Index: head/contrib/elftoolchain/common/_elftc.h
===================================================================
--- head/contrib/elftoolchain/common/_elftc.h
+++ head/contrib/elftoolchain/common/_elftc.h
@@ -374,11 +374,14 @@
 
 #include <libkern/OSByteOrder.h>
 #define	htobe32(x)	OSSwapHostToBigInt32(x)
+#define	htole32(x)	OSSwapHostToLittleInt32(x)
+#ifndef roundup2
 #define	roundup2	roundup
+#endif
 
-#define	ELFTC_BYTE_ORDER			_BYTE_ORDER
-#define	ELFTC_BYTE_ORDER_LITTLE_ENDIAN		_LITTLE_ENDIAN
-#define	ELFTC_BYTE_ORDER_BIG_ENDIAN		_BIG_ENDIAN
+#define	ELFTC_BYTE_ORDER			__DARWIN_BYTE_ORDER
+#define	ELFTC_BYTE_ORDER_LITTLE_ENDIAN		__DARWIN_LITTLE_ENDIAN
+#define	ELFTC_BYTE_ORDER_BIG_ENDIAN		__DARWIN_BIG_ENDIAN
 
 #define	ELFTC_HAVE_MMAP				1
 #define	ELFTC_HAVE_STRMODE			1
@@ -418,7 +421,9 @@
 /* Whether we need to supply {be,le}32dec. */
 #define ELFTC_NEED_BYTEORDER_EXTENSIONS		1
 
+#ifndef roundup2
 #define	roundup2	roundup
+#endif
 
 #endif	/* __GLIBC__ || __linux__ */
 
Index: head/contrib/elftoolchain/libelftc/elftc_set_timestamps.c
===================================================================
--- head/contrib/elftoolchain/libelftc/elftc_set_timestamps.c
+++ head/contrib/elftoolchain/libelftc/elftc_set_timestamps.c
@@ -37,7 +37,7 @@
  * stat'.
  */
 
-#if	defined(__FreeBSD__) || defined(__NetBSD__)
+#if	defined(__FreeBSD__) || defined(__NetBSD__) || defined(__APPLE__)
 #define	ATIME	st_atimespec
 #define	MTIME	st_mtimespec
 #define	LIBELFTC_HAVE_UTIMES	1
Index: head/lib/libelf/Makefile
===================================================================
--- head/lib/libelf/Makefile
+++ head/lib/libelf/Makefile
@@ -79,6 +79,13 @@
 #
 SRCS+=	sys/elf32.h sys/elf64.h sys/elf_common.h
 
+# Allow bootstrapping elftoolchain on Linux:
+.if defined(BOOTSTRAPPING) && ${.MAKE.OS} == "Linux"
+native-elf-format.h:
+	${ELFTCDIR}/common/native-elf-format > ${.TARGET} || rm ${.TARGET}
+SRCS+=	native-elf-format.h
+.endif
+
 GENSRCS=	libelf_fsize.c libelf_msize.c libelf_convert.c
 CLEANFILES=	${GENSRCS}
 CLEANDIRS=	sys