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/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
#ifndef LIBFDT_INTERNAL_H
#define LIBFDT_INTERNAL_H
/*
* libfdt - Flat Device Tree manipulation
* Copyright (C) 2006 David Gibson, IBM Corporation.
*/
#include <fdt.h>
#define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1))
#define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE))
int fdt_ro_probe_(const void *fdt);
#define FDT_RO_PROBE(fdt) \
{ \
int totalsize_; \
if (fdt_chk_basic()) { \
totalsize_ = fdt_ro_probe_(fdt); \
if (totalsize_ < 0) \
return totalsize_; \
} \
}
int fdt_check_node_offset_(const void *fdt, int offset);
int fdt_check_prop_offset_(const void *fdt, int offset);
const char *fdt_find_string_(const char *strtab, int tabsize, const char *s);
int fdt_node_end_offset_(void *fdt, int nodeoffset);
static inline const void *fdt_offset_ptr_(const void *fdt, int offset)
{
return (const char *)fdt + fdt_off_dt_struct(fdt) + offset;
}
static inline void *fdt_offset_ptr_w_(void *fdt, int offset)
{
return (void *)(uintptr_t)fdt_offset_ptr_(fdt, offset);
}
static inline const struct fdt_reserve_entry *fdt_mem_rsv_(const void *fdt, int n)
{
const struct fdt_reserve_entry *rsv_table =
(const struct fdt_reserve_entry *)
((const char *)fdt + fdt_off_mem_rsvmap(fdt));
return rsv_table + n;
}
static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n)
{
return (void *)(uintptr_t)fdt_mem_rsv_(fdt, n);
}
#define FDT_SW_MAGIC (~FDT_MAGIC)
/**********************************************************************/
/* Checking controls */
/**********************************************************************/
#ifndef FDT_ASSUME_MASK
#define FDT_ASSUME_MASK 0
#endif
/*
* Defines assumptions which can be enabled. Each of these can be enabled
* individually. For maximum saftey, don't enable any assumptions!
*
* For minimal code size and no safety, use FDT_ASSUME_PERFECT at your own risk.
* You should have another method of validating the device tree, such as a
* signature or hash check before using libfdt.
*
* For situations where security is not a concern it may be safe to enable
* FDT_ASSUME_FRIENDLY.
*/
enum {
/*
* This does essentially no checks. Only the latest device-tree
* version is correctly handled. Incosistencies or errors in the device
* tree may cause undefined behaviour or crashes.
*
* If an error occurs when modifying the tree it may leave the tree in
* an intermediate (but valid) state. As an example, adding a property
* where there is insufficient space may result in the property name
* being added to the string table even though the property itself is
* not added to the struct section.
*
* Only use this if you have a fully validated device tree with
* the latest supported version and wish to minimise code size.
*/
FDT_ASSUME_PERFECT = 0xff,
/*
* This assumes that the device tree is sane. i.e. header metadata
* and basic hierarchy are correct.
*
* These checks will be sufficient if you have a valid device tree with
* no internal inconsistencies. With this assumption, libfdt will
* generally not return -FDT_ERR_INTERNAL, -FDT_ERR_BADLAYOUT, etc.
*/
FDT_ASSUME_SANE = 1 << 0,
/*
* This disables checks for device-tree version and removes all code
* which handles older versions.
*
* Only enable this if you know you have a device tree with the latest
* version.
*/
FDT_ASSUME_LATEST = 1 << 1,
/*
* This disables any extensive checking of parameters and the device
* tree, making various assumptions about correctness. Normal device
* trees produced by libfdt and the compiler should be handled safely.
* Malicious device trees and complete garbage may cause libfdt to
* behave badly or crash.
*/
FDT_ASSUME_FRIENDLY = 1 << 2,
};
/** fdt_chk_basic() - see if basic checking of params and DT data is enabled */
static inline bool fdt_chk_basic(void)
{
return !(FDT_ASSUME_MASK & FDT_ASSUME_SANE);
}
/** fdt_chk_version() - see if we need to handle old versions of the DT */
static inline bool fdt_chk_version(void)
{
return !(FDT_ASSUME_MASK & FDT_ASSUME_LATEST);
}
/** fdt_chk_extra() - see if extra checking is enabled */
static inline bool fdt_chk_extra(void)
{
return !(FDT_ASSUME_MASK & FDT_ASSUME_FRIENDLY);
}
#endif /* LIBFDT_INTERNAL_H */
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