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-rw-r--r--tools/objtool/include/objtool/endianness.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/tools/objtool/include/objtool/endianness.h b/tools/objtool/include/objtool/endianness.h
new file mode 100644
index 000000000000..10241341eff3
--- /dev/null
+++ b/tools/objtool/include/objtool/endianness.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _OBJTOOL_ENDIANNESS_H
+#define _OBJTOOL_ENDIANNESS_H
+
+#include <arch/endianness.h>
+#include <linux/kernel.h>
+#include <endian.h>
+
+#ifndef __TARGET_BYTE_ORDER
+#error undefined arch __TARGET_BYTE_ORDER
+#endif
+
+#if __BYTE_ORDER != __TARGET_BYTE_ORDER
+#define __NEED_BSWAP 1
+#else
+#define __NEED_BSWAP 0
+#endif
+
+/*
+ * Does a byte swap if target endianness doesn't match the host, i.e. cross
+ * compilation for little endian on big endian and vice versa.
+ * To be used for multi-byte values conversion, which are read from / about
+ * to be written to a target native endianness ELF file.
+ */
+#define bswap_if_needed(val) \
+({ \
+ __typeof__(val) __ret; \
+ switch (sizeof(val)) { \
+ case 8: __ret = __NEED_BSWAP ? bswap_64(val) : (val); break; \
+ case 4: __ret = __NEED_BSWAP ? bswap_32(val) : (val); break; \
+ case 2: __ret = __NEED_BSWAP ? bswap_16(val) : (val); break; \
+ default: \
+ BUILD_BUG(); break; \
+ } \
+ __ret; \
+})
+
+#endif /* _OBJTOOL_ENDIANNESS_H */