hc
2024-01-31 f70575805708cabdedea7498aaa3f710fde4d920
kernel/scripts/dtc/libfdt/libfdt_internal.h
....@@ -1,65 +1,21 @@
1
+/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
12 #ifndef LIBFDT_INTERNAL_H
23 #define LIBFDT_INTERNAL_H
34 /*
45 * libfdt - Flat Device Tree manipulation
56 * Copyright (C) 2006 David Gibson, IBM Corporation.
6
- *
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- * libfdt is dual licensed: you can use it either under the terms of
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- * the GPL, or the BSD license, at your option.
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- *
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- * a) This library is free software; you can redistribute it and/or
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- * modify it under the terms of the GNU General Public License as
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- * published by the Free Software Foundation; either version 2 of the
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- * License, or (at your option) any later version.
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- *
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- * This library is distributed in the hope that it will be useful,
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- * but WITHOUT ANY WARRANTY; without even the implied warranty of
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- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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- * GNU General Public License for more details.
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- *
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- * You should have received a copy of the GNU General Public
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- * License along with this library; if not, write to the Free
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- * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
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- * MA 02110-1301 USA
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- *
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- * Alternatively,
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- *
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- * b) Redistribution and use in source and binary forms, with or
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- * without modification, are permitted provided that the following
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- * conditions are met:
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- *
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- * 1. Redistributions of source code must retain the above
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- * copyright notice, this list of conditions and the following
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- * disclaimer.
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- * 2. Redistributions in binary form must reproduce the above
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- * copyright notice, this list of conditions and the following
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- * disclaimer in the documentation and/or other materials
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- * provided with the distribution.
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- *
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- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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- * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
527 */
538 #include <fdt.h>
549
5510 #define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1))
5611 #define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE))
5712
58
-#define FDT_CHECK_HEADER(fdt) \
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- { \
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- int err_; \
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- if ((err_ = fdt_check_header(fdt)) != 0) \
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- return err_; \
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+int32_t fdt_ro_probe_(const void *fdt);
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+#define FDT_RO_PROBE(fdt) \
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+ { \
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+ int32_t totalsize_; \
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+ if ((totalsize_ = fdt_ro_probe_(fdt)) < 0) \
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+ return totalsize_; \
6319 }
6420
6521 int fdt_check_node_offset_(const void *fdt, int offset);
....@@ -92,4 +48,126 @@
9248
9349 #define FDT_SW_MAGIC (~FDT_MAGIC)
9450
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+/**********************************************************************/
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+/* Checking controls */
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+/**********************************************************************/
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+
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+#ifndef FDT_ASSUME_MASK
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+#define FDT_ASSUME_MASK 0
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+#endif
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+
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+/*
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+ * Defines assumptions which can be enabled. Each of these can be enabled
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+ * individually. For maximum safety, don't enable any assumptions!
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+ *
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+ * For minimal code size and no safety, use ASSUME_PERFECT at your own risk.
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+ * You should have another method of validating the device tree, such as a
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+ * signature or hash check before using libfdt.
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+ *
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+ * For situations where security is not a concern it may be safe to enable
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+ * ASSUME_SANE.
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+ */
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+enum {
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+ /*
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+ * This does essentially no checks. Only the latest device-tree
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+ * version is correctly handled. Inconsistencies or errors in the device
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+ * tree may cause undefined behaviour or crashes. Invalid parameters
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+ * passed to libfdt may do the same.
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+ *
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+ * If an error occurs when modifying the tree it may leave the tree in
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+ * an intermediate (but valid) state. As an example, adding a property
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+ * where there is insufficient space may result in the property name
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+ * being added to the string table even though the property itself is
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+ * not added to the struct section.
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+ *
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+ * Only use this if you have a fully validated device tree with
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+ * the latest supported version and wish to minimise code size.
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+ */
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+ ASSUME_PERFECT = 0xff,
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+
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+ /*
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+ * This assumes that the device tree is sane. i.e. header metadata
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+ * and basic hierarchy are correct.
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+ *
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+ * With this assumption enabled, normal device trees produced by libfdt
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+ * and the compiler should be handled safely. Malicious device trees and
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+ * complete garbage may cause libfdt to behave badly or crash. Truncated
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+ * device trees (e.g. those only partially loaded) can also cause
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+ * problems.
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+ *
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+ * Note: Only checks that relate exclusively to the device tree itself
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+ * (not the parameters passed to libfdt) are disabled by this
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+ * assumption. This includes checking headers, tags and the like.
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+ */
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+ ASSUME_VALID_DTB = 1 << 0,
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+
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+ /*
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+ * This builds on ASSUME_VALID_DTB and further assumes that libfdt
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+ * functions are called with valid parameters, i.e. not trigger
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+ * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any
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+ * extensive checking of parameters and the device tree, making various
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+ * assumptions about correctness.
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+ *
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+ * It doesn't make sense to enable this assumption unless
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+ * ASSUME_VALID_DTB is also enabled.
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+ */
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+ ASSUME_VALID_INPUT = 1 << 1,
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+
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+ /*
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+ * This disables checks for device-tree version and removes all code
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+ * which handles older versions.
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+ *
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+ * Only enable this if you know you have a device tree with the latest
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+ * version.
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+ */
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+ ASSUME_LATEST = 1 << 2,
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+
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+ /*
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+ * This assumes that it is OK for a failed addition to the device tree,
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+ * due to lack of space or some other problem, to skip any rollback
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+ * steps (such as dropping the property name from the string table).
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+ * This is safe to enable in most circumstances, even though it may
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+ * leave the tree in a sub-optimal state.
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+ */
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+ ASSUME_NO_ROLLBACK = 1 << 3,
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+
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+ /*
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+ * This assumes that the device tree components appear in a 'convenient'
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+ * order, i.e. the memory reservation block first, then the structure
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+ * block and finally the string block.
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+ *
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+ * This order is not specified by the device-tree specification,
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+ * but is expected by libfdt. The device-tree compiler always created
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+ * device trees with this order.
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+ *
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+ * This assumption disables a check in fdt_open_into() and removes the
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+ * ability to fix the problem there. This is safe if you know that the
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+ * device tree is correctly ordered. See fdt_blocks_misordered_().
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+ */
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+ ASSUME_LIBFDT_ORDER = 1 << 4,
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+
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+ /*
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+ * This assumes that libfdt itself does not have any internal bugs. It
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+ * drops certain checks that should never be needed unless libfdt has an
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+ * undiscovered bug.
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+ *
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+ * This can generally be considered safe to enable.
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+ */
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+ ASSUME_LIBFDT_FLAWLESS = 1 << 5,
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+};
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+
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+/**
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+ * can_assume_() - check if a particular assumption is enabled
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+ *
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+ * @mask: Mask to check (ASSUME_...)
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+ * @return true if that assumption is enabled, else false
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+ */
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+static inline bool can_assume_(int mask)
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+{
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+ return FDT_ASSUME_MASK & mask;
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+}
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+
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+/** helper macros for checking assumptions */
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+#define can_assume(_assume) can_assume_(ASSUME_ ## _assume)
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+
95173 #endif /* LIBFDT_INTERNAL_H */