UPDATING revision 253972
1Updating Information for FreeBSD current users
2
3This file is maintained and copyrighted by M. Warner Losh <imp@freebsd.org>.
4See end of file for further details.  For commonly done items, please see the
5COMMON ITEMS: section later in the file.  These instructions assume that you
6basically know what you are doing.  If not, then please consult the FreeBSD
7handbook:
8
9    http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html
10
11Items affecting the ports and packages system can be found in
12/usr/ports/UPDATING.  Please read that file before running portupgrade.
13
14NOTE: FreeBSD has switched from gcc to clang. If you have trouble bootstrapping
15from older versions of FreeBSD, try WITHOUT_CLANG to bootstrap to the tip of
16head, and then rebuild without this option. The bootstrap process from
17older version of current is a bit fragile.
18
19NOTE TO PEOPLE WHO THINK THAT FreeBSD 10.x IS SLOW:
20	FreeBSD 10.x has many debugging features turned on, in both the kernel
21	and userland.  These features attempt to detect incorrect use of
22	system primitives, and encourage loud failure through extra sanity
23	checking and fail stop semantics.  They also substantially impact
24	system performance.  If you want to do performance measurement,
25	benchmarking, and optimization, you'll want to turn them off.  This
26	includes various WITNESS- related kernel options, INVARIANTS, malloc
27	debugging flags in userland, and various verbose features in the
28	kernel.  Many developers choose to disable these features on build
29	machines to maximize performance.  (To completely disable malloc
30	debugging, define MALLOC_PRODUCTION in /etc/make.conf, or to merely
31	disable the most expensive debugging functionality run
32	"ln -s 'abort:false,junk:false' /etc/malloc.conf".)
33
3420130806:
35	Timer values in IPv6 data structures now use time_uptime instead
36	of time_second.  Although this is not a user-visible functional
37	change, userland utilities which directly use them---ndp(8),
38	rtadvd(8), and rtsold(8) in the base system---need to be updated
39	to r253970 or later.
40
4120130802:
42	find -delete can now delete the pathnames given as arguments,
43	instead of only files found below them or if the pathname did
44	not contain any slashes. Formerly, the following error message
45	would result:
46
47	find: -delete: <path>: relative path potentially not safe
48
49	Deleting the pathnames given as arguments can be prevented
50	without error messages using -mindepth 1 or by changing
51	directory and passing "." as argument to find. This works in the
52	old as well as the new version of find.
53
5420130726:
55	Behavior of devfs rules path matching has been changed.
56	Pattern is now always matched against fully qualified devfs
57	path and slash characters must be explicitly matched by
58	slashes in pattern (FNM_PATHNAME). Rulesets involving devfs
59	subdirectories must be reviewed.
60
6120130716:
62	The default ARM ABI has changed to the ARM EABI. The old ABI is
63	incompatible with the ARM EABI and all programs and modules will
64	need to be rebuilt to work with a new kernel.
65
66	To keep using the old ABI ensure the WITHOUT_ARM_EABI knob is set.
67
68	NOTE: Support for the old ABI will be removed in the future and
69	users are advised to upgrade.
70
7120130709:
72	pkg_install has been disconnected from the build if you really need it
73	you should add WITH_PKGTOOLS in your src.conf(5).
74
7520130709:
76	Most of network statistics structures were changed to be able
77	keep 64-bits counters. Thus all tools, that work with networking
78	statistics, must be rebuilt (netstat(1), bsnmpd(1), etc.)
79
8020130629:
81	Fix targets that run multiple make's to use && rather than ;
82	so that subsequent steps depend on success of previous.
83
84	NOTE: if building 'universe' with -j* on stable/8 or stable/9
85	it would be better to start the build using bmake, to avoid
86	overloading the machine.
87
8820130618:
89	Fix a bug that allowed a tracing process (e.g. gdb) to write
90	to a memory-mapped file in the traced process's address space
91	even if neither the traced process nor the tracing process had
92	write access to that file.
93
9420130615:
95	CVS has been removed from the base system.  An exact copy
96	of the code is available from the devel/cvs port.
97
9820130613:
99	Some people report the following error after the switch to bmake:
100
101		make: illegal option -- J
102		usage: make [-BPSXeiknpqrstv] [-C directory] [-D variable]
103			...
104		*** [buildworld] Error code 2
105
106	this likely due to an old instance of make in
107	${MAKEPATH} (${MAKEOBJDIRPREFIX}${.CURDIR}/make.${MACHINE})
108	which src/Makefile will use that blindly, if it exists, so if
109	you see the above error:
110
111		rm -rf `make -V MAKEPATH`
112
113	should resolve it.
114
11520130516:
116	Use bmake by default.
117	Whereas before one could choose to build with bmake via
118	-DWITH_BMAKE one must now use -DWITHOUT_BMAKE to use the old
119	make. The goal is to remove these knobs for 10-RELEASE.
120
121	It is worth noting that bmake (like gmake) treats the command
122	line as the unit of failure, rather than statements within the
123	command line.  Thus '(cd some/where && dosomething)' is safer
124	than 'cd some/where; dosomething'. The '()' allows consistent
125	behavior in parallel build.
126
12720130429:
128        Fix a bug that allows NFS clients to issue READDIR on files.
129
13020130426:
131	The WITHOUT_IDEA option has been removed because
132	the IDEA patent expired.
133
13420130426:
135	The sysctl which controls TRIM support under ZFS has been renamed
136	from vfs.zfs.trim_disable -> vfs.zfs.trim.enabled and has been
137	enabled by default.
138
13920130425:
140	The mergemaster command now uses the default MAKEOBJDIRPREFIX
141	rather than creating it's own in the temporary directory in
142	order allow access to bootstrapped versions of tools such as
143	install and mtree.  When upgrading from version of FreeBSD where
144	the install command does not support -l, you will need to
145	install a new mergemaster command if mergemaster -p is required.
146	This can be accomplished with the command (cd src/usr.sbin/mergemaster
147	&& make install).
148
14920130404:
150	Legacy ATA stack, disabled and replaced by new CAM-based one since
151	FreeBSD 9.0, completely removed from the sources.  Kernel modules
152	atadisk and atapi*, user-level tools atacontrol and burncd are
153	removed.  Kernel option `options ATA_CAM` is now permanently enabled
154	and removed.
155
15620130319:
157	SOCK_CLOEXEC and SOCK_NONBLOCK flags have been added to socket(2)
158	and socketpair(2). Software, in particular Kerberos, may
159	automatically detect and use these during building. The resulting
160	binaries will not work on older kernels.
161
16220130308:
163	CTL_DISABLE has also been added to the sparc64 GENERIC (for further
164	information, see the respective 20130304 entry).
165
16620130304:
167	Recent commits to callout(9) changed the size of struct callout,
168	so the KBI is probably heavily disturbed. Also, some functions
169	in callout(9)/sleep(9)/sleepqueue(9)/condvar(9) KPIs were replaced
170	by macros. Every kernel module using it won't load, so rebuild
171	is requested.
172
173	The ctl device has been re-enabled in GENERIC for i386 and amd64,
174	but does not initialize by default (because of the new CTL_DISABLE
175	option) to save memory.  To re-enable it, remove the CTL_DISABLE
176	option from the kernel config file or set kern.cam.ctl.disable=0
177	in /boot/loader.conf.
178
17920130301:
180	The ctl device has been disabled in GENERIC for i386 and amd64.
181	This was done due to the extra memory being allocated at system
182	initialisation time by the ctl driver which was only used if
183	a CAM target device was created.  This makes a FreeBSD system
184	unusable on 128MB or less of RAM.
185
18620130208:
187	A new compression method (lz4) has been merged to -HEAD.  Please
188	refer to zpool-features(7) for more information.
189
190	Please refer to the "ZFS notes" section of this file for information
191	on upgrading boot ZFS pools.
192
19320130129:
194	A BSD-licensed patch(1) variant has been added and is installed
195	as bsdpatch, being the GNU version the default patch.
196	To inverse the logic and use the BSD-licensed one as default,
197	while having the GNU version installed as gnupatch, rebuild
198	and install world with the WITH_BSD_PATCH knob set.
199
20020130121:
201	Due to the use of the new -l option to install(1) during build
202	and install, you must take care not to directly set the INSTALL
203	make variable in your /etc/make.conf, /etc/src.conf, or on the
204	command line.  If you wish to use the -C flag for all installs
205	you may be able to add INSTALL+=-C to /etc/make.conf or
206	/etc/src.conf.
207
20820130118:
209	The install(1) option -M has changed meaning and now takes an
210	argument that is a file or path to append logs to.  In the
211	unlikely event that -M was the last option on the command line
212	and the command line contained at least two files and a target
213	directory the first file will have logs appended to it.  The -M
214	option served little practical purpose in the last decade so its
215	use is expected to be extremely rare.
216
21720121223:
218	After switching to Clang as the default compiler some users of ZFS
219	on i386 systems started to experience stack overflow kernel panics.
220	Please consider using 'options KSTACK_PAGES=4' in such configurations.
221
22220121222:
223	GEOM_LABEL now mangles label names read from file system metadata.
224	Mangling affect labels containing spaces, non-printable characters,
225	'%' or '"'. Device names in /etc/fstab and other places may need to
226	be updated.
227
22820121217:
229	By default, only the 10 most recent kernel dumps will be saved.  To
230	restore the previous behaviour (no limit on the number of kernel dumps
231	stored in the dump directory) add the following line to /etc/rc.conf:
232
233		savecore_flags=""
234
23520121201:
236	With the addition of auditdistd(8), a new auditdistd user is now
237	depended on during installworld.  "mergemaster -p" can be used to add
238	the user prior to installworld, as documented in the handbook.
239
24020121117:
241	The sin6_scope_id member variable in struct sockaddr_in6 is now
242	filled by the kernel before passing the structure to the userland via
243	sysctl or routing socket.  This means the KAME-specific embedded scope
244	id in sin6_addr.s6_addr[2] is always cleared in userland application.
245	This behavior can be controlled by net.inet6.ip6.deembed_scopeid.
246	__FreeBSD_version is bumped to 1000025.
247
24820121105:
249	On i386 and amd64 systems WITH_CLANG_IS_CC is now the default.
250	This means that the world and kernel will be compiled with clang
251	and that clang will be installed as /usr/bin/cc, /usr/bin/c++,
252	and /usr/bin/cpp.  To disable this behavior and revert to building
253	with gcc, compile with WITHOUT_CLANG_IS_CC. Really old versions
254	of current may need to bootstrap WITHOUT_CLANG first if the clang
255	build fails (its compatibility window doesn't extend to the 9 stable
256	branch point).
257
25820121102:
259	The IPFIREWALL_FORWARD kernel option has been removed. Its
260	functionality now turned on by default.
261
26220121023:
263	The ZERO_COPY_SOCKET kernel option has been removed and
264	split into SOCKET_SEND_COW and SOCKET_RECV_PFLIP.
265	NB: SOCKET_SEND_COW uses the VM page based copy-on-write
266	mechanism which is not safe and may result in kernel crashes.
267	NB: The SOCKET_RECV_PFLIP mechanism is useless as no current
268	driver supports disposeable external page sized mbuf storage.
269	Proper replacements for both zero-copy mechanisms are under
270	consideration and will eventually lead to complete removal
271	of the two kernel options.
272
27320121023:
274	The IPv4 network stack has been converted to network byte
275	order. The following modules need to be recompiled together
276	with kernel: carp(4), divert(4), gif(4), siftr(4), gre(4),
277	pf(4), ipfw(4), ng_ipfw(4), stf(4).
278
27920121022:
280	Support for non-MPSAFE filesystems was removed from VFS. The
281	VFS_VERSION was bumped, all filesystem modules shall be
282	recompiled.
283
28420121018:
285	All the non-MPSAFE filesystems have been disconnected from
286	the build. The full list includes: codafs, hpfs, ntfs, nwfs,
287	portalfs, smbfs, xfs.
288
28920121016:
290	The interface cloning API and ABI has changed. The following
291	modules need to be recompiled together with kernel:
292	ipfw(4), pfsync(4), pflog(4), usb(4), wlan(4), stf(4),
293	vlan(4), disc(4), edsc(4), if_bridge(4), gif(4), tap(4),
294	faith(4), epair(4), enc(4), tun(4), if_lagg(4), gre(4).
295
29620121015:
297	The sdhci driver was split in two parts: sdhci (generic SD Host
298	Controller logic) and sdhci_pci (actual hardware driver).
299	No kernel config modifications are required, but if you
300	load sdhc as a module you must switch to sdhci_pci instead.
301
30220121014:
303	Import the FUSE kernel and userland support into base system.
304
30520121013:
306	The GNU sort(1) program has been removed since the BSD-licensed
307	sort(1) has been the default for quite some time and no serious
308	problems have been reported.  The corresponding WITH_GNU_SORT
309	knob has also gone.
310
31120121006:
312	The pfil(9) API/ABI for AF_INET family has been changed. Packet
313	filtering modules: pf(4), ipfw(4), ipfilter(4) need to be recompiled
314	with new kernel.
315
31620121001:
317	The net80211(4) ABI has been changed to allow for improved driver
318	PS-POLL and power-save support.  All wireless drivers need to be
319	recompiled to work with the new kernel.
320
32120120913:
322	The random(4) support for the VIA hardware random number
323	generator (`PADLOCK') is no longer enabled unconditionally.
324	Add the PADLOCK_RNG option in the custom kernel config if
325	needed.  The GENERIC kernels on i386 and amd64 do include the
326	option, so the change only affects the custom kernel
327	configurations.
328
32920120908:
330	The pf(4) packet filter ABI has been changed. pfctl(8) and
331	snmp_pf module need to be recompiled to work with new kernel.
332
33320120828:
334	A new ZFS feature flag "com.delphix:empty_bpobj" has been merged
335	to -HEAD. Pools that have empty_bpobj in active state can not be
336	imported read-write with ZFS implementations that do not support
337	this feature. For more information read the zpool-features(5)
338	manual page.
339
34020120727:
341	The sparc64 ZFS loader has been changed to no longer try to auto-
342	detect ZFS providers based on diskN aliases but now requires these
343	to be explicitly listed in the OFW boot-device environment variable. 
344
34520120712:
346	The OpenSSL has been upgraded to 1.0.1c.  Any binaries requiring
347	libcrypto.so.6 or libssl.so.6 must be recompiled.  Also, there are
348	configuration changes.  Make sure to merge /etc/ssl/openssl.cnf.
349
35020120712:
351	The following sysctls and tunables have been renamed for consistency
352	with other variables:
353	  kern.cam.da.da_send_ordered   -> kern.cam.da.send_ordered
354	  kern.cam.ada.ada_send_ordered -> kern.cam.ada.send_ordered
355
35620120628:
357	The sort utility has been replaced with BSD sort.  For now, GNU sort
358	is also available as "gnusort" or the default can be set back to
359	GNU sort by setting WITH_GNU_SORT.  In this case, BSD sort will be
360	installed as "bsdsort".
361
36220120611:
363	A new version of ZFS (pool version 5000) has been merged to -HEAD.
364	Starting with this version the old system of ZFS pool versioning
365	is superseded by "feature flags". This concept enables forward
366	compatibility against certain future changes in functionality of ZFS
367	pools. The first read-only compatible "feature flag" for ZFS pools
368	is named "com.delphix:async_destroy". For more information
369	read the new zpool-features(5) manual page.
370	Please refer to the "ZFS notes" section of this file for information
371	on upgrading boot ZFS pools.
372
37320120417:
374	The malloc(3) implementation embedded in libc now uses sources imported
375	as contrib/jemalloc.  The most disruptive API change is to
376	/etc/malloc.conf.  If your system has an old-style /etc/malloc.conf,
377	delete it prior to installworld, and optionally re-create it using the
378	new format after rebooting.  See malloc.conf(5) for details
379	(specifically the TUNING section and the "opt.*" entries in the MALLCTL
380	NAMESPACE section).
381
38220120328:
383	Big-endian MIPS TARGET_ARCH values no longer end in "eb".  mips64eb
384	is now spelled mips64.  mipsn32eb is now spelled mipsn32.  mipseb is
385	now spelled mips.  This is to aid compatibility with third-party
386	software that expects this naming scheme in uname(3).  Little-endian
387	settings are unchanged. If you are updating a big-endian mips64 machine
388	from before this change, you may need to set MACHINE_ARCH=mips64 in
389	your environment before the new build system will recognize your machine.
390
39120120306:
392	Disable by default the option VFS_ALLOW_NONMPSAFE for all supported
393	platforms.
394
39520120229:
396	Now unix domain sockets behave "as expected" on	nullfs(5). Previously
397	nullfs(5) did not pass through all behaviours to the underlying layer,
398	as a result if we bound to a socket on the lower layer we could connect
399	only to the lower path; if we bound to the upper layer we could connect
400	only to	the upper path. The new behavior is one can connect to both the
401	lower and the upper paths regardless what layer path one binds to.
402
40320120211:
404	The getifaddrs upgrade path broken with 20111215 has been restored.
405	If you have upgraded in between 20111215 and 20120209 you need to
406	recompile libc again with your kernel.  You still need to recompile
407	world to be able to configure CARP but this restriction already
408	comes from 20111215.
409
41020120114:
411	The set_rcvar() function has been removed from /etc/rc.subr.  All
412	base and ports rc.d scripts have been updated, so if you have a
413	port installed with a script in /usr/local/etc/rc.d you can either
414	hand-edit the rcvar= line, or reinstall the port.
415
416	An easy way to handle the mass-update of /etc/rc.d:
417	rm /etc/rc.d/* && mergemaster -i
418
41920120109:
420	panic(9) now stops other CPUs in the SMP systems, disables interrupts
421	on the current CPU and prevents other threads from running.
422	This behavior can be reverted using the kern.stop_scheduler_on_panic
423	tunable/sysctl.
424	The new behavior can be incompatible with kern.sync_on_panic.
425
42620111215:
427	The carp(4) facility has been changed significantly. Configuration
428	of the CARP protocol via ifconfig(8) has changed, as well as format
429	of CARP events submitted to devd(8) has changed. See manual pages
430	for more information. The arpbalance feature of carp(4) is currently
431	not supported anymore.
432
433	Size of struct in_aliasreq, struct in6_aliasreq has changed. User
434	utilities using SIOCAIFADDR, SIOCAIFADDR_IN6, e.g. ifconfig(8),
435	need to be recompiled.
436
43720111122:
438	The acpi_wmi(4) status device /dev/wmistat has been renamed to
439	/dev/wmistat0.
440
44120111108:
442	The option VFS_ALLOW_NONMPSAFE option has been added in order to
443	explicitely support non-MPSAFE filesystems.
444	It is on by default for all supported platform at this present
445	time.
446
44720111101:
448	The broken amd(4) driver has been replaced with esp(4) in the amd64,
449	i386 and pc98 GENERIC kernel configuration files.
450
45120110930:
452	sysinstall has been removed
453
45420110923:
455	The stable/9 branch created in subversion.  This corresponds to the
456	RELENG_9 branch in CVS.
457
45820110913:
459	This commit modifies vfs_register() so that it uses a hash
460	calculation to set vfc_typenum, which is enabled by default.
461	The first time a system is booted after this change, the
462	vfc_typenum values will change for all file systems. The
463	main effect of this is a change to the NFS server file handles
464	for file systems that use vfc_typenum in their fsid, such as ZFS.
465	It will, however, prevent vfc_typenum from changing when file
466	systems are loaded in a different order for subsequent reboots.
467	To disable this, you can set vfs.typenumhash=0 in /boot/loader.conf
468	until you are ready to remount all NFS clients after a reboot.
469
47020110828:
471	Bump the shared library version numbers for libraries that
472	do not use symbol versioning, have changed the ABI compared
473	to stable/8 and which shared library version was not bumped.
474	Done as part of 9.0-RELEASE cycle.
475
47620110815:
477	During the merge of Capsicum features, the fget(9) KPI was modified.
478	This may require the rebuilding of out-of-tree device drivers --
479	issues have been reported specifically with the nVidia device driver.
480	__FreeBSD_version is bumped to 900041.
481
482	Also, there is a period between 20110811 and 20110814 where the
483	special devices /dev/{stdin,stdout,stderr} did not work correctly.
484	Building world from a kernel during that window may not work.
485
48620110628:
487	The packet filter (pf) code has been updated to OpenBSD 4.5.
488	You need to update userland tools to be in sync with kernel.
489	This update breaks backward compatibility with earlier pfsync(4)
490	versions.  Care must be taken when updating redundant firewall setups.
491
49220110608:
493	The following sysctls and tunables are retired on x86 platforms:
494		machdep.hlt_cpus
495		machdep.hlt_logical_cpus
496	The following sysctl is retired:
497		machdep.hyperthreading_allowed
498	The sysctls were supposed to provide a way to dynamically offline and
499	online selected CPUs on x86 platforms, but the implementation has not
500	been reliable especially with SCHED_ULE scheduler.
501	machdep.hyperthreading_allowed tunable is still available to ignore
502	hyperthreading CPUs at OS level.
503	Individual CPUs can be disabled using hint.lapic.X.disabled tunable,
504	where X is an APIC ID of a CPU.  Be advised, though, that disabling
505	CPUs in non-uniform fashion will result in non-uniform topology and
506	may lead to sub-optimal system performance with SCHED_ULE, which is
507	a default scheduler.
508
50920110607:
510	cpumask_t type is retired and cpuset_t is used in order to describe
511	a mask of CPUs.
512
51320110531:
514	Changes to ifconfig(8) for dynamic address family detection mandate
515	that you are running a kernel of 20110525 or later.  Make sure to
516	follow the update procedure to boot a new kernel before installing
517	world.
518
51920110513:
520	Support for sun4v architecture is officially dropped
521
52220110503:
523	Several KPI breaking changes have been committed to the mii(4) layer,
524	the PHY drivers and consequently some Ethernet drivers using mii(4).
525	This means that miibus.ko and the modules of the affected Ethernet
526	drivers need to be recompiled.
527
528	Note to kernel developers: Given that the OUI bit reversion problem
529	was fixed as part of these changes all mii(4) commits related to OUIs,
530	i.e. to sys/dev/mii/miidevs, PHY driver probing and vendor specific
531	handling, no longer can be merged verbatim to stable/8 and previous
532	branches.
533
53420110430:
535	Users of the Atheros AR71xx SoC code now need to add 'device ar71xx_pci'
536	into their kernel configurations along with 'device pci'.
537
53820110427:
539	The default NFS client is now the new NFS client, so fstype "newnfs"
540	is now "nfs" and the regular/old NFS client is now fstype "oldnfs".
541	Although mounts via fstype "nfs" will usually work without userland
542	changes, it is recommended that the mount(8) and mount_nfs(8)
543	commands be rebuilt from sources and that a link to mount_nfs called
544	mount_oldnfs be created. The new client is compiled into the
545	kernel with "options NFSCL" and this is needed for diskless root
546	file systems. The GENERIC kernel configs have been changed to use
547	NFSCL and NFSD (the new server) instead of NFSCLIENT and NFSSERVER.
548	To use the regular/old client, you can "mount -t oldnfs ...". For
549	a diskless root file system, you must also include a line like:
550	
551	vfs.root.mountfrom="oldnfs:"
552
553	in the boot/loader.conf on the root fs on the NFS server to make
554	a diskless root fs use the old client.
555
55620110424:
557	The GENERIC kernels for all architectures now default to the new
558	CAM-based ATA stack. It means that all legacy ATA drivers were
559	removed and replaced by respective CAM drivers. If you are using
560	ATA device names in /etc/fstab or other places, make sure to update
561	them respectively (adX -> adaY, acdX -> cdY, afdX -> daY, astX -> saY,
562	where 'Y's are the sequential numbers starting from zero for each type
563	in order of detection, unless configured otherwise with tunables,
564	see cam(4)). There will be symbolic links created in /dev/ to map
565	old adX devices to the respective adaY. They should provide basic
566	compatibility for file systems mounting in most cases, but they do
567	not support old user-level APIs and do not have respective providers
568	in GEOM. Consider using updated management tools with new device names.
569
570	It is possible to load devices ahci, ata, siis and mvs as modules,
571	but option ATA_CAM should remain in kernel configuration to make ata
572	module work as CAM driver supporting legacy ATA controllers. Device ata
573	still can be used in modular fashion (atacore + ...). Modules atadisk
574	and atapi* are not used and won't affect operation in ATA_CAM mode.
575	Note that to use CAM-based ATA kernel should include CAM devices
576	scbus, pass, da (or explicitly ada), cd and optionally others. All of
577	them are parts of the cam module.
578
579	ataraid(4) functionality is now supported by the RAID GEOM class.
580	To use it you can load geom_raid kernel module and use graid(8) tool
581	for management. Instead of /dev/arX device names, use /dev/raid/rX.
582
583	No kernel config options or code have been removed, so if a problem
584	arises, please report it and optionally revert to the old ATA stack.
585	In order to do it you can remove from the kernel config:
586	    options        ATA_CAM
587	    device         ahci
588	    device         mvs
589	    device         siis
590	, and instead add back:
591	    device         atadisk         # ATA disk drives
592	    device         ataraid         # ATA RAID drives
593	    device         atapicd         # ATAPI CDROM drives
594	    device         atapifd         # ATAPI floppy drives
595	    device         atapist         # ATAPI tape drives
596
59720110423:
598	The default NFS server has been changed to the new server, which
599	was referred to as the experimental server. If you need to switch
600	back to the old NFS server, you must now put the "-o" option on
601	both the mountd and nfsd commands. This can be done using the
602	mountd_flags and nfs_server_flags rc.conf variables until an
603	update to the rc scripts is committed, which is coming soon.
604
60520110418:
606	The GNU Objective-C runtime library (libobjc), and other Objective-C
607	related components have been removed from the base system.  If you
608	require an Objective-C library, please use one of the available ports.
609
61020110331:
611	ath(4) has been split into bus- and device- modules. if_ath contains
612	the HAL, the TX rate control and the network device code. if_ath_pci
613	contains the PCI bus glue. For Atheros MIPS embedded systems, if_ath_ahb
614	contains the AHB glue. Users need to load both if_ath_pci and if_ath
615	in order to use ath on everything else.
616
617	TO REPEAT: if_ath_ahb is not needed for normal users. Normal users only
618	need to load if_ath and if_ath_pci for ath(4) operation.
619
62020110314:
621	As part of the replacement of sysinstall, the process of building
622	release media has changed significantly. For details, please re-read
623	release(7), which has been updated to reflect the new build process.
624
62520110218:
626	GNU binutils 2.17.50 (as of 2007-07-03) has been merged to -HEAD.  This
627	is the last available version under GPLv2.  It brings a number of new
628	features, such as support for newer x86 CPU's (with SSE-3, SSSE-3, SSE
629	4.1 and SSE 4.2), better support for powerpc64, a number of new
630	directives, and lots of other small improvements.  See the ChangeLog
631	file in contrib/binutils for the full details.
632
63320110218:
634	IPsec's HMAC_SHA256-512 support has been fixed to be RFC4868
635	compliant, and will now use half of hash for authentication.
636	This will break interoperability with all stacks (including all
637	actual FreeBSD versions) who implement
638	draft-ietf-ipsec-ciph-sha-256-00 (they use 96 bits of hash for
639	authentication).
640	The only workaround with such peers is to use another HMAC
641	algorithm for IPsec ("phase 2") authentication.
642
64320110207:
644	Remove the uio_yield prototype and symbol.  This function has
645	been misnamed since it was introduced and should not be
646	globally exposed with this name.  The equivalent functionality
647	is now available using kern_yield(curthread->td_user_pri).
648	The function remains undocumented.
649
65020110112:
651	A SYSCTL_[ADD_]UQUAD was added for unsigned uint64_t pointers,
652	symmetric with the existing SYSCTL_[ADD_]QUAD.  Type checking
653	for scalar sysctls is defined but disabled.  Code that needs
654	UQUAD to pass the type checking that must compile on older
655	systems where the define is not present can check against
656	__FreeBSD_version >= 900030.
657
658	The system dialog(1) has been replaced with a new version previously
659	in ports as devel/cdialog. dialog(1) is mostly command-line compatible
660	with the previous version, but the libdialog associated with it has
661	a largely incompatible API. As such, the original version of libdialog
662	will be kept temporarily as libodialog, until its base system consumers
663	are replaced or updated. Bump __FreeBSD_version to 900030.
664
66520110103:
666	If you are trying to run make universe on a -stable system, and you get
667	the following warning:
668	"Makefile", line 356: "Target architecture for i386/conf/GENERIC 
669	unknown.  config(8) likely too old."
670	or something similar to it, then you must upgrade your -stable system
671	to 8.2-Release or newer (really, any time after r210146 7/15/2010 in
672	stable/8) or build the config from the latest stable/8 branch and
673	install it on your system.
674
675	Prior to this date, building a current universe on 8-stable system from
676	between 7/15/2010 and 1/2/2011 would result in a weird shell parsing
677	error in the first kernel build phase.  A new config on those old 
678	systems will fix that problem for older versions of -current.
679
68020101228:
681	The TCP stack has been modified to allow Khelp modules to interact with
682	it via helper hook points and store per-connection data in the TCP
683	control block. Bump __FreeBSD_version to 900029. User space tools that
684	rely on the size of struct tcpcb in tcp_var.h (e.g. sockstat) need to
685	be recompiled.
686
68720101114:
688	Generic IEEE 802.3 annex 31B full duplex flow control support has been
689	added to mii(4) and bge(4), bce(4), msk(4), nfe(4) and stge(4) along
690	with brgphy(4), e1000phy(4) as well as ip1000phy() have been converted
691	to take advantage of it instead of using custom implementations.  This
692	means that these drivers now no longer unconditionally advertise
693	support for flow control but only do so if flow control is a selected
694	media option.  This was implemented in the generic support that way in
695	order to allow flow control to be switched on and off via ifconfig(8)
696	with the PHY specific default to typically off in order to protect
697	from unwanted effects.  Consequently, if you used flow control with
698	one of the above mentioned drivers you now need to explicitly enable
699	it, for example via:
700		ifconfig bge0 media auto mediaopt flowcontrol
701
702	Along with the above mentioned changes generic support for setting
703	1000baseT master mode also has been added and brgphy(4), ciphy(4),
704	e1000phy(4) as well as ip1000phy(4) have been converted to take
705	advantage of it.  This means that these drivers now no longer take the
706	link0 parameter for selecting master mode but the master media option
707	has to be used instead, for example like in the following:
708		ifconfig bge0 media 1000baseT mediaopt full-duplex,master
709
710	Selection of master mode now is also available with all other PHY
711	drivers supporting 1000baseT.
712
71320101111:
714	The TCP stack has received a significant update to add support for
715	modularised congestion control and generally improve the clarity of
716	congestion control decisions. Bump __FreeBSD_version to 900025. User
717	space tools that rely on the size of struct tcpcb in tcp_var.h (e.g.
718	sockstat) need to be recompiled.
719
72020101002:
721	The man(1) utility has been replaced by a new version that no longer
722	uses /etc/manpath.config. Please consult man.conf(5) for how to
723	migrate local entries to the new format.
724
72520100928:
726	The copyright strings printed by login(1) and sshd(8) at the time of a
727	new connection have been removed to follow other operating systems and
728	upstream sshd.
729
73020100915:
731	A workaround for a fixed ld bug has been removed in kernel code,
732	so make sure that your system ld is built from sources after
733	revision 210245 from 2010-07-19 (r211583 if building head kernel
734	on stable/8, r211584 for stable/7; both from 2010-08-21).
735	A symptom of incorrect ld version is different addresses for
736	set_pcpu section and __start_set_pcpu symbol in kernel and/or modules.
737
73820100913:
739	The $ipv6_prefer variable in rc.conf(5) has been split into
740	$ip6addrctl_policy and $ipv6_activate_all_interfaces.
741
742	The $ip6addrctl_policy is a variable to choose a pre-defined
743	address selection policy set by ip6addrctl(8).  A value
744	"ipv4_prefer", "ipv6_prefer" or "AUTO" can be specified.  The
745	default is "AUTO".
746
747	The $ipv6_activate_all_interfaces specifies whether IFDISABLED
748	flag (see an entry of 20090926) is set on an interface with no
749	corresponding $ifconfig_IF_ipv6 line.  The default is "NO" for
750	security reason.  If you want IPv6 link-local address on all
751	interfaces by default, set this to "YES".
752
753	The old ipv6_prefer="YES" is equivalent to
754	ipv6_activate_all_interfaces="YES" and
755	ip6addrctl_policy="ipv6_prefer".
756
75720100913:
758	DTrace has grown support for userland tracing. Due to this, DTrace is
759	now i386 and amd64 only.
760	dtruss(1) is now installed by default on those systems and a new
761	kernel module is needed for userland tracing: fasttrap.
762	No changes to your kernel config file are necessary to enable
763	userland tracing, but you might consider adding 'STRIP=' and
764	'CFLAGS+=-fno-omit-frame-pointer' to your make.conf if you want
765	to have informative userland stack traces in DTrace (ustack).
766
76720100725:
768	The acpi_aiboost(4) driver has been removed in favor of the new
769	aibs(4) driver. You should update your kernel configuration file.
770
77120100722:
772	BSD grep has been imported to the base system and it is built by
773	default.  It is completely BSD licensed, highly GNU-compatible, uses
774	less memory than its GNU counterpart and has a small codebase.
775	However, it is slower than its GNU counterpart, which is mostly
776	noticeable for larger searches, for smaller ones it is measurable
777	but not significant.  The reason is complex, the most important factor
778	is that we lack a modern and efficient regex library and GNU
779	overcomes this by optimizing the searches internally.  Future work
780	on improving the regex performance is planned, for the meantime,
781	users that need better performance, can build GNU grep instead by
782	setting the WITH_GNU_GREP knob.
783
78420100713:
785	Due to the import of powerpc64 support, all existing powerpc kernel
786	configuration files must be updated with a machine directive like this:
787	    machine powerpc powerpc
788
789	In addition, an updated config(8) is required to build powerpc kernels
790	after this change.
791
79220100713:
793	A new version of ZFS (version 15) has been merged to -HEAD.
794	This version uses a python library for the following subcommands:
795	zfs allow, zfs unallow, zfs groupspace, zfs userspace.
796	For full functionality of these commands the following port must
797	be installed: sysutils/py-zfs
798
79920100429:
800	'vm_page's are now hashed by physical address to an array of mutexes.
801	Currently this is only used to serialize access to hold_count. Over 
802	time the page queue mutex will be peeled away. This changes the size
803	of pmap on every architecture. And requires all callers of vm_page_hold
804	and vm_page_unhold to be updated. 
805 
80620100402:
807	WITH_CTF can now be specified in src.conf (not recommended, there
808	are some problems with static executables), make.conf (would also
809	affect ports which do not use GNU make and do not override the
810	compile targets) or in the kernel config (via "makeoptions
811	WITH_CTF=yes").
812	When WITH_CTF was specified there before this was silently ignored,
813	so make sure that WITH_CTF is not used in places which could lead
814	to unwanted behavior.
815
81620100311:
817	The kernel option COMPAT_IA32 has been replaced with COMPAT_FREEBSD32
818	to allow 32-bit compatibility on non-x86 platforms. All kernel
819	configurations on amd64 and ia64 platforms using these options must
820	be modified accordingly.
821
82220100113:
823	The utmp user accounting database has been replaced with utmpx,
824	the user accounting interface standardized by POSIX.
825	Unfortunately the semantics of utmp and utmpx don't match,
826	making it practically impossible to support both interfaces.
827	The user accounting database is used by tools like finger(1),
828	last(1), talk(1), w(1) and ac(8).
829
830	All applications in the base system use utmpx.  This means only
831	local binaries (e.g. from the ports tree) may still use these
832	utmp database files.  These applications must be rebuilt to make
833	use of utmpx.
834
835	After the system has been upgraded, it is safe to remove the old
836	log files (/var/run/utmp, /var/log/lastlog and /var/log/wtmp*),
837	assuming their contents is of no importance anymore.  Old wtmp
838	databases can only be used by last(1) and ac(8) after they have
839	been converted to the new format using wtmpcvt(1).
840
84120100108:
842	Introduce the kernel thread "deadlock resolver" (which can be enabled
843	via the DEADLKRES option, see NOTES for more details) and the
844	sleepq_type() function for sleepqueues.
845
84620091202:
847	The rc.firewall and rc.firewall6 were unified, and
848	rc.firewall6 and rc.d/ip6fw were removed.
849	According to the removal of rc.d/ip6fw, ipv6_firewall_* rc
850	variables are obsoleted.  Instead, the following new rc
851	variables are added to rc.d/ipfw:
852
853		firewall_client_net_ipv6, firewall_simple_iif_ipv6,
854		firewall_simple_inet_ipv6, firewall_simple_oif_ipv6,
855		firewall_simple_onet_ipv6, firewall_trusted_ipv6
856
857	The meanings correspond to the relevant IPv4 variables.
858
85920091125:
860	8.0-RELEASE.
861
86220091113:
863	The default terminal emulation for syscons(4) has been changed
864	from cons25 to xterm on all platforms except pc98.  This means
865	that the /etc/ttys file needs to be updated to ensure correct
866	operation of applications on the console.
867
868	The terminal emulation style can be toggled per window by using
869	vidcontrol(1)'s -T flag.  The TEKEN_CONS25 kernel configuration
870	options can be used to change the compile-time default back to
871	cons25.
872
873	To prevent graphical artifacts, make sure the TERM environment
874	variable is set to match the terminal emulation that is being
875	performed by syscons(4).
876
87720091109:
878	The layout of the structure ieee80211req_scan_result has changed.
879	Applications that require wireless scan results (e.g. ifconfig(8))
880	from net80211 need to be recompiled.
881
882	Applications such as wpa_supplicant(8) may require a full world
883	build without using NO_CLEAN in order to get synchronized with the
884	new structure.
885
88620091025:
887	The iwn(4) driver has been updated to support the 5000 and 5150 series.
888	There's one kernel module for each firmware. Adding "device iwnfw"
889	to the kernel configuration file means including all three firmware
890	images inside the kernel. If you want to include just the one for
891	your wireless card, use the devices iwn4965fw, iwn5000fw or
892	iwn5150fw.
893
89420090926:
895	The rc.d/network_ipv6, IPv6 configuration script has been integrated
896	into rc.d/netif.  The changes are the following:
897
898	1. To use IPv6, simply define $ifconfig_IF_ipv6 like $ifconfig_IF
899	   for IPv4.  For aliases, $ifconfig_IF_aliasN should be used.
900	   Note that both variables need the "inet6" keyword at the head.
901
902	   Do not set $ipv6_network_interfaces manually if you do not
903	   understand what you are doing.  It is not needed in most cases. 
904
905	   $ipv6_ifconfig_IF and $ipv6_ifconfig_IF_aliasN still work, but
906	   they are obsolete.
907
908	2. $ipv6_enable is obsolete.  Use $ipv6_prefer and
909	   "inet6 accept_rtadv" keyword in ifconfig(8) instead.
910
911	   If you define $ipv6_enable=YES, it means $ipv6_prefer=YES and
912	   all configured interfaces have "inet6 accept_rtadv" in the
913	   $ifconfig_IF_ipv6.  These are for backward compatibility.
914
915	3. A new variable $ipv6_prefer has been added.  If NO, IPv6
916	   functionality of interfaces with no corresponding
917	   $ifconfig_IF_ipv6 is disabled by using "inet6 ifdisabled" flag,
918	   and the default address selection policy of ip6addrctl(8) 
919	   is the IPv4-preferred one (see rc.d/ip6addrctl for more details).
920	   Note that if you want to configure IPv6 functionality on the
921	   disabled interfaces after boot, first you need to clear the flag by
922	   using ifconfig(8) like:
923
924		ifconfig em0 inet6 -ifdisabled
925
926	   If YES, the default address selection policy is set as
927	   IPv6-preferred.
928
929	   The default value of $ipv6_prefer is NO.
930
931	4. If your system need to receive Router Advertisement messages,
932	   define "inet6 accept_rtadv" in $ifconfig_IF_ipv6.  The rc(8)
933	   scripts automatically invoke rtsol(8) when the interface becomes
934	   UP.  The Router Advertisement messages are used for SLAAC
935	   (State-Less Address AutoConfiguration).
936
93720090922:
938	802.11s D3.03 support was committed. This is incompatible with the
939	previous code, which was based on D3.0.
940
94120090912:
942	A sysctl variable net.inet6.ip6.accept_rtadv now sets the default value
943	of a per-interface flag ND6_IFF_ACCEPT_RTADV, not a global knob to
944	control whether accepting Router Advertisement messages or not.
945	Also, a per-interface flag ND6_IFF_AUTO_LINKLOCAL has been added and
946	a sysctl variable net.inet6.ip6.auto_linklocal is its default value.
947	The ifconfig(8) utility now supports these flags.
948
94920090910:
950	ZFS snapshots are now mounted with MNT_IGNORE flag. Use -v option for
951	mount(8) and -a option for df(1) to see them.
952
95320090825:
954	The old tunable hw.bus.devctl_disable has been superseded by
955	hw.bus.devctl_queue.  hw.bus.devctl_disable=1 in loader.conf should be
956	replaced by hw.bus.devctl_queue=0.  The default for this new tunable
957	is 1000.
958
95920090813:
960	Remove the option STOP_NMI.  The default action is now to use NMI only
961	for KDB via the newly introduced function stop_cpus_hard() and
962	maintain stop_cpus() to just use a normal IPI_STOP on ia32 and amd64.
963
96420090803:
965	The stable/8 branch created in subversion.  This corresponds to the
966	RELENG_8 branch in CVS.
967
96820090719:
969	Bump the shared library version numbers for all libraries that do not
970	use symbol versioning as part of the 8.0-RELEASE cycle.  Bump
971	__FreeBSD_version to 800105.
972
97320090714:
974	Due to changes in the implementation of virtual network stack support,
975	all network-related kernel modules must be recompiled.  As this change
976	breaks the ABI, bump __FreeBSD_version to 800104.
977
97820090713:
979	The TOE interface to the TCP syncache has been modified to remove
980	struct tcpopt (<netinet/tcp_var.h>) from the ABI of the network stack.
981	The cxgb driver is the only TOE consumer affected by this change, and
982	needs to be recompiled along with the kernel. As this change breaks
983	the ABI, bump __FreeBSD_version to 800103.
984
98520090712: 
986	Padding has been added to struct tcpcb, sackhint and tcpstat in
987	<netinet/tcp_var.h> to facilitate future MFCs and bug fixes whilst
988	maintaining the ABI. However, this change breaks the ABI, so bump
989	__FreeBSD_version to 800102. User space tools that rely on the size of
990	any of these structs (e.g. sockstat) need to be recompiled.
991
99220090630:
993	The NFS_LEGACYRPC option has been removed along with the old kernel
994	RPC implementation that this option selected. Kernel configurations
995	may need to be adjusted.
996
99720090629:
998	The network interface device nodes at /dev/net/<interface> have been
999	removed.  All ioctl operations can be performed the normal way using
1000	routing sockets.  The kqueue functionality can generally be replaced
1001	with routing sockets.
1002
100320090628:
1004	The documentation from the FreeBSD Documentation Project (Handbook,
1005	FAQ, etc.) is now installed via packages by sysinstall(8) and under
1006	the /usr/local/share/doc/freebsd directory instead of /usr/share/doc.
1007
100820090624:
1009	The ABI of various structures related to the SYSV IPC API have been
1010	changed.  As a result, the COMPAT_FREEBSD[456] and COMPAT_43 kernel
1011	options now all require COMPAT_FREEBSD7.  Bump __FreeBSD_version to
1012	800100.
1013
101420090622:
1015	Layout of struct vnet has changed as routing related variables were
1016	moved to their own Vimage module. Modules need to be recompiled.  Bump
1017	__FreeBSD_version to 800099.
1018
101920090619:
1020	NGROUPS_MAX and NGROUPS have been increased from 16 to 1023 and 1024
1021	respectively.  As long as no more than 16 groups per process are used,
1022	no changes should be visible.  When more than 16 groups are used, old
1023	binaries may fail if they call getgroups() or getgrouplist() with
1024	statically sized storage.  Recompiling will work around this, but
1025	applications should be modified to use dynamically allocated storage
1026	for group arrays as POSIX.1-2008 does not cap an implementation's
1027	number of supported groups at NGROUPS_MAX+1 as previous versions did.
1028
1029	NFS and portalfs mounts may also be affected as the list of groups is
1030	truncated to 16.  Users of NFS who use more than 16 groups, should
1031	take care that negative group permissions are not used on the exported
1032	file systems as they will not be reliable unless a GSSAPI based
1033	authentication method is used.
1034
103520090616: 
1036	The compiling option ADAPTIVE_LOCKMGRS has been introduced.  This
1037	option compiles in the support for adaptive spinning for lockmgrs
1038	which want to enable it.  The lockinit() function now accepts the flag
1039	LK_ADAPTIVE in order to make the lock object subject to adaptive
1040	spinning when both held in write and read mode.
1041
104220090613:
1043	The layout of the structure returned by IEEE80211_IOC_STA_INFO has
1044	changed.  User applications that use this ioctl need to be rebuilt.
1045
104620090611:
1047	The layout of struct thread has changed.  Kernel and modules need to
1048	be rebuilt.
1049
105020090608:
1051	The layout of structs ifnet, domain, protosw and vnet_net has changed.
1052	Kernel modules need to be rebuilt.  Bump __FreeBSD_version to 800097.
1053
105420090602:
1055	window(1) has been removed from the base system. It can now be
1056	installed from ports. The port is called misc/window.
1057
105820090601:
1059	The way we are storing and accessing `routing table' entries has
1060	changed. Programs reading the FIB, like netstat, need to be
1061	re-compiled.
1062
106320090601:
1064	A new netisr implementation has been added for FreeBSD 8.  Network
1065	file system modules, such as igmp, ipdivert, and others, should be
1066	rebuilt.
1067	Bump __FreeBSD_version to 800096.
1068
106920090530:
1070	Remove the tunable/sysctl debug.mpsafevfs as its initial purpose is no
1071	more valid.
1072
107320090530:
1074	Add VOP_ACCESSX(9).  File system modules need to be rebuilt.
1075	Bump __FreeBSD_version to 800094.
1076
107720090529:
1078	Add mnt_xflag field to 'struct mount'.  File system modules need to be
1079	rebuilt.
1080	Bump __FreeBSD_version to 800093.
1081
108220090528:
1083	The compiling option ADAPTIVE_SX has been retired while it has been
1084	introduced the option NO_ADAPTIVE_SX which handles the reversed logic.
1085	The KPI for sx_init_flags() changes as accepting flags:
1086	SX_ADAPTIVESPIN flag has been retired while the SX_NOADAPTIVE flag has
1087	been introduced in order to handle the reversed logic.
1088	Bump __FreeBSD_version to 800092.
1089
109020090527:
1091	Add support for hierarchical jails.  Remove global securelevel.
1092	Bump __FreeBSD_version to 800091.
1093
109420090523:
1095	The layout of struct vnet_net has changed, therefore modules
1096	need to be rebuilt.
1097	Bump __FreeBSD_version to 800090.
1098
109920090523:
1100	The newly imported zic(8) produces a new format in the output. Please
1101	run tzsetup(8) to install the newly created data to /etc/localtime.
1102
110320090520:
1104	The sysctl tree for the usb stack has renamed from hw.usb2.* to
1105	hw.usb.* and is now consistent again with previous releases.
1106
110720090520:
1108	802.11 monitor mode support was revised and driver api's were changed.
1109	Drivers dependent on net80211 now support DLT_IEEE802_11_RADIO instead
1110	of DLT_IEEE802_11.  No user-visible data structures were changed but
1111	applications that use DLT_IEEE802_11 may require changes.
1112	Bump __FreeBSD_version to 800088.
1113
111420090430:
1115	The layout of the following structs has changed: sysctl_oid,
1116	socket, ifnet, inpcbinfo, tcpcb, syncache_head, vnet_inet,
1117	vnet_inet6 and vnet_ipfw.  Most modules need to be rebuild or
1118	panics may be experienced.  World rebuild is required for
1119	correctly checking networking state from userland.
1120	Bump __FreeBSD_version to 800085.
1121
112220090429:
1123	MLDv2 and Source-Specific Multicast (SSM) have been merged
1124	to the IPv6 stack. VIMAGE hooks are in but not yet used.
1125	The implementation of SSM within FreeBSD's IPv6 stack closely
1126	follows the IPv4 implementation.
1127
1128	For kernel developers:
1129
1130	* The most important changes are that the ip6_output() and
1131	  ip6_input() paths no longer take the IN6_MULTI_LOCK,
1132	  and this lock has been downgraded to a non-recursive mutex.
1133
1134	* As with the changes to the IPv4 stack to support SSM, filtering
1135	  of inbound multicast traffic must now be performed by transport
1136	  protocols within the IPv6 stack. This does not apply to TCP and
1137	  SCTP, however, it does apply to UDP in IPv6 and raw IPv6.
1138
1139	* The KPIs used by IPv6 multicast are similar to those used by
1140	  the IPv4 stack, with the following differences:
1141	   * im6o_mc_filter() is analogous to imo_multicast_filter().
1142	   * The legacy KAME entry points in6_joingroup and in6_leavegroup()
1143	     are shimmed to in6_mc_join() and in6_mc_leave() respectively.
1144	   * IN6_LOOKUP_MULTI() has been deprecated and removed.
1145	   * IPv6 relies on MLD for the DAD mechanism. KAME's internal KPIs
1146	     for MLDv1 have an additional 'timer' argument which is used to
1147	     jitter the initial membership report for the solicited-node
1148	     multicast membership on-link.
1149	   * This is not strictly needed for MLDv2, which already jitters
1150	     its report transmissions.  However, the 'timer' argument is
1151	     preserved in case MLDv1 is active on the interface.
1152
1153	* The KAME linked-list based IPv6 membership implementation has
1154	  been refactored to use a vector similar to that used by the IPv4
1155	  stack.
1156	  Code which maintains a list of its own multicast memberships
1157	  internally, e.g. carp, has been updated to reflect the new
1158	  semantics.
1159
1160	* There is a known Lock Order Reversal (LOR) due to in6_setscope()
1161	  acquiring the IF_AFDATA_LOCK and being called within ip6_output().
1162	  Whilst MLDv2 tries to avoid this otherwise benign LOR, it is an
1163	  implementation constraint which needs to be addressed in HEAD.
1164
1165	For application developers:
1166
1167	* The changes are broadly similar to those made for the IPv4
1168	  stack.
1169
1170	* The use of IPv4 and IPv6 multicast socket options on the same
1171	  socket, using mapped addresses, HAS NOT been tested or supported.
1172
1173	* There are a number of issues with the implementation of various
1174	  IPv6 multicast APIs which need to be resolved in the API surface
1175	  before the implementation is fully compatible with KAME userland
1176	  use, and these are mostly to do with interface index treatment.
1177
1178	* The literature available discusses the use of either the delta / ASM
1179	  API with setsockopt(2)/getsockopt(2), or the full-state / ASM API
1180	  using setsourcefilter(3)/getsourcefilter(3). For more information
1181	  please refer to RFC 3768, 'Socket Interface Extensions for
1182	  Multicast Source Filters'.
1183
1184	* Applications which use the published RFC 3678 APIs should be fine.
1185
1186	For systems administrators:
1187
1188	* The mtest(8) utility has been refactored to support IPv6, in
1189	  addition to IPv4. Interface addresses are no longer accepted
1190	  as arguments, their names must be used instead. The utility
1191	  will map the interface name to its first IPv4 address as
1192	  returned by getifaddrs(3).
1193
1194	* The ifmcstat(8) utility has also been updated to print the MLDv2
1195	  endpoint state and source filter lists via sysctl(3).
1196
1197	* The net.inet6.ip6.mcast.loop sysctl may be tuned to 0 to disable
1198	  loopback of IPv6 multicast datagrams by default; it defaults to 1
1199	  to preserve the existing behaviour. Disabling multicast loopback is
1200	  recommended for optimal system performance.
1201
1202	* The IPv6 MROUTING code has been changed to examine this sysctl
1203	  instead of attempting to perform a group lookup before looping
1204	  back forwarded datagrams.
1205
1206	Bump __FreeBSD_version to 800084.
1207
120820090422:
1209	Implement low-level Bluetooth HCI API.
1210	Bump __FreeBSD_version to 800083.
1211
121220090419:
1213	The layout of struct malloc_type, used by modules to register new
1214	memory allocation types, has changed.  Most modules will need to
1215	be rebuilt or panics may be experienced.
1216	Bump __FreeBSD_version to 800081.
1217
121820090415:
1219	Anticipate overflowing inp_flags - add inp_flags2.
1220	This changes most offsets in inpcb, so checking v4 connection
1221	state will require a world rebuild.
1222	Bump __FreeBSD_version to 800080.
1223
122420090415:
1225	Add an llentry to struct route and struct route_in6. Modules
1226	embedding a struct route will need to be recompiled.
1227	Bump __FreeBSD_version to 800079.
1228
122920090414:
1230	The size of rt_metrics_lite and by extension rtentry has changed.
1231	Networking administration apps will need to be recompiled.
1232	The route command now supports show as an alias for get, weighting
1233	of routes, sticky and nostick flags to alter the behavior of stateful
1234	load balancing.
1235	Bump __FreeBSD_version to 800078.
1236
123720090408:
1238	Do not use Giant for kbdmux(4) locking. This is wrong and
1239	apparently causing more problems than it solves. This will
1240	re-open the issue where interrupt handlers may race with
1241	kbdmux(4) in polling mode. Typical symptoms include (but
1242	not limited to) duplicated and/or missing characters when
1243	low level console functions (such as gets) are used while
1244	interrupts are enabled (for example geli password prompt,
1245	mountroot prompt etc.). Disabling kbdmux(4) may help.
1246
124720090407:
1248	The size of structs vnet_net, vnet_inet and vnet_ipfw has changed;
1249	kernel modules referencing any of the above need to be recompiled.
1250	Bump __FreeBSD_version to 800075.
1251
125220090320:
1253	GEOM_PART has become the default partition slicer for storage devices,
1254	replacing GEOM_MBR, GEOM_BSD, GEOM_PC98 and GEOM_GPT slicers. It
1255	introduces some changes:
1256
1257	MSDOS/EBR: the devices created from MSDOS extended partition entries
1258	(EBR) can be named differently than with GEOM_MBR and are now symlinks
1259	to devices with offset-based names. fstabs may need to be modified.
1260
1261	BSD: the "geometry does not match label" warning is harmless in most
1262	cases but it points to problems in file system misalignment with
1263	disk geometry. The "c" partition is now implicit, covers the whole
1264	top-level drive and cannot be (mis)used by users.
1265
1266	General: Kernel dumps are now not allowed to be written to devices
1267	whose partition types indicate they are meant to be used for file
1268	systems (or, in case of MSDOS partitions, as something else than
1269	the "386BSD" type).
1270
1271	Most of these changes date approximately from 200812.
1272
127320090319:
1274	The uscanner(4) driver has been removed from the kernel. This follows
1275	Linux removing theirs in 2.6 and making libusb the default interface
1276	(supported by sane).
1277
127820090319:
1279	The multicast forwarding code has been cleaned up. netstat(1)
1280	only relies on KVM now for printing bandwidth upcall meters.
1281	The IPv4 and IPv6 modules are split into ip_mroute_mod and
1282	ip6_mroute_mod respectively. The config(5) options for statically
1283	compiling this code remain the same, i.e. 'options MROUTING'.
1284
128520090315:
1286	Support for the IFF_NEEDSGIANT network interface flag has been
1287	removed, which means that non-MPSAFE network device drivers are no
1288	longer supported.  In particular, if_ar, if_sr, and network device
1289	drivers from the old (legacy) USB stack can no longer be built or
1290	used.
1291
129220090313:
1293	POSIX.1 Native Language Support (NLS) has been enabled in libc and
1294	a bunch of new language catalog files have also been added.
1295	This means that some common libc messages are now localized and
1296	they depend on the LC_MESSAGES environmental variable.
1297
129820090313:
1299	The k8temp(4) driver has been renamed to amdtemp(4) since
1300	support for Family 10 and Family 11 CPU families was added.
1301
130220090309:
1303	IGMPv3 and Source-Specific Multicast (SSM) have been merged
1304	to the IPv4 stack. VIMAGE hooks are in but not yet used.
1305
1306	For kernel developers, the most important changes are that the
1307	ip_output() and ip_input() paths no longer take the IN_MULTI_LOCK(),
1308	and this lock has been downgraded to a non-recursive mutex.
1309
1310	Transport protocols (UDP, Raw IP) are now responsible for filtering
1311	inbound multicast traffic according to group membership and source
1312	filters. The imo_multicast_filter() KPI exists for this purpose.
1313	Transports which do not use multicast (SCTP, TCP) already reject
1314	multicast by default. Forwarding and receive performance may improve
1315	as a mutex acquisition is no longer needed in the ip_input()
1316	low-level input path.  in_addmulti() and in_delmulti() are shimmed
1317	to new KPIs which exist to support SSM in-kernel.
1318
1319	For application developers, it is recommended that loopback of
1320	multicast datagrams be disabled for best performance, as this
1321	will still cause the lock to be taken for each looped-back
1322	datagram transmission. The net.inet.ip.mcast.loop sysctl may
1323	be tuned to 0 to disable loopback by default; it defaults to 1
1324	to preserve the existing behaviour.
1325
1326	For systems administrators, to obtain best performance with
1327	multicast reception and multiple groups, it is always recommended
1328	that a card with a suitably precise hash filter is used. Hash
1329	collisions will still result in the lock being taken within the
1330	transport protocol input path to check group membership.
1331
1332	If deploying FreeBSD in an environment with IGMP snooping switches,
1333	it is recommended that the net.inet.igmp.sendlocal sysctl remain
1334	enabled; this forces 224.0.0.0/24 group membership to be announced
1335	via IGMP.
1336
1337	The size of 'struct igmpstat' has changed; netstat needs to be
1338	recompiled to reflect this.
1339	Bump __FreeBSD_version to 800070.
1340
134120090309:
1342	libusb20.so.1 is now installed as libusb.so.1 and the ports system
1343	updated to use it. This requires a buildworld/installworld in order to
1344	update the library and dependencies (usbconfig, etc). Its advisable to
1345	rebuild all ports which uses libusb. More specific directions are given
1346	in the ports collection UPDATING file. Any /etc/libmap.conf entries for
1347	libusb are no longer required and can be removed.
1348
134920090302:
1350	A workaround is committed to allow the creation of System V shared
1351	memory segment of size > 2 GB on the 64-bit architectures.
1352	Due to a limitation of the existing ABI, the shm_segsz member
1353	of the struct shmid_ds, returned by shmctl(IPC_STAT) call is
1354	wrong for large segments. Note that limits must be explicitly
1355	raised to allow such segments to be created.
1356
135720090301:
1358	The layout of struct ifnet has changed, requiring a rebuild of all
1359	network device driver modules.
1360
136120090227:
1362	The /dev handling for the new USB stack has changed, a
1363	buildworld/installworld is required for libusb20.
1364
136520090223:
1366	The new USB2 stack has now been permanently moved in and all kernel and
1367	module names reverted to their previous values (eg, usb, ehci, ohci,
1368	ums, ...).  The old usb stack can be compiled in by prefixing the name
1369	with the letter 'o', the old usb modules have been removed.
1370	Updating entry 20090216 for xorg and 20090215 for libmap may still
1371	apply.
1372
137320090217:
1374	The rc.conf(5) option if_up_delay has been renamed to
1375	defaultroute_delay to better reflect its purpose. If you have
1376	customized this setting in /etc/rc.conf you need to update it to
1377	use the new name.
1378
137920090216:
1380	xorg 7.4 wants to configure its input devices via hald which does not
1381	yet work with USB2. If the keyboard/mouse does not work in xorg then
1382	add
1383		Option "AllowEmptyInput" "off"
1384	to your ServerLayout section.  This will cause X to use the configured
1385	kbd and mouse sections from your xorg.conf.
1386
138720090215:
1388	The GENERIC kernels for all architectures now default to the new USB2
1389	stack. No kernel config options or code have been removed so if a
1390	problem arises please report it and optionally revert to the old USB
1391	stack. If you are loading USB kernel modules or have a custom kernel
1392	that includes GENERIC then ensure that usb names are also changed over,
1393	eg uftdi -> usb2_serial_ftdi.
1394
1395	Older programs linked against the ports libusb 0.1 need to be
1396	redirected to the new stack's libusb20.  /etc/libmap.conf can
1397	be used for this:
1398		# Map old usb library to new one for usb2 stack
1399		libusb-0.1.so.8	libusb20.so.1
1400
140120090209:
1402	All USB ethernet devices now attach as interfaces under the name ueN
1403	(eg. ue0). This is to provide a predictable name as vendors often
1404	change usb chipsets in a product without notice.
1405
140620090203:
1407	The ichsmb(4) driver has been changed to require SMBus slave
1408	addresses be left-justified (xxxxxxx0b) rather than right-justified.
1409	All of the other SMBus controller drivers require left-justified
1410	slave addresses, so this change makes all the drivers provide the
1411	same interface.
1412
141320090201:
1414	INET6 statistics (struct ip6stat) was updated.
1415	netstat(1) needs to be recompiled.
1416
141720090119:
1418	NTFS has been removed from GENERIC kernel on amd64 to match
1419	GENERIC on i386. Should not cause any issues since mount_ntfs(8)
1420	will load ntfs.ko module automatically when NTFS support is
1421	actually needed, unless ntfs.ko is not installed or security
1422	level prohibits loading kernel modules. If either is the case,
1423	"options NTFS" has to be added into kernel config.
1424
142520090115:
1426	TCP Appropriate Byte Counting (RFC 3465) support added to kernel.
1427	New field in struct tcpcb breaks ABI, so bump __FreeBSD_version to
1428	800061. User space tools that rely on the size of struct tcpcb in
1429	tcp_var.h (e.g. sockstat) need to be recompiled.
1430
143120081225:
1432	ng_tty(4) module updated to match the new TTY subsystem.
1433	Due to API change, user-level applications must be updated.
1434	New API support added to mpd5 CVS and expected to be present
1435	in next mpd5.3 release.
1436
143720081219:
1438	With __FreeBSD_version 800060 the makefs tool is part of
1439	the base system (it was a port).
1440
144120081216:
1442	The afdata and ifnet locks have been changed from mutexes to
1443	rwlocks, network modules will need to be re-compiled.
1444
144520081214:
1446	__FreeBSD_version 800059 incorporates the new arp-v2 rewrite.
1447	RTF_CLONING, RTF_LLINFO and RTF_WASCLONED flags are eliminated.
1448	The new code reduced struct rtentry{} by 16 bytes on 32-bit
1449	architecture and 40 bytes on 64-bit architecture. The userland
1450	applications "arp" and "ndp" have been updated accordingly.
1451	The output from "netstat -r" shows only routing entries and
1452	none of the L2 information.
1453
145420081130:
1455	__FreeBSD_version 800057 marks the switchover from the
1456	binary ath hal to source code. Users must add the line:
1457
1458	options	AH_SUPPORT_AR5416
1459
1460	to their kernel config files when specifying:
1461
1462	device	ath_hal
1463
1464	The ath_hal module no longer exists; the code is now compiled
1465	together with the driver in the ath module.  It is now
1466	possible to tailor chip support (i.e. reduce the set of chips
1467	and thereby the code size); consult ath_hal(4) for details.
1468
146920081121:
1470	__FreeBSD_version 800054 adds memory barriers to
1471	<machine/atomic.h>, new interfaces to ifnet to facilitate
1472	multiple hardware transmit queues for cards that support
1473	them, and a lock-less ring-buffer implementation to
1474	enable drivers to more efficiently manage queueing of
1475	packets.
1476
147720081117:
1478	A new version of ZFS (version 13) has been merged to -HEAD.
1479	This version has zpool attribute "listsnapshots" off by
1480	default, which means "zfs list" does not show snapshots,
1481	and is the same as Solaris behavior.
1482
148320081028:
1484	dummynet(4) ABI has changed. ipfw(8) needs to be recompiled.
1485
148620081009:
1487	The uhci, ohci, ehci and slhci USB Host controller drivers have
1488	been put into separate modules. If you load the usb module
1489	separately through loader.conf you will need to load the
1490	appropriate *hci module as well. E.g. for a UHCI-based USB 2.0
1491	controller add the following to loader.conf:
1492
1493		uhci_load="YES"
1494		ehci_load="YES"
1495
149620081009:
1497	The ABI used by the PMC toolset has changed.  Please keep
1498	userland (libpmc(3)) and the kernel module (hwpmc(4)) in
1499	sync.
1500
150120081009:
1502	atapci kernel module now includes only generic PCI ATA
1503	driver. AHCI driver moved to ataahci kernel module.
1504	All vendor-specific code moved into separate kernel modules:
1505	ataacard, ataacerlabs, ataadaptec, ataamd, ataati, atacenatek,
1506	atacypress, atacyrix, atahighpoint, ataintel, ataite, atajmicron,
1507	atamarvell, atamicron, atanational, atanetcell, atanvidia,
1508	atapromise, ataserverworks, atasiliconimage, atasis, atavia
1509
151020080820:
1511	The TTY subsystem of the kernel has been replaced by a new
1512	implementation, which provides better scalability and an
1513	improved driver model. Most common drivers have been migrated to
1514	the new TTY subsystem, while others have not. The following
1515	drivers have not yet been ported to the new TTY layer:
1516
1517	PCI/ISA:
1518		cy, digi, rc, rp, sio
1519
1520	USB:
1521		ubser, ucycom
1522
1523	Line disciplines:
1524		ng_h4, ng_tty, ppp, sl, snp
1525
1526	Adding these drivers to your kernel configuration file shall
1527	cause compilation to fail.
1528
152920080818:
1530	ntpd has been upgraded to 4.2.4p5.
1531
153220080801:
1533	OpenSSH has been upgraded to 5.1p1.
1534
1535	For many years, FreeBSD's version of OpenSSH preferred DSA
1536	over RSA for host and user authentication keys.  With this
1537	upgrade, we've switched to the vendor's default of RSA over
1538	DSA.  This may cause upgraded clients to warn about unknown
1539	host keys even for previously known hosts.  Users should
1540	follow the usual procedure for verifying host keys before
1541	accepting the RSA key.
1542
1543	This can be circumvented by setting the "HostKeyAlgorithms"
1544	option to "ssh-dss,ssh-rsa" in ~/.ssh/config or on the ssh
1545	command line.
1546
1547	Please note that the sequence of keys offered for
1548	authentication has been changed as well.  You may want to
1549	specify IdentityFile in a different order to revert this
1550	behavior.
1551
155220080713:
1553	The sio(4) driver has been removed from the i386 and amd64
1554	kernel configuration files. This means uart(4) is now the
1555	default serial port driver on those platforms as well.
1556
1557	To prevent collisions with the sio(4) driver, the uart(4) driver
1558	uses different names for its device nodes. This means the
1559	onboard serial port will now most likely be called "ttyu0"
1560	instead of "ttyd0". You may need to reconfigure applications to
1561	use the new device names.
1562
1563	When using the serial port as a boot console, be sure to update
1564	/boot/device.hints and /etc/ttys before booting the new kernel.
1565	If you forget to do so, you can still manually specify the hints
1566	at the loader prompt:
1567
1568		set hint.uart.0.at="isa"
1569		set hint.uart.0.port="0x3F8"
1570		set hint.uart.0.flags="0x10"
1571		set hint.uart.0.irq="4"
1572		boot -s
1573
157420080609:
1575	The gpt(8) utility has been removed. Use gpart(8) to partition
1576	disks instead.
1577
157820080603:
1579	The version that Linuxulator emulates was changed from 2.4.2
1580	to 2.6.16. If you experience any problems with Linux binaries
1581	please try to set sysctl compat.linux.osrelease to 2.4.2 and
1582	if it fixes the problem contact emulation mailing list.
1583
158420080525:
1585	ISDN4BSD (I4B) was removed from the src tree. You may need to
1586	update a your kernel configuration and remove relevant entries.
1587
158820080509:
1589	I have checked in code to support multiple routing tables.
1590	See the man pages setfib(1) and setfib(2).
1591	This is a hopefully backwards compatible version,
1592	but to make use of it you need to compile your kernel
1593	with options ROUTETABLES=2 (or more up to 16).
1594
159520080420:
1596	The 802.11 wireless support was redone to enable multi-bss
1597	operation on devices that are capable.  The underlying device
1598	is no longer used directly but instead wlanX devices are
1599	cloned with ifconfig.  This requires changes to rc.conf files.
1600	For example, change:
1601		ifconfig_ath0="WPA DHCP"
1602	to
1603		wlans_ath0=wlan0
1604		ifconfig_wlan0="WPA DHCP"
1605	see rc.conf(5) for more details.  In addition, mergemaster of
1606	/etc/rc.d is highly recommended.  Simultaneous update of userland
1607	and kernel wouldn't hurt either.
1608
1609	As part of the multi-bss changes the wlan_scan_ap and wlan_scan_sta
1610	modules were merged into the base wlan module.  All references
1611	to these modules (e.g. in kernel config files) must be removed.
1612
161320080408:
1614	psm(4) has gained write(2) support in native operation level.
1615	Arbitrary commands can be written to /dev/psm%d and status can
1616	be read back from it.  Therefore, an application is responsible
1617	for status validation and error recovery.  It is a no-op in
1618	other operation levels.
1619
162020080312:
1621	Support for KSE threading has been removed from the kernel.  To
1622	run legacy applications linked against KSE libmap.conf may
1623	be used.  The following libmap.conf may be used to ensure
1624	compatibility with any prior release:
1625
1626	libpthread.so.1 libthr.so.1
1627	libpthread.so.2 libthr.so.2
1628	libkse.so.3 libthr.so.3
1629
163020080301:
1631	The layout of struct vmspace has changed. This affects libkvm
1632	and any executables that link against libkvm and use the
1633	kvm_getprocs() function. In particular, but not exclusively,
1634	it affects ps(1), fstat(1), pkill(1), systat(1), top(1) and w(1).
1635	The effects are minimal, but it's advisable to upgrade world
1636	nonetheless.
1637
163820080229:
1639	The latest em driver no longer has support in it for the
1640	82575 adapter, this is now moved to the igb driver. The
1641	split was done to make new features that are incompatible
1642	with older hardware easier to do.
1643
164420080220:
1645	The new geom_lvm(4) geom class has been renamed to geom_linux_lvm(4),
1646	likewise the kernel option is now GEOM_LINUX_LVM.
1647
164820080211:
1649	The default NFS mount mode has changed from UDP to TCP for
1650	increased reliability.  If you rely on (insecurely) NFS
1651	mounting across a firewall you may need to update your
1652	firewall rules.
1653
165420080208:
1655	Belatedly note the addition of m_collapse for compacting
1656	mbuf chains.
1657
165820080126:
1659	The fts(3) structures have been changed to use adequate
1660	integer types for their members and so to be able to cope
1661	with huge file trees.  The old fts(3) ABI is preserved
1662	through symbol versioning in libc, so third-party binaries
1663	using fts(3) should still work, although they will not take
1664	advantage of the extended types.  At the same time, some
1665	third-party software might fail to build after this change
1666	due to unportable assumptions made in its source code about
1667	fts(3) structure members.  Such software should be fixed
1668	by its vendor or, in the worst case, in the ports tree.
1669	FreeBSD_version 800015 marks this change for the unlikely
1670	case that a portable fix is impossible.
1671
167220080123:
1673	To upgrade to -current after this date, you must be running
1674	FreeBSD not older than 6.0-RELEASE.  Upgrading to -current
1675	from 5.x now requires a stop over at RELENG_6 or RELENG_7 systems.
1676
167720071128:
1678	The ADAPTIVE_GIANT kernel option has been retired because its
1679	functionality is the default now.
1680
168120071118:
1682	The AT keyboard emulation of sunkbd(4) has been turned on
1683	by default. In order to make the special symbols of the Sun
1684	keyboards driven by sunkbd(4) work under X these now have
1685	to be configured the same way as Sun USB keyboards driven
1686	by ukbd(4) (which also does AT keyboard emulation), f.e.:
1687
1688	Option	"XkbLayout" "us"
1689	Option	"XkbRules" "xorg"
1690	Option	"XkbSymbols" "pc(pc105)+sun_vndr/usb(sun_usb)+us"
1691
169220071024:
1693	It has been decided that it is desirable to provide ABI
1694	backwards compatibility to the FreeBSD 4/5/6 versions of the
1695	PCIOCGETCONF, PCIOCREAD and PCIOCWRITE IOCTLs, which was
1696	broken with the introduction of PCI domain support (see the
1697	20070930 entry). Unfortunately, this required the ABI of
1698	PCIOCGETCONF to be broken again in order to be able to
1699	provide backwards compatibility to the old version of that
1700	IOCTL. Thus consumers of PCIOCGETCONF have to be recompiled
1701	again. As for prominent ports this affects neither pciutils
1702	nor xorg-server this time, the hal port needs to be rebuilt
1703	however.
1704
170520071020:
1706	The misnamed kthread_create() and friends have been renamed
1707	to kproc_create() etc. Many of the callers already
1708	used kproc_start()..
1709	I will return kthread_create() and friends in a while
1710	with implementations that actually create threads, not procs.
1711	Renaming corresponds with version 800002.
1712
171320071010:
1714	RELENG_7 branched.
1715
1716COMMON ITEMS:
1717
1718	General Notes
1719	-------------
1720	Avoid using make -j when upgrading.  While generally safe, there are
1721	sometimes problems using -j to upgrade.  If your upgrade fails with
1722	-j, please try again without -j.  From time to time in the past there
1723	have been problems using -j with buildworld and/or installworld.  This
1724	is especially true when upgrading between "distant" versions (eg one
1725	that cross a major release boundary or several minor releases, or when
1726	several months have passed on the -current branch).
1727
1728	Sometimes, obscure build problems are the result of environment
1729	poisoning.  This can happen because the make utility reads its
1730	environment when searching for values for global variables.  To run
1731	your build attempts in an "environmental clean room", prefix all make
1732	commands with 'env -i '.  See the env(1) manual page for more details.
1733
1734	When upgrading from one major version to another it is generally best
1735	to upgrade to the latest code in the currently installed branch first,
1736	then do an upgrade to the new branch. This is the best-tested upgrade
1737	path, and has the highest probability of being successful.  Please try
1738	this approach before reporting problems with a major version upgrade.
1739
1740	When upgrading a live system, having a root shell around before
1741	installing anything can help undo problems. Not having a root shell
1742	around can lead to problems if pam has changed too much from your
1743	starting point to allow continued authentication after the upgrade.
1744
1745	ZFS notes
1746	---------
1747	When upgrading the boot ZFS pool to a new version, always follow
1748	these two steps:
1749
1750	1.) recompile and reinstall the ZFS boot loader and boot block
1751	(this is part of "make buildworld" and "make installworld")
1752
1753	2.) update the ZFS boot block on your boot drive
1754
1755	The following example updates the ZFS boot block on the first
1756	partition (freebsd-boot) of a GPT partitioned drive ad0:
1757	"gpart bootcode -p /boot/gptzfsboot -i 1 ad0"
1758
1759	Non-boot pools do not need these updates.
1760
1761	To build a kernel
1762	-----------------
1763	If you are updating from a prior version of FreeBSD (even one just
1764	a few days old), you should follow this procedure.  It is the most
1765	failsafe as it uses a /usr/obj tree with a fresh mini-buildworld,
1766
1767	make kernel-toolchain
1768	make -DALWAYS_CHECK_MAKE buildkernel KERNCONF=YOUR_KERNEL_HERE
1769	make -DALWAYS_CHECK_MAKE installkernel KERNCONF=YOUR_KERNEL_HERE
1770
1771	To test a kernel once
1772	---------------------
1773	If you just want to boot a kernel once (because you are not sure
1774	if it works, or if you want to boot a known bad kernel to provide
1775	debugging information) run
1776	make installkernel KERNCONF=YOUR_KERNEL_HERE KODIR=/boot/testkernel
1777	nextboot -k testkernel
1778
1779	To just build a kernel when you know that it won't mess you up
1780	--------------------------------------------------------------
1781	This assumes you are already running a CURRENT system.  Replace
1782	${arch} with the architecture of your machine (e.g. "i386",
1783	"arm", "amd64", "ia64", "pc98", "sparc64", "powerpc", "mips", etc).
1784
1785	cd src/sys/${arch}/conf
1786	config KERNEL_NAME_HERE
1787	cd ../compile/KERNEL_NAME_HERE
1788	make depend
1789	make
1790	make install
1791
1792	If this fails, go to the "To build a kernel" section.
1793
1794	To rebuild everything and install it on the current system.
1795	-----------------------------------------------------------
1796	# Note: sometimes if you are running current you gotta do more than
1797	# is listed here if you are upgrading from a really old current.
1798
1799	<make sure you have good level 0 dumps>
1800	make buildworld
1801	make kernel KERNCONF=YOUR_KERNEL_HERE
1802							[1]
1803	<reboot in single user>				[3]
1804	mergemaster -p					[5]
1805	make installworld
1806	mergemaster -i					[4]
1807	make delete-old					[6]
1808	<reboot>
1809
1810	To cross-install current onto a separate partition
1811	--------------------------------------------------
1812	# In this approach we use a separate partition to hold
1813	# current's root, 'usr', and 'var' directories.   A partition
1814	# holding "/", "/usr" and "/var" should be about 2GB in
1815	# size.
1816
1817	<make sure you have good level 0 dumps>
1818	<boot into -stable>
1819	make buildworld
1820	make buildkernel KERNCONF=YOUR_KERNEL_HERE
1821	<maybe newfs current's root partition>
1822	<mount current's root partition on directory ${CURRENT_ROOT}>
1823	make installworld DESTDIR=${CURRENT_ROOT}
1824	make distribution DESTDIR=${CURRENT_ROOT} # if newfs'd
1825	make installkernel KERNCONF=YOUR_KERNEL_HERE DESTDIR=${CURRENT_ROOT}
1826	cp /etc/fstab ${CURRENT_ROOT}/etc/fstab 		   # if newfs'd
1827	<edit ${CURRENT_ROOT}/etc/fstab to mount "/" from the correct partition>
1828	<reboot into current>
1829	<do a "native" rebuild/install as described in the previous section>
1830	<maybe install compatibility libraries from ports/misc/compat*>
1831	<reboot>
1832
1833
1834	To upgrade in-place from stable to current
1835	----------------------------------------------
1836	<make sure you have good level 0 dumps>
1837	make buildworld					[9]
1838	make kernel KERNCONF=YOUR_KERNEL_HERE		[8]
1839							[1]
1840	<reboot in single user>				[3]
1841	mergemaster -p					[5]
1842	make installworld
1843	mergemaster -i					[4]
1844	make delete-old					[6]
1845	<reboot>
1846
1847	Make sure that you've read the UPDATING file to understand the
1848	tweaks to various things you need.  At this point in the life
1849	cycle of current, things change often and you are on your own
1850	to cope.  The defaults can also change, so please read ALL of
1851	the UPDATING entries.
1852
1853	Also, if you are tracking -current, you must be subscribed to
1854	freebsd-current@freebsd.org.  Make sure that before you update
1855	your sources that you have read and understood all the recent
1856	messages there.  If in doubt, please track -stable which has
1857	much fewer pitfalls.
1858
1859	[1] If you have third party modules, such as vmware, you
1860	should disable them at this point so they don't crash your
1861	system on reboot.
1862
1863	[3] From the bootblocks, boot -s, and then do
1864		fsck -p
1865		mount -u /
1866		mount -a
1867		cd src
1868		adjkerntz -i		# if CMOS is wall time
1869	Also, when doing a major release upgrade, it is required that
1870	you boot into single user mode to do the installworld.
1871
1872	[4] Note: This step is non-optional.  Failure to do this step
1873	can result in a significant reduction in the functionality of the
1874	system.  Attempting to do it by hand is not recommended and those
1875	that pursue this avenue should read this file carefully, as well
1876	as the archives of freebsd-current and freebsd-hackers mailing lists
1877	for potential gotchas.  The -U option is also useful to consider.
1878	See mergemaster(8) for more information.
1879
1880	[5] Usually this step is a noop.  However, from time to time
1881	you may need to do this if you get unknown user in the following
1882	step.  It never hurts to do it all the time.  You may need to
1883	install a new mergemaster (cd src/usr.sbin/mergemaster && make
1884	install) after the buildworld before this step if you last updated
1885	from current before 20130425 or from -stable before 20130430.
1886
1887	[6] This only deletes old files and directories. Old libraries
1888	can be deleted by "make delete-old-libs", but you have to make
1889	sure that no program is using those libraries anymore.
1890
1891	[8] In order to have a kernel that can run the 4.x binaries needed to
1892	do an installworld, you must include the COMPAT_FREEBSD4 option in
1893	your kernel.  Failure to do so may leave you with a system that is
1894	hard to boot to recover. A similar kernel option COMPAT_FREEBSD5 is
1895	required to run the 5.x binaries on more recent kernels.  And so on
1896	for COMPAT_FREEBSD6 and COMPAT_FREEBSD7.
1897
1898	Make sure that you merge any new devices from GENERIC since the
1899	last time you updated your kernel config file.
1900
1901	[9] When checking out sources, you must include the -P flag to have
1902	cvs prune empty directories.
1903
1904	If CPUTYPE is defined in your /etc/make.conf, make sure to use the
1905	"?=" instead of the "=" assignment operator, so that buildworld can
1906	override the CPUTYPE if it needs to.
1907
1908	MAKEOBJDIRPREFIX must be defined in an environment variable, and
1909	not on the command line, or in /etc/make.conf.  buildworld will
1910	warn if it is improperly defined.
1911FORMAT:
1912
1913This file contains a list, in reverse chronological order, of major
1914breakages in tracking -current.  It is not guaranteed to be a complete
1915list of such breakages, and only contains entries since October 10, 2007.
1916If you need to see UPDATING entries from before that date, you will need
1917to fetch an UPDATING file from an older FreeBSD release.
1918
1919Copyright information:
1920
1921Copyright 1998-2009 M. Warner Losh.  All Rights Reserved.
1922
1923Redistribution, publication, translation and use, with or without
1924modification, in full or in part, in any form or format of this
1925document are permitted without further permission from the author.
1926
1927THIS DOCUMENT IS PROVIDED BY WARNER LOSH ``AS IS'' AND ANY EXPRESS OR
1928IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1929WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1930DISCLAIMED.  IN NO EVENT SHALL WARNER LOSH BE LIABLE FOR ANY DIRECT,
1931INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1932(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
1933SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
1934HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
1935STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
1936IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1937POSSIBILITY OF SUCH DAMAGE.
1938
1939Contact Warner Losh if you have any questions about your use of
1940this document.
1941
1942$FreeBSD: head/UPDATING 253972 2013-08-05 20:30:15Z hrs $
1943