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/crash_dump.h>
12 #include <linux/crc32.h>
13 #include <linux/kernel.h>
14 #include <linux/initrd.h>
15 #include <linux/memblock.h>
16 #include <linux/mutex.h>
18 #include <linux/of_fdt.h>
19 #include <linux/of_reserved_mem.h>
20 #include <linux/sizes.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/slab.h>
24 #include <linux/libfdt.h>
25 #include <linux/debugfs.h>
26 #include <linux/serial_core.h>
27 #include <linux/sysfs.h>
28 #include <linux/random.h>
30 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
33 #include "of_private.h"
36 * of_fdt_limit_memory - limit the number of regions in the /memory node
37 * @limit: maximum entries
39 * Adjust the flattened device tree to have at most 'limit' number of
40 * memory entries in the /memory node. This function may be called
41 * any time after initial_boot_param is set.
43 void __init of_fdt_limit_memory(int limit)
48 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
49 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
50 const __be32 *addr_prop;
51 const __be32 *size_prop;
55 root_offset = fdt_path_offset(initial_boot_params, "/");
59 addr_prop = fdt_getprop(initial_boot_params, root_offset,
60 "#address-cells", NULL);
62 nr_address_cells = fdt32_to_cpu(*addr_prop);
64 size_prop = fdt_getprop(initial_boot_params, root_offset,
67 nr_size_cells = fdt32_to_cpu(*size_prop);
69 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
71 memory = fdt_path_offset(initial_boot_params, "/memory");
73 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
74 if (len > limit*cell_size) {
75 len = limit*cell_size;
76 pr_debug("Limiting number of entries to %d\n", limit);
77 fdt_setprop(initial_boot_params, memory, "reg", val,
83 static bool of_fdt_device_is_available(const void *blob, unsigned long node)
85 const char *status = fdt_getprop(blob, node, "status", NULL);
90 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
96 static void *unflatten_dt_alloc(void **mem, unsigned long size,
101 *mem = PTR_ALIGN(*mem, align);
108 static void populate_properties(const void *blob,
111 struct device_node *np,
112 const char *nodename,
115 struct property *pp, **pprev = NULL;
117 bool has_name = false;
119 pprev = &np->properties;
120 for (cur = fdt_first_property_offset(blob, offset);
122 cur = fdt_next_property_offset(blob, cur)) {
127 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
129 pr_warn("Cannot locate property at 0x%x\n", cur);
134 pr_warn("Cannot find property name at 0x%x\n", cur);
138 if (!strcmp(pname, "name"))
141 pp = unflatten_dt_alloc(mem, sizeof(struct property),
142 __alignof__(struct property));
146 /* We accept flattened tree phandles either in
147 * ePAPR-style "phandle" properties, or the
148 * legacy "linux,phandle" properties. If both
149 * appear and have different values, things
150 * will get weird. Don't do that.
152 if (!strcmp(pname, "phandle") ||
153 !strcmp(pname, "linux,phandle")) {
155 np->phandle = be32_to_cpup(val);
158 /* And we process the "ibm,phandle" property
159 * used in pSeries dynamic device tree
162 if (!strcmp(pname, "ibm,phandle"))
163 np->phandle = be32_to_cpup(val);
165 pp->name = (char *)pname;
167 pp->value = (__be32 *)val;
172 /* With version 0x10 we may not have the name property,
173 * recreate it here from the unit name if absent
176 const char *p = nodename, *ps = p, *pa = NULL;
182 else if ((*p) == '/')
190 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
191 __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);
205 static int populate_node(const void *blob,
208 struct device_node *dad,
209 struct device_node **pnp,
212 struct device_node *np;
216 pathp = fdt_get_name(blob, offset, &len);
224 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
225 __alignof__(struct device_node));
229 np->full_name = fn = ((char *)np) + sizeof(*np);
231 memcpy(fn, pathp, len);
235 np->sibling = dad->child;
240 populate_properties(blob, offset, mem, np, pathp, dryrun);
242 np->name = of_get_property(np, "name", NULL);
251 static void reverse_nodes(struct device_node *parent)
253 struct device_node *child, *next;
256 child = parent->child;
258 reverse_nodes(child);
260 child = child->sibling;
263 /* Reverse the nodes in the child list */
264 child = parent->child;
265 parent->child = NULL;
267 next = child->sibling;
269 child->sibling = parent->child;
270 parent->child = child;
276 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
277 * @blob: The parent device tree blob
278 * @mem: Memory chunk to use for allocating device nodes and properties
279 * @dad: Parent struct device_node
280 * @nodepp: The device_node tree created by the call
282 * Return: The size of unflattened device tree or error code
284 static int unflatten_dt_nodes(const void *blob,
286 struct device_node *dad,
287 struct device_node **nodepp)
289 struct device_node *root;
290 int offset = 0, depth = 0, initial_depth = 0;
291 #define FDT_MAX_DEPTH 64
292 struct device_node *nps[FDT_MAX_DEPTH];
301 * We're unflattening device sub-tree if @dad is valid. There are
302 * possibly multiple nodes in the first level of depth. We need
303 * set @depth to 1 to make fdt_next_node() happy as it bails
304 * immediately when negative @depth is found. Otherwise, the device
305 * nodes except the first one won't be unflattened successfully.
308 depth = initial_depth = 1;
314 offset >= 0 && depth >= initial_depth;
315 offset = fdt_next_node(blob, offset, &depth)) {
316 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
319 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
320 !of_fdt_device_is_available(blob, offset))
323 ret = populate_node(blob, offset, &mem, nps[depth],
324 &nps[depth+1], dryrun);
328 if (!dryrun && nodepp && !*nodepp)
329 *nodepp = nps[depth+1];
330 if (!dryrun && !root)
334 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
335 pr_err("Error %d processing FDT\n", offset);
340 * Reverse the child list. Some drivers assumes node order matches .dts
350 * __unflatten_device_tree - create tree of device_nodes from flat blob
351 * @blob: The blob to expand
352 * @dad: Parent device node
353 * @mynodes: The device_node tree created by the call
354 * @dt_alloc: An allocator that provides a virtual address to memory
355 * for the resulting tree
356 * @detached: if true set OF_DETACHED on @mynodes
358 * unflattens a device-tree, creating the tree of struct device_node. It also
359 * fills the "name" and "type" pointers of the nodes so the normal device-tree
360 * walking functions can be used.
362 * Return: NULL on failure or the memory chunk containing the unflattened
363 * device tree on success.
365 void *__unflatten_device_tree(const void *blob,
366 struct device_node *dad,
367 struct device_node **mynodes,
368 void *(*dt_alloc)(u64 size, u64 align),
378 pr_debug(" -> unflatten_device_tree()\n");
381 pr_debug("No device tree pointer\n");
385 pr_debug("Unflattening device tree:\n");
386 pr_debug("magic: %08x\n", fdt_magic(blob));
387 pr_debug("size: %08x\n", fdt_totalsize(blob));
388 pr_debug("version: %08x\n", fdt_version(blob));
390 if (fdt_check_header(blob)) {
391 pr_err("Invalid device tree blob header\n");
395 /* First pass, scan for size */
396 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
400 size = ALIGN(size, 4);
401 pr_debug(" size is %d, allocating...\n", size);
403 /* Allocate memory for the expanded device tree */
404 mem = dt_alloc(size + 4, __alignof__(struct device_node));
408 memset(mem, 0, size);
410 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
412 pr_debug(" unflattening %p...\n", mem);
414 /* Second pass, do actual unflattening */
415 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
417 if (be32_to_cpup(mem + size) != 0xdeadbeef)
418 pr_warn("End of tree marker overwritten: %08x\n",
419 be32_to_cpup(mem + size));
424 if (detached && mynodes && *mynodes) {
425 of_node_set_flag(*mynodes, OF_DETACHED);
426 pr_debug("unflattened tree is detached\n");
429 pr_debug(" <- unflatten_device_tree()\n");
433 static void *kernel_tree_alloc(u64 size, u64 align)
435 return kzalloc(size, GFP_KERNEL);
438 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
441 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
442 * @blob: Flat device tree blob
443 * @dad: Parent device node
444 * @mynodes: The device tree created by the call
446 * unflattens the device-tree passed by the firmware, creating the
447 * tree of struct device_node. It also fills the "name" and "type"
448 * pointers of the nodes so the normal device-tree walking functions
451 * Return: NULL on failure or the memory chunk containing the unflattened
452 * device tree on success.
454 void *of_fdt_unflatten_tree(const unsigned long *blob,
455 struct device_node *dad,
456 struct device_node **mynodes)
460 mutex_lock(&of_fdt_unflatten_mutex);
461 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
463 mutex_unlock(&of_fdt_unflatten_mutex);
467 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
469 /* Everything below here references initial_boot_params directly. */
470 int __initdata dt_root_addr_cells;
471 int __initdata dt_root_size_cells;
473 void *initial_boot_params __ro_after_init;
475 #ifdef CONFIG_OF_EARLY_FLATTREE
477 static u32 of_fdt_crc32;
479 static int __init early_init_dt_reserve_memory_arch(phys_addr_t base,
480 phys_addr_t size, bool nomap)
484 * If the memory is already reserved (by another region), we
485 * should not allow it to be marked nomap.
487 if (memblock_is_region_reserved(base, size))
490 return memblock_mark_nomap(base, size);
492 return memblock_reserve(base, size);
496 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
498 static int __init __reserved_mem_reserve_reg(unsigned long node,
501 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
502 phys_addr_t base, size;
508 prop = of_get_flat_dt_prop(node, "reg", &len);
512 if (len && len % t_len != 0) {
513 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
518 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
520 while (len >= t_len) {
521 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
522 size = dt_mem_next_cell(dt_root_size_cells, &prop);
525 early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
526 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
527 uname, &base, (unsigned long)(size / SZ_1M));
529 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
530 uname, &base, (unsigned long)(size / SZ_1M));
534 fdt_reserved_mem_save_node(node, uname, base, size);
542 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
543 * in /reserved-memory matches the values supported by the current implementation,
544 * also check if ranges property has been provided
546 static int __init __reserved_mem_check_root(unsigned long node)
550 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
551 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
554 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
555 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
558 prop = of_get_flat_dt_prop(node, "ranges", NULL);
565 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
567 static int __init fdt_scan_reserved_mem(void)
570 const void *fdt = initial_boot_params;
572 node = fdt_path_offset(fdt, "/reserved-memory");
576 if (__reserved_mem_check_root(node) != 0) {
577 pr_err("Reserved memory: unsupported node format, ignoring\n");
581 fdt_for_each_subnode(child, fdt, node) {
585 if (!of_fdt_device_is_available(fdt, child))
588 uname = fdt_get_name(fdt, child, NULL);
590 err = __reserved_mem_reserve_reg(child, uname);
591 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
592 fdt_reserved_mem_save_node(child, uname, 0, 0);
598 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
600 * This function reserves the memory occupied by an elf core header
601 * described in the device tree. This region contains all the
602 * information about primary kernel's core image and is used by a dump
603 * capture kernel to access the system memory on primary kernel.
605 static void __init fdt_reserve_elfcorehdr(void)
607 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
610 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
611 pr_warn("elfcorehdr is overlapped\n");
615 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
617 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
618 elfcorehdr_size >> 10, elfcorehdr_addr);
622 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
624 * This function grabs memory from early allocator for device exclusive use
625 * defined in device tree structures. It should be called by arch specific code
626 * once the early allocator (i.e. memblock) has been fully activated.
628 void __init early_init_fdt_scan_reserved_mem(void)
633 if (!initial_boot_params)
636 /* Process header /memreserve/ fields */
638 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
641 early_init_dt_reserve_memory_arch(base, size, false);
644 fdt_scan_reserved_mem();
645 fdt_init_reserved_mem();
646 fdt_reserve_elfcorehdr();
650 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
652 void __init early_init_fdt_reserve_self(void)
654 if (!initial_boot_params)
657 /* Reserve the dtb region */
658 early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
659 fdt_totalsize(initial_boot_params),
664 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
665 * @it: callback function
666 * @data: context data pointer
668 * This function is used to scan the flattened device-tree, it is
669 * used to extract the memory information at boot before we can
672 int __init of_scan_flat_dt(int (*it)(unsigned long node,
673 const char *uname, int depth,
677 const void *blob = initial_boot_params;
679 int offset, rc = 0, depth = -1;
684 for (offset = fdt_next_node(blob, -1, &depth);
685 offset >= 0 && depth >= 0 && !rc;
686 offset = fdt_next_node(blob, offset, &depth)) {
688 pathp = fdt_get_name(blob, offset, NULL);
689 rc = it(offset, pathp, depth, data);
695 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
696 * @parent: parent node
697 * @it: callback function
698 * @data: context data pointer
700 * This function is used to scan sub-nodes of a node.
702 int __init of_scan_flat_dt_subnodes(unsigned long parent,
703 int (*it)(unsigned long node,
708 const void *blob = initial_boot_params;
711 fdt_for_each_subnode(node, blob, parent) {
715 pathp = fdt_get_name(blob, node, NULL);
716 rc = it(node, pathp, data);
724 * of_get_flat_dt_subnode_by_name - get the subnode by given name
726 * @node: the parent node
727 * @uname: the name of subnode
728 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
731 int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
733 return fdt_subnode_offset(initial_boot_params, node, uname);
737 * of_get_flat_dt_root - find the root node in the flat blob
739 unsigned long __init of_get_flat_dt_root(void)
745 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
747 * This function can be used within scan_flattened_dt callback to get
748 * access to properties
750 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
753 return fdt_getprop(initial_boot_params, node, name, size);
757 * of_fdt_is_compatible - Return true if given node from the given blob has
758 * compat in its compatible list
759 * @blob: A device tree blob
760 * @node: node to test
761 * @compat: compatible string to compare with compatible list.
763 * Return: a non-zero value on match with smaller values returned for more
764 * specific compatible values.
766 static int of_fdt_is_compatible(const void *blob,
767 unsigned long node, const char *compat)
771 unsigned long l, score = 0;
773 cp = fdt_getprop(blob, node, "compatible", &cplen);
778 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
789 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
790 * @node: node to test
791 * @compat: compatible string to compare with compatible list.
793 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
795 return of_fdt_is_compatible(initial_boot_params, node, compat);
799 * of_flat_dt_match - Return true if node matches a list of compatible values
801 static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
803 unsigned int tmp, score = 0;
809 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
810 if (tmp && (score == 0 || (tmp < score)))
819 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
821 uint32_t __init of_get_flat_dt_phandle(unsigned long node)
823 return fdt_get_phandle(initial_boot_params, node);
826 struct fdt_scan_status {
831 int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
835 const char * __init of_flat_dt_get_machine_name(void)
838 unsigned long dt_root = of_get_flat_dt_root();
840 name = of_get_flat_dt_prop(dt_root, "model", NULL);
842 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
847 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
849 * @default_match: A machine specific ptr to return in case of no match.
850 * @get_next_compat: callback function to return next compatible match table.
852 * Iterate through machine match tables to find the best match for the machine
853 * compatible string in the FDT.
855 const void * __init of_flat_dt_match_machine(const void *default_match,
856 const void * (*get_next_compat)(const char * const**))
858 const void *data = NULL;
859 const void *best_data = default_match;
860 const char *const *compat;
861 unsigned long dt_root;
862 unsigned int best_score = ~1, score = 0;
864 dt_root = of_get_flat_dt_root();
865 while ((data = get_next_compat(&compat))) {
866 score = of_flat_dt_match(dt_root, compat);
867 if (score > 0 && score < best_score) {
876 pr_err("\n unrecognized device tree list:\n[ ");
878 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
881 printk("'%s' ", prop);
882 size -= strlen(prop) + 1;
883 prop += strlen(prop) + 1;
890 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
895 static void __early_init_dt_declare_initrd(unsigned long start,
898 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
899 * enabled since __va() is called too early. ARM64 does make use
900 * of phys_initrd_start/phys_initrd_size so we can skip this
903 if (!IS_ENABLED(CONFIG_ARM64)) {
904 initrd_start = (unsigned long)__va(start);
905 initrd_end = (unsigned long)__va(end);
906 initrd_below_start_ok = 1;
911 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
912 * @node: reference to node containing initrd location ('chosen')
914 static void __init early_init_dt_check_for_initrd(unsigned long node)
920 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
923 pr_debug("Looking for initrd properties... ");
925 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
928 start = of_read_number(prop, len/4);
930 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
933 end = of_read_number(prop, len/4);
935 __early_init_dt_declare_initrd(start, end);
936 phys_initrd_start = start;
937 phys_initrd_size = end - start;
939 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
943 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
945 * @node: reference to node containing elfcorehdr location ('chosen')
947 static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
952 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
955 pr_debug("Looking for elfcorehdr property... ");
957 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
958 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
961 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
962 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
964 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
965 elfcorehdr_addr, elfcorehdr_size);
968 static phys_addr_t cap_mem_addr;
969 static phys_addr_t cap_mem_size;
972 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
973 * location from flat tree
974 * @node: reference to node containing usable memory range location ('chosen')
976 static void __init early_init_dt_check_for_usable_mem_range(unsigned long node)
981 pr_debug("Looking for usable-memory-range property... ");
983 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
984 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
987 cap_mem_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
988 cap_mem_size = dt_mem_next_cell(dt_root_size_cells, &prop);
990 pr_debug("cap_mem_start=%pa cap_mem_size=%pa\n", &cap_mem_addr,
994 #ifdef CONFIG_SERIAL_EARLYCON
996 int __init early_init_dt_scan_chosen_stdout(void)
999 const char *p, *q, *options = NULL;
1001 const struct earlycon_id *match;
1002 const void *fdt = initial_boot_params;
1004 offset = fdt_path_offset(fdt, "/chosen");
1006 offset = fdt_path_offset(fdt, "/chosen@0");
1010 p = fdt_getprop(fdt, offset, "stdout-path", &l);
1012 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
1016 q = strchrnul(p, ':');
1021 /* Get the node specified by stdout-path */
1022 offset = fdt_path_offset_namelen(fdt, p, l);
1024 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
1028 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
1029 if (!match->compatible[0])
1032 if (fdt_node_check_compatible(fdt, offset, match->compatible))
1035 if (of_setup_earlycon(match, offset, options) == 0)
1043 * early_init_dt_scan_root - fetch the top level address and size cells
1045 int __init early_init_dt_scan_root(void)
1048 const void *fdt = initial_boot_params;
1049 int node = fdt_path_offset(fdt, "/");
1054 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1055 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1057 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1059 dt_root_size_cells = be32_to_cpup(prop);
1060 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1062 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1064 dt_root_addr_cells = be32_to_cpup(prop);
1065 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1070 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1072 const __be32 *p = *cellp;
1075 return of_read_number(p, s);
1079 * early_init_dt_scan_memory - Look for and parse memory nodes
1081 int __init early_init_dt_scan_memory(void)
1084 const void *fdt = initial_boot_params;
1086 fdt_for_each_subnode(node, fdt, 0) {
1087 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1088 const __be32 *reg, *endp;
1092 /* We are scanning "memory" nodes only */
1093 if (type == NULL || strcmp(type, "memory") != 0)
1096 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1098 reg = of_get_flat_dt_prop(node, "reg", &l);
1102 endp = reg + (l / sizeof(__be32));
1103 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1105 pr_debug("memory scan node %s, reg size %d,\n",
1106 fdt_get_name(fdt, node, NULL), l);
1108 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1111 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1112 size = dt_mem_next_cell(dt_root_size_cells, ®);
1116 pr_debug(" - %llx, %llx\n", base, size);
1118 early_init_dt_add_memory_arch(base, size);
1123 if (memblock_mark_hotplug(base, size))
1124 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1131 int __init early_init_dt_scan_chosen(char *cmdline)
1135 const void *rng_seed;
1136 const void *fdt = initial_boot_params;
1138 node = fdt_path_offset(fdt, "/chosen");
1140 node = fdt_path_offset(fdt, "/chosen@0");
1144 early_init_dt_check_for_initrd(node);
1145 early_init_dt_check_for_elfcorehdr(node);
1146 early_init_dt_check_for_usable_mem_range(node);
1148 /* Retrieve command line */
1149 p = of_get_flat_dt_prop(node, "bootargs", &l);
1150 if (p != NULL && l > 0)
1151 strlcpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1154 * CONFIG_CMDLINE is meant to be a default in case nothing else
1155 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1156 * is set in which case we override whatever was found earlier.
1158 #ifdef CONFIG_CMDLINE
1159 #if defined(CONFIG_CMDLINE_EXTEND)
1160 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1161 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1162 #elif defined(CONFIG_CMDLINE_FORCE)
1163 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1165 /* No arguments from boot loader, use kernel's cmdl*/
1166 if (!((char *)cmdline)[0])
1167 strlcpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1169 #endif /* CONFIG_CMDLINE */
1171 pr_debug("Command line is: %s\n", (char *)cmdline);
1173 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1174 if (rng_seed && l > 0) {
1175 add_bootloader_randomness(rng_seed, l);
1177 /* try to clear seed so it won't be found. */
1178 fdt_nop_property(initial_boot_params, node, "rng-seed");
1180 /* update CRC check value */
1181 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1182 fdt_totalsize(initial_boot_params));
1188 #ifndef MIN_MEMBLOCK_ADDR
1189 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1191 #ifndef MAX_MEMBLOCK_ADDR
1192 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1195 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1197 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1199 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1200 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1205 if (!PAGE_ALIGNED(base)) {
1206 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1207 base = PAGE_ALIGN(base);
1211 if (base > MAX_MEMBLOCK_ADDR) {
1212 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1217 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1218 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1219 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1220 size = MAX_MEMBLOCK_ADDR - base + 1;
1223 if (base + size < phys_offset) {
1224 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1228 if (base < phys_offset) {
1229 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1231 size -= phys_offset - base;
1234 memblock_add(base, size);
1237 static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1239 void *ptr = memblock_alloc(size, align);
1242 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1243 __func__, size, align);
1248 bool __init early_init_dt_verify(void *params)
1253 /* check device tree validity */
1254 if (fdt_check_header(params))
1257 /* Setup flat device-tree pointer */
1258 initial_boot_params = params;
1259 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1260 fdt_totalsize(initial_boot_params));
1265 void __init early_init_dt_scan_nodes(void)
1269 /* Initialize {size,address}-cells info */
1270 early_init_dt_scan_root();
1272 /* Retrieve various information from the /chosen node */
1273 rc = early_init_dt_scan_chosen(boot_command_line);
1275 pr_warn("No chosen node found, continuing without\n");
1277 /* Setup memory, calling early_init_dt_add_memory_arch */
1278 early_init_dt_scan_memory();
1280 /* Handle linux,usable-memory-range property */
1281 memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
1284 bool __init early_init_dt_scan(void *params)
1288 status = early_init_dt_verify(params);
1292 early_init_dt_scan_nodes();
1297 * unflatten_device_tree - create tree of device_nodes from flat blob
1299 * unflattens the device-tree passed by the firmware, creating the
1300 * tree of struct device_node. It also fills the "name" and "type"
1301 * pointers of the nodes so the normal device-tree walking functions
1304 void __init unflatten_device_tree(void)
1306 __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1307 early_init_dt_alloc_memory_arch, false);
1309 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1310 of_alias_scan(early_init_dt_alloc_memory_arch);
1312 unittest_unflatten_overlay_base();
1316 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1318 * Copies and unflattens the device-tree passed by the firmware, creating the
1319 * tree of struct device_node. It also fills the "name" and "type"
1320 * pointers of the nodes so the normal device-tree walking functions
1321 * can be used. This should only be used when the FDT memory has not been
1322 * reserved such is the case when the FDT is built-in to the kernel init
1323 * section. If the FDT memory is reserved already then unflatten_device_tree
1324 * should be used instead.
1326 void __init unflatten_and_copy_device_tree(void)
1331 if (!initial_boot_params) {
1332 pr_warn("No valid device tree found, continuing without\n");
1336 size = fdt_totalsize(initial_boot_params);
1337 dt = early_init_dt_alloc_memory_arch(size,
1338 roundup_pow_of_two(FDT_V17_SIZE));
1341 memcpy(dt, initial_boot_params, size);
1342 initial_boot_params = dt;
1344 unflatten_device_tree();
1348 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1349 struct bin_attribute *bin_attr,
1350 char *buf, loff_t off, size_t count)
1352 memcpy(buf, initial_boot_params + off, count);
1356 static int __init of_fdt_raw_init(void)
1358 static struct bin_attribute of_fdt_raw_attr =
1359 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1361 if (!initial_boot_params)
1364 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1365 fdt_totalsize(initial_boot_params))) {
1366 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1369 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1370 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1372 late_initcall(of_fdt_raw_init);
1375 #endif /* CONFIG_OF_EARLY_FLATTREE */