mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-08 22:24:32 +00:00
64045a6a17
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>
304 lines
13 KiB
C
304 lines
13 KiB
C
/* 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 */
|