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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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