UPDATING revision 253679
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
3420130726:
35	Behavior of devfs rules path matching has been changed.
36	Pattern is now always matched against fully qualified devfs
37	path and slash characters must be explicitly matched by
38	slashes in pattern (FNM_PATHNAME). Rulesets involving devfs
39	subdirectories must be reviewed.
40
4120130716:
42	The default ARM ABI has changed to the ARM EABI. The old ABI is
43	incompatible with the ARM EABI and all programs and modules will
44	need to be rebuilt to work with a new kernel.
45
46	To keep using the old ABI ensure the WITHOUT_ARM_EABI knob is set.
47
48	NOTE: Support for the old ABI will be removed in the future and
49	users are advised to upgrade.
50
5120130709:
52	pkg_install has been disconnected from the build if you really need it
53	you should add WITH_PKGTOOLS in your src.conf(5).
54
5520130709:
56	Most of network statistics structures were changed to be able
57	keep 64-bits counters. Thus all tools, that work with networking
58	statistics, must be rebuilt (netstat(1), bsnmpd(1), etc.)
59
6020130629:
61	Fix targets that run multiple make's to use && rather than ;
62	so that subsequent steps depend on success of previous.
63
64	NOTE: if building 'universe' with -j* on stable/8 or stable/9
65	it would be better to start the build using bmake, to avoid
66	overloading the machine.
67
6820130618:
69	Fix a bug that allowed a tracing process (e.g. gdb) to write
70	to a memory-mapped file in the traced process's address space
71	even if neither the traced process nor the tracing process had
72	write access to that file.
73
7420130615:
75	CVS has been removed from the base system.  An exact copy
76	of the code is available from the devel/cvs port.
77
7820130613:
79	Some people report the following error after the switch to bmake:
80
81		make: illegal option -- J
82		usage: make [-BPSXeiknpqrstv] [-C directory] [-D variable]
83			...
84		*** [buildworld] Error code 2
85
86	this likely due to an old instance of make in
87	${MAKEPATH} (${MAKEOBJDIRPREFIX}${.CURDIR}/make.${MACHINE})
88	which src/Makefile will use that blindly, if it exists, so if
89	you see the above error:
90
91		rm -rf `make -V MAKEPATH`
92
93	should resolve it.
94
9520130516:
96	Use bmake by default.
97	Whereas before one could choose to build with bmake via
98	-DWITH_BMAKE one must now use -DWITHOUT_BMAKE to use the old
99	make. The goal is to remove these knobs for 10-RELEASE.
100
101	It is worth noting that bmake (like gmake) treats the command
102	line as the unit of failure, rather than statements within the
103	command line.  Thus '(cd some/where && dosomething)' is safer
104	than 'cd some/where; dosomething'. The '()' allows consistent
105	behavior in parallel build.
106
10720130429:
108        Fix a bug that allows NFS clients to issue READDIR on files.
109
11020130426:
111	The WITHOUT_IDEA option has been removed because
112	the IDEA patent expired.
113
11420130426:
115	The sysctl which controls TRIM support under ZFS has been renamed
116	from vfs.zfs.trim_disable -> vfs.zfs.trim.enabled and has been
117	enabled by default.
118
11920130425:
120	The mergemaster command now uses the default MAKEOBJDIRPREFIX
121	rather than creating it's own in the temporary directory in
122	order allow access to bootstrapped versions of tools such as
123	install and mtree.  When upgrading from version of FreeBSD where
124	the install command does not support -l, you will need to
125	install a new mergemaster command if mergemaster -p is required.
126	This can be accomplished with the command (cd src/usr.sbin/mergemaster
127	&& make install).
128
12920130404:
130	Legacy ATA stack, disabled and replaced by new CAM-based one since
131	FreeBSD 9.0, completely removed from the sources.  Kernel modules
132	atadisk and atapi*, user-level tools atacontrol and burncd are
133	removed.  Kernel option `options ATA_CAM` is now permanently enabled
134	and removed.
135
13620130319:
137	SOCK_CLOEXEC and SOCK_NONBLOCK flags have been added to socket(2)
138	and socketpair(2). Software, in particular Kerberos, may
139	automatically detect and use these during building. The resulting
140	binaries will not work on older kernels.
141
14220130308:
143	CTL_DISABLE has also been added to the sparc64 GENERIC (for further
144	information, see the respective 20130304 entry).
145
14620130304:
147	Recent commits to callout(9) changed the size of struct callout,
148	so the KBI is probably heavily disturbed. Also, some functions
149	in callout(9)/sleep(9)/sleepqueue(9)/condvar(9) KPIs were replaced
150	by macros. Every kernel module using it won't load, so rebuild
151	is requested.
152
153	The ctl device has been re-enabled in GENERIC for i386 and amd64,
154	but does not initialize by default (because of the new CTL_DISABLE
155	option) to save memory.  To re-enable it, remove the CTL_DISABLE
156	option from the kernel config file or set kern.cam.ctl.disable=0
157	in /boot/loader.conf.
158
15920130301:
160	The ctl device has been disabled in GENERIC for i386 and amd64.
161	This was done due to the extra memory being allocated at system
162	initialisation time by the ctl driver which was only used if
163	a CAM target device was created.  This makes a FreeBSD system
164	unusable on 128MB or less of RAM.
165
16620130208:
167	A new compression method (lz4) has been merged to -HEAD.  Please
168	refer to zpool-features(7) for more information.
169
170	Please refer to the "ZFS notes" section of this file for information
171	on upgrading boot ZFS pools.
172
17320130129:
174	A BSD-licensed patch(1) variant has been added and is installed
175	as bsdpatch, being the GNU version the default patch.
176	To inverse the logic and use the BSD-licensed one as default,
177	while having the GNU version installed as gnupatch, rebuild
178	and install world with the WITH_BSD_PATCH knob set.
179
18020130121:
181	Due to the use of the new -l option to install(1) during build
182	and install, you must take care not to directly set the INSTALL
183	make variable in your /etc/make.conf, /etc/src.conf, or on the
184	command line.  If you wish to use the -C flag for all installs
185	you may be able to add INSTALL+=-C to /etc/make.conf or
186	/etc/src.conf.
187
18820130118:
189	The install(1) option -M has changed meaning and now takes an
190	argument that is a file or path to append logs to.  In the
191	unlikely event that -M was the last option on the command line
192	and the command line contained at least two files and a target
193	directory the first file will have logs appended to it.  The -M
194	option served little practical purpose in the last decade so its
195	use is expected to be extremely rare.
196
19720121223:
198	After switching to Clang as the default compiler some users of ZFS
199	on i386 systems started to experience stack overflow kernel panics.
200	Please consider using 'options KSTACK_PAGES=4' in such configurations.
201
20220121222:
203	GEOM_LABEL now mangles label names read from file system metadata.
204	Mangling affect labels containing spaces, non-printable characters,
205	'%' or '"'. Device names in /etc/fstab and other places may need to
206	be updated.
207
20820121217:
209	By default, only the 10 most recent kernel dumps will be saved.  To
210	restore the previous behaviour (no limit on the number of kernel dumps
211	stored in the dump directory) add the following line to /etc/rc.conf:
212
213		savecore_flags=""
214
21520121201:
216	With the addition of auditdistd(8), a new auditdistd user is now
217	depended on during installworld.  "mergemaster -p" can be used to add
218	the user prior to installworld, as documented in the handbook.
219
22020121117:
221	The sin6_scope_id member variable in struct sockaddr_in6 is now
222	filled by the kernel before passing the structure to the userland via
223	sysctl or routing socket.  This means the KAME-specific embedded scope
224	id in sin6_addr.s6_addr[2] is always cleared in userland application.
225	This behavior can be controlled by net.inet6.ip6.deembed_scopeid.
226	__FreeBSD_version is bumped to 1000025.
227
22820121105:
229	On i386 and amd64 systems WITH_CLANG_IS_CC is now the default.
230	This means that the world and kernel will be compiled with clang
231	and that clang will be installed as /usr/bin/cc, /usr/bin/c++,
232	and /usr/bin/cpp.  To disable this behavior and revert to building
233	with gcc, compile with WITHOUT_CLANG_IS_CC. Really old versions
234	of current may need to bootstrap WITHOUT_CLANG first if the clang
235	build fails (its compatibility window doesn't extend to the 9 stable
236	branch point).
237
23820121102:
239	The IPFIREWALL_FORWARD kernel option has been removed. Its
240	functionality now turned on by default.
241
24220121023:
243	The ZERO_COPY_SOCKET kernel option has been removed and
244	split into SOCKET_SEND_COW and SOCKET_RECV_PFLIP.
245	NB: SOCKET_SEND_COW uses the VM page based copy-on-write
246	mechanism which is not safe and may result in kernel crashes.
247	NB: The SOCKET_RECV_PFLIP mechanism is useless as no current
248	driver supports disposeable external page sized mbuf storage.
249	Proper replacements for both zero-copy mechanisms are under
250	consideration and will eventually lead to complete removal
251	of the two kernel options.
252
25320121023:
254	The IPv4 network stack has been converted to network byte
255	order. The following modules need to be recompiled together
256	with kernel: carp(4), divert(4), gif(4), siftr(4), gre(4),
257	pf(4), ipfw(4), ng_ipfw(4), stf(4).
258
25920121022:
260	Support for non-MPSAFE filesystems was removed from VFS. The
261	VFS_VERSION was bumped, all filesystem modules shall be
262	recompiled.
263
26420121018:
265	All the non-MPSAFE filesystems have been disconnected from
266	the build. The full list includes: codafs, hpfs, ntfs, nwfs,
267	portalfs, smbfs, xfs.
268
26920121016:
270	The interface cloning API and ABI has changed. The following
271	modules need to be recompiled together with kernel:
272	ipfw(4), pfsync(4), pflog(4), usb(4), wlan(4), stf(4),
273	vlan(4), disc(4), edsc(4), if_bridge(4), gif(4), tap(4),
274	faith(4), epair(4), enc(4), tun(4), if_lagg(4), gre(4).
275
27620121015:
277	The sdhci driver was split in two parts: sdhci (generic SD Host
278	Controller logic) and sdhci_pci (actual hardware driver).
279	No kernel config modifications are required, but if you
280	load sdhc as a module you must switch to sdhci_pci instead.
281
28220121014:
283	Import the FUSE kernel and userland support into base system.
284
28520121013:
286	The GNU sort(1) program has been removed since the BSD-licensed
287	sort(1) has been the default for quite some time and no serious
288	problems have been reported.  The corresponding WITH_GNU_SORT
289	knob has also gone.
290
29120121006:
292	The pfil(9) API/ABI for AF_INET family has been changed. Packet
293	filtering modules: pf(4), ipfw(4), ipfilter(4) need to be recompiled
294	with new kernel.
295
29620121001:
297	The net80211(4) ABI has been changed to allow for improved driver
298	PS-POLL and power-save support.  All wireless drivers need to be
299	recompiled to work with the new kernel.
300
30120120913:
302	The random(4) support for the VIA hardware random number
303	generator (`PADLOCK') is no longer enabled unconditionally.
304	Add the PADLOCK_RNG option in the custom kernel config if
305	needed.  The GENERIC kernels on i386 and amd64 do include the
306	option, so the change only affects the custom kernel
307	configurations.
308
30920120908:
310	The pf(4) packet filter ABI has been changed. pfctl(8) and
311	snmp_pf module need to be recompiled to work with new kernel.
312
31320120828:
314	A new ZFS feature flag "com.delphix:empty_bpobj" has been merged
315	to -HEAD. Pools that have empty_bpobj in active state can not be
316	imported read-write with ZFS implementations that do not support
317	this feature. For more information read the zpool-features(5)
318	manual page.
319
32020120727:
321	The sparc64 ZFS loader has been changed to no longer try to auto-
322	detect ZFS providers based on diskN aliases but now requires these
323	to be explicitly listed in the OFW boot-device environment variable. 
324
32520120712:
326	The OpenSSL has been upgraded to 1.0.1c.  Any binaries requiring
327	libcrypto.so.6 or libssl.so.6 must be recompiled.  Also, there are
328	configuration changes.  Make sure to merge /etc/ssl/openssl.cnf.
329
33020120712:
331	The following sysctls and tunables have been renamed for consistency
332	with other variables:
333	  kern.cam.da.da_send_ordered   -> kern.cam.da.send_ordered
334	  kern.cam.ada.ada_send_ordered -> kern.cam.ada.send_ordered
335
33620120628:
337	The sort utility has been replaced with BSD sort.  For now, GNU sort
338	is also available as "gnusort" or the default can be set back to
339	GNU sort by setting WITH_GNU_SORT.  In this case, BSD sort will be
340	installed as "bsdsort".
341
34220120611:
343	A new version of ZFS (pool version 5000) has been merged to -HEAD.
344	Starting with this version the old system of ZFS pool versioning
345	is superseded by "feature flags". This concept enables forward
346	compatibility against certain future changes in functionality of ZFS
347	pools. The first read-only compatible "feature flag" for ZFS pools
348	is named "com.delphix:async_destroy". For more information
349	read the new zpool-features(5) manual page.
350	Please refer to the "ZFS notes" section of this file for information
351	on upgrading boot ZFS pools.
352
35320120417:
354	The malloc(3) implementation embedded in libc now uses sources imported
355	as contrib/jemalloc.  The most disruptive API change is to
356	/etc/malloc.conf.  If your system has an old-style /etc/malloc.conf,
357	delete it prior to installworld, and optionally re-create it using the
358	new format after rebooting.  See malloc.conf(5) for details
359	(specifically the TUNING section and the "opt.*" entries in the MALLCTL
360	NAMESPACE section).
361
36220120328:
363	Big-endian MIPS TARGET_ARCH values no longer end in "eb".  mips64eb
364	is now spelled mips64.  mipsn32eb is now spelled mipsn32.  mipseb is
365	now spelled mips.  This is to aid compatibility with third-party
366	software that expects this naming scheme in uname(3).  Little-endian
367	settings are unchanged. If you are updating a big-endian mips64 machine
368	from before this change, you may need to set MACHINE_ARCH=mips64 in
369	your environment before the new build system will recognize your machine.
370
37120120306:
372	Disable by default the option VFS_ALLOW_NONMPSAFE for all supported
373	platforms.
374
37520120229:
376	Now unix domain sockets behave "as expected" on	nullfs(5). Previously
377	nullfs(5) did not pass through all behaviours to the underlying layer,
378	as a result if we bound to a socket on the lower layer we could connect
379	only to the lower path; if we bound to the upper layer we could connect
380	only to	the upper path. The new behavior is one can connect to both the
381	lower and the upper paths regardless what layer path one binds to.
382
38320120211:
384	The getifaddrs upgrade path broken with 20111215 has been restored.
385	If you have upgraded in between 20111215 and 20120209 you need to
386	recompile libc again with your kernel.  You still need to recompile
387	world to be able to configure CARP but this restriction already
388	comes from 20111215.
389
39020120114:
391	The set_rcvar() function has been removed from /etc/rc.subr.  All
392	base and ports rc.d scripts have been updated, so if you have a
393	port installed with a script in /usr/local/etc/rc.d you can either
394	hand-edit the rcvar= line, or reinstall the port.
395
396	An easy way to handle the mass-update of /etc/rc.d:
397	rm /etc/rc.d/* && mergemaster -i
398
39920120109:
400	panic(9) now stops other CPUs in the SMP systems, disables interrupts
401	on the current CPU and prevents other threads from running.
402	This behavior can be reverted using the kern.stop_scheduler_on_panic
403	tunable/sysctl.
404	The new behavior can be incompatible with kern.sync_on_panic.
405
40620111215:
407	The carp(4) facility has been changed significantly. Configuration
408	of the CARP protocol via ifconfig(8) has changed, as well as format
409	of CARP events submitted to devd(8) has changed. See manual pages
410	for more information. The arpbalance feature of carp(4) is currently
411	not supported anymore.
412
413	Size of struct in_aliasreq, struct in6_aliasreq has changed. User
414	utilities using SIOCAIFADDR, SIOCAIFADDR_IN6, e.g. ifconfig(8),
415	need to be recompiled.
416
41720111122:
418	The acpi_wmi(4) status device /dev/wmistat has been renamed to
419	/dev/wmistat0.
420
42120111108:
422	The option VFS_ALLOW_NONMPSAFE option has been added in order to
423	explicitely support non-MPSAFE filesystems.
424	It is on by default for all supported platform at this present
425	time.
426
42720111101:
428	The broken amd(4) driver has been replaced with esp(4) in the amd64,
429	i386 and pc98 GENERIC kernel configuration files.
430
43120110930:
432	sysinstall has been removed
433
43420110923:
435	The stable/9 branch created in subversion.  This corresponds to the
436	RELENG_9 branch in CVS.
437
43820110913:
439	This commit modifies vfs_register() so that it uses a hash
440	calculation to set vfc_typenum, which is enabled by default.
441	The first time a system is booted after this change, the
442	vfc_typenum values will change for all file systems. The
443	main effect of this is a change to the NFS server file handles
444	for file systems that use vfc_typenum in their fsid, such as ZFS.
445	It will, however, prevent vfc_typenum from changing when file
446	systems are loaded in a different order for subsequent reboots.
447	To disable this, you can set vfs.typenumhash=0 in /boot/loader.conf
448	until you are ready to remount all NFS clients after a reboot.
449
45020110828:
451	Bump the shared library version numbers for libraries that
452	do not use symbol versioning, have changed the ABI compared
453	to stable/8 and which shared library version was not bumped.
454	Done as part of 9.0-RELEASE cycle.
455
45620110815:
457	During the merge of Capsicum features, the fget(9) KPI was modified.
458	This may require the rebuilding of out-of-tree device drivers --
459	issues have been reported specifically with the nVidia device driver.
460	__FreeBSD_version is bumped to 900041.
461
462	Also, there is a period between 20110811 and 20110814 where the
463	special devices /dev/{stdin,stdout,stderr} did not work correctly.
464	Building world from a kernel during that window may not work.
465
46620110628:
467	The packet filter (pf) code has been updated to OpenBSD 4.5.
468	You need to update userland tools to be in sync with kernel.
469	This update breaks backward compatibility with earlier pfsync(4)
470	versions.  Care must be taken when updating redundant firewall setups.
471
47220110608:
473	The following sysctls and tunables are retired on x86 platforms:
474		machdep.hlt_cpus
475		machdep.hlt_logical_cpus
476	The following sysctl is retired:
477		machdep.hyperthreading_allowed
478	The sysctls were supposed to provide a way to dynamically offline and
479	online selected CPUs on x86 platforms, but the implementation has not
480	been reliable especially with SCHED_ULE scheduler.
481	machdep.hyperthreading_allowed tunable is still available to ignore
482	hyperthreading CPUs at OS level.
483	Individual CPUs can be disabled using hint.lapic.X.disabled tunable,
484	where X is an APIC ID of a CPU.  Be advised, though, that disabling
485	CPUs in non-uniform fashion will result in non-uniform topology and
486	may lead to sub-optimal system performance with SCHED_ULE, which is
487	a default scheduler.
488
48920110607:
490	cpumask_t type is retired and cpuset_t is used in order to describe
491	a mask of CPUs.
492
49320110531:
494	Changes to ifconfig(8) for dynamic address family detection mandate
495	that you are running a kernel of 20110525 or later.  Make sure to
496	follow the update procedure to boot a new kernel before installing
497	world.
498
49920110513:
500	Support for sun4v architecture is officially dropped
501
50220110503:
503	Several KPI breaking changes have been committed to the mii(4) layer,
504	the PHY drivers and consequently some Ethernet drivers using mii(4).
505	This means that miibus.ko and the modules of the affected Ethernet
506	drivers need to be recompiled.
507
508	Note to kernel developers: Given that the OUI bit reversion problem
509	was fixed as part of these changes all mii(4) commits related to OUIs,
510	i.e. to sys/dev/mii/miidevs, PHY driver probing and vendor specific
511	handling, no longer can be merged verbatim to stable/8 and previous
512	branches.
513
51420110430:
515	Users of the Atheros AR71xx SoC code now need to add 'device ar71xx_pci'
516	into their kernel configurations along with 'device pci'.
517
51820110427:
519	The default NFS client is now the new NFS client, so fstype "newnfs"
520	is now "nfs" and the regular/old NFS client is now fstype "oldnfs".
521	Although mounts via fstype "nfs" will usually work without userland
522	changes, it is recommended that the mount(8) and mount_nfs(8)
523	commands be rebuilt from sources and that a link to mount_nfs called
524	mount_oldnfs be created. The new client is compiled into the
525	kernel with "options NFSCL" and this is needed for diskless root
526	file systems. The GENERIC kernel configs have been changed to use
527	NFSCL and NFSD (the new server) instead of NFSCLIENT and NFSSERVER.
528	To use the regular/old client, you can "mount -t oldnfs ...". For
529	a diskless root file system, you must also include a line like:
530	
531	vfs.root.mountfrom="oldnfs:"
532
533	in the boot/loader.conf on the root fs on the NFS server to make
534	a diskless root fs use the old client.
535
53620110424:
537	The GENERIC kernels for all architectures now default to the new
538	CAM-based ATA stack. It means that all legacy ATA drivers were
539	removed and replaced by respective CAM drivers. If you are using
540	ATA device names in /etc/fstab or other places, make sure to update
541	them respectively (adX -> adaY, acdX -> cdY, afdX -> daY, astX -> saY,
542	where 'Y's are the sequential numbers starting from zero for each type
543	in order of detection, unless configured otherwise with tunables,
544	see cam(4)). There will be symbolic links created in /dev/ to map
545	old adX devices to the respective adaY. They should provide basic
546	compatibility for file systems mounting in most cases, but they do
547	not support old user-level APIs and do not have respective providers
548	in GEOM. Consider using updated management tools with new device names.
549
550	It is possible to load devices ahci, ata, siis and mvs as modules,
551	but option ATA_CAM should remain in kernel configuration to make ata
552	module work as CAM driver supporting legacy ATA controllers. Device ata
553	still can be used in modular fashion (atacore + ...). Modules atadisk
554	and atapi* are not used and won't affect operation in ATA_CAM mode.
555	Note that to use CAM-based ATA kernel should include CAM devices
556	scbus, pass, da (or explicitly ada), cd and optionally others. All of
557	them are parts of the cam module.
558
559	ataraid(4) functionality is now supported by the RAID GEOM class.
560	To use it you can load geom_raid kernel module and use graid(8) tool
561	for management. Instead of /dev/arX device names, use /dev/raid/rX.
562
563	No kernel config options or code have been removed, so if a problem
564	arises, please report it and optionally revert to the old ATA stack.
565	In order to do it you can remove from the kernel config:
566	    options        ATA_CAM
567	    device         ahci
568	    device         mvs
569	    device         siis
570	, and instead add back:
571	    device         atadisk         # ATA disk drives
572	    device         ataraid         # ATA RAID drives
573	    device         atapicd         # ATAPI CDROM drives
574	    device         atapifd         # ATAPI floppy drives
575	    device         atapist         # ATAPI tape drives
576
57720110423:
578	The default NFS server has been changed to the new server, which
579	was referred to as the experimental server. If you need to switch
580	back to the old NFS server, you must now put the "-o" option on
581	both the mountd and nfsd commands. This can be done using the
582	mountd_flags and nfs_server_flags rc.conf variables until an
583	update to the rc scripts is committed, which is coming soon.
584
58520110418:
586	The GNU Objective-C runtime library (libobjc), and other Objective-C
587	related components have been removed from the base system.  If you
588	require an Objective-C library, please use one of the available ports.
589
59020110331:
591	ath(4) has been split into bus- and device- modules. if_ath contains
592	the HAL, the TX rate control and the network device code. if_ath_pci
593	contains the PCI bus glue. For Atheros MIPS embedded systems, if_ath_ahb
594	contains the AHB glue. Users need to load both if_ath_pci and if_ath
595	in order to use ath on everything else.
596
597	TO REPEAT: if_ath_ahb is not needed for normal users. Normal users only
598	need to load if_ath and if_ath_pci for ath(4) operation.
599
60020110314:
601	As part of the replacement of sysinstall, the process of building
602	release media has changed significantly. For details, please re-read
603	release(7), which has been updated to reflect the new build process.
604
60520110218:
606	GNU binutils 2.17.50 (as of 2007-07-03) has been merged to -HEAD.  This
607	is the last available version under GPLv2.  It brings a number of new
608	features, such as support for newer x86 CPU's (with SSE-3, SSSE-3, SSE
609	4.1 and SSE 4.2), better support for powerpc64, a number of new
610	directives, and lots of other small improvements.  See the ChangeLog
611	file in contrib/binutils for the full details.
612
61320110218:
614	IPsec's HMAC_SHA256-512 support has been fixed to be RFC4868
615	compliant, and will now use half of hash for authentication.
616	This will break interoperability with all stacks (including all
617	actual FreeBSD versions) who implement
618	draft-ietf-ipsec-ciph-sha-256-00 (they use 96 bits of hash for
619	authentication).
620	The only workaround with such peers is to use another HMAC
621	algorithm for IPsec ("phase 2") authentication.
622
62320110207:
624	Remove the uio_yield prototype and symbol.  This function has
625	been misnamed since it was introduced and should not be
626	globally exposed with this name.  The equivalent functionality
627	is now available using kern_yield(curthread->td_user_pri).
628	The function remains undocumented.
629
63020110112:
631	A SYSCTL_[ADD_]UQUAD was added for unsigned uint64_t pointers,
632	symmetric with the existing SYSCTL_[ADD_]QUAD.  Type checking
633	for scalar sysctls is defined but disabled.  Code that needs
634	UQUAD to pass the type checking that must compile on older
635	systems where the define is not present can check against
636	__FreeBSD_version >= 900030.
637
638	The system dialog(1) has been replaced with a new version previously
639	in ports as devel/cdialog. dialog(1) is mostly command-line compatible
640	with the previous version, but the libdialog associated with it has
641	a largely incompatible API. As such, the original version of libdialog
642	will be kept temporarily as libodialog, until its base system consumers
643	are replaced or updated. Bump __FreeBSD_version to 900030.
644
64520110103:
646	If you are trying to run make universe on a -stable system, and you get
647	the following warning:
648	"Makefile", line 356: "Target architecture for i386/conf/GENERIC 
649	unknown.  config(8) likely too old."
650	or something similar to it, then you must upgrade your -stable system
651	to 8.2-Release or newer (really, any time after r210146 7/15/2010 in
652	stable/8) or build the config from the latest stable/8 branch and
653	install it on your system.
654
655	Prior to this date, building a current universe on 8-stable system from
656	between 7/15/2010 and 1/2/2011 would result in a weird shell parsing
657	error in the first kernel build phase.  A new config on those old 
658	systems will fix that problem for older versions of -current.
659
66020101228:
661	The TCP stack has been modified to allow Khelp modules to interact with
662	it via helper hook points and store per-connection data in the TCP
663	control block. Bump __FreeBSD_version to 900029. User space tools that
664	rely on the size of struct tcpcb in tcp_var.h (e.g. sockstat) need to
665	be recompiled.
666
66720101114:
668	Generic IEEE 802.3 annex 31B full duplex flow control support has been
669	added to mii(4) and bge(4), bce(4), msk(4), nfe(4) and stge(4) along
670	with brgphy(4), e1000phy(4) as well as ip1000phy() have been converted
671	to take advantage of it instead of using custom implementations.  This
672	means that these drivers now no longer unconditionally advertise
673	support for flow control but only do so if flow control is a selected
674	media option.  This was implemented in the generic support that way in
675	order to allow flow control to be switched on and off via ifconfig(8)
676	with the PHY specific default to typically off in order to protect
677	from unwanted effects.  Consequently, if you used flow control with
678	one of the above mentioned drivers you now need to explicitly enable
679	it, for example via:
680		ifconfig bge0 media auto mediaopt flowcontrol
681
682	Along with the above mentioned changes generic support for setting
683	1000baseT master mode also has been added and brgphy(4), ciphy(4),
684	e1000phy(4) as well as ip1000phy(4) have been converted to take
685	advantage of it.  This means that these drivers now no longer take the
686	link0 parameter for selecting master mode but the master media option
687	has to be used instead, for example like in the following:
688		ifconfig bge0 media 1000baseT mediaopt full-duplex,master
689
690	Selection of master mode now is also available with all other PHY
691	drivers supporting 1000baseT.
692
69320101111:
694	The TCP stack has received a significant update to add support for
695	modularised congestion control and generally improve the clarity of
696	congestion control decisions. Bump __FreeBSD_version to 900025. User
697	space tools that rely on the size of struct tcpcb in tcp_var.h (e.g.
698	sockstat) need to be recompiled.
699
70020101002:
701	The man(1) utility has been replaced by a new version that no longer
702	uses /etc/manpath.config. Please consult man.conf(5) for how to
703	migrate local entries to the new format.
704
70520100928:
706	The copyright strings printed by login(1) and sshd(8) at the time of a
707	new connection have been removed to follow other operating systems and
708	upstream sshd.
709
71020100915:
711	A workaround for a fixed ld bug has been removed in kernel code,
712	so make sure that your system ld is built from sources after
713	revision 210245 from 2010-07-19 (r211583 if building head kernel
714	on stable/8, r211584 for stable/7; both from 2010-08-21).
715	A symptom of incorrect ld version is different addresses for
716	set_pcpu section and __start_set_pcpu symbol in kernel and/or modules.
717
71820100913:
719	The $ipv6_prefer variable in rc.conf(5) has been split into
720	$ip6addrctl_policy and $ipv6_activate_all_interfaces.
721
722	The $ip6addrctl_policy is a variable to choose a pre-defined
723	address selection policy set by ip6addrctl(8).  A value
724	"ipv4_prefer", "ipv6_prefer" or "AUTO" can be specified.  The
725	default is "AUTO".
726
727	The $ipv6_activate_all_interfaces specifies whether IFDISABLED
728	flag (see an entry of 20090926) is set on an interface with no
729	corresponding $ifconfig_IF_ipv6 line.  The default is "NO" for
730	security reason.  If you want IPv6 link-local address on all
731	interfaces by default, set this to "YES".
732
733	The old ipv6_prefer="YES" is equivalent to
734	ipv6_activate_all_interfaces="YES" and
735	ip6addrctl_policy="ipv6_prefer".
736
73720100913:
738	DTrace has grown support for userland tracing. Due to this, DTrace is
739	now i386 and amd64 only.
740	dtruss(1) is now installed by default on those systems and a new
741	kernel module is needed for userland tracing: fasttrap.
742	No changes to your kernel config file are necessary to enable
743	userland tracing, but you might consider adding 'STRIP=' and
744	'CFLAGS+=-fno-omit-frame-pointer' to your make.conf if you want
745	to have informative userland stack traces in DTrace (ustack).
746
74720100725:
748	The acpi_aiboost(4) driver has been removed in favor of the new
749	aibs(4) driver. You should update your kernel configuration file.
750
75120100722:
752	BSD grep has been imported to the base system and it is built by
753	default.  It is completely BSD licensed, highly GNU-compatible, uses
754	less memory than its GNU counterpart and has a small codebase.
755	However, it is slower than its GNU counterpart, which is mostly
756	noticeable for larger searches, for smaller ones it is measurable
757	but not significant.  The reason is complex, the most important factor
758	is that we lack a modern and efficient regex library and GNU
759	overcomes this by optimizing the searches internally.  Future work
760	on improving the regex performance is planned, for the meantime,
761	users that need better performance, can build GNU grep instead by
762	setting the WITH_GNU_GREP knob.
763
76420100713:
765	Due to the import of powerpc64 support, all existing powerpc kernel
766	configuration files must be updated with a machine directive like this:
767	    machine powerpc powerpc
768
769	In addition, an updated config(8) is required to build powerpc kernels
770	after this change.
771
77220100713:
773	A new version of ZFS (version 15) has been merged to -HEAD.
774	This version uses a python library for the following subcommands:
775	zfs allow, zfs unallow, zfs groupspace, zfs userspace.
776	For full functionality of these commands the following port must
777	be installed: sysutils/py-zfs
778
77920100429:
780	'vm_page's are now hashed by physical address to an array of mutexes.
781	Currently this is only used to serialize access to hold_count. Over 
782	time the page queue mutex will be peeled away. This changes the size
783	of pmap on every architecture. And requires all callers of vm_page_hold
784	and vm_page_unhold to be updated. 
785 
78620100402:
787	WITH_CTF can now be specified in src.conf (not recommended, there
788	are some problems with static executables), make.conf (would also
789	affect ports which do not use GNU make and do not override the
790	compile targets) or in the kernel config (via "makeoptions
791	WITH_CTF=yes").
792	When WITH_CTF was specified there before this was silently ignored,
793	so make sure that WITH_CTF is not used in places which could lead
794	to unwanted behavior.
795
79620100311:
797	The kernel option COMPAT_IA32 has been replaced with COMPAT_FREEBSD32
798	to allow 32-bit compatibility on non-x86 platforms. All kernel
799	configurations on amd64 and ia64 platforms using these options must
800	be modified accordingly.
801
80220100113:
803	The utmp user accounting database has been replaced with utmpx,
804	the user accounting interface standardized by POSIX.
805	Unfortunately the semantics of utmp and utmpx don't match,
806	making it practically impossible to support both interfaces.
807	The user accounting database is used by tools like finger(1),
808	last(1), talk(1), w(1) and ac(8).
809
810	All applications in the base system use utmpx.  This means only
811	local binaries (e.g. from the ports tree) may still use these
812	utmp database files.  These applications must be rebuilt to make
813	use of utmpx.
814
815	After the system has been upgraded, it is safe to remove the old
816	log files (/var/run/utmp, /var/log/lastlog and /var/log/wtmp*),
817	assuming their contents is of no importance anymore.  Old wtmp
818	databases can only be used by last(1) and ac(8) after they have
819	been converted to the new format using wtmpcvt(1).
820
82120100108:
822	Introduce the kernel thread "deadlock resolver" (which can be enabled
823	via the DEADLKRES option, see NOTES for more details) and the
824	sleepq_type() function for sleepqueues.
825
82620091202:
827	The rc.firewall and rc.firewall6 were unified, and
828	rc.firewall6 and rc.d/ip6fw were removed.
829	According to the removal of rc.d/ip6fw, ipv6_firewall_* rc
830	variables are obsoleted.  Instead, the following new rc
831	variables are added to rc.d/ipfw:
832
833		firewall_client_net_ipv6, firewall_simple_iif_ipv6,
834		firewall_simple_inet_ipv6, firewall_simple_oif_ipv6,
835		firewall_simple_onet_ipv6, firewall_trusted_ipv6
836
837	The meanings correspond to the relevant IPv4 variables.
838
83920091125:
840	8.0-RELEASE.
841
84220091113:
843	The default terminal emulation for syscons(4) has been changed
844	from cons25 to xterm on all platforms except pc98.  This means
845	that the /etc/ttys file needs to be updated to ensure correct
846	operation of applications on the console.
847
848	The terminal emulation style can be toggled per window by using
849	vidcontrol(1)'s -T flag.  The TEKEN_CONS25 kernel configuration
850	options can be used to change the compile-time default back to
851	cons25.
852
853	To prevent graphical artifacts, make sure the TERM environment
854	variable is set to match the terminal emulation that is being
855	performed by syscons(4).
856
85720091109:
858	The layout of the structure ieee80211req_scan_result has changed.
859	Applications that require wireless scan results (e.g. ifconfig(8))
860	from net80211 need to be recompiled.
861
862	Applications such as wpa_supplicant(8) may require a full world
863	build without using NO_CLEAN in order to get synchronized with the
864	new structure.
865
86620091025:
867	The iwn(4) driver has been updated to support the 5000 and 5150 series.
868	There's one kernel module for each firmware. Adding "device iwnfw"
869	to the kernel configuration file means including all three firmware
870	images inside the kernel. If you want to include just the one for
871	your wireless card, use the devices iwn4965fw, iwn5000fw or
872	iwn5150fw.
873
87420090926:
875	The rc.d/network_ipv6, IPv6 configuration script has been integrated
876	into rc.d/netif.  The changes are the following:
877
878	1. To use IPv6, simply define $ifconfig_IF_ipv6 like $ifconfig_IF
879	   for IPv4.  For aliases, $ifconfig_IF_aliasN should be used.
880	   Note that both variables need the "inet6" keyword at the head.
881
882	   Do not set $ipv6_network_interfaces manually if you do not
883	   understand what you are doing.  It is not needed in most cases. 
884
885	   $ipv6_ifconfig_IF and $ipv6_ifconfig_IF_aliasN still work, but
886	   they are obsolete.
887
888	2. $ipv6_enable is obsolete.  Use $ipv6_prefer and
889	   "inet6 accept_rtadv" keyword in ifconfig(8) instead.
890
891	   If you define $ipv6_enable=YES, it means $ipv6_prefer=YES and
892	   all configured interfaces have "inet6 accept_rtadv" in the
893	   $ifconfig_IF_ipv6.  These are for backward compatibility.
894
895	3. A new variable $ipv6_prefer has been added.  If NO, IPv6
896	   functionality of interfaces with no corresponding
897	   $ifconfig_IF_ipv6 is disabled by using "inet6 ifdisabled" flag,
898	   and the default address selection policy of ip6addrctl(8) 
899	   is the IPv4-preferred one (see rc.d/ip6addrctl for more details).
900	   Note that if you want to configure IPv6 functionality on the
901	   disabled interfaces after boot, first you need to clear the flag by
902	   using ifconfig(8) like:
903
904		ifconfig em0 inet6 -ifdisabled
905
906	   If YES, the default address selection policy is set as
907	   IPv6-preferred.
908
909	   The default value of $ipv6_prefer is NO.
910
911	4. If your system need to receive Router Advertisement messages,
912	   define "inet6 accept_rtadv" in $ifconfig_IF_ipv6.  The rc(8)
913	   scripts automatically invoke rtsol(8) when the interface becomes
914	   UP.  The Router Advertisement messages are used for SLAAC
915	   (State-Less Address AutoConfiguration).
916
91720090922:
918	802.11s D3.03 support was committed. This is incompatible with the
919	previous code, which was based on D3.0.
920
92120090912:
922	A sysctl variable net.inet6.ip6.accept_rtadv now sets the default value
923	of a per-interface flag ND6_IFF_ACCEPT_RTADV, not a global knob to
924	control whether accepting Router Advertisement messages or not.
925	Also, a per-interface flag ND6_IFF_AUTO_LINKLOCAL has been added and
926	a sysctl variable net.inet6.ip6.auto_linklocal is its default value.
927	The ifconfig(8) utility now supports these flags.
928
92920090910:
930	ZFS snapshots are now mounted with MNT_IGNORE flag. Use -v option for
931	mount(8) and -a option for df(1) to see them.
932
93320090825:
934	The old tunable hw.bus.devctl_disable has been superseded by
935	hw.bus.devctl_queue.  hw.bus.devctl_disable=1 in loader.conf should be
936	replaced by hw.bus.devctl_queue=0.  The default for this new tunable
937	is 1000.
938
93920090813:
940	Remove the option STOP_NMI.  The default action is now to use NMI only
941	for KDB via the newly introduced function stop_cpus_hard() and
942	maintain stop_cpus() to just use a normal IPI_STOP on ia32 and amd64.
943
94420090803:
945	The stable/8 branch created in subversion.  This corresponds to the
946	RELENG_8 branch in CVS.
947
94820090719:
949	Bump the shared library version numbers for all libraries that do not
950	use symbol versioning as part of the 8.0-RELEASE cycle.  Bump
951	__FreeBSD_version to 800105.
952
95320090714:
954	Due to changes in the implementation of virtual network stack support,
955	all network-related kernel modules must be recompiled.  As this change
956	breaks the ABI, bump __FreeBSD_version to 800104.
957
95820090713:
959	The TOE interface to the TCP syncache has been modified to remove
960	struct tcpopt (<netinet/tcp_var.h>) from the ABI of the network stack.
961	The cxgb driver is the only TOE consumer affected by this change, and
962	needs to be recompiled along with the kernel. As this change breaks
963	the ABI, bump __FreeBSD_version to 800103.
964
96520090712: 
966	Padding has been added to struct tcpcb, sackhint and tcpstat in
967	<netinet/tcp_var.h> to facilitate future MFCs and bug fixes whilst
968	maintaining the ABI. However, this change breaks the ABI, so bump
969	__FreeBSD_version to 800102. User space tools that rely on the size of
970	any of these structs (e.g. sockstat) need to be recompiled.
971
97220090630:
973	The NFS_LEGACYRPC option has been removed along with the old kernel
974	RPC implementation that this option selected. Kernel configurations
975	may need to be adjusted.
976
97720090629:
978	The network interface device nodes at /dev/net/<interface> have been
979	removed.  All ioctl operations can be performed the normal way using
980	routing sockets.  The kqueue functionality can generally be replaced
981	with routing sockets.
982
98320090628:
984	The documentation from the FreeBSD Documentation Project (Handbook,
985	FAQ, etc.) is now installed via packages by sysinstall(8) and under
986	the /usr/local/share/doc/freebsd directory instead of /usr/share/doc.
987
98820090624:
989	The ABI of various structures related to the SYSV IPC API have been
990	changed.  As a result, the COMPAT_FREEBSD[456] and COMPAT_43 kernel
991	options now all require COMPAT_FREEBSD7.  Bump __FreeBSD_version to
992	800100.
993
99420090622:
995	Layout of struct vnet has changed as routing related variables were
996	moved to their own Vimage module. Modules need to be recompiled.  Bump
997	__FreeBSD_version to 800099.
998
99920090619:
1000	NGROUPS_MAX and NGROUPS have been increased from 16 to 1023 and 1024
1001	respectively.  As long as no more than 16 groups per process are used,
1002	no changes should be visible.  When more than 16 groups are used, old
1003	binaries may fail if they call getgroups() or getgrouplist() with
1004	statically sized storage.  Recompiling will work around this, but
1005	applications should be modified to use dynamically allocated storage
1006	for group arrays as POSIX.1-2008 does not cap an implementation's
1007	number of supported groups at NGROUPS_MAX+1 as previous versions did.
1008
1009	NFS and portalfs mounts may also be affected as the list of groups is
1010	truncated to 16.  Users of NFS who use more than 16 groups, should
1011	take care that negative group permissions are not used on the exported
1012	file systems as they will not be reliable unless a GSSAPI based
1013	authentication method is used.
1014
101520090616: 
1016	The compiling option ADAPTIVE_LOCKMGRS has been introduced.  This
1017	option compiles in the support for adaptive spinning for lockmgrs
1018	which want to enable it.  The lockinit() function now accepts the flag
1019	LK_ADAPTIVE in order to make the lock object subject to adaptive
1020	spinning when both held in write and read mode.
1021
102220090613:
1023	The layout of the structure returned by IEEE80211_IOC_STA_INFO has
1024	changed.  User applications that use this ioctl need to be rebuilt.
1025
102620090611:
1027	The layout of struct thread has changed.  Kernel and modules need to
1028	be rebuilt.
1029
103020090608:
1031	The layout of structs ifnet, domain, protosw and vnet_net has changed.
1032	Kernel modules need to be rebuilt.  Bump __FreeBSD_version to 800097.
1033
103420090602:
1035	window(1) has been removed from the base system. It can now be
1036	installed from ports. The port is called misc/window.
1037
103820090601:
1039	The way we are storing and accessing `routing table' entries has
1040	changed. Programs reading the FIB, like netstat, need to be
1041	re-compiled.
1042
104320090601:
1044	A new netisr implementation has been added for FreeBSD 8.  Network
1045	file system modules, such as igmp, ipdivert, and others, should be
1046	rebuilt.
1047	Bump __FreeBSD_version to 800096.
1048
104920090530:
1050	Remove the tunable/sysctl debug.mpsafevfs as its initial purpose is no
1051	more valid.
1052
105320090530:
1054	Add VOP_ACCESSX(9).  File system modules need to be rebuilt.
1055	Bump __FreeBSD_version to 800094.
1056
105720090529:
1058	Add mnt_xflag field to 'struct mount'.  File system modules need to be
1059	rebuilt.
1060	Bump __FreeBSD_version to 800093.
1061
106220090528:
1063	The compiling option ADAPTIVE_SX has been retired while it has been
1064	introduced the option NO_ADAPTIVE_SX which handles the reversed logic.
1065	The KPI for sx_init_flags() changes as accepting flags:
1066	SX_ADAPTIVESPIN flag has been retired while the SX_NOADAPTIVE flag has
1067	been introduced in order to handle the reversed logic.
1068	Bump __FreeBSD_version to 800092.
1069
107020090527:
1071	Add support for hierarchical jails.  Remove global securelevel.
1072	Bump __FreeBSD_version to 800091.
1073
107420090523:
1075	The layout of struct vnet_net has changed, therefore modules
1076	need to be rebuilt.
1077	Bump __FreeBSD_version to 800090.
1078
107920090523:
1080	The newly imported zic(8) produces a new format in the output. Please
1081	run tzsetup(8) to install the newly created data to /etc/localtime.
1082
108320090520:
1084	The sysctl tree for the usb stack has renamed from hw.usb2.* to
1085	hw.usb.* and is now consistent again with previous releases.
1086
108720090520:
1088	802.11 monitor mode support was revised and driver api's were changed.
1089	Drivers dependent on net80211 now support DLT_IEEE802_11_RADIO instead
1090	of DLT_IEEE802_11.  No user-visible data structures were changed but
1091	applications that use DLT_IEEE802_11 may require changes.
1092	Bump __FreeBSD_version to 800088.
1093
109420090430:
1095	The layout of the following structs has changed: sysctl_oid,
1096	socket, ifnet, inpcbinfo, tcpcb, syncache_head, vnet_inet,
1097	vnet_inet6 and vnet_ipfw.  Most modules need to be rebuild or
1098	panics may be experienced.  World rebuild is required for
1099	correctly checking networking state from userland.
1100	Bump __FreeBSD_version to 800085.
1101
110220090429:
1103	MLDv2 and Source-Specific Multicast (SSM) have been merged
1104	to the IPv6 stack. VIMAGE hooks are in but not yet used.
1105	The implementation of SSM within FreeBSD's IPv6 stack closely
1106	follows the IPv4 implementation.
1107
1108	For kernel developers:
1109
1110	* The most important changes are that the ip6_output() and
1111	  ip6_input() paths no longer take the IN6_MULTI_LOCK,
1112	  and this lock has been downgraded to a non-recursive mutex.
1113
1114	* As with the changes to the IPv4 stack to support SSM, filtering
1115	  of inbound multicast traffic must now be performed by transport
1116	  protocols within the IPv6 stack. This does not apply to TCP and
1117	  SCTP, however, it does apply to UDP in IPv6 and raw IPv6.
1118
1119	* The KPIs used by IPv6 multicast are similar to those used by
1120	  the IPv4 stack, with the following differences:
1121	   * im6o_mc_filter() is analogous to imo_multicast_filter().
1122	   * The legacy KAME entry points in6_joingroup and in6_leavegroup()
1123	     are shimmed to in6_mc_join() and in6_mc_leave() respectively.
1124	   * IN6_LOOKUP_MULTI() has been deprecated and removed.
1125	   * IPv6 relies on MLD for the DAD mechanism. KAME's internal KPIs
1126	     for MLDv1 have an additional 'timer' argument which is used to
1127	     jitter the initial membership report for the solicited-node
1128	     multicast membership on-link.
1129	   * This is not strictly needed for MLDv2, which already jitters
1130	     its report transmissions.  However, the 'timer' argument is
1131	     preserved in case MLDv1 is active on the interface.
1132
1133	* The KAME linked-list based IPv6 membership implementation has
1134	  been refactored to use a vector similar to that used by the IPv4
1135	  stack.
1136	  Code which maintains a list of its own multicast memberships
1137	  internally, e.g. carp, has been updated to reflect the new
1138	  semantics.
1139
1140	* There is a known Lock Order Reversal (LOR) due to in6_setscope()
1141	  acquiring the IF_AFDATA_LOCK and being called within ip6_output().
1142	  Whilst MLDv2 tries to avoid this otherwise benign LOR, it is an
1143	  implementation constraint which needs to be addressed in HEAD.
1144
1145	For application developers:
1146
1147	* The changes are broadly similar to those made for the IPv4
1148	  stack.
1149
1150	* The use of IPv4 and IPv6 multicast socket options on the same
1151	  socket, using mapped addresses, HAS NOT been tested or supported.
1152
1153	* There are a number of issues with the implementation of various
1154	  IPv6 multicast APIs which need to be resolved in the API surface
1155	  before the implementation is fully compatible with KAME userland
1156	  use, and these are mostly to do with interface index treatment.
1157
1158	* The literature available discusses the use of either the delta / ASM
1159	  API with setsockopt(2)/getsockopt(2), or the full-state / ASM API
1160	  using setsourcefilter(3)/getsourcefilter(3). For more information
1161	  please refer to RFC 3768, 'Socket Interface Extensions for
1162	  Multicast Source Filters'.
1163
1164	* Applications which use the published RFC 3678 APIs should be fine.
1165
1166	For systems administrators:
1167
1168	* The mtest(8) utility has been refactored to support IPv6, in
1169	  addition to IPv4. Interface addresses are no longer accepted
1170	  as arguments, their names must be used instead. The utility
1171	  will map the interface name to its first IPv4 address as
1172	  returned by getifaddrs(3).
1173
1174	* The ifmcstat(8) utility has also been updated to print the MLDv2
1175	  endpoint state and source filter lists via sysctl(3).
1176
1177	* The net.inet6.ip6.mcast.loop sysctl may be tuned to 0 to disable
1178	  loopback of IPv6 multicast datagrams by default; it defaults to 1
1179	  to preserve the existing behaviour. Disabling multicast loopback is
1180	  recommended for optimal system performance.
1181
1182	* The IPv6 MROUTING code has been changed to examine this sysctl
1183	  instead of attempting to perform a group lookup before looping
1184	  back forwarded datagrams.
1185
1186	Bump __FreeBSD_version to 800084.
1187
118820090422:
1189	Implement low-level Bluetooth HCI API.
1190	Bump __FreeBSD_version to 800083.
1191
119220090419:
1193	The layout of struct malloc_type, used by modules to register new
1194	memory allocation types, has changed.  Most modules will need to
1195	be rebuilt or panics may be experienced.
1196	Bump __FreeBSD_version to 800081.
1197
119820090415:
1199	Anticipate overflowing inp_flags - add inp_flags2.
1200	This changes most offsets in inpcb, so checking v4 connection
1201	state will require a world rebuild.
1202	Bump __FreeBSD_version to 800080.
1203
120420090415:
1205	Add an llentry to struct route and struct route_in6. Modules
1206	embedding a struct route will need to be recompiled.
1207	Bump __FreeBSD_version to 800079.
1208
120920090414:
1210	The size of rt_metrics_lite and by extension rtentry has changed.
1211	Networking administration apps will need to be recompiled.
1212	The route command now supports show as an alias for get, weighting
1213	of routes, sticky and nostick flags to alter the behavior of stateful
1214	load balancing.
1215	Bump __FreeBSD_version to 800078.
1216
121720090408:
1218	Do not use Giant for kbdmux(4) locking. This is wrong and
1219	apparently causing more problems than it solves. This will
1220	re-open the issue where interrupt handlers may race with
1221	kbdmux(4) in polling mode. Typical symptoms include (but
1222	not limited to) duplicated and/or missing characters when
1223	low level console functions (such as gets) are used while
1224	interrupts are enabled (for example geli password prompt,
1225	mountroot prompt etc.). Disabling kbdmux(4) may help.
1226
122720090407:
1228	The size of structs vnet_net, vnet_inet and vnet_ipfw has changed;
1229	kernel modules referencing any of the above need to be recompiled.
1230	Bump __FreeBSD_version to 800075.
1231
123220090320:
1233	GEOM_PART has become the default partition slicer for storage devices,
1234	replacing GEOM_MBR, GEOM_BSD, GEOM_PC98 and GEOM_GPT slicers. It
1235	introduces some changes:
1236
1237	MSDOS/EBR: the devices created from MSDOS extended partition entries
1238	(EBR) can be named differently than with GEOM_MBR and are now symlinks
1239	to devices with offset-based names. fstabs may need to be modified.
1240
1241	BSD: the "geometry does not match label" warning is harmless in most
1242	cases but it points to problems in file system misalignment with
1243	disk geometry. The "c" partition is now implicit, covers the whole
1244	top-level drive and cannot be (mis)used by users.
1245
1246	General: Kernel dumps are now not allowed to be written to devices
1247	whose partition types indicate they are meant to be used for file
1248	systems (or, in case of MSDOS partitions, as something else than
1249	the "386BSD" type).
1250
1251	Most of these changes date approximately from 200812.
1252
125320090319:
1254	The uscanner(4) driver has been removed from the kernel. This follows
1255	Linux removing theirs in 2.6 and making libusb the default interface
1256	(supported by sane).
1257
125820090319:
1259	The multicast forwarding code has been cleaned up. netstat(1)
1260	only relies on KVM now for printing bandwidth upcall meters.
1261	The IPv4 and IPv6 modules are split into ip_mroute_mod and
1262	ip6_mroute_mod respectively. The config(5) options for statically
1263	compiling this code remain the same, i.e. 'options MROUTING'.
1264
126520090315:
1266	Support for the IFF_NEEDSGIANT network interface flag has been
1267	removed, which means that non-MPSAFE network device drivers are no
1268	longer supported.  In particular, if_ar, if_sr, and network device
1269	drivers from the old (legacy) USB stack can no longer be built or
1270	used.
1271
127220090313:
1273	POSIX.1 Native Language Support (NLS) has been enabled in libc and
1274	a bunch of new language catalog files have also been added.
1275	This means that some common libc messages are now localized and
1276	they depend on the LC_MESSAGES environmental variable.
1277
127820090313:
1279	The k8temp(4) driver has been renamed to amdtemp(4) since
1280	support for Family 10 and Family 11 CPU families was added.
1281
128220090309:
1283	IGMPv3 and Source-Specific Multicast (SSM) have been merged
1284	to the IPv4 stack. VIMAGE hooks are in but not yet used.
1285
1286	For kernel developers, the most important changes are that the
1287	ip_output() and ip_input() paths no longer take the IN_MULTI_LOCK(),
1288	and this lock has been downgraded to a non-recursive mutex.
1289
1290	Transport protocols (UDP, Raw IP) are now responsible for filtering
1291	inbound multicast traffic according to group membership and source
1292	filters. The imo_multicast_filter() KPI exists for this purpose.
1293	Transports which do not use multicast (SCTP, TCP) already reject
1294	multicast by default. Forwarding and receive performance may improve
1295	as a mutex acquisition is no longer needed in the ip_input()
1296	low-level input path.  in_addmulti() and in_delmulti() are shimmed
1297	to new KPIs which exist to support SSM in-kernel.
1298
1299	For application developers, it is recommended that loopback of
1300	multicast datagrams be disabled for best performance, as this
1301	will still cause the lock to be taken for each looped-back
1302	datagram transmission. The net.inet.ip.mcast.loop sysctl may
1303	be tuned to 0 to disable loopback by default; it defaults to 1
1304	to preserve the existing behaviour.
1305
1306	For systems administrators, to obtain best performance with
1307	multicast reception and multiple groups, it is always recommended
1308	that a card with a suitably precise hash filter is used. Hash
1309	collisions will still result in the lock being taken within the
1310	transport protocol input path to check group membership.
1311
1312	If deploying FreeBSD in an environment with IGMP snooping switches,
1313	it is recommended that the net.inet.igmp.sendlocal sysctl remain
1314	enabled; this forces 224.0.0.0/24 group membership to be announced
1315	via IGMP.
1316
1317	The size of 'struct igmpstat' has changed; netstat needs to be
1318	recompiled to reflect this.
1319	Bump __FreeBSD_version to 800070.
1320
132120090309:
1322	libusb20.so.1 is now installed as libusb.so.1 and the ports system
1323	updated to use it. This requires a buildworld/installworld in order to
1324	update the library and dependencies (usbconfig, etc). Its advisable to
1325	rebuild all ports which uses libusb. More specific directions are given
1326	in the ports collection UPDATING file. Any /etc/libmap.conf entries for
1327	libusb are no longer required and can be removed.
1328
132920090302:
1330	A workaround is committed to allow the creation of System V shared
1331	memory segment of size > 2 GB on the 64-bit architectures.
1332	Due to a limitation of the existing ABI, the shm_segsz member
1333	of the struct shmid_ds, returned by shmctl(IPC_STAT) call is
1334	wrong for large segments. Note that limits must be explicitly
1335	raised to allow such segments to be created.
1336
133720090301:
1338	The layout of struct ifnet has changed, requiring a rebuild of all
1339	network device driver modules.
1340
134120090227:
1342	The /dev handling for the new USB stack has changed, a
1343	buildworld/installworld is required for libusb20.
1344
134520090223:
1346	The new USB2 stack has now been permanently moved in and all kernel and
1347	module names reverted to their previous values (eg, usb, ehci, ohci,
1348	ums, ...).  The old usb stack can be compiled in by prefixing the name
1349	with the letter 'o', the old usb modules have been removed.
1350	Updating entry 20090216 for xorg and 20090215 for libmap may still
1351	apply.
1352
135320090217:
1354	The rc.conf(5) option if_up_delay has been renamed to
1355	defaultroute_delay to better reflect its purpose. If you have
1356	customized this setting in /etc/rc.conf you need to update it to
1357	use the new name.
1358
135920090216:
1360	xorg 7.4 wants to configure its input devices via hald which does not
1361	yet work with USB2. If the keyboard/mouse does not work in xorg then
1362	add
1363		Option "AllowEmptyInput" "off"
1364	to your ServerLayout section.  This will cause X to use the configured
1365	kbd and mouse sections from your xorg.conf.
1366
136720090215:
1368	The GENERIC kernels for all architectures now default to the new USB2
1369	stack. No kernel config options or code have been removed so if a
1370	problem arises please report it and optionally revert to the old USB
1371	stack. If you are loading USB kernel modules or have a custom kernel
1372	that includes GENERIC then ensure that usb names are also changed over,
1373	eg uftdi -> usb2_serial_ftdi.
1374
1375	Older programs linked against the ports libusb 0.1 need to be
1376	redirected to the new stack's libusb20.  /etc/libmap.conf can
1377	be used for this:
1378		# Map old usb library to new one for usb2 stack
1379		libusb-0.1.so.8	libusb20.so.1
1380
138120090209:
1382	All USB ethernet devices now attach as interfaces under the name ueN
1383	(eg. ue0). This is to provide a predictable name as vendors often
1384	change usb chipsets in a product without notice.
1385
138620090203:
1387	The ichsmb(4) driver has been changed to require SMBus slave
1388	addresses be left-justified (xxxxxxx0b) rather than right-justified.
1389	All of the other SMBus controller drivers require left-justified
1390	slave addresses, so this change makes all the drivers provide the
1391	same interface.
1392
139320090201:
1394	INET6 statistics (struct ip6stat) was updated.
1395	netstat(1) needs to be recompiled.
1396
139720090119:
1398	NTFS has been removed from GENERIC kernel on amd64 to match
1399	GENERIC on i386. Should not cause any issues since mount_ntfs(8)
1400	will load ntfs.ko module automatically when NTFS support is
1401	actually needed, unless ntfs.ko is not installed or security
1402	level prohibits loading kernel modules. If either is the case,
1403	"options NTFS" has to be added into kernel config.
1404
140520090115:
1406	TCP Appropriate Byte Counting (RFC 3465) support added to kernel.
1407	New field in struct tcpcb breaks ABI, so bump __FreeBSD_version to
1408	800061. User space tools that rely on the size of struct tcpcb in
1409	tcp_var.h (e.g. sockstat) need to be recompiled.
1410
141120081225:
1412	ng_tty(4) module updated to match the new TTY subsystem.
1413	Due to API change, user-level applications must be updated.
1414	New API support added to mpd5 CVS and expected to be present
1415	in next mpd5.3 release.
1416
141720081219:
1418	With __FreeBSD_version 800060 the makefs tool is part of
1419	the base system (it was a port).
1420
142120081216:
1422	The afdata and ifnet locks have been changed from mutexes to
1423	rwlocks, network modules will need to be re-compiled.
1424
142520081214:
1426	__FreeBSD_version 800059 incorporates the new arp-v2 rewrite.
1427	RTF_CLONING, RTF_LLINFO and RTF_WASCLONED flags are eliminated.
1428	The new code reduced struct rtentry{} by 16 bytes on 32-bit
1429	architecture and 40 bytes on 64-bit architecture. The userland
1430	applications "arp" and "ndp" have been updated accordingly.
1431	The output from "netstat -r" shows only routing entries and
1432	none of the L2 information.
1433
143420081130:
1435	__FreeBSD_version 800057 marks the switchover from the
1436	binary ath hal to source code. Users must add the line:
1437
1438	options	AH_SUPPORT_AR5416
1439
1440	to their kernel config files when specifying:
1441
1442	device	ath_hal
1443
1444	The ath_hal module no longer exists; the code is now compiled
1445	together with the driver in the ath module.  It is now
1446	possible to tailor chip support (i.e. reduce the set of chips
1447	and thereby the code size); consult ath_hal(4) for details.
1448
144920081121:
1450	__FreeBSD_version 800054 adds memory barriers to
1451	<machine/atomic.h>, new interfaces to ifnet to facilitate
1452	multiple hardware transmit queues for cards that support
1453	them, and a lock-less ring-buffer implementation to
1454	enable drivers to more efficiently manage queueing of
1455	packets.
1456
145720081117:
1458	A new version of ZFS (version 13) has been merged to -HEAD.
1459	This version has zpool attribute "listsnapshots" off by
1460	default, which means "zfs list" does not show snapshots,
1461	and is the same as Solaris behavior.
1462
146320081028:
1464	dummynet(4) ABI has changed. ipfw(8) needs to be recompiled.
1465
146620081009:
1467	The uhci, ohci, ehci and slhci USB Host controller drivers have
1468	been put into separate modules. If you load the usb module
1469	separately through loader.conf you will need to load the
1470	appropriate *hci module as well. E.g. for a UHCI-based USB 2.0
1471	controller add the following to loader.conf:
1472
1473		uhci_load="YES"
1474		ehci_load="YES"
1475
147620081009:
1477	The ABI used by the PMC toolset has changed.  Please keep
1478	userland (libpmc(3)) and the kernel module (hwpmc(4)) in
1479	sync.
1480
148120081009:
1482	atapci kernel module now includes only generic PCI ATA
1483	driver. AHCI driver moved to ataahci kernel module.
1484	All vendor-specific code moved into separate kernel modules:
1485	ataacard, ataacerlabs, ataadaptec, ataamd, ataati, atacenatek,
1486	atacypress, atacyrix, atahighpoint, ataintel, ataite, atajmicron,
1487	atamarvell, atamicron, atanational, atanetcell, atanvidia,
1488	atapromise, ataserverworks, atasiliconimage, atasis, atavia
1489
149020080820:
1491	The TTY subsystem of the kernel has been replaced by a new
1492	implementation, which provides better scalability and an
1493	improved driver model. Most common drivers have been migrated to
1494	the new TTY subsystem, while others have not. The following
1495	drivers have not yet been ported to the new TTY layer:
1496
1497	PCI/ISA:
1498		cy, digi, rc, rp, sio
1499
1500	USB:
1501		ubser, ucycom
1502
1503	Line disciplines:
1504		ng_h4, ng_tty, ppp, sl, snp
1505
1506	Adding these drivers to your kernel configuration file shall
1507	cause compilation to fail.
1508
150920080818:
1510	ntpd has been upgraded to 4.2.4p5.
1511
151220080801:
1513	OpenSSH has been upgraded to 5.1p1.
1514
1515	For many years, FreeBSD's version of OpenSSH preferred DSA
1516	over RSA for host and user authentication keys.  With this
1517	upgrade, we've switched to the vendor's default of RSA over
1518	DSA.  This may cause upgraded clients to warn about unknown
1519	host keys even for previously known hosts.  Users should
1520	follow the usual procedure for verifying host keys before
1521	accepting the RSA key.
1522
1523	This can be circumvented by setting the "HostKeyAlgorithms"
1524	option to "ssh-dss,ssh-rsa" in ~/.ssh/config or on the ssh
1525	command line.
1526
1527	Please note that the sequence of keys offered for
1528	authentication has been changed as well.  You may want to
1529	specify IdentityFile in a different order to revert this
1530	behavior.
1531
153220080713:
1533	The sio(4) driver has been removed from the i386 and amd64
1534	kernel configuration files. This means uart(4) is now the
1535	default serial port driver on those platforms as well.
1536
1537	To prevent collisions with the sio(4) driver, the uart(4) driver
1538	uses different names for its device nodes. This means the
1539	onboard serial port will now most likely be called "ttyu0"
1540	instead of "ttyd0". You may need to reconfigure applications to
1541	use the new device names.
1542
1543	When using the serial port as a boot console, be sure to update
1544	/boot/device.hints and /etc/ttys before booting the new kernel.
1545	If you forget to do so, you can still manually specify the hints
1546	at the loader prompt:
1547
1548		set hint.uart.0.at="isa"
1549		set hint.uart.0.port="0x3F8"
1550		set hint.uart.0.flags="0x10"
1551		set hint.uart.0.irq="4"
1552		boot -s
1553
155420080609:
1555	The gpt(8) utility has been removed. Use gpart(8) to partition
1556	disks instead.
1557
155820080603:
1559	The version that Linuxulator emulates was changed from 2.4.2
1560	to 2.6.16. If you experience any problems with Linux binaries
1561	please try to set sysctl compat.linux.osrelease to 2.4.2 and
1562	if it fixes the problem contact emulation mailing list.
1563
156420080525:
1565	ISDN4BSD (I4B) was removed from the src tree. You may need to
1566	update a your kernel configuration and remove relevant entries.
1567
156820080509:
1569	I have checked in code to support multiple routing tables.
1570	See the man pages setfib(1) and setfib(2).
1571	This is a hopefully backwards compatible version,
1572	but to make use of it you need to compile your kernel
1573	with options ROUTETABLES=2 (or more up to 16).
1574
157520080420:
1576	The 802.11 wireless support was redone to enable multi-bss
1577	operation on devices that are capable.  The underlying device
1578	is no longer used directly but instead wlanX devices are
1579	cloned with ifconfig.  This requires changes to rc.conf files.
1580	For example, change:
1581		ifconfig_ath0="WPA DHCP"
1582	to
1583		wlans_ath0=wlan0
1584		ifconfig_wlan0="WPA DHCP"
1585	see rc.conf(5) for more details.  In addition, mergemaster of
1586	/etc/rc.d is highly recommended.  Simultaneous update of userland
1587	and kernel wouldn't hurt either.
1588
1589	As part of the multi-bss changes the wlan_scan_ap and wlan_scan_sta
1590	modules were merged into the base wlan module.  All references
1591	to these modules (e.g. in kernel config files) must be removed.
1592
159320080408:
1594	psm(4) has gained write(2) support in native operation level.
1595	Arbitrary commands can be written to /dev/psm%d and status can
1596	be read back from it.  Therefore, an application is responsible
1597	for status validation and error recovery.  It is a no-op in
1598	other operation levels.
1599
160020080312:
1601	Support for KSE threading has been removed from the kernel.  To
1602	run legacy applications linked against KSE libmap.conf may
1603	be used.  The following libmap.conf may be used to ensure
1604	compatibility with any prior release:
1605
1606	libpthread.so.1 libthr.so.1
1607	libpthread.so.2 libthr.so.2
1608	libkse.so.3 libthr.so.3
1609
161020080301:
1611	The layout of struct vmspace has changed. This affects libkvm
1612	and any executables that link against libkvm and use the
1613	kvm_getprocs() function. In particular, but not exclusively,
1614	it affects ps(1), fstat(1), pkill(1), systat(1), top(1) and w(1).
1615	The effects are minimal, but it's advisable to upgrade world
1616	nonetheless.
1617
161820080229:
1619	The latest em driver no longer has support in it for the
1620	82575 adapter, this is now moved to the igb driver. The
1621	split was done to make new features that are incompatible
1622	with older hardware easier to do.
1623
162420080220:
1625	The new geom_lvm(4) geom class has been renamed to geom_linux_lvm(4),
1626	likewise the kernel option is now GEOM_LINUX_LVM.
1627
162820080211:
1629	The default NFS mount mode has changed from UDP to TCP for
1630	increased reliability.  If you rely on (insecurely) NFS
1631	mounting across a firewall you may need to update your
1632	firewall rules.
1633
163420080208:
1635	Belatedly note the addition of m_collapse for compacting
1636	mbuf chains.
1637
163820080126:
1639	The fts(3) structures have been changed to use adequate
1640	integer types for their members and so to be able to cope
1641	with huge file trees.  The old fts(3) ABI is preserved
1642	through symbol versioning in libc, so third-party binaries
1643	using fts(3) should still work, although they will not take
1644	advantage of the extended types.  At the same time, some
1645	third-party software might fail to build after this change
1646	due to unportable assumptions made in its source code about
1647	fts(3) structure members.  Such software should be fixed
1648	by its vendor or, in the worst case, in the ports tree.
1649	FreeBSD_version 800015 marks this change for the unlikely
1650	case that a portable fix is impossible.
1651
165220080123:
1653	To upgrade to -current after this date, you must be running
1654	FreeBSD not older than 6.0-RELEASE.  Upgrading to -current
1655	from 5.x now requires a stop over at RELENG_6 or RELENG_7 systems.
1656
165720071128:
1658	The ADAPTIVE_GIANT kernel option has been retired because its
1659	functionality is the default now.
1660
166120071118:
1662	The AT keyboard emulation of sunkbd(4) has been turned on
1663	by default. In order to make the special symbols of the Sun
1664	keyboards driven by sunkbd(4) work under X these now have
1665	to be configured the same way as Sun USB keyboards driven
1666	by ukbd(4) (which also does AT keyboard emulation), f.e.:
1667
1668	Option	"XkbLayout" "us"
1669	Option	"XkbRules" "xorg"
1670	Option	"XkbSymbols" "pc(pc105)+sun_vndr/usb(sun_usb)+us"
1671
167220071024:
1673	It has been decided that it is desirable to provide ABI
1674	backwards compatibility to the FreeBSD 4/5/6 versions of the
1675	PCIOCGETCONF, PCIOCREAD and PCIOCWRITE IOCTLs, which was
1676	broken with the introduction of PCI domain support (see the
1677	20070930 entry). Unfortunately, this required the ABI of
1678	PCIOCGETCONF to be broken again in order to be able to
1679	provide backwards compatibility to the old version of that
1680	IOCTL. Thus consumers of PCIOCGETCONF have to be recompiled
1681	again. As for prominent ports this affects neither pciutils
1682	nor xorg-server this time, the hal port needs to be rebuilt
1683	however.
1684
168520071020:
1686	The misnamed kthread_create() and friends have been renamed
1687	to kproc_create() etc. Many of the callers already
1688	used kproc_start()..
1689	I will return kthread_create() and friends in a while
1690	with implementations that actually create threads, not procs.
1691	Renaming corresponds with version 800002.
1692
169320071010:
1694	RELENG_7 branched.
1695
1696COMMON ITEMS:
1697
1698	General Notes
1699	-------------
1700	Avoid using make -j when upgrading.  While generally safe, there are
1701	sometimes problems using -j to upgrade.  If your upgrade fails with
1702	-j, please try again without -j.  From time to time in the past there
1703	have been problems using -j with buildworld and/or installworld.  This
1704	is especially true when upgrading between "distant" versions (eg one
1705	that cross a major release boundary or several minor releases, or when
1706	several months have passed on the -current branch).
1707
1708	Sometimes, obscure build problems are the result of environment
1709	poisoning.  This can happen because the make utility reads its
1710	environment when searching for values for global variables.  To run
1711	your build attempts in an "environmental clean room", prefix all make
1712	commands with 'env -i '.  See the env(1) manual page for more details.
1713
1714	When upgrading from one major version to another it is generally best
1715	to upgrade to the latest code in the currently installed branch first,
1716	then do an upgrade to the new branch. This is the best-tested upgrade
1717	path, and has the highest probability of being successful.  Please try
1718	this approach before reporting problems with a major version upgrade.
1719
1720	When upgrading a live system, having a root shell around before
1721	installing anything can help undo problems. Not having a root shell
1722	around can lead to problems if pam has changed too much from your
1723	starting point to allow continued authentication after the upgrade.
1724
1725	ZFS notes
1726	---------
1727	When upgrading the boot ZFS pool to a new version, always follow
1728	these two steps:
1729
1730	1.) recompile and reinstall the ZFS boot loader and boot block
1731	(this is part of "make buildworld" and "make installworld")
1732
1733	2.) update the ZFS boot block on your boot drive
1734
1735	The following example updates the ZFS boot block on the first
1736	partition (freebsd-boot) of a GPT partitioned drive ad0:
1737	"gpart bootcode -p /boot/gptzfsboot -i 1 ad0"
1738
1739	Non-boot pools do not need these updates.
1740
1741	To build a kernel
1742	-----------------
1743	If you are updating from a prior version of FreeBSD (even one just
1744	a few days old), you should follow this procedure.  It is the most
1745	failsafe as it uses a /usr/obj tree with a fresh mini-buildworld,
1746
1747	make kernel-toolchain
1748	make -DALWAYS_CHECK_MAKE buildkernel KERNCONF=YOUR_KERNEL_HERE
1749	make -DALWAYS_CHECK_MAKE installkernel KERNCONF=YOUR_KERNEL_HERE
1750
1751	To test a kernel once
1752	---------------------
1753	If you just want to boot a kernel once (because you are not sure
1754	if it works, or if you want to boot a known bad kernel to provide
1755	debugging information) run
1756	make installkernel KERNCONF=YOUR_KERNEL_HERE KODIR=/boot/testkernel
1757	nextboot -k testkernel
1758
1759	To just build a kernel when you know that it won't mess you up
1760	--------------------------------------------------------------
1761	This assumes you are already running a CURRENT system.  Replace
1762	${arch} with the architecture of your machine (e.g. "i386",
1763	"arm", "amd64", "ia64", "pc98", "sparc64", "powerpc", "mips", etc).
1764
1765	cd src/sys/${arch}/conf
1766	config KERNEL_NAME_HERE
1767	cd ../compile/KERNEL_NAME_HERE
1768	make depend
1769	make
1770	make install
1771
1772	If this fails, go to the "To build a kernel" section.
1773
1774	To rebuild everything and install it on the current system.
1775	-----------------------------------------------------------
1776	# Note: sometimes if you are running current you gotta do more than
1777	# is listed here if you are upgrading from a really old current.
1778
1779	<make sure you have good level 0 dumps>
1780	make buildworld
1781	make kernel KERNCONF=YOUR_KERNEL_HERE
1782							[1]
1783	<reboot in single user>				[3]
1784	mergemaster -p					[5]
1785	make installworld
1786	mergemaster -i					[4]
1787	make delete-old					[6]
1788	<reboot>
1789
1790	To cross-install current onto a separate partition
1791	--------------------------------------------------
1792	# In this approach we use a separate partition to hold
1793	# current's root, 'usr', and 'var' directories.   A partition
1794	# holding "/", "/usr" and "/var" should be about 2GB in
1795	# size.
1796
1797	<make sure you have good level 0 dumps>
1798	<boot into -stable>
1799	make buildworld
1800	make buildkernel KERNCONF=YOUR_KERNEL_HERE
1801	<maybe newfs current's root partition>
1802	<mount current's root partition on directory ${CURRENT_ROOT}>
1803	make installworld DESTDIR=${CURRENT_ROOT}
1804	make distribution DESTDIR=${CURRENT_ROOT} # if newfs'd
1805	make installkernel KERNCONF=YOUR_KERNEL_HERE DESTDIR=${CURRENT_ROOT}
1806	cp /etc/fstab ${CURRENT_ROOT}/etc/fstab 		   # if newfs'd
1807	<edit ${CURRENT_ROOT}/etc/fstab to mount "/" from the correct partition>
1808	<reboot into current>
1809	<do a "native" rebuild/install as described in the previous section>
1810	<maybe install compatibility libraries from ports/misc/compat*>
1811	<reboot>
1812
1813
1814	To upgrade in-place from stable to current
1815	----------------------------------------------
1816	<make sure you have good level 0 dumps>
1817	make buildworld					[9]
1818	make kernel KERNCONF=YOUR_KERNEL_HERE		[8]
1819							[1]
1820	<reboot in single user>				[3]
1821	mergemaster -p					[5]
1822	make installworld
1823	mergemaster -i					[4]
1824	make delete-old					[6]
1825	<reboot>
1826
1827	Make sure that you've read the UPDATING file to understand the
1828	tweaks to various things you need.  At this point in the life
1829	cycle of current, things change often and you are on your own
1830	to cope.  The defaults can also change, so please read ALL of
1831	the UPDATING entries.
1832
1833	Also, if you are tracking -current, you must be subscribed to
1834	freebsd-current@freebsd.org.  Make sure that before you update
1835	your sources that you have read and understood all the recent
1836	messages there.  If in doubt, please track -stable which has
1837	much fewer pitfalls.
1838
1839	[1] If you have third party modules, such as vmware, you
1840	should disable them at this point so they don't crash your
1841	system on reboot.
1842
1843	[3] From the bootblocks, boot -s, and then do
1844		fsck -p
1845		mount -u /
1846		mount -a
1847		cd src
1848		adjkerntz -i		# if CMOS is wall time
1849	Also, when doing a major release upgrade, it is required that
1850	you boot into single user mode to do the installworld.
1851
1852	[4] Note: This step is non-optional.  Failure to do this step
1853	can result in a significant reduction in the functionality of the
1854	system.  Attempting to do it by hand is not recommended and those
1855	that pursue this avenue should read this file carefully, as well
1856	as the archives of freebsd-current and freebsd-hackers mailing lists
1857	for potential gotchas.  The -U option is also useful to consider.
1858	See mergemaster(8) for more information.
1859
1860	[5] Usually this step is a noop.  However, from time to time
1861	you may need to do this if you get unknown user in the following
1862	step.  It never hurts to do it all the time.  You may need to
1863	install a new mergemaster (cd src/usr.sbin/mergemaster && make
1864	install) after the buildworld before this step if you last updated
1865	from current before 20130425 or from -stable before 20130430.
1866
1867	[6] This only deletes old files and directories. Old libraries
1868	can be deleted by "make delete-old-libs", but you have to make
1869	sure that no program is using those libraries anymore.
1870
1871	[8] In order to have a kernel that can run the 4.x binaries needed to
1872	do an installworld, you must include the COMPAT_FREEBSD4 option in
1873	your kernel.  Failure to do so may leave you with a system that is
1874	hard to boot to recover. A similar kernel option COMPAT_FREEBSD5 is
1875	required to run the 5.x binaries on more recent kernels.  And so on
1876	for COMPAT_FREEBSD6 and COMPAT_FREEBSD7.
1877
1878	Make sure that you merge any new devices from GENERIC since the
1879	last time you updated your kernel config file.
1880
1881	[9] When checking out sources, you must include the -P flag to have
1882	cvs prune empty directories.
1883
1884	If CPUTYPE is defined in your /etc/make.conf, make sure to use the
1885	"?=" instead of the "=" assignment operator, so that buildworld can
1886	override the CPUTYPE if it needs to.
1887
1888	MAKEOBJDIRPREFIX must be defined in an environment variable, and
1889	not on the command line, or in /etc/make.conf.  buildworld will
1890	warn if it is improperly defined.
1891FORMAT:
1892
1893This file contains a list, in reverse chronological order, of major
1894breakages in tracking -current.  It is not guaranteed to be a complete
1895list of such breakages, and only contains entries since October 10, 2007.
1896If you need to see UPDATING entries from before that date, you will need
1897to fetch an UPDATING file from an older FreeBSD release.
1898
1899Copyright information:
1900
1901Copyright 1998-2009 M. Warner Losh.  All Rights Reserved.
1902
1903Redistribution, publication, translation and use, with or without
1904modification, in full or in part, in any form or format of this
1905document are permitted without further permission from the author.
1906
1907THIS DOCUMENT IS PROVIDED BY WARNER LOSH ``AS IS'' AND ANY EXPRESS OR
1908IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1909WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1910DISCLAIMED.  IN NO EVENT SHALL WARNER LOSH BE LIABLE FOR ANY DIRECT,
1911INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1912(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
1913SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
1914HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
1915STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
1916IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1917POSSIBILITY OF SUCH DAMAGE.
1918
1919Contact Warner Losh if you have any questions about your use of
1920this document.
1921
1922$FreeBSD: head/UPDATING 253679 2013-07-26 14:43:38Z avg $
1923