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libfdt: split fdt_region declarations out to <fdt_region.h>

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fdt_region APIs are not part of libfdt. They are U-Boot extension
for the verified boot. Split the declarations related to fdt_region
out of <fdt_region.h>. This allows <linux/libfdt.h> to become a
simple wrapper file, like Linux does.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2020-04-16 18:30:18 +09:00 committed by Simon Glass
parent 3e69db1223
commit 64045a6a17
6 changed files with 964 additions and 299 deletions
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657
common/fdt_region.c Normal file
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@ -0,0 +1,657 @@
// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause
/*
* libfdt - Flat Device Tree manipulation
* Copyright (C) 2013 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#include <linux/libfdt_env.h>
#include <fdt_region.h>
#ifndef USE_HOSTCC
#include <fdt.h>
#include <linux/libfdt.h>
#else
#include "fdt_host.h"
#endif
#define FDT_MAX_DEPTH 32
static int str_in_list(const char *str, char * const list[], int count)
{
int i;
for (i = 0; i < count; i++)
if (!strcmp(list[i], str))
return 1;
return 0;
}
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)
{
int stack[FDT_MAX_DEPTH] = { 0 };
char *end;
int nextoffset = 0;
uint32_t tag;
int count = 0;
int start = -1;
int depth = -1;
int want = 0;
int base = fdt_off_dt_struct(fdt);
end = path;
*end = '\0';
do {
const struct fdt_property *prop;
const char *name;
const char *str;
int include = 0;
int stop_at = 0;
int offset;
int len;
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
stop_at = nextoffset;
switch (tag) {
case FDT_PROP:
include = want >= 2;
stop_at = offset;
prop = fdt_get_property_by_offset(fdt, offset, NULL);
str = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
if (str_in_list(str, exc_prop, exc_prop_count))
include = 0;
break;
case FDT_NOP:
include = want >= 2;
stop_at = offset;
break;
case FDT_BEGIN_NODE:
depth++;
if (depth == FDT_MAX_DEPTH)
return -FDT_ERR_BADSTRUCTURE;
name = fdt_get_name(fdt, offset, &len);
if (end - path + 2 + len >= path_len)
return -FDT_ERR_NOSPACE;
if (end != path + 1)
*end++ = '/';
strcpy(end, name);
end += len;
stack[depth] = want;
if (want == 1)
stop_at = offset;
if (str_in_list(path, inc, inc_count))
want = 2;
else if (want)
want--;
else
stop_at = offset;
include = want;
break;
case FDT_END_NODE:
/* Depth must never go below -1 */
if (depth < 0)
return -FDT_ERR_BADSTRUCTURE;
include = want;
want = stack[depth--];
while (end > path && *--end != '/')
;
*end = '\0';
break;
case FDT_END:
include = 1;
break;
}
if (include && start == -1) {
/* Should we merge with previous? */
if (count && count <= max_regions &&
offset == region[count - 1].offset +
region[count - 1].size - base)
start = region[--count].offset - base;
else
start = offset;
}
if (!include && start != -1) {
if (count < max_regions) {
region[count].offset = base + start;
region[count].size = stop_at - start;
}
count++;
start = -1;
}
} while (tag != FDT_END);
if (nextoffset != fdt_size_dt_struct(fdt))
return -FDT_ERR_BADLAYOUT;
/* Add a region for the END tag and the string table */
if (count < max_regions) {
region[count].offset = base + start;
region[count].size = nextoffset - start;
if (add_string_tab)
region[count].size += fdt_size_dt_strings(fdt);
}
count++;
return count;
}
/**
* fdt_add_region() - Add a new region to our list
* @info: State information
* @offset: Start offset of region
* @size: Size of region
*
* 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.
*/
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;
}
/**
* fdt_add_alias_regions() - Add regions covering the aliases that we want
*
* The /aliases node is not automatically included by fdtgrep unless the
* command-line arguments cause to be included (or not excluded). However
* aliases are special in that we generally want to include those which
* reference a node that fdtgrep includes.
*
* In fact we want to include only aliases for those nodes still included in
* the fdt, and drop the other aliases since they point to nodes that will not
* be present.
*
* This function scans the aliases and adds regions for those which we want
* to keep.
*
* @fdt: Device tree to scan
* @region: List of regions
* @count: Number of regions in the list so far (i.e. starting point for this
* function)
* @max_regions: Maximum number of regions in @region list
* @info: Place to put the region state
* @return number of regions after processing, or -FDT_ERR_NOSPACE if we did
* not have enough room in the regions table for the regions we wanted to add.
*/
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;
/*
* Find the next node so that we know where the /aliases node ends. We
* need special handling if /aliases is the last node.
*/
node_end = fdt_next_subnode(fdt, node);
if (node_end == -FDT_ERR_NOTFOUND)
/* Move back to the FDT_END_NODE tag of '/' */
node_end = fdt_size_dt_struct(fdt) - sizeof(fdt32_t) * 2;
else if (node_end < 0) /* other error */
return node_end;
node_end -= sizeof(fdt32_t); /* Move to FDT_END_NODE tag of /aliases */
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;
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 FDT_END_NODE 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
* @info: State information
* @depth: Current stack depth
*
* 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.
*/
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_BADSTRUCTURE;
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;
}

1
common/image-fit-sig.c
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@ -11,6 +11,7 @@
#include <malloc.h>
DECLARE_GLOBAL_DATA_PTR;
#endif /* !USE_HOSTCC*/
#include <fdt_region.h>
#include <image.h>
#include <u-boot/rsa.h>
#include <u-boot/rsa-checksum.h>

304
include/fdt_region.h Normal file
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@ -0,0 +1,304 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FDT_REGION_H
#define _FDT_REGION_H
#ifndef SWIG /* Not available in Python */
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 many 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 /* _FDT_REGION_H */

299
include/linux/libfdt.h
View File

@ -8,305 +8,6 @@
#include "../../scripts/dtc/libfdt/libfdt.h"
/* U-Boot local hacks */
#ifndef SWIG /* Not available in Python */
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 many 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 */
extern struct fdt_header *working_fdt; /* Pointer to the working fdt */
#endif /* _INCLUDE_LIBFDT_H_ */

1
tools/fdtgrep.c
View File

@ -17,6 +17,7 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fdt_region.h>
#include "fdt_host.h"
#include "libfdt_internal.h"

1
tools/image-host.c
View File

@ -10,6 +10,7 @@
#include "mkimage.h"
#include <bootm.h>
#include <fdt_region.h>
#include <image.h>
#include <version.h>