fdt.c 18.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11
/*
 * Functions for working with the Flattened Device Tree data format
 *
 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
 * benh@kernel.crashing.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

12
#include <linux/kernel.h>
13
#include <linux/initrd.h>
14
#include <linux/module.h>
15 16
#include <linux/of.h>
#include <linux/of_fdt.h>
J
Jeremy Kerr 已提交
17 18
#include <linux/string.h>
#include <linux/errno.h>
19
#include <linux/slab.h>
20

21
#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
22 23 24 25
#ifdef CONFIG_PPC
#include <asm/machdep.h>
#endif /* CONFIG_PPC */

J
Jeremy Kerr 已提交
26 27
#include <asm/page.h>

28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
{
	return ((char *)blob) +
		be32_to_cpu(blob->off_dt_strings) + offset;
}

/**
 * of_fdt_get_property - Given a node in the given flat blob, return
 * the property ptr
 */
void *of_fdt_get_property(struct boot_param_header *blob,
		       unsigned long node, const char *name,
		       unsigned long *size)
{
	unsigned long p = node;

	do {
		u32 tag = be32_to_cpup((__be32 *)p);
		u32 sz, noff;
		const char *nstr;

		p += 4;
		if (tag == OF_DT_NOP)
			continue;
		if (tag != OF_DT_PROP)
			return NULL;

		sz = be32_to_cpup((__be32 *)p);
		noff = be32_to_cpup((__be32 *)(p + 4));
		p += 8;
		if (be32_to_cpu(blob->version) < 0x10)
			p = ALIGN(p, sz >= 8 ? 8 : 4);

		nstr = of_fdt_get_string(blob, noff);
		if (nstr == NULL) {
			pr_warning("Can't find property index name !\n");
			return NULL;
		}
		if (strcmp(name, nstr) == 0) {
			if (size)
				*size = sz;
			return (void *)p;
		}
		p += sz;
		p = ALIGN(p, 4);
	} while (1);
}

/**
 * of_fdt_is_compatible - Return true if given node from the given blob has
 * compat in its compatible list
 * @blob: A device tree blob
 * @node: node to test
 * @compat: compatible string to compare with compatible list.
82 83 84
 *
 * On match, returns a non-zero value with smaller values returned for more
 * specific compatible values.
85 86 87 88 89
 */
int of_fdt_is_compatible(struct boot_param_header *blob,
		      unsigned long node, const char *compat)
{
	const char *cp;
90
	unsigned long cplen, l, score = 0;
91 92 93 94 95

	cp = of_fdt_get_property(blob, node, "compatible", &cplen);
	if (cp == NULL)
		return 0;
	while (cplen > 0) {
96
		score++;
97
		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
98
			return score;
99 100 101 102 103 104 105 106
		l = strlen(cp) + 1;
		cp += l;
		cplen -= l;
	}

	return 0;
}

107 108 109 110
/**
 * of_fdt_match - Return true if node matches a list of compatible values
 */
int of_fdt_match(struct boot_param_header *blob, unsigned long node,
111
                 const char *const *compat)
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
{
	unsigned int tmp, score = 0;

	if (!compat)
		return 0;

	while (*compat) {
		tmp = of_fdt_is_compatible(blob, node, *compat);
		if (tmp && (score == 0 || (tmp < score)))
			score = tmp;
		compat++;
	}

	return score;
}

128
static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
129 130 131 132
				       unsigned long align)
{
	void *res;

133
	*mem = ALIGN(*mem, align);
134 135 136 137 138 139 140 141
	res = (void *)*mem;
	*mem += size;

	return res;
}

/**
 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
142
 * @blob: The parent device tree blob
A
Andres Salomon 已提交
143
 * @mem: Memory chunk to use for allocating device nodes and properties
144 145 146 147 148
 * @p: pointer to node in flat tree
 * @dad: Parent struct device_node
 * @allnextpp: pointer to ->allnext from last allocated device_node
 * @fpsize: Size of the node path up at the current depth.
 */
A
Andres Salomon 已提交
149
static unsigned long unflatten_dt_node(struct boot_param_header *blob,
150 151 152 153 154
				unsigned long mem,
				unsigned long *p,
				struct device_node *dad,
				struct device_node ***allnextpp,
				unsigned long fpsize)
155 156 157 158 159 160 161 162 163
{
	struct device_node *np;
	struct property *pp, **prev_pp = NULL;
	char *pathp;
	u32 tag;
	unsigned int l, allocl;
	int has_name = 0;
	int new_format = 0;

164
	tag = be32_to_cpup((__be32 *)(*p));
165 166 167 168 169 170 171
	if (tag != OF_DT_BEGIN_NODE) {
		pr_err("Weird tag at start of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	pathp = (char *)*p;
	l = allocl = strlen(pathp) + 1;
172
	*p = ALIGN(*p + l, 4);
173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188

	/* version 0x10 has a more compact unit name here instead of the full
	 * path. we accumulate the full path size using "fpsize", we'll rebuild
	 * it later. We detect this because the first character of the name is
	 * not '/'.
	 */
	if ((*pathp) != '/') {
		new_format = 1;
		if (fpsize == 0) {
			/* root node: special case. fpsize accounts for path
			 * plus terminating zero. root node only has '/', so
			 * fpsize should be 2, but we want to avoid the first
			 * level nodes to have two '/' so we use fpsize 1 here
			 */
			fpsize = 1;
			allocl = 2;
189 190
			l = 1;
			*pathp = '\0';
191 192 193 194 195 196 197 198 199 200 201 202
		} else {
			/* account for '/' and path size minus terminal 0
			 * already in 'l'
			 */
			fpsize += l;
			allocl = fpsize;
		}
	}

	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
				__alignof__(struct device_node));
	if (allnextpp) {
203
		char *fn;
204
		memset(np, 0, sizeof(*np));
205
		np->full_name = fn = ((char *)np) + sizeof(*np);
206 207 208 209 210 211 212 213 214 215 216 217 218 219
		if (new_format) {
			/* rebuild full path for new format */
			if (dad && dad->parent) {
				strcpy(fn, dad->full_name);
#ifdef DEBUG
				if ((strlen(fn) + l + 1) != allocl) {
					pr_debug("%s: p: %d, l: %d, a: %d\n",
						pathp, (int)strlen(fn),
						l, allocl);
				}
#endif
				fn += strlen(fn);
			}
			*(fn++) = '/';
220 221 222
		}
		memcpy(fn, pathp, l);

223 224 225 226 227 228 229 230 231 232 233 234 235 236
		prev_pp = &np->properties;
		**allnextpp = np;
		*allnextpp = &np->allnext;
		if (dad != NULL) {
			np->parent = dad;
			/* we temporarily use the next field as `last_child'*/
			if (dad->next == NULL)
				dad->child = np;
			else
				dad->next->sibling = np;
			dad->next = np;
		}
		kref_init(&np->kref);
	}
A
Andres Salomon 已提交
237
	/* process properties */
238 239 240 241
	while (1) {
		u32 sz, noff;
		char *pname;

242
		tag = be32_to_cpup((__be32 *)(*p));
243 244 245 246 247 248 249
		if (tag == OF_DT_NOP) {
			*p += 4;
			continue;
		}
		if (tag != OF_DT_PROP)
			break;
		*p += 4;
250 251
		sz = be32_to_cpup((__be32 *)(*p));
		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);
257 258 259 260 261 262 263 264 265 266
		if (pname == NULL) {
			pr_info("Can't find property name in list !\n");
			break;
		}
		if (strcmp(pname, "name") == 0)
			has_name = 1;
		l = strlen(pname) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
					__alignof__(struct property));
		if (allnextpp) {
267 268 269 270 271 272 273
			/* We accept flattened tree phandles either in
			 * ePAPR-style "phandle" properties, or the
			 * legacy "linux,phandle" properties.  If both
			 * appear and have different values, things
			 * will get weird.  Don't do that. */
			if ((strcmp(pname, "phandle") == 0) ||
			    (strcmp(pname, "linux,phandle") == 0)) {
274
				if (np->phandle == 0)
G
Grant Likely 已提交
275
					np->phandle = be32_to_cpup((__be32*)*p);
276
			}
277 278 279
			/* And we process the "ibm,phandle" property
			 * used in pSeries dynamic device tree
			 * stuff */
280
			if (strcmp(pname, "ibm,phandle") == 0)
G
Grant Likely 已提交
281
				np->phandle = be32_to_cpup((__be32 *)*p);
282 283 284 285 286 287
			pp->name = pname;
			pp->length = sz;
			pp->value = (void *)*p;
			*prev_pp = pp;
			prev_pp = &pp->next;
		}
288
		*p = ALIGN((*p) + sz, 4);
289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
	}
	/* with version 0x10 we may not have the name property, recreate
	 * it here from the unit name if absent
	 */
	if (!has_name) {
		char *p1 = pathp, *ps = pathp, *pa = NULL;
		int sz;

		while (*p1) {
			if ((*p1) == '@')
				pa = p1;
			if ((*p1) == '/')
				ps = p1 + 1;
			p1++;
		}
		if (pa < ps)
			pa = p1;
		sz = (pa - ps) + 1;
		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
					__alignof__(struct property));
		if (allnextpp) {
			pp->name = "name";
			pp->length = sz;
			pp->value = pp + 1;
			*prev_pp = pp;
			prev_pp = &pp->next;
			memcpy(pp->value, ps, sz - 1);
			((char *)pp->value)[sz - 1] = 0;
			pr_debug("fixed up name for %s -> %s\n", pathp,
				(char *)pp->value);
		}
	}
	if (allnextpp) {
		*prev_pp = NULL;
		np->name = of_get_property(np, "name", NULL);
		np->type = of_get_property(np, "device_type", NULL);

		if (!np->name)
			np->name = "<NULL>";
		if (!np->type)
			np->type = "<NULL>";
	}
331 332 333 334
	while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
		if (tag == OF_DT_NOP)
			*p += 4;
		else
335 336
			mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
						fpsize);
337
		tag = be32_to_cpup((__be32 *)(*p));
338 339 340 341 342 343 344 345
	}
	if (tag != OF_DT_END_NODE) {
		pr_err("Weird tag at end of node: %x\n", tag);
		return mem;
	}
	*p += 4;
	return mem;
}
346

347 348 349 350 351 352 353 354 355 356 357 358
/**
 * __unflatten_device_tree - create tree of device_nodes from flat blob
 *
 * unflattens a device-tree, creating the
 * tree of struct device_node. It also fills the "name" and "type"
 * pointers of the nodes so the normal device-tree walking functions
 * can be used.
 * @blob: The blob to expand
 * @mynodes: The device_node tree created by the call
 * @dt_alloc: An allocator that provides a virtual address to memory
 * for the resulting tree
 */
A
Andres Salomon 已提交
359
static void __unflatten_device_tree(struct boot_param_header *blob,
360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394
			     struct device_node **mynodes,
			     void * (*dt_alloc)(u64 size, u64 align))
{
	unsigned long start, mem, size;
	struct device_node **allnextp = mynodes;

	pr_debug(" -> unflatten_device_tree()\n");

	if (!blob) {
		pr_debug("No device tree pointer\n");
		return;
	}

	pr_debug("Unflattening device tree:\n");
	pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
	pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
	pr_debug("version: %08x\n", be32_to_cpu(blob->version));

	if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
		pr_err("Invalid device tree blob header\n");
		return;
	}

	/* First pass, scan for size */
	start = ((unsigned long)blob) +
		be32_to_cpu(blob->off_dt_struct);
	size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
	size = (size | 3) + 1;

	pr_debug("  size is %lx, allocating...\n", size);

	/* Allocate memory for the expanded device tree */
	mem = (unsigned long)
		dt_alloc(size + 4, __alignof__(struct device_node));

395 396
	memset((void *)mem, 0, size);

397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436
	((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);

	pr_debug("  unflattening %lx...\n", mem);

	/* Second pass, do actual unflattening */
	start = ((unsigned long)blob) +
		be32_to_cpu(blob->off_dt_struct);
	unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
	if (be32_to_cpup((__be32 *)start) != OF_DT_END)
		pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
	if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
		pr_warning("End of tree marker overwritten: %08x\n",
			   be32_to_cpu(((__be32 *)mem)[size / 4]));
	*allnextp = NULL;

	pr_debug(" <- unflatten_device_tree()\n");
}

static void *kernel_tree_alloc(u64 size, u64 align)
{
	return kzalloc(size, GFP_KERNEL);
}

/**
 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
 *
 * unflattens the device-tree passed by the firmware, creating the
 * tree of struct device_node. It also fills the "name" and "type"
 * pointers of the nodes so the normal device-tree walking functions
 * can be used.
 */
void of_fdt_unflatten_tree(unsigned long *blob,
			struct device_node **mynodes)
{
	struct boot_param_header *device_tree =
		(struct boot_param_header *)blob;
	__unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
}
EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);

437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465
/* Everything below here references initial_boot_params directly. */
int __initdata dt_root_addr_cells;
int __initdata dt_root_size_cells;

struct boot_param_header *initial_boot_params;

#ifdef CONFIG_OF_EARLY_FLATTREE

/**
 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
 * @it: callback function
 * @data: context data pointer
 *
 * This function is used to scan the flattened device-tree, it is
 * used to extract the memory information at boot before we can
 * unflatten the tree
 */
int __init of_scan_flat_dt(int (*it)(unsigned long node,
				     const char *uname, int depth,
				     void *data),
			   void *data)
{
	unsigned long p = ((unsigned long)initial_boot_params) +
		be32_to_cpu(initial_boot_params->off_dt_struct);
	int rc = 0;
	int depth = -1;

	do {
		u32 tag = be32_to_cpup((__be32 *)p);
F
Fabio Estevam 已提交
466
		const char *pathp;
467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492

		p += 4;
		if (tag == OF_DT_END_NODE) {
			depth--;
			continue;
		}
		if (tag == OF_DT_NOP)
			continue;
		if (tag == OF_DT_END)
			break;
		if (tag == OF_DT_PROP) {
			u32 sz = be32_to_cpup((__be32 *)p);
			p += 8;
			if (be32_to_cpu(initial_boot_params->version) < 0x10)
				p = ALIGN(p, sz >= 8 ? 8 : 4);
			p += sz;
			p = ALIGN(p, 4);
			continue;
		}
		if (tag != OF_DT_BEGIN_NODE) {
			pr_err("Invalid tag %x in flat device tree!\n", tag);
			return -EINVAL;
		}
		depth++;
		pathp = (char *)p;
		p = ALIGN(p + strlen(pathp) + 1, 4);
493 494
		if (*pathp == '/')
			pathp = kbasename(pathp);
495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
		rc = it(p, pathp, depth, data);
		if (rc != 0)
			break;
	} while (1);

	return rc;
}

/**
 * of_get_flat_dt_root - find the root node in the flat blob
 */
unsigned long __init of_get_flat_dt_root(void)
{
	unsigned long p = ((unsigned long)initial_boot_params) +
		be32_to_cpu(initial_boot_params->off_dt_struct);

	while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
		p += 4;
	BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
	p += 4;
	return ALIGN(p + strlen((char *)p) + 1, 4);
}

/**
 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
 *
 * This function can be used within scan_flattened_dt callback to get
 * access to properties
 */
void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
				 unsigned long *size)
{
	return of_fdt_get_property(initial_boot_params, node, name, size);
}

/**
 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
 * @node: node to test
 * @compat: compatible string to compare with compatible list.
 */
int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
{
	return of_fdt_is_compatible(initial_boot_params, node, compat);
}

540 541 542
/**
 * of_flat_dt_match - Return true if node matches a list of compatible values
 */
543
int __init of_flat_dt_match(unsigned long node, const char *const *compat)
544 545 546 547
{
	return of_fdt_match(initial_boot_params, node, compat);
}

548 549 550 551 552 553 554
#ifdef CONFIG_BLK_DEV_INITRD
/**
 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
 * @node: reference to node containing initrd location ('chosen')
 */
void __init early_init_dt_check_for_initrd(unsigned long node)
{
555 556
	u64 start, end;
	unsigned long len;
557
	__be32 *prop;
558 559 560 561

	pr_debug("Looking for initrd properties... ");

	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
562 563
	if (!prop)
		return;
564
	start = of_read_number(prop, len/4);
565 566 567 568

	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
	if (!prop)
		return;
569
	end = of_read_number(prop, len/4);
570

571
	early_init_dt_setup_initrd_arch(start, end);
572 573
	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
		 (unsigned long long)start, (unsigned long long)end);
574 575 576 577 578 579 580
}
#else
inline void early_init_dt_check_for_initrd(unsigned long node)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */

581 582 583 584 585 586
/**
 * early_init_dt_scan_root - fetch the top level address and size cells
 */
int __init early_init_dt_scan_root(unsigned long node, const char *uname,
				   int depth, void *data)
{
587
	__be32 *prop;
588 589 590 591

	if (depth != 0)
		return 0;

592 593 594
	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;

595
	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
596 597
	if (prop)
		dt_root_size_cells = be32_to_cpup(prop);
598 599 600
	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);

	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
601 602
	if (prop)
		dt_root_addr_cells = be32_to_cpup(prop);
603 604 605 606 607 608
	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);

	/* break now */
	return 1;
}

609
u64 __init dt_mem_next_cell(int s, __be32 **cellp)
G
Grant Likely 已提交
610
{
611
	__be32 *p = *cellp;
G
Grant Likely 已提交
612 613 614 615 616

	*cellp = p + s;
	return of_read_number(p, s);
}

617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665
/**
 * early_init_dt_scan_memory - Look for an parse memory nodes
 */
int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
				     int depth, void *data)
{
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
	__be32 *reg, *endp;
	unsigned long l;

	/* We are scanning "memory" nodes only */
	if (type == NULL) {
		/*
		 * The longtrail doesn't have a device_type on the
		 * /memory node, so look for the node called /memory@0.
		 */
		if (depth != 1 || strcmp(uname, "memory@0") != 0)
			return 0;
	} else if (strcmp(type, "memory") != 0)
		return 0;

	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
	if (reg == NULL)
		reg = of_get_flat_dt_prop(node, "reg", &l);
	if (reg == NULL)
		return 0;

	endp = reg + (l / sizeof(__be32));

	pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
	    uname, l, reg[0], reg[1], reg[2], reg[3]);

	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
		u64 base, size;

		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
		size = dt_mem_next_cell(dt_root_size_cells, &reg);

		if (size == 0)
			continue;
		pr_debug(" - %llx ,  %llx\n", (unsigned long long)base,
		    (unsigned long long)size);

		early_init_dt_add_memory_arch(base, size);
	}

	return 0;
}

666 667 668 669 670 671 672 673
int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
				     int depth, void *data)
{
	unsigned long l;
	char *p;

	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);

674
	if (depth != 1 || !data ||
675 676 677 678 679
	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
		return 0;

	early_init_dt_check_for_initrd(node);

L
Lucas De Marchi 已提交
680
	/* Retrieve command line */
681 682
	p = of_get_flat_dt_prop(node, "bootargs", &l);
	if (p != NULL && l > 0)
683
		strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
684

685 686 687 688 689
	/*
	 * CONFIG_CMDLINE is meant to be a default in case nothing else
	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
	 * is set in which case we override whatever was found earlier.
	 */
690 691
#ifdef CONFIG_CMDLINE
#ifndef CONFIG_CMDLINE_FORCE
692
	if (!((char *)data)[0])
693
#endif
694
		strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
695 696
#endif /* CONFIG_CMDLINE */

697
	pr_debug("Command line is: %s\n", (char*)data);
698 699 700 701 702

	/* break now */
	return 1;
}

703 704 705 706 707 708 709 710 711 712
/**
 * unflatten_device_tree - create tree of device_nodes from flat blob
 *
 * unflattens the device-tree passed by the firmware, creating the
 * tree of struct device_node. It also fills the "name" and "type"
 * pointers of the nodes so the normal device-tree walking functions
 * can be used.
 */
void __init unflatten_device_tree(void)
{
713
	__unflatten_device_tree(initial_boot_params, &of_allnodes,
714
				early_init_dt_alloc_memory_arch);
715

716
	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
717
	of_alias_scan(early_init_dt_alloc_memory_arch);
718
}
719 720

#endif /* CONFIG_OF_EARLY_FLATTREE */