diff --git a/newlib/libc/sys/rtems/include/README b/newlib/libc/sys/rtems/include/README
new file mode 100644
index 000000000..8232ef160
--- /dev/null
+++ b/newlib/libc/sys/rtems/include/README
@@ -0,0 +1,79 @@
+Some files in this directory are imported from FreeBSD.  The last
+synchronization point with FreeBSD is the following FreeBSD commit:
+
+commit 3bf66365129a13933f77d1f4421d5136861cffb4
+Author: Brooks Davis <brooks@FreeBSD.org>
+Date:   Wed Jul 6 14:03:48 2022 +0100
+
+    cddl/*: add a WITH(OUT)_DTRACE option
+
+    Add an option to enable/disable DTrace without disabling ZFS.  New
+    architectures such as CHERI may support ZFS before they support DTrace
+    and the old model of WITHOUT_CDDL disabling both wasn't helpful.
+
+    For compatiblity, the CDDL option remains and WITHOUT_CDDL implies
+    WITHOUT_DTRACE.  WITHOUT_DTRACE also implies WITHOUT_CTF.
+
+    As part of this change, largely convert cddl/*/Makefile to using the
+    more compact SUBDIR.${MK_<FOO>}+= form rather than using intermediate
+    variables.
+
+    Reviewed by:    markj
+    Obtained from:  CheriBSD
+    Sponsored by:   DARPA, AFRL
+    Differential Revision:  https://reviews.freebsd.org/D35718
+
+The files imported from FreeSD may be updated to a new FreeBSD baseline through
+a patch set generated by this Git command:
+
+git format-patch 3bf66365129a13933f77d1f4421d5136861cffb4 -- \
+include/arpa/inet.h include/netdb.h include/termios.h sys/net/if.h \
+sys/netinet6/in6.h sys/netinet/in.h sys/netinet/tcp.h sys/sys/filio.h \
+sys/sys/ioccom.h sys/sys/_iovec.h sys/sys/mman.h sys/sys/poll.h \
+sys/sys/_sockaddr_storage.h sys/sys/socket.h sys/sys/sockio.h \
+sys/sys/syslog.h sys/sys/_termios.h sys/sys/ttycom.h sys/sys/ttydefaults.h \
+sys/sys/_uio.h sys/sys/uio.h sys/sys/un.h
+
+Use the follwing commands to map FreeBSD paths to Newlib paths:
+
+sed -i 's,include/arpa/inet.h,newlib/libc/sys/rtems/include/arpa/inet.h,g' *.patch
+sed -i 's,include/netdb.h,newlib/libc/sys/rtems/include/netdb.h,g' *.patch
+sed -i 's,include/termios.h,newlib/libc/sys/rtems/include/termios.h,g' *.patch
+sed -i 's,sys/net/if.h,newlib/libc/sys/rtems/include/net/if.h,g' *.patch
+sed -i 's,sys/netinet6/in6.h,newlib/libc/sys/rtems/include/netinet6/in6.h,g' *.patch
+sed -i 's,sys/netinet/in.h,newlib/libc/sys/rtems/include/netinet/in.h,g' *.patch
+sed -i 's,sys/netinet/tcp.h,newlib/libc/sys/rtems/include/netinet/tcp.h,g' *.patch
+sed -i 's,sys/sys/filio.h,newlib/libc/sys/rtems/include/sys/filio.h,g' *.patch
+sed -i 's,sys/sys/ioccom.h,newlib/libc/sys/rtems/include/sys/ioccom.h,g' *.patch
+sed -i 's,sys/sys/_iovec.h,newlib/libc/sys/rtems/include/sys/_iovec.h,g' *.patch
+sed -i 's,sys/sys/mman.h,newlib/libc/sys/rtems/include/sys/mman.h,g' *.patch
+sed -i 's,sys/sys/poll.h,newlib/libc/sys/rtems/include/sys/poll.h,g' *.patch
+sed -i 's,sys/sys/_sockaddr_storage.h,newlib/libc/sys/rtems/include/sys/_sockaddr_storage.h,g' *.patch
+sed -i 's,sys/sys/socket.h,newlib/libc/sys/rtems/include/sys/socket.h,g' *.patch
+sed -i 's,sys/sys/sockio.h,newlib/libc/sys/rtems/include/sys/sockio.h,g' *.patch
+sed -i 's,sys/sys/syslog.h,newlib/libc/sys/rtems/include/sys/syslog.h,g' *.patch
+sed -i 's,sys/sys/_termios.h,newlib/libc/sys/rtems/include/sys/_termios.h,g' *.patch
+sed -i 's,sys/sys/ttycom.h,newlib/libc/sys/rtems/include/sys/ttycom.h,g' *.patch
+sed -i 's,sys/sys/ttydefaults.h,newlib/libc/sys/rtems/include/sys/ttydefaults.h,g' *.patch
+sed -i 's,sys/sys/_uio.h,newlib/libc/sys/rtems/include/sys/_uio.h,g' *.patch
+sed -i 's,sys/sys/uio.h,newlib/libc/sys/rtems/include/sys/uio.h,g' *.patch
+sed -i 's,sys/sys/un.h,newlib/libc/sys/rtems/include/sys/un.h,g' *.patch
+
+Some patches may change kernel space parts of the above header files.  These
+parts are contained in kernel space header files provided by RTEMS or LibBSD.
+Gather all patches and hunks of patches which belong to the kernel space so
+that they can be applied to RTEMS or LibBSD.  Use the following commands to map
+Newlib paths to kernel space header files.
+
+sed -i 's,newlib/libc/sys/rtems/include/netinet6/in6.h,cpukit/include/machine/_kernel_in6.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/netinet/in.h,cpukit/include/machine/_kernel_in.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/cpuset.h,cpukit/include/machine/_kernel_cpuset.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/mman.h,cpukit/include/machine/_kernel_mman.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/param.h,cpukit/include/machine/_kernel_param.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/time.h,cpukit/include/machine/_kernel_time.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/types.h,cpukit/include/machine/_kernel_types.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/uio.h,cpukit/include/machine/_kernel_uio.h,g' *.patch
+
+sed -i 's,newlib/libc/sys/rtems/include/net/if.h,rtemsbsd/include/machine/_kernel_if.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/lock.h,rtemsbsd/include/machine/_kernel_lock.h,g' *.patch
+sed -i 's,newlib/libc/sys/rtems/include/sys/socket.h,rtemsbsd/include/machine/_kernel_socket.h,g' *.patch