2 * Functions for working with the Flattened Device Tree data format
4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5 * benh@kernel.crashing.org
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.
12 #include <linux/kernel.h>
13 #include <linux/initrd.h>
15 #include <linux/of_fdt.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
20 #include <asm/machdep.h>
21 #endif /* CONFIG_PPC */
25 int __initdata dt_root_addr_cells
;
26 int __initdata dt_root_size_cells
;
28 struct boot_param_header
*initial_boot_params
;
30 #ifdef CONFIG_OF_EARLY_FLATTREE
32 char *find_flat_dt_string(u32 offset
)
34 return ((char *)initial_boot_params
) +
35 be32_to_cpu(initial_boot_params
->off_dt_strings
) + offset
;
39 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
40 * @it: callback function
41 * @data: context data pointer
43 * This function is used to scan the flattened device-tree, it is
44 * used to extract the memory information at boot before we can
47 int __init
of_scan_flat_dt(int (*it
)(unsigned long node
,
48 const char *uname
, int depth
,
52 unsigned long p
= ((unsigned long)initial_boot_params
) +
53 be32_to_cpu(initial_boot_params
->off_dt_struct
);
58 u32 tag
= be32_to_cpup((__be32
*)p
);
62 if (tag
== OF_DT_END_NODE
) {
70 if (tag
== OF_DT_PROP
) {
71 u32 sz
= be32_to_cpup((__be32
*)p
);
73 if (be32_to_cpu(initial_boot_params
->version
) < 0x10)
74 p
= ALIGN(p
, sz
>= 8 ? 8 : 4);
79 if (tag
!= OF_DT_BEGIN_NODE
) {
80 pr_err("Invalid tag %x in flat device tree!\n", tag
);
85 p
= ALIGN(p
+ strlen(pathp
) + 1, 4);
86 if ((*pathp
) == '/') {
88 for (lp
= NULL
, np
= pathp
; *np
; np
++)
94 rc
= it(p
, pathp
, depth
, data
);
103 * of_get_flat_dt_root - find the root node in the flat blob
105 unsigned long __init
of_get_flat_dt_root(void)
107 unsigned long p
= ((unsigned long)initial_boot_params
) +
108 be32_to_cpu(initial_boot_params
->off_dt_struct
);
110 while (be32_to_cpup((__be32
*)p
) == OF_DT_NOP
)
112 BUG_ON(be32_to_cpup((__be32
*)p
) != OF_DT_BEGIN_NODE
);
114 return ALIGN(p
+ strlen((char *)p
) + 1, 4);
118 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
120 * This function can be used within scan_flattened_dt callback to get
121 * access to properties
123 void *__init
of_get_flat_dt_prop(unsigned long node
, const char *name
,
126 unsigned long p
= node
;
129 u32 tag
= be32_to_cpup((__be32
*)p
);
134 if (tag
== OF_DT_NOP
)
136 if (tag
!= OF_DT_PROP
)
139 sz
= be32_to_cpup((__be32
*)p
);
140 noff
= be32_to_cpup((__be32
*)(p
+ 4));
142 if (be32_to_cpu(initial_boot_params
->version
) < 0x10)
143 p
= ALIGN(p
, sz
>= 8 ? 8 : 4);
145 nstr
= find_flat_dt_string(noff
);
147 pr_warning("Can't find property index name !\n");
150 if (strcmp(name
, nstr
) == 0) {
161 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
162 * @node: node to test
163 * @compat: compatible string to compare with compatible list.
165 int __init
of_flat_dt_is_compatible(unsigned long node
, const char *compat
)
168 unsigned long cplen
, l
;
170 cp
= of_get_flat_dt_prop(node
, "compatible", &cplen
);
174 if (of_compat_cmp(cp
, compat
, strlen(compat
)) == 0)
184 static void *__init
unflatten_dt_alloc(unsigned long *mem
, unsigned long size
,
189 *mem
= ALIGN(*mem
, align
);
197 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
198 * @p: pointer to node in flat tree
199 * @dad: Parent struct device_node
200 * @allnextpp: pointer to ->allnext from last allocated device_node
201 * @fpsize: Size of the node path up at the current depth.
203 unsigned long __init
unflatten_dt_node(unsigned long mem
,
205 struct device_node
*dad
,
206 struct device_node
***allnextpp
,
207 unsigned long fpsize
)
209 struct device_node
*np
;
210 struct property
*pp
, **prev_pp
= NULL
;
213 unsigned int l
, allocl
;
217 tag
= be32_to_cpup((__be32
*)(*p
));
218 if (tag
!= OF_DT_BEGIN_NODE
) {
219 pr_err("Weird tag at start of node: %x\n", tag
);
224 l
= allocl
= strlen(pathp
) + 1;
225 *p
= ALIGN(*p
+ l
, 4);
227 /* version 0x10 has a more compact unit name here instead of the full
228 * path. we accumulate the full path size using "fpsize", we'll rebuild
229 * it later. We detect this because the first character of the name is
232 if ((*pathp
) != '/') {
235 /* root node: special case. fpsize accounts for path
236 * plus terminating zero. root node only has '/', so
237 * fpsize should be 2, but we want to avoid the first
238 * level nodes to have two '/' so we use fpsize 1 here
243 /* account for '/' and path size minus terminal 0
251 np
= unflatten_dt_alloc(&mem
, sizeof(struct device_node
) + allocl
,
252 __alignof__(struct device_node
));
254 memset(np
, 0, sizeof(*np
));
255 np
->full_name
= ((char *)np
) + sizeof(struct device_node
);
257 char *fn
= np
->full_name
;
258 /* rebuild full path for new format */
259 if (dad
&& dad
->parent
) {
260 strcpy(fn
, dad
->full_name
);
262 if ((strlen(fn
) + l
+ 1) != allocl
) {
263 pr_debug("%s: p: %d, l: %d, a: %d\n",
264 pathp
, (int)strlen(fn
),
271 memcpy(fn
, pathp
, l
);
273 memcpy(np
->full_name
, pathp
, l
);
274 prev_pp
= &np
->properties
;
276 *allnextpp
= &np
->allnext
;
279 /* we temporarily use the next field as `last_child'*/
280 if (dad
->next
== NULL
)
283 dad
->next
->sibling
= np
;
286 kref_init(&np
->kref
);
292 tag
= be32_to_cpup((__be32
*)(*p
));
293 if (tag
== OF_DT_NOP
) {
297 if (tag
!= OF_DT_PROP
)
300 sz
= be32_to_cpup((__be32
*)(*p
));
301 noff
= be32_to_cpup((__be32
*)((*p
) + 4));
303 if (be32_to_cpu(initial_boot_params
->version
) < 0x10)
304 *p
= ALIGN(*p
, sz
>= 8 ? 8 : 4);
306 pname
= find_flat_dt_string(noff
);
308 pr_info("Can't find property name in list !\n");
311 if (strcmp(pname
, "name") == 0)
313 l
= strlen(pname
) + 1;
314 pp
= unflatten_dt_alloc(&mem
, sizeof(struct property
),
315 __alignof__(struct property
));
317 /* We accept flattened tree phandles either in
318 * ePAPR-style "phandle" properties, or the
319 * legacy "linux,phandle" properties. If both
320 * appear and have different values, things
321 * will get weird. Don't do that. */
322 if ((strcmp(pname
, "phandle") == 0) ||
323 (strcmp(pname
, "linux,phandle") == 0)) {
324 if (np
->phandle
== 0)
325 np
->phandle
= be32_to_cpup((__be32
*)*p
);
327 /* And we process the "ibm,phandle" property
328 * used in pSeries dynamic device tree
330 if (strcmp(pname
, "ibm,phandle") == 0)
331 np
->phandle
= be32_to_cpup((__be32
*)*p
);
334 pp
->value
= (void *)*p
;
338 *p
= ALIGN((*p
) + sz
, 4);
340 /* with version 0x10 we may not have the name property, recreate
341 * it here from the unit name if absent
344 char *p1
= pathp
, *ps
= pathp
, *pa
= NULL
;
357 pp
= unflatten_dt_alloc(&mem
, sizeof(struct property
) + sz
,
358 __alignof__(struct property
));
365 memcpy(pp
->value
, ps
, sz
- 1);
366 ((char *)pp
->value
)[sz
- 1] = 0;
367 pr_debug("fixed up name for %s -> %s\n", pathp
,
373 np
->name
= of_get_property(np
, "name", NULL
);
374 np
->type
= of_get_property(np
, "device_type", NULL
);
381 while (tag
== OF_DT_BEGIN_NODE
|| tag
== OF_DT_NOP
) {
382 if (tag
== OF_DT_NOP
)
385 mem
= unflatten_dt_node(mem
, p
, np
, allnextpp
, fpsize
);
386 tag
= be32_to_cpup((__be32
*)(*p
));
388 if (tag
!= OF_DT_END_NODE
) {
389 pr_err("Weird tag at end of node: %x\n", tag
);
396 #ifdef CONFIG_BLK_DEV_INITRD
398 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
399 * @node: reference to node containing initrd location ('chosen')
401 void __init
early_init_dt_check_for_initrd(unsigned long node
)
403 unsigned long start
, end
, len
;
406 pr_debug("Looking for initrd properties... ");
408 prop
= of_get_flat_dt_prop(node
, "linux,initrd-start", &len
);
411 start
= of_read_ulong(prop
, len
/4);
413 prop
= of_get_flat_dt_prop(node
, "linux,initrd-end", &len
);
416 end
= of_read_ulong(prop
, len
/4);
418 early_init_dt_setup_initrd_arch(start
, end
);
419 pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start
, end
);
422 inline void early_init_dt_check_for_initrd(unsigned long node
)
425 #endif /* CONFIG_BLK_DEV_INITRD */
428 * early_init_dt_scan_root - fetch the top level address and size cells
430 int __init
early_init_dt_scan_root(unsigned long node
, const char *uname
,
431 int depth
, void *data
)
438 dt_root_size_cells
= OF_ROOT_NODE_SIZE_CELLS_DEFAULT
;
439 dt_root_addr_cells
= OF_ROOT_NODE_ADDR_CELLS_DEFAULT
;
441 prop
= of_get_flat_dt_prop(node
, "#size-cells", NULL
);
443 dt_root_size_cells
= be32_to_cpup(prop
);
444 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells
);
446 prop
= of_get_flat_dt_prop(node
, "#address-cells", NULL
);
448 dt_root_addr_cells
= be32_to_cpup(prop
);
449 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells
);
455 u64 __init
dt_mem_next_cell(int s
, __be32
**cellp
)
460 return of_read_number(p
, s
);
464 * early_init_dt_scan_memory - Look for an parse memory nodes
466 int __init
early_init_dt_scan_memory(unsigned long node
, const char *uname
,
467 int depth
, void *data
)
469 char *type
= of_get_flat_dt_prop(node
, "device_type", NULL
);
473 /* We are scanning "memory" nodes only */
476 * The longtrail doesn't have a device_type on the
477 * /memory node, so look for the node called /memory@0.
479 if (depth
!= 1 || strcmp(uname
, "memory@0") != 0)
481 } else if (strcmp(type
, "memory") != 0)
484 reg
= of_get_flat_dt_prop(node
, "linux,usable-memory", &l
);
486 reg
= of_get_flat_dt_prop(node
, "reg", &l
);
490 endp
= reg
+ (l
/ sizeof(__be32
));
492 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
493 uname
, l
, reg
[0], reg
[1], reg
[2], reg
[3]);
495 while ((endp
- reg
) >= (dt_root_addr_cells
+ dt_root_size_cells
)) {
498 base
= dt_mem_next_cell(dt_root_addr_cells
, ®
);
499 size
= dt_mem_next_cell(dt_root_size_cells
, ®
);
503 pr_debug(" - %llx , %llx\n", (unsigned long long)base
,
504 (unsigned long long)size
);
506 early_init_dt_add_memory_arch(base
, size
);
512 int __init
early_init_dt_scan_chosen(unsigned long node
, const char *uname
,
513 int depth
, void *data
)
518 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth
, uname
);
521 (strcmp(uname
, "chosen") != 0 && strcmp(uname
, "chosen@0") != 0))
524 early_init_dt_check_for_initrd(node
);
526 /* Retreive command line */
527 p
= of_get_flat_dt_prop(node
, "bootargs", &l
);
528 if (p
!= NULL
&& l
> 0)
529 strlcpy(cmd_line
, p
, min((int)l
, COMMAND_LINE_SIZE
));
531 #ifdef CONFIG_CMDLINE
532 #ifndef CONFIG_CMDLINE_FORCE
533 if (p
== NULL
|| l
== 0 || (l
== 1 && (*p
) == 0))
535 strlcpy(cmd_line
, CONFIG_CMDLINE
, COMMAND_LINE_SIZE
);
536 #endif /* CONFIG_CMDLINE */
538 pr_debug("Command line is: %s\n", cmd_line
);
545 * unflatten_device_tree - create tree of device_nodes from flat blob
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
552 void __init
unflatten_device_tree(void)
554 unsigned long start
, mem
, size
;
555 struct device_node
**allnextp
= &allnodes
;
557 pr_debug(" -> unflatten_device_tree()\n");
559 if (!initial_boot_params
) {
560 pr_debug("No device tree pointer\n");
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
));
569 if (be32_to_cpu(initial_boot_params
->magic
) != OF_DT_HEADER
) {
570 pr_err("Invalid device tree blob header\n");
574 /* First pass, scan for size */
575 start
= ((unsigned long)initial_boot_params
) +
576 be32_to_cpu(initial_boot_params
->off_dt_struct
);
577 size
= unflatten_dt_node(0, &start
, NULL
, NULL
, 0);
578 size
= (size
| 3) + 1;
580 pr_debug(" size is %lx, allocating...\n", size
);
582 /* Allocate memory for the expanded device tree */
583 mem
= early_init_dt_alloc_memory_arch(size
+ 4,
584 __alignof__(struct device_node
));
585 mem
= (unsigned long) __va(mem
);
587 ((__be32
*)mem
)[size
/ 4] = cpu_to_be32(0xdeadbeef);
589 pr_debug(" unflattening %lx...\n", mem
);
591 /* Second pass, do actual unflattening */
592 start
= ((unsigned long)initial_boot_params
) +
593 be32_to_cpu(initial_boot_params
->off_dt_struct
);
594 unflatten_dt_node(mem
, &start
, NULL
, &allnextp
, 0);
595 if (be32_to_cpup((__be32
*)start
) != OF_DT_END
)
596 pr_warning("Weird tag at end of tree: %08x\n", *((u32
*)start
));
597 if (be32_to_cpu(((__be32
*)mem
)[size
/ 4]) != 0xdeadbeef)
598 pr_warning("End of tree marker overwritten: %08x\n",
599 be32_to_cpu(((__be32
*)mem
)[size
/ 4]));
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");
607 pr_debug(" <- unflatten_device_tree()\n");
610 #endif /* CONFIG_OF_EARLY_FLATTREE */