Macros
#define	FDT_FIRST_SUPPORTED_VERSION 0x10

#define	FDT_LAST_SUPPORTED_VERSION 0x11

#define	FDT_ERR_NOTFOUND 1

#define	FDT_ERR_EXISTS 2

#define	FDT_ERR_NOSPACE 3

#define	FDT_ERR_BADOFFSET 4

#define	FDT_ERR_BADPATH 5

#define	FDT_ERR_BADPHANDLE 6

#define	FDT_ERR_BADSTATE 7

#define	FDT_ERR_TRUNCATED 8

#define	FDT_ERR_BADMAGIC 9

#define	FDT_ERR_BADVERSION 10

#define	FDT_ERR_BADSTRUCTURE 11

#define	FDT_ERR_BADLAYOUT 12

#define	FDT_ERR_INTERNAL 13

#define	FDT_ERR_BADNCELLS 14

#define	FDT_ERR_BADVALUE 15

#define	FDT_ERR_BADOVERLAY 16

#define	FDT_ERR_NOPHANDLES 17

#define	FDT_ERR_MAX 17

#define	fdt_for_each_subnode(node, fdt, parent)

#define	fdt_get_header(fdt, field) (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))

#define	fdt_magic(fdt) (fdt_get_header(fdt, magic))

#define	fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))

#define	fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))

#define	fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))

#define	fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))

#define	fdt_version(fdt) (fdt_get_header(fdt, version))

#define	fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))

#define	fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))

#define	fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))

#define	fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))

#define	__fdt_set_hdr(name)

Functions
const void *	fdt_offset_ptr (const void *fdt, int offset, unsigned int checklen)

uint32_t	fdt_next_tag (const void fdt, int offset, int nextoffset)

int	fdt_next_node (const void fdt, int offset, int depth)

int	fdt_first_subnode (const void *fdt, int offset)

int	fdt_next_subnode (const void *fdt, int offset)

	__fdt_set_hdr (magic)

	__fdt_set_hdr (totalsize)

	__fdt_set_hdr (off_dt_struct)

	__fdt_set_hdr (off_dt_strings)

	__fdt_set_hdr (off_mem_rsvmap)

	__fdt_set_hdr (version)

	__fdt_set_hdr (last_comp_version)

	__fdt_set_hdr (boot_cpuid_phys)

	__fdt_set_hdr (size_dt_strings)

	__fdt_set_hdr (size_dt_struct)

int	fdt_check_header (const void *fdt)

int	fdt_move (const void fdt, void buf, int bufsize)

const char *	fdt_string (const void *fdt, int stroffset)

uint32_t	fdt_get_max_phandle (const void *fdt)

int	fdt_num_mem_rsv (const void *fdt)

int	fdt_get_mem_rsv (const void fdt, int n, uint64_t address, uint64_t *size)

: name of the property to find
fdt_getprop - retrieve the value of a given property : pointer to the device tree blob : offset of the node whose property to find : pointer to an integer variable (will be overwritten) or NULL fdt_getprop() retrieves a pointer to the value of the property named 'name' of the node at offset nodeoffset (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. returns: pointer to the property's value if lenp is non-NULL, lenp contains the length of the property value (>=0) NULL, on error if lenp is non-NULL, lenp contains an error code (<0): -FDT_ERR_NOTFOUND, node does not have named property -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings
const struct fdt_property *	fdt_get_property_namelen (const void fdt, int nodeoffset, const char name, int namelen, int *lenp)

const struct fdt_property *	fdt_get_property (const void fdt, int nodeoffset, const char name, int *lenp)

const void *	fdt_getprop_by_offset (const void fdt, int offset, const char namep, int lenp)

const void *	fdt_getprop_namelen (const void fdt, int nodeoffset, const char name, int namelen, int *lenp)

const void *	fdt_getprop (const void fdt, int nodeoffset, const char name, int *lenp)

uint32_t	fdt_get_phandle (const void *fdt, int nodeoffset)

: name of the property to nop
fdt_delprop - delete a property : pointer to the device tree blob : offset of the node whose property to nop fdt_del_property() will delete the given property. This function will delete data from the blob, and will therefore change the offsets of some existing nodes. returns: 0, on success -FDT_ERR_NOTFOUND, node does not have the named property -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADLAYOUT, -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings
int	fdt_nop_property (void fdt, int nodeoffset, const char name)

int	fdt_nop_node (void *fdt, int nodeoffset)

int	fdt_create (void *buf, int bufsize)

int	fdt_resize (void fdt, void buf, int bufsize)

int	fdt_add_reservemap_entry (void *fdt, uint64_t addr, uint64_t size)

int	fdt_finish_reservemap (void *fdt)

int	fdt_begin_node (void fdt, const char name)

int	fdt_property (void fdt, const char name, const void *val, int len)

int	fdt_delprop (void fdt, int nodeoffset, const char name)

: name to give the node
fdt_set_name - change the name of a given node : pointer to the device tree blob : structure block offset of a node fdt_set_name() replaces the name (including unit address, if any) of the given node with the given string. NOTE: this function can't efficiently check if the new name is unique amongst the given node's siblings; results are undefined if this function is invoked with a name equal to one of the given node's siblings. This function may insert or delete data from the blob, and will therefore change the offsets of some existing nodes. returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new name -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, standard meanings
int	fdt_set_name (void fdt, int nodeoffset, const char name)

: name of the property to append to
fdt_appendprop - append to or create a property : pointer to the device tree blob : offset of the node whose property to change : pointer to data to append to the property value : length of the data to append to the property value fdt_appendprop() appends the value to the named property in the given node, creating the property if it does not already exist. This function may insert data into the blob, and will therefore change the offsets of some existing nodes. returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new property value -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADLAYOUT, -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings
int	fdt_appendprop (void fdt, int nodeoffset, const char name, const void *val, int len)

: name of the subnode to locate
fdt_add_subnode - creates a new node : pointer to the device tree blob : structure block offset of a node fdt_add_subnode() creates a new node as a subnode of the node at structure block offset parentoffset, with the given name (which should include the unit address, if any). This function will insert data into the blob, and will therefore change the offsets of some existing nodes. returns: structure block offset of the created nodeequested subnode (>=0), on success -FDT_ERR_NOTFOUND, if the requested subnode does not exist -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of the given name -FDT_ERR_NOSPACE, if there is insufficient free space in the blob to contain the new node -FDT_ERR_NOSPACE -FDT_ERR_BADLAYOUT -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings.
#define	fdt_for_each_property_offset(property, fdt, node)

int	fdt_subnode_offset_namelen (const void fdt, int parentoffset, const char name, int namelen)

int	fdt_subnode_offset (const void fdt, int parentoffset, const char name)

int	fdt_path_offset_namelen (const void fdt, const char path, int namelen)

int	fdt_path_offset (const void fdt, const char path)

const char *	fdt_get_name (const void fdt, int nodeoffset, int lenp)

int	fdt_first_property_offset (const void *fdt, int nodeoffset)

int	fdt_next_property_offset (const void *fdt, int offset)

const struct fdt_property *	fdt_get_property_by_offset (const void fdt, int offset, int lenp)

int	fdt_add_subnode_namelen (void fdt, int parentoffset, const char name, int namelen)

int	fdt_add_subnode (void fdt, int parentoffset, const char name)

int	fdt_del_node (void *fdt, int nodeoffset)

int	fdt_overlay_apply (void fdt, void fdto)

const char *	fdt_strerror (int errval)

: name of the alias th look up
fdt_get_alias - retrieve the path referenced by a given alias : pointer to the device tree blob fdt_get_alias() retrieves the value of a given alias. That is, the value of the property named 'name' in the node /aliases. returns: a pointer to the expansion of the alias named 'name', if it exists NULL, if the given alias or the /aliases node does not exist
#define	FDT_MAX_NCELLS 4

const char *	fdt_get_alias_namelen (const void fdt, const char name, int namelen)

const char *	fdt_get_alias (const void fdt, const char name)

int	fdt_get_path (const void fdt, int nodeoffset, char buf, int buflen)

int	fdt_supernode_atdepth_offset (const void fdt, int nodeoffset, int supernodedepth, int nodedepth)

int	fdt_node_depth (const void *fdt, int nodeoffset)

int	fdt_parent_offset (const void *fdt, int nodeoffset)

int	fdt_node_offset_by_prop_value (const void fdt, int startoffset, const char propname, const void *propval, int proplen)

int	fdt_node_offset_by_phandle (const void *fdt, uint32_t phandle)

int	fdt_node_check_compatible (const void fdt, int nodeoffset, const char compatible)

int	fdt_node_offset_by_compatible (const void fdt, int startoffset, const char compatible)

int	fdt_stringlist_contains (const char strlist, int listlen, const char str)

int	fdt_stringlist_count (const void fdt, int nodeoffset, const char property)

int	fdt_stringlist_search (const void fdt, int nodeoffset, const char property, const char *string)

const char *	fdt_stringlist_get (const void fdt, int nodeoffset, const char property, int index, int *lenp)

int	fdt_address_cells (const void *fdt, int nodeoffset)

int	fdt_size_cells (const void *fdt, int nodeoffset)

: name of the property to change
fdt_appendprop_string - append a string to a property : pointer to the device tree blob : offset of the node whose property to change : string value to append to the property fdt_appendprop_string() appends the given string to the value of the named property in the given node, or creates a new property with that value if it does not already exist. This function may insert data into the blob, and will therefore change the offsets of some existing nodes. returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new property value -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADLAYOUT, -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings
#define	fdt_setprop_string(fdt, nodeoffset, name, str) fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)

#define	fdt_setprop_empty(fdt, nodeoffset, name) fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)

#define	fdt_appendprop_string(fdt, nodeoffset, name, str) fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)

int	fdt_setprop_inplace_namelen_partial (void fdt, int nodeoffset, const char name, int namelen, uint32_t idx, const void *val, int len)

int	fdt_setprop_inplace (void fdt, int nodeoffset, const char name, const void *val, int len)

int	fdt_setprop (void fdt, int nodeoffset, const char name, const void *val, int len)

int	fdt_setprop_placeholder (void fdt, int nodeoffset, const char name, int len, void **prop_data)

: name of property to add
fdt_property_placeholder - add a new property and return a ptr to its value : pointer to the device tree blob : length of property value in bytes : returns a pointer to where where the value should be placed returns: 0, on success -FDT_ERR_BADMAGIC, -FDT_ERR_NOSPACE, standard meanings
#define	fdt_property_string(fdt, name, str) fdt_property(fdt, name, str, strlen(str)+1)

int	fdt_property_placeholder (void fdt, const char name, int len, void **valp)

int	fdt_end_node (void *fdt)

int	fdt_finish (void *fdt)

int	fdt_create_empty_tree (void *buf, int bufsize)

int	fdt_open_into (const void fdt, void buf, int bufsize)

int	fdt_pack (void *fdt)

int	fdt_add_mem_rsv (void *fdt, uint64_t address, uint64_t size)

int	fdt_del_mem_rsv (void *fdt, int n)

Macro Definition Documentation

#define __fdt_set_hdr ( name )

Value:

static inline void fdt_set_##name(void *fdt, uint32_t val) \
  { \
    struct fdt_header *fdth = (struct fdt_header *)fdt; \
    fdth->name = cpu_to_fdt32(val); \
  }

#define fdt_appendprop_string	(	fdt,
		nodeoffset,
		name,
		str
	)	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

#define fdt_boot_cpuid_phys ( fdt ) (fdt_get_header(fdt, boot_cpuid_phys))

#define FDT_ERR_BADLAYOUT 12

#define FDT_ERR_BADMAGIC 9

#define FDT_ERR_BADNCELLS 14

#define FDT_ERR_BADOFFSET 4

#define FDT_ERR_BADOVERLAY 16

#define FDT_ERR_BADPATH 5

#define FDT_ERR_BADPHANDLE 6

#define FDT_ERR_BADSTATE 7

#define FDT_ERR_BADSTRUCTURE 11

#define FDT_ERR_BADVALUE 15

#define FDT_ERR_BADVERSION 10

#define FDT_ERR_EXISTS 2

#define FDT_ERR_INTERNAL 13

#define FDT_ERR_MAX 17

#define FDT_ERR_NOPHANDLES 17

#define FDT_ERR_NOSPACE 3

#define FDT_ERR_NOTFOUND 1

#define FDT_ERR_TRUNCATED 8

#define FDT_FIRST_SUPPORTED_VERSION 0x10

#define fdt_for_each_property_offset	(	property,
		fdt,
		node
	)

Value:

for (property = fdt_first_property_offset(fdt, node); \
       property >= 0;         \
       property = fdt_next_property_offset(fdt, property))

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

#define fdt_for_each_subnode	(	node,
		fdt,
		parent
	)

Value:

for (node = fdt_first_subnode(fdt, parent); \
       node >= 0;         \
       node = fdt_next_subnode(fdt, node))

fdt_for_each_subnode - iterate over all subnodes of a parent

: child node (int, lvalue) : FDT blob (const void *) : parent node (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_subnode(node, fdt, parent) { Use node ... }

if ((node < 0) && (node != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and is used as iterator in the loop. The parent variable be constant or even a literal.

#define fdt_get_header	(	fdt,
		field
	)	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))

#define fdt_last_comp_version ( fdt ) (fdt_get_header(fdt, last_comp_version))

#define FDT_LAST_SUPPORTED_VERSION 0x11

#define fdt_magic ( fdt ) (fdt_get_header(fdt, magic))

#define FDT_MAX_NCELLS 4

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

#define fdt_off_dt_strings ( fdt ) (fdt_get_header(fdt, off_dt_strings))

#define fdt_off_dt_struct ( fdt ) (fdt_get_header(fdt, off_dt_struct))

#define fdt_off_mem_rsvmap ( fdt ) (fdt_get_header(fdt, off_mem_rsvmap))

#define fdt_property_string	(	fdt,
		name,
		str
	)	fdt_property(fdt, name, str, strlen(str)+1)

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

#define fdt_setprop_empty	(	fdt,
		nodeoffset,
		name
	)	fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

#define fdt_setprop_string	(	fdt,
		nodeoffset,
		name,
		str
	)	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

#define fdt_size_dt_strings ( fdt ) (fdt_get_header(fdt, size_dt_strings))

#define fdt_size_dt_struct ( fdt ) (fdt_get_header(fdt, size_dt_struct))

#define fdt_totalsize ( fdt ) (fdt_get_header(fdt, totalsize))

#define fdt_version ( fdt ) (fdt_get_header(fdt, version))

Function Documentation

__fdt_set_hdr ( magic )

__fdt_set_hdr ( totalsize )

__fdt_set_hdr ( off_dt_struct )

__fdt_set_hdr ( off_dt_strings )

__fdt_set_hdr ( off_mem_rsvmap )

__fdt_set_hdr ( version )

__fdt_set_hdr ( last_comp_version )

__fdt_set_hdr ( boot_cpuid_phys )

__fdt_set_hdr ( size_dt_strings )

__fdt_set_hdr ( size_dt_struct )

int fdt_add_mem_rsv	(	void *	fdt,
		uint64_t	address,
		uint64_t	size
	)

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_add_reservemap_entry	(	void *	fdt,
		uint64_t	addr,
		uint64_t	size
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_add_subnode	(	void *	fdt,
		int	parentoffset,
		const char *	name
	)

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

int fdt_add_subnode_namelen	(	void *	fdt,
		int	parentoffset,
		const char *	name,
		int	namelen
	)

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

int fdt_address_cells	(	const void *	fdt,
		int	nodeoffset
	)

fdt_address_cells - retrieve address size for a bus represented in the tree : pointer to the device tree blob : offset of the node to find the address size for

When the node has a valid #address-cells property, returns its value.

returns: 0 <= n < FDT_MAX_NCELLS, on success 2, if the node has no #address-cells property -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #address-cells property -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_appendprop	(	void *	fdt,
		int	nodeoffset,
		const char *	name,
		const void *	val,
		int	len
	)

int fdt_begin_node	(	void *	fdt,
		const char *	name
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_check_header ( const void * fdt )

fdt_check_header - sanity check a device tree or possible device tree : pointer to data which might be a flattened device tree

fdt_check_header() checks that the given buffer contains what appears to be a flattened device tree with sane information in its header.

returns: 0, if the buffer appears to contain a valid device tree -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, standard meanings, as above

int fdt_create	(	void *	buf,
		int	bufsize
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_create_empty_tree	(	void *	buf,
		int	bufsize
	)

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_del_mem_rsv	(	void *	fdt,
		int	n
	)

fdt_del_mem_rsv - remove a memory reserve map entry : pointer to the device tree blob
: entry to remove

fdt_del_mem_rsv() removes the n-th memory reserve map entry from the blob.

This function will delete data from the reservation table and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there are less than n+1 reserve map entries) -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_del_node	(	void *	fdt,
		int	nodeoffset
	)

fdt_del_node - delete a node (subtree) : pointer to the device tree blob : offset of the node to nop

fdt_del_node() will remove the given node, including all its subnodes if any, from the blob.

This function will delete data from the blob, and will therefore change the offsets of some existing nodes.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADLAYOUT, -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_delprop	(	void *	fdt,
		int	nodeoffset,
		const char *	name
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_end_node ( void * fdt )

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_finish ( void * fdt )

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_finish_reservemap ( void * fdt )

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_first_property_offset	(	const void *	fdt,
		int	nodeoffset
	)

fdt_first_property_offset - find the offset of a node's first property : pointer to the device tree blob : structure block offset of a node

fdt_first_property_offset() finds the first property of the node at the given structure block offset.

returns: structure block offset of the property (>=0), on success -FDT_ERR_NOTFOUND, if the requested node has no properties -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings.

int fdt_first_subnode	(	const void *	fdt,
		int	offset
	)

fdt_first_subnode() - get offset of first direct subnode

: FDT blob : Offset of node to check

Returns: offset of first subnode, or -FDT_ERR_NOTFOUND if there is none

const char* fdt_get_alias	(	const void *	fdt,
		const char *	name
	)

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

const char* fdt_get_alias_namelen	(	const void *	fdt,
		const char *	name,
		int	namelen
	)

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

uint32_t fdt_get_max_phandle ( const void * fdt )

fdt_get_max_phandle - retrieves the highest phandle in a tree : pointer to the device tree blob

fdt_get_max_phandle retrieves the highest phandle in the given device tree. This will ignore badly formatted phandles, or phandles with a value of 0 or -1.

returns: the highest phandle on success 0, if no phandle was found in the device tree -1, if an error occurred

int fdt_get_mem_rsv	(	const void *	fdt,
		int	n,
		uint64_t *	address,
		uint64_t *	size
	)

fdt_get_mem_rsv - retrieve one memory reserve map entry : pointer to the device tree blob , : pointers to 64-bit variables

On success, *address and *size will contain the address and size of the n-th reserve map entry from the device tree blob, in native-endian format.

returns: 0, on success -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, standard meanings

const char* fdt_get_name	(	const void *	fdt,
		int	nodeoffset,
		int *	lenp
	)

fdt_get_name - retrieve the name of a given node : pointer to the device tree blob : structure block offset of the starting node : pointer to an integer variable (will be overwritten) or NULL

fdt_get_name() retrieves the name (including unit address) of the device tree node at structure block offset nodeoffset. If lenp is non-NULL, the length of this name is also returned, in the integer pointed to by lenp.

returns: pointer to the node's name, on success If lenp is non-NULL, *lenp contains the length of that name (>=0) NULL, on error if lenp is non-NULL *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, standard meanings

int fdt_get_path	(	const void *	fdt,
		int	nodeoffset,
		char *	buf,
		int	buflen
	)

fdt_get_path - determine the full path of a node : pointer to the device tree blob : offset of the node whose path to find : character buffer to contain the returned path (will be overwritten) : size of the character buffer at buf

fdt_get_path() computes the full path of the node at offset nodeoffset, and records that path in the buffer at buf.

NOTE: This function is expensive, as it must scan the device tree structure from the start to nodeoffset.

returns: 0, on success buf contains the absolute path of the node at nodeoffset, as a NUL-terminated string. -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1) characters and will not fit in the given buffer. -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

uint32_t fdt_get_phandle	(	const void *	fdt,
		int	nodeoffset
	)

fdt_get_phandle - retrieve the phandle of a given node : pointer to the device tree blob : structure block offset of the node

fdt_get_phandle() retrieves the phandle of the device tree node at structure block offset nodeoffset.

returns: the phandle of the node at nodeoffset, on success (!= 0, != -1) 0, if the node has no phandle, or another error occurs

const struct fdt_property* fdt_get_property	(	const void *	fdt,
		int	nodeoffset,
		const char *	name,
		int *	lenp
	)

fdt_getprop_by_offset - retrieve the value of a property at a given offset : pointer to the device tree blob : offset of the property to read : pointer to a string variable (will be overwritten) or NULL : pointer to an integer variable (will be overwritten) or NULL

fdt_getprop_by_offset() retrieves a pointer to the value of the property at structure block offset 'offset' (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. If namep is non-NULL, the property's namne will also be returned in the char * pointed to by namep (this will be a pointer to within the device tree's string block, not a new copy of the name).

returns: pointer to the property's value if lenp is non-NULL, *lenp contains the length of the property value (>=0) if namep is non-NULL *namep contiains a pointer to the property name. NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const struct fdt_property* fdt_get_property_by_offset	(	const void *	fdt,
		int	offset,
		int *	lenp
	)

fdt_get_property_by_offset - retrieve the property at a given offset : pointer to the device tree blob : offset of the property to retrieve : pointer to an integer variable (will be overwritten) or NULL

fdt_get_property_by_offset() retrieves a pointer to the fdt_property structure within the device tree blob at the given offset. If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp.

returns: pointer to the structure representing the property if lenp is non-NULL, *lenp contains the length of the property value (>=0) NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const struct fdt_property* fdt_get_property_namelen	(	const void *	fdt,
		int	nodeoffset,
		const char *	name,
		int	namelen,
		int *	lenp
	)

fdt_getprop_by_offset - retrieve the value of a property at a given offset : pointer to the device tree blob : offset of the property to read : pointer to a string variable (will be overwritten) or NULL : pointer to an integer variable (will be overwritten) or NULL

fdt_getprop_by_offset() retrieves a pointer to the value of the property at structure block offset 'offset' (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. If namep is non-NULL, the property's namne will also be returned in the char * pointed to by namep (this will be a pointer to within the device tree's string block, not a new copy of the name).

returns: pointer to the property's value if lenp is non-NULL, *lenp contains the length of the property value (>=0) if namep is non-NULL *namep contiains a pointer to the property name. NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const void* fdt_getprop	(	const void *	fdt,
		int	nodeoffset,
		const char *	name,
		int *	lenp
	)

fdt_getprop_by_offset - retrieve the value of a property at a given offset : pointer to the device tree blob : offset of the property to read : pointer to a string variable (will be overwritten) or NULL : pointer to an integer variable (will be overwritten) or NULL

fdt_getprop_by_offset() retrieves a pointer to the value of the property at structure block offset 'offset' (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. If namep is non-NULL, the property's namne will also be returned in the char * pointed to by namep (this will be a pointer to within the device tree's string block, not a new copy of the name).

returns: pointer to the property's value if lenp is non-NULL, *lenp contains the length of the property value (>=0) if namep is non-NULL *namep contiains a pointer to the property name. NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const void* fdt_getprop_by_offset	(	const void *	fdt,
		int	offset,
		const char **	namep,
		int *	lenp
	)

fdt_getprop_by_offset - retrieve the value of a property at a given offset : pointer to the device tree blob : offset of the property to read : pointer to a string variable (will be overwritten) or NULL : pointer to an integer variable (will be overwritten) or NULL

fdt_getprop_by_offset() retrieves a pointer to the value of the property at structure block offset 'offset' (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. If namep is non-NULL, the property's namne will also be returned in the char * pointed to by namep (this will be a pointer to within the device tree's string block, not a new copy of the name).

returns: pointer to the property's value if lenp is non-NULL, *lenp contains the length of the property value (>=0) if namep is non-NULL *namep contiains a pointer to the property name. NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const void* fdt_getprop_namelen	(	const void *	fdt,
		int	nodeoffset,
		const char *	name,
		int	namelen,
		int *	lenp
	)

fdt_getprop_by_offset - retrieve the value of a property at a given offset : pointer to the device tree blob : offset of the property to read : pointer to a string variable (will be overwritten) or NULL : pointer to an integer variable (will be overwritten) or NULL

fdt_getprop_by_offset() retrieves a pointer to the value of the property at structure block offset 'offset' (this will be a pointer to within the device blob itself, not a copy of the value). If lenp is non-NULL, the length of the property value is also returned, in the integer pointed to by lenp. If namep is non-NULL, the property's namne will also be returned in the char * pointed to by namep (this will be a pointer to within the device tree's string block, not a new copy of the name).

returns: pointer to the property's value if lenp is non-NULL, *lenp contains the length of the property value (>=0) if namep is non-NULL *namep contiains a pointer to the property name. NULL, on error if lenp is non-NULL, *lenp contains an error code (<0): -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_move	(	const void *	fdt,
		void *	buf,
		int	bufsize
	)

fdt_move - move a device tree around in memory : pointer to the device tree to move : pointer to memory where the device is to be moved : size of the memory space at buf

fdt_move() relocates, if possible, the device tree blob located at fdt to the buffer at buf of size bufsize. The buffer may overlap with the existing device tree blob at fdt. Therefore, fdt_move(fdt, fdt, fdt_totalsize(fdt)) should always succeed.

returns: 0, on success -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, standard meanings

int fdt_next_node	(	const void *	fdt,
		int	offset,
		int *	depth
	)

int fdt_next_property_offset	(	const void *	fdt,
		int	offset
	)

fdt_next_property_offset - step through a node's properties : pointer to the device tree blob : structure block offset of a property

fdt_next_property_offset() finds the property immediately after the one at the given structure block offset. This will be a property of the same node as the given property.

returns: structure block offset of the next property (>=0), on success -FDT_ERR_NOTFOUND, if the given property is the last in its node -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings.

int fdt_next_subnode	(	const void *	fdt,
		int	offset
	)

fdt_next_subnode() - get offset of next direct subnode

After first calling fdt_first_subnode(), call this function repeatedly to get direct subnodes of a parent node.

: FDT blob : Offset of previous subnode

Returns: offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more subnodes

uint32_t fdt_next_tag	(	const void *	fdt,
		int	offset,
		int *	nextoffset
	)

int fdt_node_check_compatible	(	const void *	fdt,
		int	nodeoffset,
		const char *	compatible
	)

fdt_node_check_compatible: check a node's compatible property : pointer to the device tree blob : offset of a tree node : string to match against

fdt_node_check_compatible() returns 0 if the given node contains a 'compatible' property with the given string as one of its elements, it returns non-zero otherwise, or on error.

returns: 0, if the node has a 'compatible' property listing the given string 1, if the node has a 'compatible' property, but it does not list the given string -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_node_depth	(	const void *	fdt,
		int	nodeoffset
	)

fdt_node_depth - find the depth of a given node : pointer to the device tree blob : offset of the node whose parent to find

fdt_node_depth() finds the depth of a given node. The root node has depth 0, its immediate subnodes depth 1 and so forth.

NOTE: This function is expensive, as it must scan the device tree structure from the start to nodeoffset.

returns: depth of the node at nodeoffset (>=0), on success -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_node_offset_by_compatible	(	const void *	fdt,
		int	startoffset,
		const char *	compatible
	)

fdt_node_offset_by_compatible - find nodes with a given 'compatible' value : pointer to the device tree blob : only find nodes after this offset : 'compatible' string to match against

fdt_node_offset_by_compatible() returns the offset of the first node after startoffset, which has a 'compatible' property which lists the given compatible string; or if startoffset is -1, the very first such node in the tree.

To iterate through all nodes matching the criterion, the following idiom can be used: offset = fdt_node_offset_by_compatible(fdt, -1, compatible); while (offset != -FDT_ERR_NOTFOUND) { // other code here offset = fdt_node_offset_by_compatible(fdt, offset, compatible); }

Note the -1 in the first call to the function, if 0 is used here instead, the function will never locate the root node, even if it matches the criterion.

returns: structure block offset of the located node (>= 0, >startoffset), on success -FDT_ERR_NOTFOUND, no node matching the criterion exists in the tree after startoffset -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_node_offset_by_phandle	(	const void *	fdt,
		uint32_t	phandle
	)

fdt_node_offset_by_phandle - find the node with a given phandle : pointer to the device tree blob : phandle value

fdt_node_offset_by_phandle() returns the offset of the node which has the given phandle value. If there is more than one node in the tree with the given phandle (an invalid tree), results are undefined.

returns: structure block offset of the located node (>= 0), on success -FDT_ERR_NOTFOUND, no node with that phandle exists -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1) -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_node_offset_by_prop_value	(	const void *	fdt,
		int	startoffset,
		const char *	propname,
		const void *	propval,
		int	proplen
	)

fdt_node_offset_by_prop_value - find nodes with a given property value : pointer to the device tree blob : only find nodes after this offset : property name to check : property value to search for : length of the value in propval

fdt_node_offset_by_prop_value() returns the offset of the first node after startoffset, which has a property named propname whose value is of length proplen and has value equal to propval; or if startoffset is -1, the very first such node in the tree.

To iterate through all nodes matching the criterion, the following idiom can be used: offset = fdt_node_offset_by_prop_value(fdt, -1, propname, propval, proplen); while (offset != -FDT_ERR_NOTFOUND) { // other code here offset = fdt_node_offset_by_prop_value(fdt, offset, propname, propval, proplen); }

Note the -1 in the first call to the function, if 0 is used here instead, the function will never locate the root node, even if it matches the criterion.

returns: structure block offset of the located node (>= 0, >startoffset), on success -FDT_ERR_NOTFOUND, no node matching the criterion exists in the tree after startoffset -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_nop_node	(	void *	fdt,
		int	nodeoffset
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_nop_property	(	void *	fdt,
		int	nodeoffset,
		const char *	name
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_num_mem_rsv ( const void * fdt )

fdt_num_mem_rsv - retrieve the number of memory reserve map entries : pointer to the device tree blob

Returns the number of entries in the device tree blob's memory reservation map. This does not include the terminating 0,0 entry or any other (0,0) entries reserved for expansion.

returns: the number of entries

const void* fdt_offset_ptr	(	const void *	fdt,
		int	offset,
		unsigned int	checklen
	)

int fdt_open_into	(	const void *	fdt,
		void *	buf,
		int	bufsize
	)

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_overlay_apply	(	void *	fdt,
		void *	fdto
	)

fdt_overlay_apply - Applies a DT overlay on a base DT : pointer to the base device tree blob : pointer to the device tree overlay blob

fdt_overlay_apply() will apply the given device tree overlay on the given base device tree.

Expect the base device tree to be modified, even if the function returns an error.

returns: 0, on success -FDT_ERR_NOSPACE, there's not enough space in the base device tree -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or properties in the base DT -FDT_ERR_BADPHANDLE, -FDT_ERR_BADOVERLAY, -FDT_ERR_NOPHANDLES, -FDT_ERR_INTERNAL, -FDT_ERR_BADLAYOUT, -FDT_ERR_BADMAGIC, -FDT_ERR_BADOFFSET, -FDT_ERR_BADPATH, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADSTATE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_pack ( void * fdt )

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_parent_offset	(	const void *	fdt,
		int	nodeoffset
	)

fdt_parent_offset - find the parent of a given node : pointer to the device tree blob : offset of the node whose parent to find

fdt_parent_offset() locates the parent node of a given node (that is, it finds the offset of the node which contains the node at nodeoffset as a subnode).

NOTE: This function is expensive, as it must scan the device tree structure from the start to nodeoffset, twice.

returns: structure block offset of the parent of the node at nodeoffset (>=0), on success -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

int fdt_path_offset	(	const void *	fdt,
		const char *	path
	)

fdt_path_offset - find a tree node by its full path : pointer to the device tree blob : full path of the node to locate

fdt_path_offset() finds a node of a given path in the device tree. Each path component may omit the unit address portion, but the results of this are undefined if any such path component is ambiguous (that is if there are multiple nodes at the relevant level matching the given component, differentiated only by unit address).

returns: structure block offset of the node with the requested path (>=0), on success -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid -FDT_ERR_NOTFOUND, if the requested node does not exist -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings.

int fdt_path_offset_namelen	(	const void *	fdt,
		const char *	path,
		int	namelen
	)

fdt_path_offset_namelen - find a tree node by its full path : pointer to the device tree blob : full path of the node to locate : number of characters of path to consider

Identical to fdt_path_offset(), but only consider the first namelen characters of path as the path name.

int fdt_property	(	void *	fdt,
		const char *	name,
		const void *	val,
		int	len
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_property_placeholder	(	void *	fdt,
		const char *	name,
		int	len,
		void **	valp
	)

fdt_add_mem_rsv - add one memory reserve map entry : pointer to the device tree blob , : 64-bit values (native endian)

Adds a reserve map entry to the given blob reserving a region at address address of length size.

This function will insert data into the reserve map and will therefore change the indexes of some entries in the table.

returns: 0, on success -FDT_ERR_NOSPACE, there is insufficient free space in the blob to contain the new reservation entry -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_BADLAYOUT, -FDT_ERR_TRUNCATED, standard meanings

int fdt_resize	(	void *	fdt,
		void *	buf,
		int	bufsize
	)

fdt_nop_node - replace a node (subtree) with nop tags : pointer to the device tree blob : offset of the node to nop

fdt_nop_node() will replace a given node's representation in the blob, including all its subnodes, if any, with FDT_NOP tags, effectively removing it from the tree.

This function will alter only the bytes in the blob which contain the node and its properties and subnodes, and will not alter or move any other part of the tree.

returns: 0, on success -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

int fdt_set_name	(	void *	fdt,
		int	nodeoffset,
		const char *	name
	)

int fdt_setprop	(	void *	fdt,
		int	nodeoffset,
		const char *	name,
		const void *	val,
		int	len
	)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

int fdt_setprop_inplace	(	void *	fdt,
		int	nodeoffset,
		const char *	name,
		const void *	val,
		int	len
	)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

int fdt_setprop_inplace_namelen_partial	(	void *	fdt,
		int	nodeoffset,
		const char *	name,
		int	namelen,
		uint32_t	idx,
		const void *	val,
		int	len
	)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

int fdt_setprop_placeholder	(	void *	fdt,
		int	nodeoffset,
		const char *	name,
		int	len,
		void **	prop_data
	)

fdt_setprop_inplace_cell - change the value of a single-cell property

This is an alternative name for fdt_setprop_inplace_u32()

int fdt_size_cells	(	const void *	fdt,
		int	nodeoffset
	)

fdt_size_cells - retrieve address range size for a bus represented in the tree : pointer to the device tree blob : offset of the node to find the address range size for

When the node has a valid #size-cells property, returns its value.

returns: 0 <= n < FDT_MAX_NCELLS, on success 2, if the node has no #address-cells property -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid #size-cells property -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings

const char* fdt_strerror ( int errval )

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

const char* fdt_string	(	const void *	fdt,
		int	stroffset
	)

fdt_string - retrieve a string from the strings block of a device tree : pointer to the device tree blob : offset of the string within the strings block (native endian)

fdt_string() retrieves a pointer to a single string from the strings block of the device tree blob at fdt.

returns: a pointer to the string, on success NULL, if stroffset is out of bounds

int fdt_stringlist_contains	(	const char *	strlist,
		int	listlen,
		const char *	str
	)

fdt_stringlist_contains - check a string list property for a string : Property containing a list of strings to check : Length of property : String to search for

This is a utility function provided for convenience. The list contains one or more strings, each terminated by \0, as is found in a device tree "compatible" property.

Returns: : 1 if the string is found in the list, 0 not found, or invalid list

int fdt_stringlist_count	(	const void *	fdt,
		int	nodeoffset,
		const char *	property
	)

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

const char* fdt_stringlist_get	(	const void *	fdt,
		int	nodeoffset,
		const char *	property,
		int	index,
		int *	lenp
	)

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

int fdt_stringlist_search	(	const void *	fdt,
		int	nodeoffset,
		const char *	property,
		const char *	string
	)

FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells

This is the maximum value for #address-cells, #size-cells and similar properties that will be processed by libfdt. IEE1275 requires that OF implementations handle values up to 4. Implementations may support larger values, but in practice higher values aren't used.

int fdt_subnode_offset	(	const void *	fdt,
		int	parentoffset,
		const char *	name
	)

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

int fdt_subnode_offset_namelen	(	const void *	fdt,
		int	parentoffset,
		const char *	name,
		int	namelen
	)

fdt_for_each_property_offset - iterate over all properties of a node

: property offset (int, lvalue) : FDT blob (const void *) : node offset (int)

This is actually a wrapper around a for loop and would be used like so:

fdt_for_each_property_offset(property, fdt, node) { Use property ... }

if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) { Error handling }

Note that this is implemented as a macro and property is used as iterator in the loop. The node variable can be constant or even a literal.

int fdt_supernode_atdepth_offset	(	const void *	fdt,
		int	nodeoffset,
		int	supernodedepth,
		int *	nodedepth
	)

fdt_supernode_atdepth_offset - find a specific ancestor of a node : pointer to the device tree blob : offset of the node whose parent to find : depth of the ancestor to find : pointer to an integer variable (will be overwritten) or NULL

fdt_supernode_atdepth_offset() finds an ancestor of the given node at a specific depth from the root (where the root itself has depth 0, its immediate subnodes depth 1 and so forth). So fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL); will always return 0, the offset of the root node. If the node at nodeoffset has depth D, then: fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL); will return nodeoffset itself.

NOTE: This function is expensive, as it must scan the device tree structure from the start to nodeoffset.

returns: structure block offset of the node at node offset's ancestor of depth supernodedepth (>=0), on success -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, standard meanings

Macros

Functions

: name of the subnode to locate

: name of the alias th look up

: name of the property to change

: name of property to add

Macro Definition Documentation

Function Documentation