Clean up our patches against kconfig

Our kconfig-to-buildroot2.patch hasn't been kept up to date with all
the changes made into package/config, and a single patch wasn't very
practical to maintain all our changes. Therefore, this commit adds a
package/config/patches directory, which contains a Quilt series of
patches that correspond to our modifications to the kconfig mechanism.

The huge kconfig-to-buildroot2.patch has been split into 16 smaller
patches. The purpose of some of the modifications has been clearly
identified, while some others were not identified.

The 16 patches together do match exactly the old
kconfig-to-buildroot2.patch. We have been very careful in making sure
that we wouldn't loose any of our modifications.

The only modifications made are :

 * Instead of renaming the kernel Makefile to Makefile.kconfig and
   naming the Buildroot Makefile just 'Makefile', we instead keep the
   original package/config/Makefile from the kernel
   scripts/kconfig/Makefile and name the Buildroot Makefile
   package/config/Makefile.br. The main Buildroot Makefile is modified
   accordingly.

 * The documentation README.buildroot2 is updated to explain how to
   upgrade to a newer version of scripts/kconfig.

 * The kconfig-language.txt documentation is removed, as anybody can
   easily find it in the kernel sources so there's no need to
   duplicate it here.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 0 insertions, 379 deletions

diff --git a/package/config/kconfig-language.txt b/package/config/kconfig-language.txt
deleted file mode 100644
index c412c2458..000000000
--- a/package/config/kconfig-language.txt
+++ /dev/null
@@ -1,379 +0,0 @@
-Introduction
-------------
-
-The configuration database is a collection of configuration options
-organized in a tree structure:
-
-	+- Code maturity level options
-	|  +- Prompt for development and/or incomplete code/drivers
-	+- General setup
-	|  +- Networking support
-	|  +- System V IPC
-	|  +- BSD Process Accounting
-	|  +- Sysctl support
-	+- Loadable module support
-	|  +- Enable loadable module support
-	|     +- Set version information on all module symbols
-	|     +- Kernel module loader
-	+- ...
-
-Every entry has its own dependencies. These dependencies are used
-to determine the visibility of an entry. Any child entry is only
-visible if its parent entry is also visible.
-
-Menu entries
-------------
-
-Most entries define a config option; all other entries help to organize
-them. A single configuration option is defined like this:
-
-config MODVERSIONS
-	bool "Set version information on all module symbols"
-	depends on MODULES
-	help
-	  Usually, modules have to be recompiled whenever you switch to a new
-	  kernel.  ...
-
-Every line starts with a key word and can be followed by multiple
-arguments.  "config" starts a new config entry. The following lines
-define attributes for this config option. Attributes can be the type of
-the config option, input prompt, dependencies, help text and default
-values. A config option can be defined multiple times with the same
-name, but every definition can have only a single input prompt and the
-type must not conflict.
-
-Menu attributes
----------------
-
-A menu entry can have a number of attributes. Not all of them are
-applicable everywhere (see syntax).
-
-- type definition: "bool"/"tristate"/"string"/"hex"/"int"
-  Every config option must have a type. There are only two basic types:
-  tristate and string; the other types are based on these two. The type
-  definition optionally accepts an input prompt, so these two examples
-  are equivalent:
-
-	bool "Networking support"
-  and
-	bool
-	prompt "Networking support"
-
-- input prompt: "prompt" <prompt> ["if" <expr>]
-  Every menu entry can have at most one prompt, which is used to display
-  to the user. Optionally dependencies only for this prompt can be added
-  with "if".
-
-- default value: "default" <expr> ["if" <expr>]
-  A config option can have any number of default values. If multiple
-  default values are visible, only the first defined one is active.
-  Default values are not limited to the menu entry where they are
-  defined. This means the default can be defined somewhere else or be
-  overridden by an earlier definition.
-  The default value is only assigned to the config symbol if no other
-  value was set by the user (via the input prompt above). If an input
-  prompt is visible the default value is presented to the user and can
-  be overridden by him.
-  Optionally, dependencies only for this default value can be added with
-  "if".
-
-- type definition + default value:
-	"def_bool"/"def_tristate" <expr> ["if" <expr>]
-  This is a shorthand notation for a type definition plus a value.
-  Optionally dependencies for this default value can be added with "if".
-
-- dependencies: "depends on" <expr>
-  This defines a dependency for this menu entry. If multiple
-  dependencies are defined, they are connected with '&&'. Dependencies
-  are applied to all other options within this menu entry (which also
-  accept an "if" expression), so these two examples are equivalent:
-
-	bool "foo" if BAR
-	default y if BAR
-  and
-	depends on BAR
-	bool "foo"
-	default y
-
-- reverse dependencies: "select" <symbol> ["if" <expr>]
-  While normal dependencies reduce the upper limit of a symbol (see
-  below), reverse dependencies can be used to force a lower limit of
-  another symbol. The value of the current menu symbol is used as the
-  minimal value <symbol> can be set to. If <symbol> is selected multiple
-  times, the limit is set to the largest selection.
-  Reverse dependencies can only be used with boolean or tristate
-  symbols.
-  Note:
-	select should be used with care. select will force
-	a symbol to a value without visiting the dependencies.
-	By abusing select you are able to select a symbol FOO even
-	if FOO depends on BAR that is not set.
-	In general use select only for non-visible symbols
-	(no prompts anywhere) and for symbols with no dependencies.
-	That will limit the usefulness but on the other hand avoid
-	the illegal configurations all over.
-	kconfig should one day warn about such things.
-
-- numerical ranges: "range" <symbol> <symbol> ["if" <expr>]
-  This allows to limit the range of possible input values for int
-  and hex symbols. The user can only input a value which is larger than
-  or equal to the first symbol and smaller than or equal to the second
-  symbol.
-
-- help text: "help" or "---help---"
-  This defines a help text. The end of the help text is determined by
-  the indentation level, this means it ends at the first line which has
-  a smaller indentation than the first line of the help text.
-  "---help---" and "help" do not differ in behaviour, "---help---" is
-  used to help visually separate configuration logic from help within
-  the file as an aid to developers.
-
-- misc options: "option" <symbol>[=<value>]
-  Various less common options can be defined via this option syntax,
-  which can modify the behaviour of the menu entry and its config
-  symbol. These options are currently possible:
-
-  - "defconfig_list"
-    This declares a list of default entries which can be used when
-    looking for the default configuration (which is used when the main
-    .config doesn't exists yet.)
-
-  - "modules"
-    This declares the symbol to be used as the MODULES symbol, which
-    enables the third modular state for all config symbols.
-
-  - "env"=<value>
-    This imports the environment variable into Kconfig. It behaves like
-    a default, except that the value comes from the environment, this
-    also means that the behaviour when mixing it with normal defaults is
-    undefined at this point. The symbol is currently not exported back
-    to the build environment (if this is desired, it can be done via
-    another symbol).
-
-Menu dependencies
------------------
-
-Dependencies define the visibility of a menu entry and can also reduce
-the input range of tristate symbols. The tristate logic used in the
-expressions uses one more state than normal boolean logic to express the
-module state. Dependency expressions have the following syntax:
-
-<expr> ::= <symbol>                             (1)
-           <symbol> '=' <symbol>                (2)
-           <symbol> '!=' <symbol>               (3)
-           '(' <expr> ')'                       (4)
-           '!' <expr>                           (5)
-           <expr> '&&' <expr>                   (6)
-           <expr> '||' <expr>                   (7)
-
-Expressions are listed in decreasing order of precedence. 
-
-(1) Convert the symbol into an expression. Boolean and tristate symbols
-    are simply converted into the respective expression values. All
-    other symbol types result in 'n'.
-(2) If the values of both symbols are equal, it returns 'y',
-    otherwise 'n'.
-(3) If the values of both symbols are equal, it returns 'n',
-    otherwise 'y'.
-(4) Returns the value of the expression. Used to override precedence.
-(5) Returns the result of (2-/expr/).
-(6) Returns the result of min(/expr/, /expr/).
-(7) Returns the result of max(/expr/, /expr/).
-
-An expression can have a value of 'n', 'm' or 'y' (or 0, 1, 2
-respectively for calculations). A menu entry becomes visible when it's
-expression evaluates to 'm' or 'y'.
-
-There are two types of symbols: constant and non-constant symbols.
-Non-constant symbols are the most common ones and are defined with the
-'config' statement. Non-constant symbols consist entirely of alphanumeric
-characters or underscores.
-Constant symbols are only part of expressions. Constant symbols are
-always surrounded by single or double quotes. Within the quote, any
-other character is allowed and the quotes can be escaped using '\'.
-
-Menu structure
---------------
-
-The position of a menu entry in the tree is determined in two ways. First
-it can be specified explicitly:
-
-menu "Network device support"
-	depends on NET
-
-config NETDEVICES
-	...
-
-endmenu
-
-All entries within the "menu" ... "endmenu" block become a submenu of
-"Network device support". All subentries inherit the dependencies from
-the menu entry, e.g. this means the dependency "NET" is added to the
-dependency list of the config option NETDEVICES.
-
-The other way to generate the menu structure is done by analyzing the
-dependencies. If a menu entry somehow depends on the previous entry, it
-can be made a submenu of it. First, the previous (parent) symbol must
-be part of the dependency list and then one of these two conditions
-must be true:
-- the child entry must become invisible, if the parent is set to 'n'
-- the child entry must only be visible, if the parent is visible
-
-config MODULES
-	bool "Enable loadable module support"
-
-config MODVERSIONS
-	bool "Set version information on all module symbols"
-	depends on MODULES
-
-comment "module support disabled"
-	depends on !MODULES
-
-MODVERSIONS directly depends on MODULES, this means it's only visible if
-MODULES is different from 'n'. The comment on the other hand is always
-visible when MODULES is visible (the (empty) dependency of MODULES is
-also part of the comment dependencies).
-
-
-Kconfig syntax
---------------
-
-The configuration file describes a series of menu entries, where every
-line starts with a keyword (except help texts). The following keywords
-end a menu entry:
-- config
-- menuconfig
-- choice/endchoice
-- comment
-- menu/endmenu
-- if/endif
-- source
-The first five also start the definition of a menu entry.
-
-config:
-
-	"config" <symbol>
-	<config options>
-
-This defines a config symbol <symbol> and accepts any of above
-attributes as options.
-
-menuconfig:
-	"menuconfig" <symbol>
-	<config options>
-
-This is similar to the simple config entry above, but it also gives a
-hint to front ends, that all suboptions should be displayed as a
-separate list of options.
-
-choices:
-
-	"choice"
-	<choice options>
-	<choice block>
-	"endchoice"
-
-This defines a choice group and accepts any of the above attributes as
-options. A choice can only be of type bool or tristate, while a boolean
-choice only allows a single config entry to be selected, a tristate
-choice also allows any number of config entries to be set to 'm'. This
-can be used if multiple drivers for a single hardware exists and only a
-single driver can be compiled/loaded into the kernel, but all drivers
-can be compiled as modules.
-A choice accepts another option "optional", which allows to set the
-choice to 'n' and no entry needs to be selected.
-
-comment:
-
-	"comment" <prompt>
-	<comment options>
-
-This defines a comment which is displayed to the user during the
-configuration process and is also echoed to the output files. The only
-possible options are dependencies.
-
-menu:
-
-	"menu" <prompt>
-	<menu options>
-	<menu block>
-	"endmenu"
-
-This defines a menu block, see "Menu structure" above for more
-information. The only possible options are dependencies.
-
-if:
-
-	"if" <expr>
-	<if block>
-	"endif"
-
-This defines an if block. The dependency expression <expr> is appended
-to all enclosed menu entries.
-
-source:
-
-	"source" <prompt>
-
-This reads the specified configuration file. This file is always parsed.
-
-mainmenu:
-
-	"mainmenu" <prompt>
-
-This sets the config program's title bar if the config program chooses
-to use it.
-
-
-Kconfig hints
--------------
-This is a collection of Kconfig tips, most of which aren't obvious at
-first glance and most of which have become idioms in several Kconfig
-files.
-
-Adding common features and make the usage configurable
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-It is a common idiom to implement a feature/functionality that are
-relevant for some architectures but not all.
-The recommended way to do so is to use a config variable named HAVE_*
-that is defined in a common Kconfig file and selected by the relevant
-architectures.
-An example is the generic IOMAP functionality.
-
-We would in lib/Kconfig see:
-
-# Generic IOMAP is used to ...
-config HAVE_GENERIC_IOMAP
-
-config GENERIC_IOMAP
-	depends on HAVE_GENERIC_IOMAP && FOO
-
-And in lib/Makefile we would see:
-obj-$(CONFIG_GENERIC_IOMAP) += iomap.o
-
-For each architecture using the generic IOMAP functionality we would see:
-
-config X86
-	select ...
-	select HAVE_GENERIC_IOMAP
-	select ...
-
-Note: we use the existing config option and avoid creating a new
-config variable to select HAVE_GENERIC_IOMAP.
-
-Note: the use of the internal config variable HAVE_GENERIC_IOMAP, it is
-introduced to overcome the limitation of select which will force a
-config option to 'y' no matter the dependencies.
-The dependencies are moved to the symbol GENERIC_IOMAP and we avoid the
-situation where select forces a symbol equals to 'y'.
-
-Build as module only
-~~~~~~~~~~~~~~~~~~~~
-To restrict a component build to module-only, qualify its config symbol
-with "depends on m".  E.g.:
-
-config FOO
-	depends on BAR && m
-
-limits FOO to module (=m) or disabled (=n).
-