1 // SPDX-License-Identifier: GPL-2.0
3 * Functions for working with the Flattened Device Tree data format
5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
6 * benh@kernel.crashing.org
9 #define pr_fmt(fmt) "OF: fdt: " fmt
11 #include <linux/crc32.h>
12 #include <linux/kernel.h>
13 #include <linux/initrd.h>
14 #include <linux/memblock.h>
15 #include <linux/mutex.h>
17 #include <linux/of_fdt.h>
18 #include <linux/of_reserved_mem.h>
19 #include <linux/sizes.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/libfdt.h>
24 #include <linux/debugfs.h>
25 #include <linux/serial_core.h>
26 #include <linux/sysfs.h>
27 #include <linux/random.h>
29 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
32 #include "of_private.h"
35 * of_fdt_limit_memory - limit the number of regions in the /memory node
36 * @limit: maximum entries
38 * Adjust the flattened device tree to have at most 'limit' number of
39 * memory entries in the /memory node. This function may be called
40 * any time after initial_boot_param is set.
42 void __init of_fdt_limit_memory(int limit)
47 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
48 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
49 const __be32 *addr_prop;
50 const __be32 *size_prop;
54 root_offset = fdt_path_offset(initial_boot_params, "/");
58 addr_prop = fdt_getprop(initial_boot_params, root_offset,
59 "#address-cells", NULL);
61 nr_address_cells = fdt32_to_cpu(*addr_prop);
63 size_prop = fdt_getprop(initial_boot_params, root_offset,
66 nr_size_cells = fdt32_to_cpu(*size_prop);
68 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
70 memory = fdt_path_offset(initial_boot_params, "/memory");
72 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
73 if (len > limit*cell_size) {
74 len = limit*cell_size;
75 pr_debug("Limiting number of entries to %d\n", limit);
76 fdt_setprop(initial_boot_params, memory, "reg", val,
82 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
84 const char *status = fdt_getprop(blob, node, "status", NULL);
89 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
95 static void *unflatten_dt_alloc(void **mem, unsigned long size,
100 *mem = PTR_ALIGN(*mem, align);
107 static void populate_properties(const void *blob,
110 struct device_node *np,
111 const char *nodename,
114 struct property *pp, **pprev = NULL;
116 bool has_name = false;
118 pprev = &np->properties;
119 for (cur = fdt_first_property_offset(blob, offset);
121 cur = fdt_next_property_offset(blob, cur)) {
126 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
128 pr_warn("Cannot locate property at 0x%x\n", cur);
133 pr_warn("Cannot find property name at 0x%x\n", cur);
137 if (!strcmp(pname, "name"))
140 pp = unflatten_dt_alloc(mem, sizeof(struct property),
141 __alignof__(struct property));
145 /* We accept flattened tree phandles either in
146 * ePAPR-style "phandle" properties, or the
147 * legacy "linux,phandle" properties. If both
148 * appear and have different values, things
149 * will get weird. Don't do that.
151 if (!strcmp(pname, "phandle") ||
152 !strcmp(pname, "linux,phandle")) {
154 np->phandle = be32_to_cpup(val);
157 /* And we process the "ibm,phandle" property
158 * used in pSeries dynamic device tree
161 if (!strcmp(pname, "ibm,phandle"))
162 np->phandle = be32_to_cpup(val);
164 pp->name = (char *)pname;
166 pp->value = (__be32 *)val;
171 /* With version 0x10 we may not have the name property,
172 * recreate it here from the unit name if absent
175 const char *p = nodename, *ps = p, *pa = NULL;
181 else if ((*p) == '/')
189 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
190 __alignof__(struct property));
197 memcpy(pp->value, ps, len - 1);
198 ((char *)pp->value)[len - 1] = 0;
199 pr_debug("fixed up name for %s -> %s\n",
200 nodename, (char *)pp->value);
208 static bool populate_node(const void *blob,
211 struct device_node *dad,
212 struct device_node **pnp,
215 struct device_node *np;
217 unsigned int l, allocl;
219 pathp = fdt_get_name(blob, offset, &l);
227 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
228 __alignof__(struct device_node));
232 np->full_name = fn = ((char *)np) + sizeof(*np);
234 memcpy(fn, pathp, l);
238 np->sibling = dad->child;
243 populate_properties(blob, offset, mem, np, pathp, dryrun);
245 np->name = of_get_property(np, "name", NULL);
254 static void reverse_nodes(struct device_node *parent)
256 struct device_node *child, *next;
259 child = parent->child;
261 reverse_nodes(child);
263 child = child->sibling;
266 /* Reverse the nodes in the child list */
267 child = parent->child;
268 parent->child = NULL;
270 next = child->sibling;
272 child->sibling = parent->child;
273 parent->child = child;
279 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
280 * @blob: The parent device tree blob
281 * @mem: Memory chunk to use for allocating device nodes and properties
282 * @dad: Parent struct device_node
283 * @nodepp: The device_node tree created by the call
285 * Return: The size of unflattened device tree or error code
287 static int unflatten_dt_nodes(const void *blob,
289 struct device_node *dad,
290 struct device_node **nodepp)
292 struct device_node *root;
293 int offset = 0, depth = 0, initial_depth = 0;
294 #define FDT_MAX_DEPTH 64
295 struct device_node *nps[FDT_MAX_DEPTH];
303 * We're unflattening device sub-tree if @dad is valid. There are
304 * possibly multiple nodes in the first level of depth. We need
305 * set @depth to 1 to make fdt_next_node() happy as it bails
306 * immediately when negative @depth is found. Otherwise, the device
307 * nodes except the first one won't be unflattened successfully.
310 depth = initial_depth = 1;
316 offset >= 0 && depth >= initial_depth;
317 offset = fdt_next_node(blob, offset, &depth)) {
318 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
321 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
322 !of_fdt_device_is_available(blob, offset))
325 if (!populate_node(blob, offset, &mem, nps[depth],
326 &nps[depth+1], dryrun))
329 if (!dryrun && nodepp && !*nodepp)
330 *nodepp = nps[depth+1];
331 if (!dryrun && !root)
335 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
336 pr_err("Error %d processing FDT\n", offset);
341 * Reverse the child list. Some drivers assumes node order matches .dts
351 * __unflatten_device_tree - create tree of device_nodes from flat blob
352 * @blob: The blob to expand
353 * @dad: Parent device node
354 * @mynodes: The device_node tree created by the call
355 * @dt_alloc: An allocator that provides a virtual address to memory
356 * for the resulting tree
357 * @detached: if true set OF_DETACHED on @mynodes
359 * unflattens a device-tree, creating the tree of struct device_node. It also
360 * fills the "name" and "type" pointers of the nodes so the normal device-tree
361 * walking functions can be used.
363 * Return: NULL on failure or the memory chunk containing the unflattened
364 * device tree on success.
366 void *__unflatten_device_tree(const void *blob,
367 struct device_node *dad,
368 struct device_node **mynodes,
369 void *(*dt_alloc)(u64 size, u64 align),
375 pr_debug(" -> unflatten_device_tree()\n");
378 pr_debug("No device tree pointer\n");
382 pr_debug("Unflattening device tree:\n");
383 pr_debug("magic: %08x\n", fdt_magic(blob));
384 pr_debug("size: %08x\n", fdt_totalsize(blob));
385 pr_debug("version: %08x\n", fdt_version(blob));
387 if (fdt_check_header(blob)) {
388 pr_err("Invalid device tree blob header\n");
392 /* First pass, scan for size */
393 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
397 size = ALIGN(size, 4);
398 pr_debug(" size is %d, allocating...\n", size);
400 /* Allocate memory for the expanded device tree */
401 mem = dt_alloc(size + 4, __alignof__(struct device_node));
405 memset(mem, 0, size);
407 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
409 pr_debug(" unflattening %p...\n", mem);
411 /* Second pass, do actual unflattening */
412 unflatten_dt_nodes(blob, mem, dad, mynodes);
413 if (be32_to_cpup(mem + size) != 0xdeadbeef)
414 pr_warn("End of tree marker overwritten: %08x\n",
415 be32_to_cpup(mem + size));
417 if (detached && mynodes) {
418 of_node_set_flag(*mynodes, OF_DETACHED);
419 pr_debug("unflattened tree is detached\n");
422 pr_debug(" <- unflatten_device_tree()\n");
426 static void *kernel_tree_alloc(u64 size, u64 align)
428 return kzalloc(size, GFP_KERNEL);
431 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
434 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
435 * @blob: Flat device tree blob
436 * @dad: Parent device node
437 * @mynodes: The device tree created by the call
439 * unflattens the device-tree passed by the firmware, creating the
440 * tree of struct device_node. It also fills the "name" and "type"
441 * pointers of the nodes so the normal device-tree walking functions
444 * Return: NULL on failure or the memory chunk containing the unflattened
445 * device tree on success.
447 void *of_fdt_unflatten_tree(const unsigned long *blob,
448 struct device_node *dad,
449 struct device_node **mynodes)
453 mutex_lock(&of_fdt_unflatten_mutex);
454 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
456 mutex_unlock(&of_fdt_unflatten_mutex);
460 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
462 /* Everything below here references initial_boot_params directly. */
463 int __initdata dt_root_addr_cells;
464 int __initdata dt_root_size_cells;
466 void *initial_boot_params __ro_after_init;
468 #ifdef CONFIG_OF_EARLY_FLATTREE
470 static u32 of_fdt_crc32;
473 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
475 static int __init __reserved_mem_reserve_reg(unsigned long node,
478 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
479 phys_addr_t base, size;
485 prop = of_get_flat_dt_prop(node, "reg", &len);
489 if (len && len % t_len != 0) {
490 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
495 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
497 while (len >= t_len) {
498 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
499 size = dt_mem_next_cell(dt_root_size_cells, &prop);
502 early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
503 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
504 uname, &base, (unsigned long)(size / SZ_1M));
506 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
507 uname, &base, (unsigned long)(size / SZ_1M));
511 fdt_reserved_mem_save_node(node, uname, base, size);
519 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
520 * in /reserved-memory matches the values supported by the current implementation,
521 * also check if ranges property has been provided
523 static int __init __reserved_mem_check_root(unsigned long node)
527 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
528 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
531 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
532 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
535 prop = of_get_flat_dt_prop(node, "ranges", NULL);
542 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
544 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
545 int depth, void *data)
550 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
551 if (__reserved_mem_check_root(node) != 0) {
552 pr_err("Reserved memory: unsupported node format, ignoring\n");
562 } else if (found && depth < 2) {
563 /* scanning of /reserved-memory has been finished */
567 if (!of_fdt_device_is_available(initial_boot_params, node))
570 err = __reserved_mem_reserve_reg(node, uname);
571 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
572 fdt_reserved_mem_save_node(node, uname, 0, 0);
579 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
581 * This function grabs memory from early allocator for device exclusive use
582 * defined in device tree structures. It should be called by arch specific code
583 * once the early allocator (i.e. memblock) has been fully activated.
585 void __init early_init_fdt_scan_reserved_mem(void)
590 if (!initial_boot_params)
593 /* Process header /memreserve/ fields */
595 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
598 early_init_dt_reserve_memory_arch(base, size, false);
601 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
602 fdt_init_reserved_mem();
606 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
608 void __init early_init_fdt_reserve_self(void)
610 if (!initial_boot_params)
613 /* Reserve the dtb region */
614 early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
615 fdt_totalsize(initial_boot_params),
620 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
621 * @it: callback function
622 * @data: context data pointer
624 * This function is used to scan the flattened device-tree, it is
625 * used to extract the memory information at boot before we can
628 int __init of_scan_flat_dt(int (*it)(unsigned long node,
629 const char *uname, int depth,
633 const void *blob = initial_boot_params;
635 int offset, rc = 0, depth = -1;
640 for (offset = fdt_next_node(blob, -1, &depth);
641 offset >= 0 && depth >= 0 && !rc;
642 offset = fdt_next_node(blob, offset, &depth)) {
644 pathp = fdt_get_name(blob, offset, NULL);
645 rc = it(offset, pathp, depth, data);
651 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
652 * @it: callback function
653 * @data: context data pointer
655 * This function is used to scan sub-nodes of a node.
657 int __init of_scan_flat_dt_subnodes(unsigned long parent,
658 int (*it)(unsigned long node,
663 const void *blob = initial_boot_params;
666 fdt_for_each_subnode(node, blob, parent) {
670 pathp = fdt_get_name(blob, node, NULL);
671 rc = it(node, pathp, data);
679 * of_get_flat_dt_subnode_by_name - get the subnode by given name
681 * @node: the parent node
682 * @uname: the name of subnode
683 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
686 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
688 return fdt_subnode_offset(initial_boot_params, node, uname);
692 * of_get_flat_dt_root - find the root node in the flat blob
694 unsigned long __init of_get_flat_dt_root(void)
700 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
702 * This function can be used within scan_flattened_dt callback to get
703 * access to properties
705 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
708 return fdt_getprop(initial_boot_params, node, name, size);
712 * of_fdt_is_compatible - Return true if given node from the given blob has
713 * compat in its compatible list
714 * @blob: A device tree blob
715 * @node: node to test
716 * @compat: compatible string to compare with compatible list.
718 * Return: a non-zero value on match with smaller values returned for more
719 * specific compatible values.
721 static int of_fdt_is_compatible(const void *blob,
722 unsigned long node, const char *compat)
726 unsigned long l, score = 0;
728 cp = fdt_getprop(blob, node, "compatible", &cplen);
733 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
744 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
745 * @node: node to test
746 * @compat: compatible string to compare with compatible list.
748 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
750 return of_fdt_is_compatible(initial_boot_params, node, compat);
754 * of_flat_dt_match - Return true if node matches a list of compatible values
756 static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
758 unsigned int tmp, score = 0;
764 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
765 if (tmp && (score == 0 || (tmp < score)))
774 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
776 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
778 return fdt_get_phandle(initial_boot_params, node);
781 struct fdt_scan_status {
786 int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
790 const char * __init of_flat_dt_get_machine_name(void)
793 unsigned long dt_root = of_get_flat_dt_root();
795 name = of_get_flat_dt_prop(dt_root, "model", NULL);
797 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
802 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
804 * @default_match: A machine specific ptr to return in case of no match.
805 * @get_next_compat: callback function to return next compatible match table.
807 * Iterate through machine match tables to find the best match for the machine
808 * compatible string in the FDT.
810 const void * __init of_flat_dt_match_machine(const void *default_match,
811 const void * (*get_next_compat)(const char * const**))
813 const void *data = NULL;
814 const void *best_data = default_match;
815 const char *const *compat;
816 unsigned long dt_root;
817 unsigned int best_score = ~1, score = 0;
819 dt_root = of_get_flat_dt_root();
820 while ((data = get_next_compat(&compat))) {
821 score = of_flat_dt_match(dt_root, compat);
822 if (score > 0 && score < best_score) {
831 pr_err("\n unrecognized device tree list:\n[ ");
833 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
836 printk("'%s' ", prop);
837 size -= strlen(prop) + 1;
838 prop += strlen(prop) + 1;
845 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
850 #ifdef CONFIG_BLK_DEV_INITRD
851 static void __early_init_dt_declare_initrd(unsigned long start,
854 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
855 * enabled since __va() is called too early. ARM64 does make use
856 * of phys_initrd_start/phys_initrd_size so we can skip this
859 if (!IS_ENABLED(CONFIG_ARM64)) {
860 initrd_start = (unsigned long)__va(start);
861 initrd_end = (unsigned long)__va(end);
862 initrd_below_start_ok = 1;
867 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
868 * @node: reference to node containing initrd location ('chosen')
870 static void __init early_init_dt_check_for_initrd(unsigned long node)
876 pr_debug("Looking for initrd properties... ");
878 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
881 start = of_read_number(prop, len/4);
883 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
886 end = of_read_number(prop, len/4);
888 __early_init_dt_declare_initrd(start, end);
889 phys_initrd_start = start;
890 phys_initrd_size = end - start;
892 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
893 (unsigned long long)start, (unsigned long long)end);
896 static inline void early_init_dt_check_for_initrd(unsigned long node)
899 #endif /* CONFIG_BLK_DEV_INITRD */
901 #ifdef CONFIG_SERIAL_EARLYCON
903 int __init early_init_dt_scan_chosen_stdout(void)
906 const char *p, *q, *options = NULL;
908 const struct earlycon_id **p_match;
909 const void *fdt = initial_boot_params;
911 offset = fdt_path_offset(fdt, "/chosen");
913 offset = fdt_path_offset(fdt, "/chosen@0");
917 p = fdt_getprop(fdt, offset, "stdout-path", &l);
919 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
923 q = strchrnul(p, ':');
928 /* Get the node specified by stdout-path */
929 offset = fdt_path_offset_namelen(fdt, p, l);
931 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
935 for (p_match = __earlycon_table; p_match < __earlycon_table_end;
937 const struct earlycon_id *match = *p_match;
939 if (!match->compatible[0])
942 if (fdt_node_check_compatible(fdt, offset, match->compatible))
945 if (of_setup_earlycon(match, offset, options) == 0)
953 * early_init_dt_scan_root - fetch the top level address and size cells
955 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
956 int depth, void *data)
963 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
964 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
966 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
968 dt_root_size_cells = be32_to_cpup(prop);
969 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
971 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
973 dt_root_addr_cells = be32_to_cpup(prop);
974 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
980 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
982 const __be32 *p = *cellp;
985 return of_read_number(p, s);
989 * early_init_dt_scan_memory - Look for and parse memory nodes
991 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
992 int depth, void *data)
994 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
995 const __be32 *reg, *endp;
999 /* We are scanning "memory" nodes only */
1000 if (type == NULL || strcmp(type, "memory") != 0)
1003 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1005 reg = of_get_flat_dt_prop(node, "reg", &l);
1009 endp = reg + (l / sizeof(__be32));
1010 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1012 pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1014 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1017 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1018 size = dt_mem_next_cell(dt_root_size_cells, ®);
1022 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
1023 (unsigned long long)size);
1025 early_init_dt_add_memory_arch(base, size);
1030 if (early_init_dt_mark_hotplug_memory_arch(base, size))
1031 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1038 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1039 int depth, void *data)
1043 const void *rng_seed;
1045 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1047 if (depth != 1 || !data ||
1048 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1051 early_init_dt_check_for_initrd(node);
1053 /* Retrieve command line */
1054 p = of_get_flat_dt_prop(node, "bootargs", &l);
1055 if (p != NULL && l > 0)
1056 strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
1059 * CONFIG_CMDLINE is meant to be a default in case nothing else
1060 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1061 * is set in which case we override whatever was found earlier.
1063 #ifdef CONFIG_CMDLINE
1064 #if defined(CONFIG_CMDLINE_EXTEND)
1065 strlcat(data, " ", COMMAND_LINE_SIZE);
1066 strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1067 #elif defined(CONFIG_CMDLINE_FORCE)
1068 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1070 /* No arguments from boot loader, use kernel's cmdl*/
1071 if (!((char *)data)[0])
1072 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1074 #endif /* CONFIG_CMDLINE */
1076 pr_debug("Command line is: %s\n", (char *)data);
1078 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1079 if (rng_seed && l > 0) {
1080 add_bootloader_randomness(rng_seed, l);
1082 /* try to clear seed so it won't be found. */
1083 fdt_nop_property(initial_boot_params, node, "rng-seed");
1085 /* update CRC check value */
1086 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1087 fdt_totalsize(initial_boot_params));
1094 #ifndef MIN_MEMBLOCK_ADDR
1095 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1097 #ifndef MAX_MEMBLOCK_ADDR
1098 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1101 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1103 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1105 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1106 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1111 if (!PAGE_ALIGNED(base)) {
1112 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1113 base = PAGE_ALIGN(base);
1117 if (base > MAX_MEMBLOCK_ADDR) {
1118 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1123 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1124 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1125 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1126 size = MAX_MEMBLOCK_ADDR - base + 1;
1129 if (base + size < phys_offset) {
1130 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1134 if (base < phys_offset) {
1135 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1137 size -= phys_offset - base;
1140 memblock_add(base, size);
1143 int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1145 return memblock_mark_hotplug(base, size);
1148 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1149 phys_addr_t size, bool nomap)
1153 * If the memory is already reserved (by another region), we
1154 * should not allow it to be marked nomap.
1156 if (memblock_is_region_reserved(base, size))
1159 return memblock_mark_nomap(base, size);
1161 return memblock_reserve(base, size);
1164 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1166 void *ptr = memblock_alloc(size, align);
1169 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1170 __func__, size, align);
1175 bool __init early_init_dt_verify(void *params)
1180 /* check device tree validity */
1181 if (fdt_check_header(params))
1184 /* Setup flat device-tree pointer */
1185 initial_boot_params = params;
1186 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1187 fdt_totalsize(initial_boot_params));
1192 void __init early_init_dt_scan_nodes(void)
1196 /* Retrieve various information from the /chosen node */
1197 rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1199 pr_warn("No chosen node found, continuing without\n");
1201 /* Initialize {size,address}-cells info */
1202 of_scan_flat_dt(early_init_dt_scan_root, NULL);
1204 /* Setup memory, calling early_init_dt_add_memory_arch */
1205 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1208 bool __init early_init_dt_scan(void *params)
1212 status = early_init_dt_verify(params);
1216 early_init_dt_scan_nodes();
1221 * unflatten_device_tree - create tree of device_nodes from flat blob
1223 * unflattens the device-tree passed by the firmware, creating the
1224 * tree of struct device_node. It also fills the "name" and "type"
1225 * pointers of the nodes so the normal device-tree walking functions
1228 void __init unflatten_device_tree(void)
1230 __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1231 early_init_dt_alloc_memory_arch, false);
1233 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1234 of_alias_scan(early_init_dt_alloc_memory_arch);
1236 unittest_unflatten_overlay_base();
1240 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1242 * Copies and unflattens the device-tree passed by the firmware, creating the
1243 * tree of struct device_node. It also fills the "name" and "type"
1244 * pointers of the nodes so the normal device-tree walking functions
1245 * can be used. This should only be used when the FDT memory has not been
1246 * reserved such is the case when the FDT is built-in to the kernel init
1247 * section. If the FDT memory is reserved already then unflatten_device_tree
1248 * should be used instead.
1250 void __init unflatten_and_copy_device_tree(void)
1255 if (!initial_boot_params) {
1256 pr_warn("No valid device tree found, continuing without\n");
1260 size = fdt_totalsize(initial_boot_params);
1261 dt = early_init_dt_alloc_memory_arch(size,
1262 roundup_pow_of_two(FDT_V17_SIZE));
1265 memcpy(dt, initial_boot_params, size);
1266 initial_boot_params = dt;
1268 unflatten_device_tree();
1272 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1273 struct bin_attribute *bin_attr,
1274 char *buf, loff_t off, size_t count)
1276 memcpy(buf, initial_boot_params + off, count);
1280 static int __init of_fdt_raw_init(void)
1282 static struct bin_attribute of_fdt_raw_attr =
1283 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1285 if (!initial_boot_params)
1288 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1289 fdt_totalsize(initial_boot_params))) {
1290 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1293 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1294 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1296 late_initcall(of_fdt_raw_init);
1299 #endif /* CONFIG_OF_EARLY_FLATTREE */