X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=include%2Flibfdt.h;h=e2bc2e00c184e6e163711b18e02aea340dd4b126;hb=80e4bbfcd92d28dc806abc41190cd0ab324956b5;hp=c93ae28833e172c3bca7ee188da1c200f3eb27c5;hpb=f04821a8ca714459481bd9fd315af2b5f92d99a6;p=people%2Fms%2Fu-boot.git diff --git a/include/libfdt.h b/include/libfdt.h index c93ae28833..e2bc2e00c1 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -61,7 +61,7 @@ #define FDT_ERR_NOTFOUND 1 /* FDT_ERR_NOTFOUND: The requested node or property does not exist */ #define FDT_ERR_EXISTS 2 - /* FDT_ERR_EXISTS: Attemped to create a node or property which + /* 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 @@ -79,8 +79,10 @@ * (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 - * value. phandle values of 0 and -1 are not permitted. */ + /* 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 @@ -116,7 +118,31 @@ * Should never be returned, if it is, it indicates a bug in * libfdt itself. */ -#define FDT_ERR_MAX 13 +/* 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) */ @@ -136,6 +162,56 @@ uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset); 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 */ /**********************************************************************/ @@ -156,7 +232,7 @@ int fdt_next_node(const void *fdt, int offset, int *depth); #define __fdt_set_hdr(name) \ static inline void fdt_set_##name(void *fdt, uint32_t val) \ { \ - struct fdt_header *fdth = (struct fdt_header*)fdt; \ + struct fdt_header *fdth = (struct fdt_header *)fdt; \ fdth->name = cpu_to_fdt32(val); \ } __fdt_set_hdr(magic); @@ -226,6 +302,21 @@ int fdt_move(const void *fdt, void *buf, int bufsize); */ 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 @@ -286,8 +377,9 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, * 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_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE + * tag + * -FDT_ERR_BADMAGIC, * -FDT_ERR_BADVERSION, * -FDT_ERR_BADSTATE, * -FDT_ERR_BADSTRUCTURE, @@ -295,6 +387,17 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset, */ 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. + */ +int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen); + /** * fdt_path_offset - find a tree node by its full path * @fdt: pointer to the device tree blob @@ -308,7 +411,8 @@ int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name); * address). * * returns: - * structure block offset of the node with the requested path (>=0), on success + * 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, @@ -332,10 +436,12 @@ int fdt_path_offset(const void *fdt, const char *path); * * returns: * pointer to the node's name, on success - * If lenp is non-NULL, *lenp contains the length of that name (>=0) + * 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_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE + * tag * -FDT_ERR_BADMAGIC, * -FDT_ERR_BADVERSION, * -FDT_ERR_BADSTATE, standard meanings @@ -383,6 +489,33 @@ int fdt_first_property_offset(const void *fdt, int nodeoffset); */ 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 @@ -419,8 +552,8 @@ const struct fdt_property *fdt_get_property_by_offset(const void *fdt, * @namelen: number of characters of name to consider * @lenp: pointer to an integer variable (will be overwritten) or NULL * - * Identical to fdt_get_property_namelen(), but only examine the first - * namelen characters of name for matching the property name. + * Identical to fdt_get_property(), but only examine the first namelen + * characters of name for matching the property name. */ const struct fdt_property *fdt_get_property_namelen(const void *fdt, int nodeoffset, @@ -447,7 +580,8 @@ const struct fdt_property *fdt_get_property_namelen(const void *fdt, * 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_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE + * tag * -FDT_ERR_BADMAGIC, * -FDT_ERR_BADVERSION, * -FDT_ERR_BADSTATE, @@ -511,6 +645,13 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset, */ 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); +} /** * fdt_getprop - retrieve the value of a given property @@ -532,7 +673,8 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, * 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_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE + * tag * -FDT_ERR_BADMAGIC, * -FDT_ERR_BADVERSION, * -FDT_ERR_BADSTATE, @@ -574,7 +716,7 @@ const char *fdt_get_alias_namelen(const void *fdt, const char *name, int namelen); /** - * fdt_get_alias - retreive the path referenced by a given alias + * 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 * @@ -582,7 +724,7 @@ const char *fdt_get_alias_namelen(const void *fdt, * value of the property named 'name' in the node /aliases. * * returns: - * a pointer to the expansion of the alias named 'name', of it exists + * 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); @@ -634,11 +776,11 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen); * 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_NOTFOUND, supernodedepth was greater than the depth of + * nodeoffset * -FDT_ERR_BADMAGIC, * -FDT_ERR_BADVERSION, * -FDT_ERR_BADSTATE, @@ -709,7 +851,7 @@ int fdt_parent_offset(const void *fdt, int nodeoffset); * offset = fdt_node_offset_by_prop_value(fdt, -1, propname, * propval, proplen); * while (offset != -FDT_ERR_NOTFOUND) { - * ... other code here ... + * // other code here * offset = fdt_node_offset_by_prop_value(fdt, offset, propname, * propval, proplen); * } @@ -794,7 +936,7 @@ int fdt_node_check_compatible(const void *fdt, int nodeoffset, * idiom can be used: * offset = fdt_node_offset_by_compatible(fdt, -1, compatible); * while (offset != -FDT_ERR_NOTFOUND) { - * ... other code here ... + * // other code here * offset = fdt_node_offset_by_compatible(fdt, offset, compatible); * } * @@ -816,10 +958,164 @@ int fdt_node_check_compatible(const void *fdt, int nodeoffset, 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. + */ +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 - change a property's value, but not its size * @fdt: pointer to the device tree blob @@ -882,8 +1178,8 @@ int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset, const char *name, uint32_t val) { - val = cpu_to_fdt32(val); - return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val)); + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -917,8 +1213,8 @@ static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset, static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset, const char *name, uint64_t val) { - val = cpu_to_fdt64(val); - return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val)); + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -987,24 +1283,41 @@ 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); static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val) { - val = cpu_to_fdt32(val); - return fdt_property(fdt, name, &val, sizeof(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) { - val = cpu_to_fdt64(val); - return fdt_property(fdt, name, &val, sizeof(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); @@ -1154,8 +1467,8 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name, static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name, uint32_t val) { - val = cpu_to_fdt32(val); - return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val)); + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -1189,8 +1502,8 @@ static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name, static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name, uint64_t val) { - val = cpu_to_fdt64(val); - return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val)); + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -1296,8 +1609,8 @@ int fdt_appendprop(void *fdt, int nodeoffset, const char *name, static inline int fdt_appendprop_u32(void *fdt, int nodeoffset, const char *name, uint32_t val) { - val = cpu_to_fdt32(val); - return fdt_appendprop(fdt, nodeoffset, name, &val, sizeof(val)); + fdt32_t tmp = cpu_to_fdt32(val); + return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -1331,8 +1644,8 @@ static inline int fdt_appendprop_u32(void *fdt, int nodeoffset, static inline int fdt_appendprop_u64(void *fdt, int nodeoffset, const char *name, uint64_t val) { - val = cpu_to_fdt64(val); - return fdt_appendprop(fdt, nodeoffset, name, &val, sizeof(val)); + fdt64_t tmp = cpu_to_fdt64(val); + return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp)); } /** @@ -1429,9 +1742,11 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset, * change the offsets of some existing nodes. * returns: - * structure block offset of the created nodeequested subnode (>=0), on success + * 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_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 @@ -1469,10 +1784,354 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name); */ 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 */ /**********************************************************************/ 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 /* _LIBFDT_H */