From: Simon Glass Date: Tue, 23 Jun 2015 21:38:27 +0000 (-0600) Subject: fdt: Add fdt_first/next_region() functions X-Git-Tag: v2015.10-rc1~178 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=c3c4c00563abfca63f5b846f4f4f6fc390e58563;p=oweals%2Fu-boot.git fdt: Add fdt_first/next_region() functions These have been sent upstream but not accepted to libfdt. For now, bring these into U-Boot to enable fdtgrep to operate. We will use fdtgrep to cut device tree files down for SPL. Signed-off-by: Simon Glass --- diff --git a/include/libfdt.h b/include/libfdt.h index d0017d8865..e48c21aced 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -121,7 +121,12 @@ /* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells * or similar property with a bad format or value */ -#define FDT_ERR_MAX 14 +#define FDT_ERR_TOODEEP 15 + /* 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 15 /**********************************************************************/ /* Low-level functions (you probably don't need these) */ @@ -1668,6 +1673,77 @@ struct fdt_region { 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 * @@ -1727,4 +1803,165 @@ int fdt_find_regions(const void *fdt, char * const inc[], int inc_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 */ diff --git a/lib/libfdt/Makefile b/lib/libfdt/Makefile index 2f5413f90d..934d6142c3 100644 --- a/lib/libfdt/Makefile +++ b/lib/libfdt/Makefile @@ -6,4 +6,4 @@ # obj-y += fdt.o fdt_ro.o fdt_rw.o fdt_strerror.o fdt_sw.o fdt_wip.o \ - fdt_empty_tree.o fdt_addresses.o + fdt_empty_tree.o fdt_addresses.o fdt_region.o diff --git a/lib/libfdt/fdt_region.c b/lib/libfdt/fdt_region.c new file mode 100644 index 0000000000..9fea775a97 --- /dev/null +++ b/lib/libfdt/fdt_region.c @@ -0,0 +1,492 @@ +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2013 Google, Inc + * Written by Simon Glass + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + */ + +#include "libfdt_env.h" + +#ifndef USE_HOSTCC +#include +#include +#else +#include "fdt_host.h" +#endif + +#include "libfdt_internal.h" + +/** + * fdt_add_region() - Add a new region to our list + * + * The region is added if there is space, but in any case we increment the + * count. If permitted, and the new region overlaps the last one, we merge + * them. + * + * @info: State information + * @offset: Start offset of region + * @size: Size of region + */ +static int fdt_add_region(struct fdt_region_state *info, int offset, int size) +{ + struct fdt_region *reg; + + reg = info->region ? &info->region[info->count - 1] : NULL; + if (info->can_merge && info->count && + info->count <= info->max_regions && + reg && offset <= reg->offset + reg->size) { + reg->size = offset + size - reg->offset; + } else if (info->count++ < info->max_regions) { + if (reg) { + reg++; + reg->offset = offset; + reg->size = size; + } + } else { + return -1; + } + + return 0; +} + +static int region_list_contains_offset(struct fdt_region_state *info, + const void *fdt, int target) +{ + struct fdt_region *reg; + int num; + + target += fdt_off_dt_struct(fdt); + for (reg = info->region, num = 0; num < info->count; reg++, num++) { + if (target >= reg->offset && target < reg->offset + reg->size) + return 1; + } + + return 0; +} + +int fdt_add_alias_regions(const void *fdt, struct fdt_region *region, int count, + int max_regions, struct fdt_region_state *info) +{ + int base = fdt_off_dt_struct(fdt); + int node, node_end, offset; + int did_alias_header; + + node = fdt_subnode_offset(fdt, 0, "aliases"); + if (node < 0) + return -FDT_ERR_NOTFOUND; + + /* The aliases node must come before the others */ + node_end = fdt_next_subnode(fdt, node); + if (node_end <= 0) + return -FDT_ERR_BADLAYOUT; + node_end -= sizeof(fdt32_t); + + did_alias_header = 0; + info->region = region; + info->count = count; + info->can_merge = 0; + info->max_regions = max_regions; + + for (offset = fdt_first_property_offset(fdt, node); + offset >= 0; + offset = fdt_next_property_offset(fdt, offset)) { + const struct fdt_property *prop; + const char *name; + int target, next; + + prop = fdt_get_property_by_offset(fdt, offset, NULL); + name = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); + target = fdt_path_offset(fdt, name); + if (!region_list_contains_offset(info, fdt, target)) + continue; + next = fdt_next_property_offset(fdt, offset); + if (next < 0) + next = node_end - sizeof(fdt32_t); + + if (!did_alias_header) { + fdt_add_region(info, base + node, 12); + did_alias_header = 1; + } + fdt_add_region(info, base + offset, next - offset); + } + + /* Add the 'end' tag */ + if (did_alias_header) + fdt_add_region(info, base + node_end, sizeof(fdt32_t)); + + return info->count < max_regions ? info->count : -FDT_ERR_NOSPACE; +} + +/** + * fdt_include_supernodes() - Include supernodes required by this node + * + * When we decided to include a node or property which is not at the top + * level, this function forces the inclusion of higher level nodes. For + * example, given this tree: + * + * / { + * testing { + * } + * } + * + * If we decide to include testing then we need the root node to have a valid + * tree. This function adds those regions. + * + * @info: State information + * @depth: Current stack depth + */ +static int fdt_include_supernodes(struct fdt_region_state *info, int depth) +{ + int base = fdt_off_dt_struct(info->fdt); + int start, stop_at; + int i; + + /* + * Work down the stack looking for supernodes that we didn't include. + * The algortihm here is actually pretty simple, since we know that + * no previous subnode had to include these nodes, or if it did, we + * marked them as included (on the stack) already. + */ + for (i = 0; i <= depth; i++) { + if (!info->stack[i].included) { + start = info->stack[i].offset; + + /* Add the FDT_BEGIN_NODE tag of this supernode */ + fdt_next_tag(info->fdt, start, &stop_at); + if (fdt_add_region(info, base + start, stop_at - start)) + return -1; + + /* Remember that this supernode is now included */ + info->stack[i].included = 1; + info->can_merge = 1; + } + + /* Force (later) generation of the FDT_END_NODE tag */ + if (!info->stack[i].want) + info->stack[i].want = WANT_NODES_ONLY; + } + + return 0; +} + +enum { + FDT_DONE_NOTHING, + FDT_DONE_MEM_RSVMAP, + FDT_DONE_STRUCT, + FDT_DONE_END, + FDT_DONE_STRINGS, + FDT_DONE_ALL, +}; + +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) +{ + struct fdt_region_ptrs *p = &info->ptrs; + + /* Set up our state */ + info->fdt = fdt; + info->can_merge = 1; + info->max_regions = 1; + info->start = -1; + p->want = WANT_NOTHING; + p->end = path; + *p->end = '\0'; + p->nextoffset = 0; + p->depth = -1; + p->done = FDT_DONE_NOTHING; + + return fdt_next_region(fdt, h_include, priv, region, + path, path_len, flags, info); +} + +/* + * Theory of operation + * + * + * + +Note: in this description 'included' means that a node (or other part of +the tree) should be included in the region list, i.e. it will have a region +which covers its part of the tree. + +This function maintains some state from the last time it is called. It +checks the next part of the tree that it is supposed to look at +(p.nextoffset) to see if that should be included or not. When it finds +something to include, it sets info->start to its offset. This marks the +start of the region we want to include. + +Once info->start is set to the start (i.e. not -1), we continue scanning +until we find something that we don't want included. This will be the end +of a region. At this point we can close off the region and add it to the +list. So we do so, and reset info->start to -1. + +One complication here is that we want to merge regions. So when we come to +add another region later, we may in fact merge it with the previous one if +one ends where the other starts. + +The function fdt_add_region() will return -1 if it fails to add the region, +because we already have a region ready to be returned, and the new one +cannot be merged in with it. In this case, we must return the region we +found, and wait for another call to this function. When it comes, we will +repeat the processing of the tag and again try to add a region. This time it +will succeed. + +The current state of the pointers (stack, offset, etc.) is maintained in +a ptrs member. At the start of every loop iteration we make a copy of it. +The copy is then updated as the tag is processed. Only if we get to the end +of the loop iteration (and successfully call fdt_add_region() if we need +to) can we commit the changes we have made to these pointers. For example, +if we see an FDT_END_NODE tag we will decrement the depth value. But if we +need to add a region for this tag (let's say because the previous tag is +included and this FDT_END_NODE tag is not included) then we will only commit +the result if we were able to add the region. That allows us to retry again +next time. + +We keep track of a variable called 'want' which tells us what we want to +include when there is no specific information provided by the h_include +function for a particular property. This basically handles the inclusion of +properties which are pulled in by virtue of the node they are in. So if you +include a node, its properties are also included. In this case 'want' will +be WANT_NODES_AND_PROPS. The FDT_REG_DIRECT_SUBNODES feature also makes use +of 'want'. While we are inside the subnode, 'want' will be set to +WANT_NODES_ONLY, so that only the subnode's FDT_BEGIN_NODE and FDT_END_NODE +tags will be included, and properties will be skipped. If WANT_NOTHING is +selected, then we will just rely on what the h_include() function tells us. + +Using 'want' we work out 'include', which tells us whether this current tag +should be included or not. As you can imagine, if the value of 'include' +changes, that means we are on a boundary between nodes to include and nodes +to exclude. At this point we either close off a previous region and add it +to the list, or mark the start of a new region. + +Apart from the nodes, we have mem_rsvmap, the FDT_END tag and the string +list. Each of these dealt with as a whole (i.e. we create a region for each +if it is to be included). For mem_rsvmap we don't allow it to merge with +the first struct region. For the stringlist we don't allow it to merge with +the last struct region (which contains at minimum the FDT_END tag). +*/ +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) +{ + int base = fdt_off_dt_struct(fdt); + int last_node = 0; + const char *str; + + info->region = region; + info->count = 0; + if (info->ptrs.done < FDT_DONE_MEM_RSVMAP && + (flags & FDT_REG_ADD_MEM_RSVMAP)) { + /* Add the memory reserve map into its own region */ + if (fdt_add_region(info, fdt_off_mem_rsvmap(fdt), + fdt_off_dt_struct(fdt) - + fdt_off_mem_rsvmap(fdt))) + return 0; + info->can_merge = 0; /* Don't allow merging with this */ + info->ptrs.done = FDT_DONE_MEM_RSVMAP; + } + + /* + * Work through the tags one by one, deciding whether each needs to + * be included or not. We set the variable 'include' to indicate our + * decision. 'want' is used to track what we want to include - it + * allows us to pick up all the properties (and/or subnode tags) of + * a node. + */ + while (info->ptrs.done < FDT_DONE_STRUCT) { + const struct fdt_property *prop; + struct fdt_region_ptrs p; + const char *name; + int include = 0; + int stop_at = 0; + uint32_t tag; + int offset; + int val; + int len; + + /* + * Make a copy of our pointers. If we make it to the end of + * this block then we will commit them back to info->ptrs. + * Otherwise we can try again from the same starting state + * next time we are called. + */ + p = info->ptrs; + + /* + * Find the tag, and the offset of the next one. If we need to + * stop including tags, then by default we stop *after* + * including the current tag + */ + offset = p.nextoffset; + tag = fdt_next_tag(fdt, offset, &p.nextoffset); + stop_at = p.nextoffset; + + switch (tag) { + case FDT_PROP: + stop_at = offset; + prop = fdt_get_property_by_offset(fdt, offset, NULL); + str = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); + val = h_include(priv, fdt, last_node, FDT_IS_PROP, str, + strlen(str) + 1); + if (val == -1) { + include = p.want >= WANT_NODES_AND_PROPS; + } else { + include = val; + /* + * Make sure we include the } for this block. + * It might be more correct to have this done + * by the call to fdt_include_supernodes() in + * the case where it adds the node we are + * currently in, but this is equivalent. + */ + if ((flags & FDT_REG_SUPERNODES) && val && + !p.want) + p.want = WANT_NODES_ONLY; + } + + /* Value grepping is not yet supported */ + break; + + case FDT_NOP: + include = p.want >= WANT_NODES_AND_PROPS; + stop_at = offset; + break; + + case FDT_BEGIN_NODE: + last_node = offset; + p.depth++; + if (p.depth == FDT_MAX_DEPTH) + return -FDT_ERR_TOODEEP; + name = fdt_get_name(fdt, offset, &len); + if (p.end - path + 2 + len >= path_len) + return -FDT_ERR_NOSPACE; + + /* Build the full path of this node */ + if (p.end != path + 1) + *p.end++ = '/'; + strcpy(p.end, name); + p.end += len; + info->stack[p.depth].want = p.want; + info->stack[p.depth].offset = offset; + + /* + * If we are not intending to include this node unless + * it matches, make sure we stop *before* its tag. + */ + if (p.want == WANT_NODES_ONLY || + !(flags & (FDT_REG_DIRECT_SUBNODES | + FDT_REG_ALL_SUBNODES))) { + stop_at = offset; + p.want = WANT_NOTHING; + } + val = h_include(priv, fdt, offset, FDT_IS_NODE, path, + p.end - path + 1); + + /* Include this if requested */ + if (val) { + p.want = (flags & FDT_REG_ALL_SUBNODES) ? + WANT_ALL_NODES_AND_PROPS : + WANT_NODES_AND_PROPS; + } + + /* If not requested, decay our 'p.want' value */ + else if (p.want) { + if (p.want != WANT_ALL_NODES_AND_PROPS) + p.want--; + + /* Not including this tag, so stop now */ + } else { + stop_at = offset; + } + + /* + * Decide whether to include this tag, and update our + * stack with the state for this node + */ + include = p.want; + info->stack[p.depth].included = include; + break; + + case FDT_END_NODE: + include = p.want; + if (p.depth < 0) + return -FDT_ERR_BADSTRUCTURE; + + /* + * If we don't want this node, stop right away, unless + * we are including subnodes + */ + if (!p.want && !(flags & FDT_REG_DIRECT_SUBNODES)) + stop_at = offset; + p.want = info->stack[p.depth].want; + p.depth--; + while (p.end > path && *--p.end != '/') + ; + *p.end = '\0'; + break; + + case FDT_END: + /* We always include the end tag */ + include = 1; + p.done = FDT_DONE_STRUCT; + break; + } + + /* If this tag is to be included, mark it as region start */ + if (include && info->start == -1) { + /* Include any supernodes required by this one */ + if (flags & FDT_REG_SUPERNODES) { + if (fdt_include_supernodes(info, p.depth)) + return 0; + } + info->start = offset; + } + + /* + * If this tag is not to be included, finish up the current + * region. + */ + if (!include && info->start != -1) { + if (fdt_add_region(info, base + info->start, + stop_at - info->start)) + return 0; + info->start = -1; + info->can_merge = 1; + } + + /* If we have made it this far, we can commit our pointers */ + info->ptrs = p; + } + + /* Add a region for the END tag and a separate one for string table */ + if (info->ptrs.done < FDT_DONE_END) { + if (info->ptrs.nextoffset != fdt_size_dt_struct(fdt)) + return -FDT_ERR_BADSTRUCTURE; + + if (fdt_add_region(info, base + info->start, + info->ptrs.nextoffset - info->start)) + return 0; + info->ptrs.done++; + } + if (info->ptrs.done < FDT_DONE_STRINGS) { + if (flags & FDT_REG_ADD_STRING_TAB) { + info->can_merge = 0; + if (fdt_off_dt_strings(fdt) < + base + info->ptrs.nextoffset) + return -FDT_ERR_BADLAYOUT; + if (fdt_add_region(info, fdt_off_dt_strings(fdt), + fdt_size_dt_strings(fdt))) + return 0; + } + info->ptrs.done++; + } + + return info->count > 0 ? 0 : -FDT_ERR_NOTFOUND; +}