diff options
Diffstat (limited to 'lib/libfdt')
| -rw-r--r-- | lib/libfdt/fdt.h | 67 | ||||
| -rw-r--r-- | lib/libfdt/libfdt.h | 2144 |
2 files changed, 2211 insertions, 0 deletions
diff --git a/lib/libfdt/fdt.h b/lib/libfdt/fdt.h new file mode 100644 index 0000000000..3134d78332 --- /dev/null +++ b/lib/libfdt/fdt.h @@ -0,0 +1,67 @@ +#ifndef _FDT_H +#define _FDT_H +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + * Copyright 2012 Kim Phillips, Freescale Semiconductor. + * + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + */ + +#ifndef __ASSEMBLY__ + +struct fdt_header { + fdt32_t magic; /* magic word FDT_MAGIC */ + fdt32_t totalsize; /* total size of DT block */ + fdt32_t off_dt_struct; /* offset to structure */ + fdt32_t off_dt_strings; /* offset to strings */ + fdt32_t off_mem_rsvmap; /* offset to memory reserve map */ + fdt32_t version; /* format version */ + fdt32_t last_comp_version; /* last compatible version */ + + /* version 2 fields below */ + fdt32_t boot_cpuid_phys; /* Which physical CPU id we're + booting on */ + /* version 3 fields below */ + fdt32_t size_dt_strings; /* size of the strings block */ + + /* version 17 fields below */ + fdt32_t size_dt_struct; /* size of the structure block */ +}; + +struct fdt_reserve_entry { + fdt64_t address; + fdt64_t size; +}; + +struct fdt_node_header { + fdt32_t tag; + char name[0]; +}; + +struct fdt_property { + fdt32_t tag; + fdt32_t len; + fdt32_t nameoff; + char data[0]; +}; + +#endif /* !__ASSEMBLY */ + +#define FDT_MAGIC 0xd00dfeed /* 4: version, 4: total size */ +#define FDT_TAGSIZE sizeof(fdt32_t) + +#define FDT_BEGIN_NODE 0x1 /* Start node: full name */ +#define FDT_END_NODE 0x2 /* End node */ +#define FDT_PROP 0x3 /* Property: name off, + size, content */ +#define FDT_NOP 0x4 /* nop */ +#define FDT_END 0x9 + +#define FDT_V1_SIZE (7*sizeof(fdt32_t)) +#define FDT_V2_SIZE (FDT_V1_SIZE + sizeof(fdt32_t)) +#define FDT_V3_SIZE (FDT_V2_SIZE + sizeof(fdt32_t)) +#define FDT_V16_SIZE FDT_V3_SIZE +#define FDT_V17_SIZE (FDT_V16_SIZE + sizeof(fdt32_t)) + +#endif /* _FDT_H */ diff --git a/lib/libfdt/libfdt.h b/lib/libfdt/libfdt.h new file mode 100644 index 0000000000..2f7ebf8e06 --- /dev/null +++ b/lib/libfdt/libfdt.h @@ -0,0 +1,2144 @@ +#ifndef _LIBFDT_H +#define _LIBFDT_H +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + * + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + */ + +#include <libfdt_env.h> +#include <fdt.h> + +#define FDT_FIRST_SUPPORTED_VERSION 0x10 +#define FDT_LAST_SUPPORTED_VERSION 0x11 + +/* Error codes: informative error codes */ +#define FDT_ERR_NOTFOUND 1 + /* FDT_ERR_NOTFOUND: The requested node or property does not exist */ +#define FDT_ERR_EXISTS 2 + /* FDT_ERR_EXISTS: Attempted to create a node or property which + * already exists */ +#define FDT_ERR_NOSPACE 3 + /* FDT_ERR_NOSPACE: Operation needed to expand the device + * tree, but its buffer did not have sufficient space to + * contain the expanded tree. Use fdt_open_into() to move the + * device tree to a buffer with more space. */ + +/* Error codes: codes for bad parameters */ +#define FDT_ERR_BADOFFSET 4 + /* FDT_ERR_BADOFFSET: Function was passed a structure block + * offset which is out-of-bounds, or which points to an + * unsuitable part of the structure for the operation. */ +#define FDT_ERR_BADPATH 5 + /* FDT_ERR_BADPATH: Function was passed a badly formatted path + * (e.g. missing a leading / for a function which requires an + * absolute path) */ +#define FDT_ERR_BADPHANDLE 6 + /* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle. + * This can be caused either by an invalid phandle property + * length, or the phandle value was either 0 or -1, which are + * not permitted. */ +#define FDT_ERR_BADSTATE 7 + /* FDT_ERR_BADSTATE: Function was passed an incomplete device + * tree created by the sequential-write functions, which is + * not sufficiently complete for the requested operation. */ + +/* Error codes: codes for bad device tree blobs */ +#define FDT_ERR_TRUNCATED 8 + /* FDT_ERR_TRUNCATED: Structure block of the given device tree + * ends without an FDT_END tag. */ +#define FDT_ERR_BADMAGIC 9 + /* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a + * device tree at all - it is missing the flattened device + * tree magic number. */ +#define FDT_ERR_BADVERSION 10 + /* FDT_ERR_BADVERSION: Given device tree has a version which + * can't be handled by the requested operation. For + * read-write functions, this may mean that fdt_open_into() is + * required to convert the tree to the expected version. */ +#define FDT_ERR_BADSTRUCTURE 11 + /* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt + * structure block or other serious error (e.g. misnested + * nodes, or subnodes preceding properties). */ +#define FDT_ERR_BADLAYOUT 12 + /* FDT_ERR_BADLAYOUT: For read-write functions, the given + * device tree has it's sub-blocks in an order that the + * function can't handle (memory reserve map, then structure, + * then strings). Use fdt_open_into() to reorganize the tree + * into a form suitable for the read-write operations. */ + +/* "Can't happen" error indicating a bug in libfdt */ +#define FDT_ERR_INTERNAL 13 + /* FDT_ERR_INTERNAL: libfdt has failed an internal assertion. + * Should never be returned, if it is, it indicates a bug in + * libfdt itself. */ + +/* Errors in device tree content */ +#define FDT_ERR_BADNCELLS 14 + /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells + * or similar property with a bad format or value */ + +#define FDT_ERR_BADVALUE 15 + /* FDT_ERR_BADVALUE: Device tree has a property with an unexpected + * value. For example: a property expected to contain a string list + * is not NUL-terminated within the length of its value. */ + +#define FDT_ERR_BADOVERLAY 16 + /* FDT_ERR_BADOVERLAY: The device tree overlay, while + * correctly structured, cannot be applied due to some + * unexpected or missing value, property or node. */ + +#define FDT_ERR_NOPHANDLES 17 + /* FDT_ERR_NOPHANDLES: The device tree doesn't have any + * phandle available anymore without causing an overflow */ + +#define FDT_ERR_TOODEEP 18 + /* FDT_ERR_TOODEEP: The depth of a node has exceeded the internal + * libfdt limit. This can happen if you have more than + * FDT_MAX_DEPTH nested nodes. */ + +#define FDT_ERR_MAX 18 + +/**********************************************************************/ +/* Low-level functions (you probably don't need these) */ +/**********************************************************************/ + +#ifndef SWIG /* This function is not useful in Python */ +const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen); +#endif +static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen) +{ + return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen); +} + +uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset); + +/**********************************************************************/ +/* Traversal functions */ +/**********************************************************************/ + +int fdt_next_node(const void *fdt, int offset, int *depth); + +/** + * fdt_first_subnode() - get offset of first direct subnode + * + * @fdt: FDT blob + * @offset: Offset of node to check + * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none + */ +int fdt_first_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: FDT blob + * @offset: Offset of previous subnode + * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more + * subnodes + */ +int fdt_next_subnode(const void *fdt, int offset); + +/** + * fdt_for_each_subnode - iterate over all subnodes of a parent + * + * @node: child node (int, lvalue) + * @fdt: FDT blob (const void *) + * @parent: 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 @node is used as + * iterator in the loop. The parent variable be constant or even a + * literal. + * + */ +#define fdt_for_each_subnode(node, fdt, parent) \ + for (node = fdt_first_subnode(fdt, parent); \ + node >= 0; \ + node = fdt_next_subnode(fdt, node)) + +/**********************************************************************/ +/* General functions */ +/**********************************************************************/ +#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) \ + 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); \ + } +__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); +#undef __fdt_set_hdr + +/** + * fdt_check_header - sanity check a device tree or possible device tree + * @fdt: 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_check_header(const void *fdt); + +/** + * fdt_move - move a device tree around in memory + * @fdt: pointer to the device tree to move + * @buf: pointer to memory where the device is to be moved + * @bufsize: 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_move(const void *fdt, void *buf, int bufsize); + +/**********************************************************************/ +/* Read-only functions */ +/**********************************************************************/ + +/** + * fdt_string - retrieve a string from the strings block of a device tree + * @fdt: pointer to the device tree blob + * @stroffset: 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 + */ +const char *fdt_string(const void *fdt, int stroffset); + +/** + * fdt_get_max_phandle - retrieves the highest phandle in a tree + * @fdt: 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 + */ +uint32_t fdt_get_max_phandle(const void *fdt); + +/** + * fdt_num_mem_rsv - retrieve the number of memory reserve map entries + * @fdt: 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 + */ +int fdt_num_mem_rsv(const void *fdt); + +/** + * fdt_get_mem_rsv - retrieve one memory reserve map entry + * @fdt: pointer to the device tree blob + * @address, @size: 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 + */ +int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size); + +/** + * fdt_subnode_offset_namelen - find a subnode based on substring + * @fdt: pointer to the device tree blob + * @parentoffset: structure block offset of a node + * @name: name of the subnode to locate + * @namelen: number of characters of name to consider + * + * Identical to fdt_subnode_offset(), but only examine the first + * namelen characters of name for matching the subnode name. This is + * useful for finding subnodes based on a portion of a larger string, + * such as a full path. + */ +#ifndef SWIG /* Not available in Python */ +int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, + const char *name, int namelen); +#endif +/** + * fdt_subnode_offset - find a subnode of a given node + * @fdt: pointer to the device tree blob + * @parentoffset: structure block offset of a node + * @name: name of the subnode to locate + * + * fdt_subnode_offset() finds a subnode of the node at structure block + * offset parentoffset with the given name. name may include a unit + * address, in which case fdt_subnode_offset() will find the subnode + * with that unit address, or the unit address may be omitted, in + * which case fdt_subnode_offset() will find an arbitrary subnode + * whose name excluding unit address matches the given name. + * + * returns: + * structure block offset of the requested 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_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_TRUNCATED, standard meanings. + */ +int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name); + +/** + * fdt_path_offset_namelen - find a tree node by its full path + * @fdt: pointer to the device tree blob + * @path: full path of the node to locate + * @namelen: 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. + */ +#ifndef SWIG /* Not available in Python */ +int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen); +#endif + +/** + * fdt_path_offset - find a tree node by its full path + * @fdt: pointer to the device tree blob + * @path: 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(const void *fdt, const char *path); + +/** + * fdt_get_name - retrieve the name of a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: structure block offset of the starting node + * @lenp: 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 + */ +const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp); + +/** + * fdt_first_property_offset - find the offset of a node's first property + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_property_offset(const void *fdt, int nodeoffset); + +/** + * fdt_next_property_offset - step through a node's properties + * @fdt: pointer to the device tree blob + * @offset: 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_property_offset(const void *fdt, int offset); + +/** + * fdt_for_each_property_offset - iterate over all properties of a node + * + * @property_offset: property offset (int, lvalue) + * @fdt: FDT blob (const void *) + * @node: 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_property_offset(property, fdt, node) \ + for (property = fdt_first_property_offset(fdt, node); \ + property >= 0; \ + property = fdt_next_property_offset(fdt, property)) + +/** + * fdt_get_property_by_offset - retrieve the property at a given offset + * @fdt: pointer to the device tree blob + * @offset: offset of the property to retrieve + * @lenp: 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_by_offset(const void *fdt, + int offset, + int *lenp); + +/** + * fdt_get_property_namelen - find a property based on substring + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to find + * @name: name of the property to find + * @namelen: number of characters of name to consider + * @lenp: pointer to an integer variable (will be overwritten) or NULL + * + * Identical to fdt_get_property(), but only examine the first namelen + * characters of name for matching the property name. + */ +#ifndef SWIG /* Not available in Python */ +const struct fdt_property *fdt_get_property_namelen(const void *fdt, + int nodeoffset, + const char *name, + int namelen, int *lenp); +#endif + +/** + * fdt_get_property - find a given property in a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to find + * @name: name of the property to find + * @lenp: pointer to an integer variable (will be overwritten) or NULL + * + * fdt_get_property() retrieves a pointer to the fdt_property + * structure within the device tree blob corresponding to the property + * named 'name' of the node at offset nodeoffset. 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_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(const void *fdt, int nodeoffset, + const char *name, int *lenp); +static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset, + const char *name, + int *lenp) +{ + return (struct fdt_property *)(uintptr_t) + fdt_get_property(fdt, nodeoffset, name, lenp); +} + +/** + * fdt_getprop_by_offset - retrieve the value of a property at a given offset + * @fdt: pointer to the device tree blob + * @ffset: offset of the property to read + * @namep: pointer to a string variable (will be overwritten) or NULL + * @lenp: 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 + */ +#ifndef SWIG /* This function is not useful in Python */ +const void *fdt_getprop_by_offset(const void *fdt, int offset, + const char **namep, int *lenp); +#endif + +/** + * fdt_getprop_namelen - get property value based on substring + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to find + * @name: name of the property to find + * @namelen: number of characters of name to consider + * @lenp: pointer to an integer variable (will be overwritten) or NULL + * + * Identical to fdt_getprop(), but only examine the first namelen + * characters of name for matching the property name. + */ +#ifndef SWIG /* Not available in Python */ +const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, + const char *name, int namelen, int *lenp); +static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset, + const char *name, int namelen, + int *lenp) +{ + return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name, + namelen, lenp); +} +#endif + +/** + * fdt_getprop - retrieve the value of a given property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to find + * @name: name of the property to find + * @lenp: 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 void *fdt_getprop(const void *fdt, int nodeoffset, + const char *name, int *lenp); +static inline void *fdt_getprop_w(void *fdt, int nodeoffset, + const char *name, int *lenp) +{ + return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp); +} + +/** + * fdt_get_phandle - retrieve the phandle of a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: 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 + */ +uint32_t fdt_get_phandle(const void *fdt, int nodeoffset); + +/** + * fdt_get_alias_namelen - get alias based on substring + * @fdt: pointer to the device tree blob + * @name: name of the alias th look up + * @namelen: number of characters of name to consider + * + * Identical to fdt_get_alias(), but only examine the first namelen + * characters of name for matching the alias name. + */ +#ifndef SWIG /* Not available in Python */ +const char *fdt_get_alias_namelen(const void *fdt, + const char *name, int namelen); +#endif + +/** + * fdt_get_alias - retrieve the path referenced by a given alias + * @fdt: pointer to the device tree blob + * @name: name of the alias th look up + * + * 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 + */ +const char *fdt_get_alias(const void *fdt, const char *name); + +/** + * fdt_get_path - determine the full path of a node + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose path to find + * @buf: character buffer to contain the returned path (will be overwritten) + * @buflen: 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 + */ +int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen); + +/** + * fdt_supernode_atdepth_offset - find a specific ancestor of a node + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose parent to find + * @supernodedepth: depth of the ancestor to find + * @nodedepth: 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 + */ +int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset, + int supernodedepth, int *nodedepth); + +/** + * fdt_node_depth - find the depth of a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_depth(const void *fdt, int nodeoffset); + +/** + * fdt_parent_offset - find the parent of a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_parent_offset(const void *fdt, int nodeoffset); + +/** + * fdt_node_offset_by_prop_value - find nodes with a given property value + * @fdt: pointer to the device tree blob + * @startoffset: only find nodes after this offset + * @propname: property name to check + * @propval: property value to search for + * @proplen: 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_node_offset_by_prop_value(const void *fdt, int startoffset, + const char *propname, + const void *propval, int proplen); + +/** + * fdt_node_offset_by_phandle - find the node with a given phandle + * @fdt: pointer to the device tree blob + * @phandle: 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_phandle(const void *fdt, uint32_t phandle); + +/** + * fdt_node_check_compatible: check a node's compatible property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of a tree node + * @compatible: 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_check_compatible(const void *fdt, int nodeoffset, + const char *compatible); + +/** + * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value + * @fdt: pointer to the device tree blob + * @startoffset: only find nodes after this offset + * @compatible: '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_compatible(const void *fdt, int startoffset, + const char *compatible); + +/** + * fdt_stringlist_contains - check a string list property for a string + * @strlist: Property containing a list of strings to check + * @listlen: Length of property + * @str: 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. + * + * @return: 1 if the string is found in the list, 0 not found, or invalid list + */ +int fdt_stringlist_contains(const char *strlist, int listlen, const char *str); + +/** + * fdt_stringlist_count - count the number of strings in a string list + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of a tree node + * @property: name of the property containing the string list + * @return: + * the number of strings in the given property + * -FDT_ERR_BADVALUE if the property value is not NUL-terminated + * -FDT_ERR_NOTFOUND if the property does not exist + */ +int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property); + +/** + * fdt_stringlist_search - find a string in a string list and return its index + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of a tree node + * @property: name of the property containing the string list + * @string: string to look up in the string list + * + * Note that it is possible for this function to succeed on property values + * that are not NUL-terminated. That's because the function will stop after + * finding the first occurrence of @string. This can for example happen with + * small-valued cell properties, such as #address-cells, when searching for + * the empty string. + * + * @return: + * the index of the string in the list of strings + * -FDT_ERR_BADVALUE if the property value is not NUL-terminated + * -FDT_ERR_NOTFOUND if the property does not exist or does not contain + * the given string + */ +int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property, + const char *string); + +/** + * fdt_stringlist_get() - obtain the string at a given index in a string list + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of a tree node + * @property: name of the property containing the string list + * @index: index of the string to return + * @lenp: return location for the string length or an error code on failure + * + * Note that this will successfully extract strings from properties with + * non-NUL-terminated values. For example on small-valued cell properties + * this function will return the empty string. + * + * If non-NULL, the length of the string (on success) or a negative error-code + * (on failure) will be stored in the integer pointer to by lenp. + * + * @return: + * A pointer to the string at the given index in the string list or NULL on + * failure. On success the length of the string will be stored in the memory + * location pointed to by the lenp parameter, if non-NULL. On failure one of + * the following negative error codes will be returned in the lenp parameter + * (if non-NULL): + * -FDT_ERR_BADVALUE if the property value is not NUL-terminated + * -FDT_ERR_NOTFOUND if the property does not exist + */ +const char *fdt_stringlist_get(const void *fdt, int nodeoffset, + const char *property, int index, + int *lenp); + +/**********************************************************************/ +/* Read-only functions (addressing related) */ +/**********************************************************************/ + +/** + * 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_MAX_NCELLS 4 + +/** + * fdt_address_cells - retrieve address size for a bus represented in the tree + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_address_cells(const void *fdt, int nodeoffset); + +/** + * fdt_size_cells - retrieve address range size for a bus represented in the + * tree + * @fdt: pointer to the device tree blob + * @nodeoffset: 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 + */ +int fdt_size_cells(const void *fdt, int nodeoffset); + + +/**********************************************************************/ +/* Write-in-place functions */ +/**********************************************************************/ + +/** + * fdt_setprop_inplace_namelen_partial - change a property's value, + * but not its size + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @namelen: number of characters of name to consider + * @idx: index of the property to change in the array + * @val: pointer to data to replace the property value with + * @len: length of the property value + * + * Identical to fdt_setprop_inplace(), but modifies the given property + * starting from the given index, and using only the first characters + * of the name. It is useful when you want to manipulate only one value of + * an array and you have a string that doesn't end with \0. + */ +#ifndef SWIG /* Not available in Python */ +int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset, + const char *name, int namelen, + uint32_t idx, const void *val, + int len); +#endif + +/** + * fdt_setprop_inplace - change a property's value, but not its size + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: pointer to data to replace the property value with + * @len: length of the property value + * + * fdt_setprop_inplace() replaces the value of a given property with + * the data in val, of length len. This function cannot change the + * size of a property, and so will only work if len is equal to the + * current length of the property. + * + * This function will alter only the bytes in the blob which contain + * the given property value, and will not alter or move any other part + * of the tree. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, if len is not equal to the property's current length + * -FDT_ERR_NOTFOUND, node does not have the 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 + */ +#ifndef SWIG /* Not available in Python */ +int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, + const void *val, int len); +#endif + +/** + * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 32-bit integer value to replace the property with + * + * fdt_setprop_inplace_u32() replaces the value of a given property + * with the 32-bit integer value in val, converting val to big-endian + * if necessary. This function cannot change the size of a property, + * and so will only work if the property already exists and has length + * 4. + * + * This function will alter only the bytes in the blob which contain + * the given property value, and will not alter or move any other part + * of the tree. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, if the property's length is not equal to 4 + * -FDT_ERR_NOTFOUND, node does not have the 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 + */ +static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset, + const char *name, uint32_t val) +{ + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 64-bit integer value to replace the property with + * + * fdt_setprop_inplace_u64() replaces the value of a given property + * with the 64-bit integer value in val, converting val to big-endian + * if necessary. This function cannot change the size of a property, + * and so will only work if the property already exists and has length + * 8. + * + * This function will alter only the bytes in the blob which contain + * the given property value, and will not alter or move any other part + * of the tree. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, if the property's length is not equal to 8 + * -FDT_ERR_NOTFOUND, node does not have the 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 + */ +static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset, + const char *name, uint64_t val) +{ + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_setprop_inplace_cell - change the value of a single-cell property + * + * This is an alternative name for fdt_setprop_inplace_u32() + */ +static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset, + const char *name, uint32_t val) +{ + return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val); +} + +/** + * fdt_nop_property - replace a property with nop tags + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to nop + * @name: name of the property to nop + * + * fdt_nop_property() will replace a given property's representation + * in the blob with FDT_NOP tags, effectively removing it from the + * tree. + * + * This function will alter only the bytes in the blob which contain + * the property, and will not alter or move any other part of the + * tree. + * + * 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_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 + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_node(void *fdt, int nodeoffset); + +/**********************************************************************/ +/* Sequential write functions */ +/**********************************************************************/ + +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); +static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val) +{ + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_property(fdt, name, &tmp, sizeof(tmp)); +} +static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val) +{ + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_property(fdt, name, &tmp, sizeof(tmp)); +} +static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val) +{ + return fdt_property_u32(fdt, name, val); +} + +/** + * fdt_property_placeholder - add a new property and return a ptr to its value + * + * @fdt: pointer to the device tree blob + * @name: name of property to add + * @len: length of property value in bytes + * @valp: returns a pointer to where where the value should be placed + * + * returns: + * 0, on success + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_NOSPACE, standard meanings + */ +int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp); + +#define fdt_property_string(fdt, name, str) \ + fdt_property(fdt, name, str, strlen(str)+1) +int fdt_end_node(void *fdt); +int fdt_finish(void *fdt); + +/**********************************************************************/ +/* Read-write functions */ +/**********************************************************************/ + +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); + +/** + * fdt_add_mem_rsv - add one memory reserve map entry + * @fdt: pointer to the device tree blob + * @address, @size: 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_mem_rsv(void *fdt, uint64_t address, uint64_t size); + +/** + * fdt_del_mem_rsv - remove a memory reserve map entry + * @fdt: pointer to the device tree blob + * @n: 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_mem_rsv(void *fdt, int n); + +/** + * fdt_set_name - change the name of a given node + * @fdt: pointer to the device tree blob + * @nodeoffset: structure block offset of a node + * @name: name to give the 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); + +/** + * fdt_setprop - create or change a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: pointer to data to set the property value to + * @len: length of the property value + * + * fdt_setprop() sets the value of the named property in the given + * node to the given value and length, creating the property if it + * does not already exist. + * + * 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 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_setprop(void *fdt, int nodeoffset, const char *name, + const void *val, int len); + +/** + * fdt_setprop_u32 - set a property to a 32-bit integer + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 32-bit integer value for the property (native endian) + * + * fdt_setprop_u32() sets the value of the named property in the given + * node to the given 32-bit integer value (converting to big-endian if + * necessary), or creates a new property with that value if it does + * not already exist. + * + * 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 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 + */ +static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name, + uint32_t val) +{ + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_setprop_u64 - set a property to a 64-bit integer + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 64-bit integer value for the property (native endian) + * + * fdt_setprop_u64() sets the value of the named property in the given + * node to the given 64-bit integer value (converting to big-endian if + * necessary), or creates a new property with that value if it does + * not already exist. + * + * 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 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 + */ +static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name, + uint64_t val) +{ + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_setprop_cell - set a property to a single cell value + * + * This is an alternative name for fdt_setprop_u32() + */ +static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name, + uint32_t val) +{ + return fdt_setprop_u32(fdt, nodeoffset, name, val); +} + +/** + * fdt_setprop_string - set a property to a string value + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @str: string value for the property + * + * fdt_setprop_string() sets the value of the named property in the + * given node to the given string value (using the length of the + * string to determine the new length of the property), or creates a + * new property with that value if it does not already exist. + * + * 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 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) + + +/** + * fdt_setprop_empty - set a property to an empty value + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * + * fdt_setprop_empty() sets the value of the named property in the + * given node to an empty (zero length) value, or creates a new empty + * property if it does not already exist. + * + * 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 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_empty(fdt, nodeoffset, name) \ + fdt_setprop((fdt), (nodeoffset), (name), NULL, 0) + +/** + * fdt_appendprop - append to or create a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to append to + * @val: pointer to data to append to the property value + * @len: 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); + +/** + * fdt_appendprop_u32 - append a 32-bit integer value to a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 32-bit integer value to append to the property (native endian) + * + * fdt_appendprop_u32() appends the given 32-bit integer value + * (converting to big-endian if necessary) 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 + */ +static inline int fdt_appendprop_u32(void *fdt, int nodeoffset, + const char *name, uint32_t val) +{ + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_appendprop_u64 - append a 64-bit integer value to a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 64-bit integer value to append to the property (native endian) + * + * fdt_appendprop_u64() appends the given 64-bit integer value + * (converting to big-endian if necessary) 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 + */ +static inline int fdt_appendprop_u64(void *fdt, int nodeoffset, + const char *name, uint64_t val) +{ + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); +} + +/** + * fdt_appendprop_cell - append a single cell value to a property + * + * This is an alternative name for fdt_appendprop_u32() + */ +static inline int fdt_appendprop_cell(void *fdt, int nodeoffset, + const char *name, uint32_t val) +{ + return fdt_appendprop_u32(fdt, nodeoffset, name, val); +} + +/** + * fdt_appendprop_string - append a string to a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @str: 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_appendprop_string(fdt, nodeoffset, name, str) \ + fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1) + +/** + * fdt_delprop - delete a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to nop + * @name: name of the 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_delprop(void *fdt, int nodeoffset, const char *name); + +/** + * fdt_add_subnode_namelen - creates a new node based on substring + * @fdt: pointer to the device tree blob + * @parentoffset: structure block offset of a node + * @name: name of the subnode to locate + * @namelen: number of characters of name to consider + * + * Identical to fdt_add_subnode(), but use only the first namelen + * characters of name as the name of the new node. This is useful for + * creating subnodes based on a portion of a larger string, such as a + * full path. + */ +#ifndef SWIG /* Not available in Python */ +int fdt_add_subnode_namelen(void *fdt, int parentoffset, + const char *name, int namelen); +#endif + +/** + * fdt_add_subnode - creates a new node + * @fdt: pointer to the device tree blob + * @parentoffset: structure block offset of a node + * @name: name of the subnode to locate + * + * 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. + */ +int fdt_add_subnode(void *fdt, int parentoffset, const char *name); + +/** + * fdt_del_node - delete a node (subtree) + * @fdt: pointer to the device tree blob + * @nodeoffset: 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_del_node(void *fdt, int nodeoffset); + +/** + * fdt_overlay_apply - Applies a DT overlay on a base DT + * @fdt: pointer to the base device tree blob + * @fdto: 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_overlay_apply(void *fdt, void *fdto); + +/**********************************************************************/ +/* Debugging / informational functions */ +/**********************************************************************/ + +#ifndef SWIG /* Not available in Python */ +const char *fdt_strerror(int errval); + +/** + * fdt_remove_unused_strings() - Remove any unused strings from an FDT + * + * This creates a new device tree in @new with unused strings removed. The + * called can then use fdt_pack() to minimise the space consumed. + * + * @old: Old device tree blog + * @new: Place to put new device tree blob, which must be as large as + * @old + * @return + * 0, on success + * -FDT_ERR_BADOFFSET, corrupt device tree + * -FDT_ERR_NOSPACE, out of space, which should not happen unless there + * is something very wrong with the device tree input + */ +int fdt_remove_unused_strings(const void *old, void *new); + +struct fdt_region { + int offset; + int size; +}; + +/* + * Flags for fdt_find_regions() + * + * Add a region for the string table (always the last region) + */ +#define FDT_REG_ADD_STRING_TAB (1 << 0) + +/* + * Add all supernodes of a matching node/property, useful for creating a + * valid subset tree + */ +#define FDT_REG_SUPERNODES (1 << 1) + +/* Add the FDT_BEGIN_NODE tags of subnodes, including their names */ +#define FDT_REG_DIRECT_SUBNODES (1 << 2) + +/* Add all subnodes of a matching node */ +#define FDT_REG_ALL_SUBNODES (1 << 3) + +/* Add a region for the mem_rsvmap table (always the first region) */ +#define FDT_REG_ADD_MEM_RSVMAP (1 << 4) + +/* Indicates what an fdt part is (node, property, value) */ +#define FDT_IS_NODE (1 << 0) +#define FDT_IS_PROP (1 << 1) +#define FDT_IS_VALUE (1 << 2) /* not supported */ +#define FDT_IS_COMPAT (1 << 3) /* used internally */ +#define FDT_NODE_HAS_PROP (1 << 4) /* node contains prop */ + +#define FDT_ANY_GLOBAL (FDT_IS_NODE | FDT_IS_PROP | FDT_IS_VALUE | \ + FDT_IS_COMPAT) +#define FDT_IS_ANY 0x1f /* all the above */ + +/* We set a reasonable limit on the number of nested nodes */ +#define FDT_MAX_DEPTH 32 + +/* Decribes what we want to include from the current tag */ +enum want_t { + WANT_NOTHING, + WANT_NODES_ONLY, /* No properties */ + WANT_NODES_AND_PROPS, /* Everything for one level */ + WANT_ALL_NODES_AND_PROPS /* Everything for all levels */ +}; + +/* Keeps track of the state at parent nodes */ +struct fdt_subnode_stack { + int offset; /* Offset of node */ + enum want_t want; /* The 'want' value here */ + int included; /* 1 if we included this node, 0 if not */ +}; + +struct fdt_region_ptrs { + int depth; /* Current tree depth */ + int done; /* What we have completed scanning */ + enum want_t want; /* What we are currently including */ + char *end; /* Pointer to end of full node path */ + int nextoffset; /* Next node offset to check */ +}; + +/* The state of our finding algortihm */ +struct fdt_region_state { + struct fdt_subnode_stack stack[FDT_MAX_DEPTH]; /* node stack */ + struct fdt_region *region; /* Contains list of regions found */ + int count; /* Numnber of regions found */ + const void *fdt; /* FDT blob */ + int max_regions; /* Maximum regions to find */ + int can_merge; /* 1 if we can merge with previous region */ + int start; /* Start position of current region */ + struct fdt_region_ptrs ptrs; /* Pointers for what we are up to */ +}; + +/** + * fdt_find_regions() - find regions in device tree + * + * Given a list of nodes to include and properties to exclude, find + * the regions of the device tree which describe those included parts. + * + * The intent is to get a list of regions which will be invariant provided + * those parts are invariant. For example, if you request a list of regions + * for all nodes but exclude the property "data", then you will get the + * same region contents regardless of any change to "data" properties. + * + * This function can be used to produce a byte-stream to send to a hashing + * function to verify that critical parts of the FDT have not changed. + * + * Nodes which are given in 'inc' are included in the region list, as + * are the names of the immediate subnodes nodes (but not the properties + * or subnodes of those subnodes). + * + * For eaxample "/" means to include the root node, all root properties + * and the FDT_BEGIN_NODE and FDT_END_NODE of all subnodes of /. The latter + * ensures that we capture the names of the subnodes. In a hashing situation + * it prevents the root node from changing at all Any change to non-excluded + * properties, names of subnodes or number of subnodes would be detected. + * + * When used with FITs this provides the ability to hash and sign parts of + * the FIT based on different configurations in the FIT. Then it is + * impossible to change anything about that configuration (include images + * attached to the configuration), but it may be possible to add new + * configurations, new images or new signatures within the existing + * framework. + * + * Adding new properties to a device tree may result in the string table + * being extended (if the new property names are different from those + * already added). This function can optionally include a region for + * the string table so that this can be part of the hash too. + * + * The device tree header is not included in the list. + * + * @fdt: Device tree to check + * @inc: List of node paths to included + * @inc_count: Number of node paths in list + * @exc_prop: List of properties names to exclude + * @exc_prop_count: Number of properties in exclude list + * @region: Returns list of regions + * @max_region: Maximum length of region list + * @path: Pointer to a temporary string for the function to use for + * building path names + * @path_len: Length of path, must be large enough to hold the longest + * path in the tree + * @add_string_tab: 1 to add a region for the string table + * @return number of regions in list. If this is >max_regions then the + * region array was exhausted. You should increase max_regions and try + * the call again. + */ +int fdt_find_regions(const void *fdt, char * const inc[], int inc_count, + char * const exc_prop[], int exc_prop_count, + struct fdt_region region[], int max_regions, + char *path, int path_len, int add_string_tab); + +/** + * fdt_first_region() - find regions in device tree + * + * Given a nodes and properties to include and properties to exclude, find + * the regions of the device tree which describe those included parts. + * + * The use for this function is twofold. Firstly it provides a convenient + * way of performing a structure-aware grep of the tree. For example it is + * possible to grep for a node and get all the properties associated with + * that node. Trees can be subsetted easily, by specifying the nodes that + * are required, and then writing out the regions returned by this function. + * This is useful for small resource-constrained systems, such as boot + * loaders, which want to use an FDT but do not need to know about all of + * it. + * + * Secondly it makes it easy to hash parts of the tree and detect changes. + * The intent is to get a list of regions which will be invariant provided + * those parts are invariant. For example, if you request a list of regions + * for all nodes but exclude the property "data", then you will get the + * same region contents regardless of any change to "data" properties. + * + * This function can be used to produce a byte-stream to send to a hashing + * function to verify that critical parts of the FDT have not changed. + * Note that semantically null changes in order could still cause false + * hash misses. Such reordering might happen if the tree is regenerated + * from source, and nodes are reordered (the bytes-stream will be emitted + * in a different order and mnay hash functions will detect this). However + * if an existing tree is modified using libfdt functions, such as + * fdt_add_subnode() and fdt_setprop(), then this problem is avoided. + * + * The nodes/properties to include/exclude are defined by a function + * provided by the caller. This function is called for each node and + * property, and must return: + * + * 0 - to exclude this part + * 1 - to include this part + * -1 - for FDT_IS_PROP only: no information is available, so include + * if its containing node is included + * + * The last case is only used to deal with properties. Often a property is + * included if its containing node is included - this is the case where + * -1 is returned.. However if the property is specifically required to be + * included/excluded, then 0 or 1 can be returned. Note that including a + * property when the FDT_REG_SUPERNODES flag is given will force its + * containing node to be included since it is not valid to have a property + * that is not in a node. + * + * Using the information provided, the inclusion of a node can be controlled + * either by a node name or its compatible string, or any other property + * that the function can determine. + * + * As an example, including node "/" means to include the root node and all + * root properties. A flag provides a way of also including supernodes (of + * which there is none for the root node), and another flag includes + * immediate subnodes, so in this case we would get the FDT_BEGIN_NODE and + * FDT_END_NODE of all subnodes of /. + * + * The subnode feature helps in a hashing situation since it prevents the + * root node from changing at all. Any change to non-excluded properties, + * names of subnodes or number of subnodes would be detected. + * + * When used with FITs this provides the ability to hash and sign parts of + * the FIT based on different configurations in the FIT. Then it is + * impossible to change anything about that configuration (include images + * attached to the configuration), but it may be possible to add new + * configurations, new images or new signatures within the existing + * framework. + * + * Adding new properties to a device tree may result in the string table + * being extended (if the new property names are different from those + * already added). This function can optionally include a region for + * the string table so that this can be part of the hash too. This is always + * the last region. + * + * The FDT also has a mem_rsvmap table which can also be included, and is + * always the first region if so. + * + * The device tree header is not included in the region list. Since the + * contents of the FDT are changing (shrinking, often), the caller will need + * to regenerate the header anyway. + * + * @fdt: Device tree to check + * @h_include: Function to call to determine whether to include a part or + * not: + * + * @priv: Private pointer as passed to fdt_find_regions() + * @fdt: Pointer to FDT blob + * @offset: Offset of this node / property + * @type: Type of this part, FDT_IS_... + * @data: Pointer to data (node name, property name, compatible + * string, value (not yet supported) + * @size: Size of data, or 0 if none + * @return 0 to exclude, 1 to include, -1 if no information is + * available + * @priv: Private pointer passed to h_include + * @region: Returns list of regions, sorted by offset + * @max_regions: Maximum length of region list + * @path: Pointer to a temporary string for the function to use for + * building path names + * @path_len: Length of path, must be large enough to hold the longest + * path in the tree + * @flags: Various flags that control the region algortihm, see + * FDT_REG_... + * @return number of regions in list. If this is >max_regions then the + * region array was exhausted. You should increase max_regions and try + * the call again. Only the first max_regions elements are available in the + * array. + * + * On error a -ve value is return, which can be: + * + * -FDT_ERR_BADSTRUCTURE (too deep or more END tags than BEGIN tags + * -FDT_ERR_BADLAYOUT + * -FDT_ERR_NOSPACE (path area is too small) + */ +int fdt_first_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info); + +/** fdt_next_region() - find next region + * + * See fdt_first_region() for full description. This function finds the + * next region according to the provided parameters, which must be the same + * as passed to fdt_first_region(). + * + * This function can additionally return -FDT_ERR_NOTFOUND when there are no + * more regions + */ +int fdt_next_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info); + +/** + * fdt_add_alias_regions() - find aliases that point to existing regions + * + * Once a device tree grep is complete some of the nodes will be present + * and some will have been dropped. This function checks all the alias nodes + * to figure out which points point to nodes which are still present. These + * aliases need to be kept, along with the nodes they reference. + * + * Given a list of regions function finds the aliases that still apply and + * adds more regions to the list for these. This function is called after + * fdt_next_region() has finished returning regions and requires the same + * state. + * + * @fdt: Device tree file to reference + * @region: List of regions that will be kept + * @count: Number of regions + * @max_regions: Number of entries that can fit in @region + * @info: Region state as returned from fdt_next_region() + * @return new number of regions in @region (i.e. count + the number added) + * or -FDT_ERR_NOSPACE if there was not enough space. + */ +int fdt_add_alias_regions(const void *fdt, struct fdt_region *region, int count, + int max_regions, struct fdt_region_state *info); +#endif /* SWIG */ + +#endif /* _LIBFDT_H */ |