Update Documentation/kbuild/kconfig.txt, which mostly contains
user help for using the kernel config tools.

- Add mention of 'nconfig' embedded help text.
- Make the section on new config symbols readable.
- Correct how to find menuconfig search help.
- Add section on 'nconfig' usage.
- Mention that gconfig has multiple viewing modes/options.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

As commit cedd55d4 ("kconfig: Remove silentoldconfig from help
and docs; fix kconfig/conf's help") mentioned, 'silentoldconfig' is a
historical misnomer.  That commit removed it from help and docs since
it is an internal interface.  If so, it should be allowed to rename
it to something more intuitive.  'syncconfig' is the one I came up
with because it updates the .config if necessary, then synchronize
include/generated/autoconf.h and include/config/* with it.

You should not manually invoke 'silentoldcofig'.  Display warning if
used in case existing scripts are doing wrong.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NUlf Magnusson <ulfalizer@gmail.com>

Signed-off-by: NRegid Ichira <regid23@nt1.in>
Acked-by: NRob Landley <rob@landley.net>
[yann.morin.1998@free.fr: fix trailing whitespace, commit subject]
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

Re-phrase the explanations on the sorting of search results, in a more
concise and complete way.

Drop reference to the user's locale when sorting alphabetically, since
this is implicit.
Reported-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Jean Delvare <jdelvare@suse.de>
Reviewed-by: NJean Delvare <jdelvare@suse.de>

When searching for symbols, return the symbols sorted by relevance.

Sorting is done as thus:
  - first, symbols that match exactly
  - then, alphabetical sort

Since the search can be a regexp, it is possible that more than one symbol
matches exactly. In this case, we can't decide which to sort first, so we
fallback to alphabeticall sort.

Explain this (new!) sorting heuristic in the documentation.
Reported-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Roland Eggner <edvx1@systemanalysen.net>
Cc: Wang YanQing <udknight@gmail.com>

--
Changes v1->v2:
  - drop the previous, complex heuristic in favour of a simpler heuristic
    that is both easier to understand, *and* to maintain (Jean)
  - explain sorting heuristic in the doc  (Jean)

Ever since commit 45f035ab ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off.  Remove all the remaining references to it.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently the odds to set each symbol is (rounded):
    booleans:   y: 50%          n: 50%
    tristates:  y: 33%  m: 33%  n: 33%

Introduce a KCONFIG_PROBABILITY environment variable to tweak the
probabilities (in percentage), as such:
    KCONFIG_PROBABILITY     y:n split           y:m:n split
    -----------------------------------------------------------------
[1] unset or empty          50  : 50            33  : 33  : 34
[2] N                        N  : 100-N         N/2 : N/2 : 100-N
    N:M                     N+M : 100-(N+M)      N  :  M  : 100-(N+M)
    N:M:L                    N  : 100-N          M  :  L  : 100-(M+L)

[1] The current behaviour is kept as default, for backward compatibility
[2] The solution initially implemented by Peter for Buildroot, see:
    http://git.buildroot.org/buildroot/commit/?id=3435c1afb5Signed-off-by: NPeter Korsgaard <jacmet@uclibc.org>
[yann.morin.1998@free.fr: add to Documentation/]
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

For reproducibility, it can be useful to be able to specify the
seed to use to seed the RNG.

Add a new KCONFIG_SEED environment variable which can be set to
the seed to use:
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config
    $ make KCONFIG_SEED=42 randconfig
    $ sha1sum .config
    70a128c8dcc61303069e1be352cce64114dfcbca  .config

It's very usefull for eg. debugging the kconfig parser.
Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

Signed-off-by: N"Yann E. MORIN" <yann.morin.1998@free.fr>

- Only try to read the file specified if KCONFIG_ALL_CONFIG is set to
  something other than the empty string or "1".

- Don't use stat to check the name passed to conf_read_simple so that
  zconf_fopen can find the file in the current directory or in SRCTREE
  removing a extremely source of confusing failure, where KCONFIG_ALL_CONFIG
  was not interpreted with respect to the directory make was called in.

- If conf_read_simple fails complain clearly and stop processing.
  Allowing the simple debugging of typos.

- Clearly document the behavior so it is clear to users which
  values are treated as flags and which values are treated as
  filenames.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

The kconfig documentation suggests using plain 'diff' to compare config
files and then adds "Yes, we need something better here".  Commit
a717417e ("kconfig: add diffconfig utility") added what that comment
was looking for.
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

alldefconfig create a configuration with all values set
to their default value (form the Kconfig files).

This may be useful when we try to use more sensible default
values and may also be used in combination with
the minimal defconfigs.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

[Ss]ytem => [Ss]ystem
udpate => update
paramters => parameters
orginal => original
Signed-off-by: NThomas Weber <swirl@gmx.li>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

To make it easier for module-init-tools and scripts like mkinitrd to
distinguish builtin and missing modules, install a modules.builtin file
listing all builtin modules. This is done by generating an additional
config file (tristate.conf) with tristate options set to uppercase 'Y'
or 'M'. If we source that config file, the builtin modules appear in
obj-Y.
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

All the KCONFIG_ environment variables were previously located in a
section "Environment variables in 'menuconfig'", but neither are they
restricted to 'menuconfig' nor are they all used by 'menuconfig'.

Introduce the following three sections for these variables:
  * Environment variables for '*config'
  * Environment variables for '{allyes/allmod/allno/rand}config'
  * Environment variables for 'silentoldconfig'

Furthermore this puts MENUCONFIG_MODE next to MENUCONFIG_COLOR into a
common section "User interface options for 'menuconfig'".
Signed-off-by: NMarkus Heidelberg <markus.heidelberg@web.de>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Create a kconfig user assistance guide, with a few tips and hints
about using menuconfig, xconfig, and gconfig.

Mostly contains user interface, environment variables, and search topics,
along with mini.config/custom.config usage.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>