tree(void)
740 {
741 __unflatten_device_tree(initial_boot_params, &of_allnodes,
742 early_init_dt_alloc_memory_arch);
743
744 /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
745 of_alias_scan(early_init_dt_alloc_memory_arch);
746 }
747
748 #endif /* CONFIG_OF_EARLY_FLATTREE */
749