linux/drivers/of/fdt.c

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/*
* 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.
*/
#include <linux/kernel.h>
#include <linux/initrd.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
#include <linux/sizes.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/libfdt.h>
#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
#include <asm/page.h>
/**
* 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.
*
* On match, returns a non-zero value with smaller values returned for more
* specific compatible values.
*/
int of_fdt_is_compatible(struct boot_param_header *blob,
unsigned long node, const char *compat)
{
const char *cp;
int cplen;
unsigned long l, score = 0;
cp = fdt_getprop(blob, node, "compatible", &cplen);
if (cp == NULL)
return 0;
while (cplen > 0) {
score++;
if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
return score;
l = strlen(cp) + 1;
cp += l;
cplen -= l;
}
return 0;
}
/**
* 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,
const char *const *compat)
{
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;
}
static void *unflatten_dt_alloc(void **mem, unsigned long size,
unsigned long align)
{
void *res;
*mem = PTR_ALIGN(*mem, align);
res = *mem;
*mem += size;
return res;
}
/**
* unflatten_dt_node - Alloc and populate a device_node from the flat tree
* @blob: The parent device tree blob
* @mem: Memory chunk to use for allocating device nodes and properties
* @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.
*/
static void * unflatten_dt_node(struct boot_param_header *blob,
void *mem,
int *poffset,
struct device_node *dad,
struct device_node ***allnextpp,
unsigned long fpsize)
{
const __be32 *p;
struct device_node *np;
struct property *pp, **prev_pp = NULL;
const char *pathp;
unsigned int l, allocl;
static int depth = 0;
int old_depth;
int offset;
int has_name = 0;
int new_format = 0;
pathp = fdt_get_name(blob, *poffset, &l);
if (!pathp)
return mem;
allocl = l++;
/* 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;
l = 1;
pathp = "";
} 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) {
char *fn;
of_node_init(np);
np->full_name = fn = ((char *)np) + sizeof(*np);
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++) = '/';
}
memcpy(fn, pathp, l);
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;
}
}
/* process properties */
for (offset = fdt_first_property_offset(blob, *poffset);
(offset >= 0);
(offset = fdt_next_property_offset(blob, offset))) {
const char *pname;
u32 sz;
if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
offset = -FDT_ERR_INTERNAL;
break;
}
if (pname == NULL) {
pr_info("Can't find property name in list !\n");
break;
}
if (strcmp(pname, "name") == 0)
has_name = 1;
pp = unflatten_dt_alloc(&mem, sizeof(struct property),
__alignof__(struct property));
if (allnextpp) {
/* 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)) {
if (np->phandle == 0)
np->phandle = be32_to_cpup(p);
}
/* And we process the "ibm,phandle" property
* used in pSeries dynamic device tree
* stuff */
if (strcmp(pname, "ibm,phandle") == 0)
np->phandle = be32_to_cpup(p);
pp->name = (char *)pname;
pp->length = sz;
pp->value = (__be32 *)p;
*prev_pp = pp;
prev_pp = &pp->next;
}
}
/* with version 0x10 we may not have the name property, recreate
* it here from the unit name if absent
*/
if (!has_name) {
const 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>";
}
old_depth = depth;
*poffset = fdt_next_node(blob, *poffset, &depth);
if (depth < 0)
depth = 0;
while (*poffset > 0 && depth > old_depth)
mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp,
fpsize);
if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
pr_err("unflatten: error %d processing FDT\n", *poffset);
return mem;
}
/**
* __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
*/
static void __unflatten_device_tree(struct boot_param_header *blob,
struct device_node **mynodes,
void * (*dt_alloc)(u64 size, u64 align))
{
unsigned long size;
int start;
void *mem;
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 = 0;
size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
size = ALIGN(size, 4);
pr_debug(" size is %lx, allocating...\n", size);
/* Allocate memory for the expanded device tree */
mem = dt_alloc(size + 4, __alignof__(struct device_node));
memset(mem, 0, size);
*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
pr_debug(" unflattening %p...\n", mem);
/* Second pass, do actual unflattening */
start = 0;
unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
if (be32_to_cpup(mem + size) != 0xdeadbeef)
pr_warning("End of tree marker overwritten: %08x\n",
be32_to_cpup(mem + size));
*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);
/* 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
/**
* res_mem_reserve_reg() - reserve all memory described in 'reg' property
*/
static int __init __reserved_mem_reserve_reg(unsigned long node,
const char *uname)
{
int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
phys_addr_t base, size;
int len;
const __be32 *prop;
int nomap, first = 1;
prop = of_get_flat_dt_prop(node, "reg", &len);
if (!prop)
return -ENOENT;
if (len && len % t_len != 0) {
pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
uname);
return -EINVAL;
}
nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
while (len >= t_len) {
base = dt_mem_next_cell(dt_root_addr_cells, &prop);
size = dt_mem_next_cell(dt_root_size_cells, &prop);
if (base && size &&
early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
uname, &base, (unsigned long)size / SZ_1M);
else
pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
uname, &base, (unsigned long)size / SZ_1M);
len -= t_len;
if (first) {
fdt_reserved_mem_save_node(node, uname, base, size);
first = 0;
}
}
return 0;
}
/**
* __reserved_mem_check_root() - check if #size-cells, #address-cells provided
* in /reserved-memory matches the values supported by the current implementation,
* also check if ranges property has been provided
*/
static int __init __reserved_mem_check_root(unsigned long node)
{
const __be32 *prop;
prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
return -EINVAL;
prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
return -EINVAL;
prop = of_get_flat_dt_prop(node, "ranges", NULL);
if (!prop)
return -EINVAL;
return 0;
}
/**
* fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
*/
static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
int depth, void *data)
{
static int found;
const char *status;
int err;
if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
if (__reserved_mem_check_root(node) != 0) {
pr_err("Reserved memory: unsupported node format, ignoring\n");
/* break scan */
return 1;
}
found = 1;
/* scan next node */
return 0;
} else if (!found) {
/* scan next node */
return 0;
} else if (found && depth < 2) {
/* scanning of /reserved-memory has been finished */
return 1;
}
status = of_get_flat_dt_prop(node, "status", NULL);
if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
return 0;
err = __reserved_mem_reserve_reg(node, uname);
if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
fdt_reserved_mem_save_node(node, uname, 0, 0);
/* scan next node */
return 0;
}
/**
* early_init_fdt_scan_reserved_mem() - create reserved memory regions
*
* This function grabs memory from early allocator for device exclusive use
* defined in device tree structures. It should be called by arch specific code
* once the early allocator (i.e. memblock) has been fully activated.
*/
void __init early_init_fdt_scan_reserved_mem(void)
{
if (!initial_boot_params)
return;
of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
fdt_init_reserved_mem();
}
/**
* 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)
{
const void *blob = initial_boot_params;
const char *pathp;
int offset, rc = 0, depth = -1;
for (offset = fdt_next_node(blob, -1, &depth);
offset >= 0 && depth >= 0 && !rc;
offset = fdt_next_node(blob, offset, &depth)) {
pathp = fdt_get_name(blob, offset, NULL);
if (*pathp == '/')
pathp = kbasename(pathp);
rc = it(offset, pathp, depth, data);
}
return rc;
}
/**
* of_get_flat_dt_root - find the root node in the flat blob
*/
unsigned long __init of_get_flat_dt_root(void)
{
return 0;
}
/**
* 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
*/
const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
int *size)
{
return fdt_getprop(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);
}
/**
* of_flat_dt_match - Return true if node matches a list of compatible values
*/
int __init of_flat_dt_match(unsigned long node, const char *const *compat)
{
return of_fdt_match(initial_boot_params, node, compat);
}
struct fdt_scan_status {
const char *name;
int namelen;
int depth;
int found;
int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
void *data;
};
const char * __init of_flat_dt_get_machine_name(void)
{
const char *name;
unsigned long dt_root = of_get_flat_dt_root();
name = of_get_flat_dt_prop(dt_root, "model", NULL);
if (!name)
name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
return name;
}
/**
* of_flat_dt_match_machine - Iterate match tables to find matching machine.
*
* @default_match: A machine specific ptr to return in case of no match.
* @get_next_compat: callback function to return next compatible match table.
*
* Iterate through machine match tables to find the best match for the machine
* compatible string in the FDT.
*/
const void * __init of_flat_dt_match_machine(const void *default_match,
const void * (*get_next_compat)(const char * const**))
{
const void *data = NULL;
const void *best_data = default_match;
const char *const *compat;
unsigned long dt_root;
unsigned int best_score = ~1, score = 0;
dt_root = of_get_flat_dt_root();
while ((data = get_next_compat(&compat))) {
score = of_flat_dt_match(dt_root, compat);
if (score > 0 && score < best_score) {
best_data = data;
best_score = score;
}
}
if (!best_data) {
const char *prop;
int size;
pr_err("\n unrecognized device tree list:\n[ ");
prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
if (prop) {
while (size > 0) {
printk("'%s' ", prop);
size -= strlen(prop) + 1;
prop += strlen(prop) + 1;
}
}
printk("]\n\n");
return NULL;
}
pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
return best_data;
}
#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')
*/
static void __init early_init_dt_check_for_initrd(unsigned long node)
{
u64 start, end;
int len;
const __be32 *prop;
pr_debug("Looking for initrd properties... ");
prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
if (!prop)
return;
start = of_read_number(prop, len/4);
prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
if (!prop)
return;
end = of_read_number(prop, len/4);
initrd_start = (unsigned long)__va(start);
initrd_end = (unsigned long)__va(end);
initrd_below_start_ok = 1;
pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
(unsigned long long)start, (unsigned long long)end);
}
#else
static inline void early_init_dt_check_for_initrd(unsigned long node)
{
}
#endif /* CONFIG_BLK_DEV_INITRD */
/**
* 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)
{
const __be32 *prop;
if (depth != 0)
return 0;
dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
if (prop)
dt_root_size_cells = be32_to_cpup(prop);
pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
if (prop)
dt_root_addr_cells = be32_to_cpup(prop);
pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
/* break now */
return 1;
}
u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
{
const __be32 *p = *cellp;
*cellp = p + s;
return of_read_number(p, s);
}
/**
* 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)
{
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
const __be32 *reg, *endp;
int 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 %d, 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;
}
int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
int depth, void *data)
{
int l;
const char *p;
pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
if (depth != 1 || !data ||
(strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
return 0;
early_init_dt_check_for_initrd(node);
/* Retrieve command line */
p = of_get_flat_dt_prop(node, "bootargs", &l);
if (p != NULL && l > 0)
strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
/*
* 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.
*/
#ifdef CONFIG_CMDLINE
#ifndef CONFIG_CMDLINE_FORCE
if (!((char *)data)[0])
#endif
strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
#endif /* CONFIG_CMDLINE */
pr_debug("Command line is: %s\n", (char*)data);
/* break now */
return 1;
}
#ifdef CONFIG_HAVE_MEMBLOCK
void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
{
const u64 phys_offset = __pa(PAGE_OFFSET);
base &= PAGE_MASK;
size &= PAGE_MASK;
if (base + size < phys_offset) {
pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
base, base + size);
return;
}
if (base < phys_offset) {
pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
base, phys_offset);
size -= phys_offset - base;
base = phys_offset;
}
memblock_add(base, size);
}
int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
phys_addr_t size, bool nomap)
{
if (memblock_is_region_reserved(base, size))
return -EBUSY;
if (nomap)
return memblock_remove(base, size);
return memblock_reserve(base, size);
}
/*
* called from unflatten_device_tree() to bootstrap devicetree itself
* Architectures can override this definition if memblock isn't used
*/
void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
{
return __va(memblock_alloc(size, align));
}
#else
int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
phys_addr_t size, bool nomap)
{
pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
base, size, nomap ? " (nomap)" : "");
return -ENOSYS;
}
#endif
bool __init early_init_dt_scan(void *params)
{
if (!params)
return false;
/* Setup flat device-tree pointer */
initial_boot_params = params;
/* check device tree validity */
if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
initial_boot_params = NULL;
return false;
}
/* Retrieve various information from the /chosen node */
of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
/* Initialize {size,address}-cells info */
of_scan_flat_dt(early_init_dt_scan_root, NULL);
/* Setup memory, calling early_init_dt_add_memory_arch */
of_scan_flat_dt(early_init_dt_scan_memory, NULL);
return true;
}
/**
* 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)
{
__unflatten_device_tree(initial_boot_params, &of_allnodes,
early_init_dt_alloc_memory_arch);
/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
of_alias_scan(early_init_dt_alloc_memory_arch);
}
/**
* unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
*
* Copies and 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. This should only be used when the FDT memory has not been
* reserved such is the case when the FDT is built-in to the kernel init
* section. If the FDT memory is reserved already then unflatten_device_tree
* should be used instead.
*/
void __init unflatten_and_copy_device_tree(void)
{
int size;
void *dt;
if (!initial_boot_params) {
pr_warn("No valid device tree found, continuing without\n");
return;
}
size = __be32_to_cpu(initial_boot_params->totalsize);
dt = early_init_dt_alloc_memory_arch(size,
__alignof__(struct boot_param_header));
if (dt) {
memcpy(dt, initial_boot_params, size);
initial_boot_params = dt;
}
unflatten_device_tree();
}
#endif /* CONFIG_OF_EARLY_FLATTREE */