[PATCH 5/6] docs/kbuild/makefiles: clean up indentation and whitespace

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Remove the leading whitespaces, and clean up indentation and whitespace
in general.

Although the diff looks massive, it's trivial with 'diff -w' or 'git
show -w'.

Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
 Documentation/kbuild/makefiles.rst | 1885 ++++++++++++++--------------
 1 file changed, 958 insertions(+), 927 deletions(-)

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 0180a49fefbf..6a1ff67eed34 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -22,6 +22,7 @@ The top Makefile is responsible for building two major products: vmlinux
 (the resident kernel image) and modules (any module files).
 It builds these goals by recursively descending into the subdirectories of
 the kernel source tree.
+
 The list of subdirectories which are visited depends upon the kernel
 configuration. The top Makefile textually includes an arch Makefile
 with the name arch/$(SRCARCH)/Makefile. The arch Makefile supplies
@@ -35,7 +36,6 @@ any built-in or modular targets.
 scripts/Makefile.* contains all the definitions/rules etc. that
 are used to build the kernel based on the kbuild makefiles.
 
-
 Who does what
 =============
 
@@ -68,6 +68,7 @@ The kbuild files
 Most Makefiles within the kernel are kbuild Makefiles that use the
 kbuild infrastructure. This chapter introduces the syntax used in the
 kbuild makefiles.
+
 The preferred name for the kbuild files are 'Makefile' but 'Kbuild' can
 be used and if both a 'Makefile' and a 'Kbuild' file exists, then the 'Kbuild'
 file will be used.
@@ -78,618 +79,624 @@ more details, with real examples.
 Goal definitions
 ----------------
 
-	Goal definitions are the main part (heart) of the kbuild Makefile.
-	These lines define the files to be built, any special compilation
-	options, and any subdirectories to be entered recursively.
+Goal definitions are the main part (heart) of the kbuild Makefile.
+These lines define the files to be built, any special compilation
+options, and any subdirectories to be entered recursively.
 
-	The most simple kbuild makefile contains one line:
+The most simple kbuild makefile contains one line:
 
-	Example::
+Example::
 
-		obj-y += foo.o
+  obj-y += foo.o
 
-	This tells kbuild that there is one object in that directory, named
-	foo.o. foo.o will be built from foo.c or foo.S.
+This tells kbuild that there is one object in that directory, named
+foo.o. foo.o will be built from foo.c or foo.S.
 
-	If foo.o shall be built as a module, the variable obj-m is used.
-	Therefore the following pattern is often used:
+If foo.o shall be built as a module, the variable obj-m is used.
+Therefore the following pattern is often used:
 
-	Example::
+Example::
 
-		obj-$(CONFIG_FOO) += foo.o
+  obj-$(CONFIG_FOO) += foo.o
 
-	$(CONFIG_FOO) evaluates to either y (for built-in) or m (for module).
-	If CONFIG_FOO is neither y nor m, then the file will not be compiled
-	nor linked.
+$(CONFIG_FOO) evaluates to either y (for built-in) or m (for module).
+If CONFIG_FOO is neither y nor m, then the file will not be compiled
+nor linked.
 
 Built-in object goals - obj-y
 -----------------------------
 
-	The kbuild Makefile specifies object files for vmlinux
-	in the $(obj-y) lists.  These lists depend on the kernel
-	configuration.
+The kbuild Makefile specifies object files for vmlinux
+in the $(obj-y) lists.  These lists depend on the kernel
+configuration.
 
-	Kbuild compiles all the $(obj-y) files.  It then calls
-	"$(AR) rcSTP" to merge these files into one built-in.a file.
-	This is a thin archive without a symbol table. It will be later
-	linked into vmlinux by scripts/link-vmlinux.sh
+Kbuild compiles all the $(obj-y) files.  It then calls
+"$(AR) rcSTP" to merge these files into one built-in.a file.
+This is a thin archive without a symbol table. It will be later
+linked into vmlinux by scripts/link-vmlinux.sh
 
-	The order of files in $(obj-y) is significant.  Duplicates in
-	the lists are allowed: the first instance will be linked into
-	built-in.a and succeeding instances will be ignored.
+The order of files in $(obj-y) is significant.  Duplicates in
+the lists are allowed: the first instance will be linked into
+built-in.a and succeeding instances will be ignored.
 
-	Link order is significant, because certain functions
-	(module_init() / __initcall) will be called during boot in the
-	order they appear. So keep in mind that changing the link
-	order may e.g. change the order in which your SCSI
-	controllers are detected, and thus your disks are renumbered.
+Link order is significant, because certain functions
+(module_init() / __initcall) will be called during boot in the
+order they appear. So keep in mind that changing the link
+order may e.g. change the order in which your SCSI
+controllers are detected, and thus your disks are renumbered.
 
-	Example::
+Example::
 
-		#drivers/isdn/i4l/Makefile
-		# Makefile for the kernel ISDN subsystem and device drivers.
-		# Each configuration option enables a list of files.
-		obj-$(CONFIG_ISDN_I4L)         += isdn.o
-		obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
+  #drivers/isdn/i4l/Makefile
+  # Makefile for the kernel ISDN subsystem and device drivers.
+  # Each configuration option enables a list of files.
+  obj-$(CONFIG_ISDN_I4L)         += isdn.o
+  obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
 
 Loadable module goals - obj-m
 -----------------------------
 
-	$(obj-m) specifies object files which are built as loadable
-	kernel modules.
+$(obj-m) specifies object files which are built as loadable
+kernel modules.
 
-	A module may be built from one source file or several source
-	files. In the case of one source file, the kbuild makefile
-	simply adds the file to $(obj-m).
+A module may be built from one source file or several source
+files. In the case of one source file, the kbuild makefile
+simply adds the file to $(obj-m).
 
-	Example::
+Example::
 
-		#drivers/isdn/i4l/Makefile
-		obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
+  #drivers/isdn/i4l/Makefile
+  obj-$(CONFIG_ISDN_PPP_BSDCOMP) += isdn_bsdcomp.o
 
-	Note: In this example $(CONFIG_ISDN_PPP_BSDCOMP) evaluates to 'm'
+Note: In this example $(CONFIG_ISDN_PPP_BSDCOMP) evaluates to 'm'
 
-	If a kernel module is built from several source files, you specify
-	that you want to build a module in the same way as above; however,
-	kbuild needs to know which object files you want to build your
-	module from, so you have to tell it by setting a $(<module_name>-y)
-	variable.
+If a kernel module is built from several source files, you specify
+that you want to build a module in the same way as above; however,
+kbuild needs to know which object files you want to build your
+module from, so you have to tell it by setting a $(<module_name>-y)
+variable.
 
-	Example::
+Example::
 
-		#drivers/isdn/i4l/Makefile
-		obj-$(CONFIG_ISDN_I4L) += isdn.o
-		isdn-y := isdn_net_lib.o isdn_v110.o isdn_common.o
+  #drivers/isdn/i4l/Makefile
+  obj-$(CONFIG_ISDN_I4L) += isdn.o
+  isdn-y := isdn_net_lib.o isdn_v110.o isdn_common.o
 
-	In this example, the module name will be isdn.o. Kbuild will
-	compile the objects listed in $(isdn-y) and then run
-	"$(LD) -r" on the list of these files to generate isdn.o.
+In this example, the module name will be isdn.o. Kbuild will
+compile the objects listed in $(isdn-y) and then run
+"$(LD) -r" on the list of these files to generate isdn.o.
 
-	Due to kbuild recognizing $(<module_name>-y) for composite objects,
-	you can use the value of a `CONFIG_` symbol to optionally include an
-	object file as part of a composite object.
+Due to kbuild recognizing $(<module_name>-y) for composite objects,
+you can use the value of a `CONFIG_` symbol to optionally include an
+object file as part of a composite object.
 
-	Example::
+Example::
 
-		#fs/ext2/Makefile
-	        obj-$(CONFIG_EXT2_FS) += ext2.o
-		ext2-y := balloc.o dir.o file.o ialloc.o inode.o ioctl.o \
-			  namei.o super.o symlink.o
-	        ext2-$(CONFIG_EXT2_FS_XATTR) += xattr.o xattr_user.o \
-						xattr_trusted.o
+  #fs/ext2/Makefile
+  obj-$(CONFIG_EXT2_FS) += ext2.o
+  ext2-y := balloc.o dir.o file.o ialloc.o inode.o ioctl.o \
+    namei.o super.o symlink.o
+  ext2-$(CONFIG_EXT2_FS_XATTR) += xattr.o xattr_user.o \
+    xattr_trusted.o
 
-	In this example, xattr.o, xattr_user.o and xattr_trusted.o are only
-	part of the composite object ext2.o if $(CONFIG_EXT2_FS_XATTR)
-	evaluates to 'y'.
+In this example, xattr.o, xattr_user.o and xattr_trusted.o are only
+part of the composite object ext2.o if $(CONFIG_EXT2_FS_XATTR)
+evaluates to 'y'.
 
-	Note: Of course, when you are building objects into the kernel,
-	the syntax above will also work. So, if you have CONFIG_EXT2_FS=y,
-	kbuild will build an ext2.o file for you out of the individual
-	parts and then link this into built-in.a, as you would expect.
+Note: Of course, when you are building objects into the kernel,
+the syntax above will also work. So, if you have CONFIG_EXT2_FS=y,
+kbuild will build an ext2.o file for you out of the individual
+parts and then link this into built-in.a, as you would expect.
 
 Library file goals - lib-y
 --------------------------
 
-	Objects listed with obj-* are used for modules, or
-	combined in a built-in.a for that specific directory.
-	There is also the possibility to list objects that will
-	be included in a library, lib.a.
-	All objects listed with lib-y are combined in a single
-	library for that directory.
-	Objects that are listed in obj-y and additionally listed in
-	lib-y will not be included in the library, since they will
-	be accessible anyway.
-	For consistency, objects listed in lib-m will be included in lib.a.
+Objects listed with obj-* are used for modules, or
+combined in a built-in.a for that specific directory.
+There is also the possibility to list objects that will
+be included in a library, lib.a.
+All objects listed with lib-y are combined in a single
+library for that directory.
+Objects that are listed in obj-y and additionally listed in
+lib-y will not be included in the library, since they will
+be accessible anyway.
+For consistency, objects listed in lib-m will be included in lib.a.
 
-	Note that the same kbuild makefile may list files to be built-in
-	and to be part of a library. Therefore the same directory
-	may contain both a built-in.a and a lib.a file.
+Note that the same kbuild makefile may list files to be built-in
+and to be part of a library. Therefore the same directory
+may contain both a built-in.a and a lib.a file.
 
-	Example::
+Example::
 
-		#arch/x86/lib/Makefile
-		lib-y    := delay.o
+  #arch/x86/lib/Makefile
+  lib-y    := delay.o
 
-	This will create a library lib.a based on delay.o. For kbuild to
-	actually recognize that there is a lib.a being built, the directory
-	shall be listed in libs-y.
+This will create a library lib.a based on delay.o. For kbuild to
+actually recognize that there is a lib.a being built, the directory
+shall be listed in libs-y.
 
-	See also `List directories to visit when descending`_.
+See also `List directories to visit when descending`_.
 
-	Use of lib-y is normally restricted to `lib/` and `arch/*/lib`.
+Use of lib-y is normally restricted to `lib/` and `arch/*/lib`.
 
 Descending down in directories
 ------------------------------
 
-	A Makefile is only responsible for building objects in its own
-	directory. Files in subdirectories should be taken care of by
-	Makefiles in these subdirs. The build system will automatically
-	invoke make recursively in subdirectories, provided you let it know of
-	them.
+A Makefile is only responsible for building objects in its own
+directory. Files in subdirectories should be taken care of by
+Makefiles in these subdirs. The build system will automatically
+invoke make recursively in subdirectories, provided you let it know of
+them.
 
-	To do so, obj-y and obj-m are used.
-	ext2 lives in a separate directory, and the Makefile present in fs/
-	tells kbuild to descend down using the following assignment.
+To do so, obj-y and obj-m are used.
+ext2 lives in a separate directory, and the Makefile present in fs/
+tells kbuild to descend down using the following assignment.
 
-	Example::
+Example::
 
-		#fs/Makefile
-		obj-$(CONFIG_EXT2_FS) += ext2/
+  #fs/Makefile
+  obj-$(CONFIG_EXT2_FS) += ext2/
 
-	If CONFIG_EXT2_FS is set to either 'y' (built-in) or 'm' (modular)
-	the corresponding obj- variable will be set, and kbuild will descend
-	down in the ext2 directory.
+If CONFIG_EXT2_FS is set to either 'y' (built-in) or 'm' (modular)
+the corresponding obj- variable will be set, and kbuild will descend
+down in the ext2 directory.
 
-	Kbuild uses this information not only to decide that it needs to visit
-	the directory, but also to decide whether or not to link objects from
-	the directory into vmlinux.
+Kbuild uses this information not only to decide that it needs to visit
+the directory, but also to decide whether or not to link objects from
+the directory into vmlinux.
 
-	When Kbuild descends into the directory with 'y', all built-in objects
-	from that directory are combined into the built-in.a, which will be
-	eventually linked into vmlinux.
+When Kbuild descends into the directory with 'y', all built-in objects
+from that directory are combined into the built-in.a, which will be
+eventually linked into vmlinux.
 
-	When Kbuild descends into the directory with 'm', in contrast, nothing
-	from that directory will be linked into vmlinux. If the Makefile in
-	that directory specifies obj-y, those objects will be left orphan.
-	It is very likely a bug of the Makefile or of dependencies in Kconfig.
+When Kbuild descends into the directory with 'm', in contrast, nothing
+from that directory will be linked into vmlinux. If the Makefile in
+that directory specifies obj-y, those objects will be left orphan.
+It is very likely a bug of the Makefile or of dependencies in Kconfig.
 
-	Kbuild also supports dedicated syntax, subdir-y and subdir-m, for
-	descending into subdirectories. It is a good fit when you know they
-	do not contain kernel-space objects at all. A typical usage is to let
-	Kbuild descend into subdirectories to build tools.
+Kbuild also supports dedicated syntax, subdir-y and subdir-m, for
+descending into subdirectories. It is a good fit when you know they
+do not contain kernel-space objects at all. A typical usage is to let
+Kbuild descend into subdirectories to build tools.
 
-	Examples::
+Examples::
 
-		# scripts/Makefile
-		subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
-		subdir-$(CONFIG_MODVERSIONS) += genksyms
-		subdir-$(CONFIG_SECURITY_SELINUX) += selinux
+  # scripts/Makefile
+  subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
+  subdir-$(CONFIG_MODVERSIONS) += genksyms
+  subdir-$(CONFIG_SECURITY_SELINUX) += selinux
 
-	Unlike obj-y/m, subdir-y/m does not need the trailing slash since this
-	syntax is always used for directories.
+Unlike obj-y/m, subdir-y/m does not need the trailing slash since this
+syntax is always used for directories.
 
-	It is good practice to use a `CONFIG_` variable when assigning directory
-	names. This allows kbuild to totally skip the directory if the
-	corresponding `CONFIG_` option is neither 'y' nor 'm'.
+It is good practice to use a `CONFIG_` variable when assigning directory
+names. This allows kbuild to totally skip the directory if the
+corresponding `CONFIG_` option is neither 'y' nor 'm'.
 
 Non-builtin vmlinux targets - extra-y
 -------------------------------------
 
-	extra-y specifies targets which are needed for building vmlinux,
-	but not combined into built-in.a.
+extra-y specifies targets which are needed for building vmlinux,
+but not combined into built-in.a.
 
-	Examples are:
+Examples are:
 
-	1) vmlinux linker script
+1) vmlinux linker script
 
-	    The linker script for vmlinux is located at
-	    arch/$(SRCARCH)/kernel/vmlinux.lds
+   The linker script for vmlinux is located at
+   arch/$(SRCARCH)/kernel/vmlinux.lds
 
-	Example::
+Example::
 
-		# arch/x86/kernel/Makefile
-		extra-y	+= vmlinux.lds
+  # arch/x86/kernel/Makefile
+  extra-y	+= vmlinux.lds
 
-	$(extra-y) should only contain targets needed for vmlinux.
+$(extra-y) should only contain targets needed for vmlinux.
 
-	Kbuild skips extra-y when vmlinux is apparently not a final goal.
-	(e.g. 'make modules', or building external modules)
+Kbuild skips extra-y when vmlinux is apparently not a final goal.
+(e.g. 'make modules', or building external modules)
 
-	If you intend to build targets unconditionally, always-y (explained
-	in the next section) is the correct syntax to use.
+If you intend to build targets unconditionally, always-y (explained
+in the next section) is the correct syntax to use.
 
 Always built goals - always-y
 -----------------------------
 
-	always-y specifies targets which are literally always built when
-	Kbuild visits the Makefile.
+always-y specifies targets which are literally always built when
+Kbuild visits the Makefile.
+
+Example::
 
-	Example::
-	  # ./Kbuild
-	  offsets-file := include/generated/asm-offsets.h
-	  always-y += $(offsets-file)
+  # ./Kbuild
+  offsets-file := include/generated/asm-offsets.h
+  always-y += $(offsets-file)
 
 Compilation flags
 -----------------
 
-    ccflags-y, asflags-y and ldflags-y
-	These three flags apply only to the kbuild makefile in which they
-	are assigned. They are used for all the normal cc, as and ld
-	invocations happening during a recursive build.
-	Note: Flags with the same behaviour were previously named:
-	EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS.
-	They are still supported but their usage is deprecated.
+ccflags-y, asflags-y and ldflags-y
+  These three flags apply only to the kbuild makefile in which they
+  are assigned. They are used for all the normal cc, as and ld
+  invocations happening during a recursive build.
+  Note: Flags with the same behaviour were previously named:
+  EXTRA_CFLAGS, EXTRA_AFLAGS and EXTRA_LDFLAGS.
+  They are still supported but their usage is deprecated.
 
-	ccflags-y specifies options for compiling with $(CC).
+  ccflags-y specifies options for compiling with $(CC).
 
-	Example::
+  Example::
 
-		# drivers/acpi/acpica/Makefile
-		ccflags-y			:= -Os -D_LINUX -DBUILDING_ACPICA
-		ccflags-$(CONFIG_ACPI_DEBUG)	+= -DACPI_DEBUG_OUTPUT
+    # drivers/acpi/acpica/Makefile
+    ccflags-y				:= -Os -D_LINUX -DBUILDING_ACPICA
+    ccflags-$(CONFIG_ACPI_DEBUG)	+= -DACPI_DEBUG_OUTPUT
 
-	This variable is necessary because the top Makefile owns the
-	variable $(KBUILD_CFLAGS) and uses it for compilation flags for the
-	entire tree.
+  This variable is necessary because the top Makefile owns the
+  variable $(KBUILD_CFLAGS) and uses it for compilation flags for the
+  entire tree.
 
-	asflags-y specifies assembler options.
+  asflags-y specifies assembler options.
 
-	Example::
+  Example::
 
-		#arch/sparc/kernel/Makefile
-		asflags-y := -ansi
+    #arch/sparc/kernel/Makefile
+    asflags-y := -ansi
 
-	ldflags-y specifies options for linking with $(LD).
+  ldflags-y specifies options for linking with $(LD).
 
-	Example::
+  Example::
 
-		#arch/cris/boot/compressed/Makefile
-		ldflags-y += -T $(srctree)/$(src)/decompress_$(arch-y).lds
+    #arch/cris/boot/compressed/Makefile
+    ldflags-y += -T $(srctree)/$(src)/decompress_$(arch-y).lds
 
-    subdir-ccflags-y, subdir-asflags-y
-	The two flags listed above are similar to ccflags-y and asflags-y.
-	The difference is that the subdir- variants have effect for the kbuild
-	file where they are present and all subdirectories.
-	Options specified using subdir-* are added to the commandline before
-	the options specified using the non-subdir variants.
+subdir-ccflags-y, subdir-asflags-y
+  The two flags listed above are similar to ccflags-y and asflags-y.
+  The difference is that the subdir- variants have effect for the kbuild
+  file where they are present and all subdirectories.
+  Options specified using subdir-* are added to the commandline before
+  the options specified using the non-subdir variants.
 
-	Example::
+  Example::
 
-		subdir-ccflags-y := -Werror
+    subdir-ccflags-y := -Werror
 
-    ccflags-remove-y, asflags-remove-y
-	These flags are used to remove particular flags for the compiler,
-	assembler invocations.
+ccflags-remove-y, asflags-remove-y
+  These flags are used to remove particular flags for the compiler,
+  assembler invocations.
 
-	Example::
+  Example::
 
-		ccflags-remove-$(CONFIG_MCOUNT) += -pg
+    ccflags-remove-$(CONFIG_MCOUNT) += -pg
 
-    CFLAGS_$@, AFLAGS_$@
-	CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
-	kbuild makefile.
+CFLAGS_$@, AFLAGS_$@
+  CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
+  kbuild makefile.
 
-	$(CFLAGS_$@) specifies per-file options for $(CC).  The $@
-	part has a literal value which specifies the file that it is for.
+  $(CFLAGS_$@) specifies per-file options for $(CC).  The $@
+  part has a literal value which specifies the file that it is for.
 
-	CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
-	can re-add compiler flags that were removed by ccflags-remove-y.
+  CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
+  can re-add compiler flags that were removed by ccflags-remove-y.
 
-	Example::
+  Example::
 
-		# drivers/scsi/Makefile
-		CFLAGS_aha152x.o =   -DAHA152X_STAT -DAUTOCONF
+    # drivers/scsi/Makefile
+    CFLAGS_aha152x.o =   -DAHA152X_STAT -DAUTOCONF
 
-	This line specify compilation flags for aha152x.o.
+  This line specify compilation flags for aha152x.o.
 
-	$(AFLAGS_$@) is a similar feature for source files in assembly
-	languages.
+  $(AFLAGS_$@) is a similar feature for source files in assembly
+  languages.
 
-	AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
-	can re-add assembler flags that were removed by asflags-remove-y.
+  AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
+  can re-add assembler flags that were removed by asflags-remove-y.
 
-	Example::
-
-		# arch/arm/kernel/Makefile
-		AFLAGS_head.o        := -DTEXT_OFFSET=$(TEXT_OFFSET)
-		AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
-		AFLAGS_iwmmxt.o      := -Wa,-mcpu=iwmmxt
+  Example::
 
+    # arch/arm/kernel/Makefile
+    AFLAGS_head.o        := -DTEXT_OFFSET=$(TEXT_OFFSET)
+    AFLAGS_crunch-bits.o := -Wa,-mcpu=ep9312
+    AFLAGS_iwmmxt.o      := -Wa,-mcpu=iwmmxt
 
 Dependency tracking
 -------------------
 
-	Kbuild tracks dependencies on the following:
+Kbuild tracks dependencies on the following:
 
-	1) All prerequisite files (both `*.c` and `*.h`)
-	2) `CONFIG_` options used in all prerequisite files
-	3) Command-line used to compile target
+1) All prerequisite files (both `*.c` and `*.h`)
+2) `CONFIG_` options used in all prerequisite files
+3) Command-line used to compile target
 
-	Thus, if you change an option to $(CC) all affected files will
-	be re-compiled.
+Thus, if you change an option to $(CC) all affected files will
+be re-compiled.
 
 Custom Rules
 ------------
 
-	Custom rules are used when the kbuild infrastructure does
-	not provide the required support. A typical example is
-	header files generated during the build process.
-	Another example are the architecture-specific Makefiles which
-	need custom rules to prepare boot images etc.
+Custom rules are used when the kbuild infrastructure does
+not provide the required support. A typical example is
+header files generated during the build process.
+Another example are the architecture-specific Makefiles which
+need custom rules to prepare boot images etc.
 
-	Custom rules are written as normal Make rules.
-	Kbuild is not executing in the directory where the Makefile is
-	located, so all custom rules shall use a relative
-	path to prerequisite files and target files.
+Custom rules are written as normal Make rules.
+Kbuild is not executing in the directory where the Makefile is
+located, so all custom rules shall use a relative
+path to prerequisite files and target files.
 
-	Two variables are used when defining custom rules:
+Two variables are used when defining custom rules:
 
-	$(src)
-	    $(src) is a relative path which points to the directory
-	    where the Makefile is located. Always use $(src) when
-	    referring to files located in the src tree.
+$(src)
+  $(src) is a relative path which points to the directory
+  where the Makefile is located. Always use $(src) when
+  referring to files located in the src tree.
 
-	$(obj)
-	    $(obj) is a relative path which points to the directory
-	    where the target is saved. Always use $(obj) when
-	    referring to generated files.
+$(obj)
+  $(obj) is a relative path which points to the directory
+  where the target is saved. Always use $(obj) when
+  referring to generated files.
 
-	    Example::
+  Example::
 
-		#drivers/scsi/Makefile
-		$(obj)/53c8xx_d.h: $(src)/53c7,8xx.scr $(src)/script_asm.pl
-			$(CPP) -DCHIP=810 - < $< | ... $(src)/script_asm.pl
+    #drivers/scsi/Makefile
+    $(obj)/53c8xx_d.h: $(src)/53c7,8xx.scr $(src)/script_asm.pl
+    $(CPP) -DCHIP=810 - < $< | ... $(src)/script_asm.pl
 
-	    This is a custom rule, following the normal syntax
-	    required by make.
+  This is a custom rule, following the normal syntax
+  required by make.
 
-	    The target file depends on two prerequisite files. References
-	    to the target file are prefixed with $(obj), references
-	    to prerequisites are referenced with $(src) (because they are not
-	    generated files).
+  The target file depends on two prerequisite files. References
+  to the target file are prefixed with $(obj), references
+  to prerequisites are referenced with $(src) (because they are not
+  generated files).
 
-	$(kecho)
-	    echoing information to user in a rule is often a good practice
-	    but when execution "make -s" one does not expect to see any output
-	    except for warnings/errors.
-	    To support this kbuild defines $(kecho) which will echo out the
-	    text following $(kecho) to stdout except if "make -s" is used.
+$(kecho)
+  echoing information to user in a rule is often a good practice
+  but when execution "make -s" one does not expect to see any output
+  except for warnings/errors.
+  To support this kbuild defines $(kecho) which will echo out the
+  text following $(kecho) to stdout except if "make -s" is used.
 
-	Example::
+  Example::
 
-		# arch/arm/Makefile
-		$(BOOT_TARGETS): vmlinux
-			$(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $(boot)/$@
-			@$(kecho) '  Kernel: $(boot)/$@ is ready'
+    # arch/arm/Makefile
+    $(BOOT_TARGETS): vmlinux
+            $(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $(boot)/$@
+            @$(kecho) '  Kernel: $(boot)/$@ is ready'
 
-	When kbuild is executing with KBUILD_VERBOSE unset, then only a shorthand
-	of a command is normally displayed.
-	To enable this behaviour for custom commands kbuild requires
-	two variables to be set::
+  When kbuild is executing with KBUILD_VERBOSE unset, then only a shorthand
+  of a command is normally displayed.
+  To enable this behaviour for custom commands kbuild requires
+  two variables to be set::
 
-		quiet_cmd_<command>	- what shall be echoed
-		      cmd_<command>	- the command to execute
+    quiet_cmd_<command> - what shall be echoed
+          cmd_<command> - the command to execute
 
-	Example::
+  Example::
 
-		# lib/Makefile
-		quiet_cmd_crc32 = GEN     $@
-		      cmd_crc32 = $< > $@
+    # lib/Makefile
+    quiet_cmd_crc32 = GEN     $@
+          cmd_crc32 = $< > $@
 
-		$(obj)/crc32table.h: $(obj)/gen_crc32table
-			$(call cmd,crc32)
+    $(obj)/crc32table.h: $(obj)/gen_crc32table
+            $(call cmd,crc32)
 
-	When updating the $(obj)/crc32table.h target, the line:
+  When updating the $(obj)/crc32table.h target, the line::
 
-		  GEN     lib/crc32table.h
+    GEN     lib/crc32table.h
 
-	will be displayed with "make KBUILD_VERBOSE=".
+  will be displayed with "make KBUILD_VERBOSE=".
 
 Command change detection
 ------------------------
 
-	When the rule is evaluated, timestamps are compared between the target
-	and its prerequisite files. GNU Make updates the target when any of the
-	prerequisites is newer than that.
+When the rule is evaluated, timestamps are compared between the target
+and its prerequisite files. GNU Make updates the target when any of the
+prerequisites is newer than that.
 
-	The target should be rebuilt also when the command line has changed
-	since the last invocation. This is not supported by Make itself, so
-	Kbuild achieves this by a kind of meta-programming.
+The target should be rebuilt also when the command line has changed
+since the last invocation. This is not supported by Make itself, so
+Kbuild achieves this by a kind of meta-programming.
 
-	if_changed is the macro used for this purpose, in the following form::
+if_changed is the macro used for this purpose, in the following form::
 
-		quiet_cmd_<command> = ...
-		      cmd_<command> = ...
+  quiet_cmd_<command> = ...
+        cmd_<command> = ...
 
-		<target>: <source(s)> FORCE
-			$(call if_changed,<command>)
+  <target>: <source(s)> FORCE
+          $(call if_changed,<command>)
 
-	Any target that utilizes if_changed must be listed in $(targets),
-	otherwise the command line check will fail, and the target will
-	always be built.
+Any target that utilizes if_changed must be listed in $(targets),
+otherwise the command line check will fail, and the target will
+always be built.
 
-	If the target is already listed in the recognized syntax such as
-	obj-y/m, lib-y/m, extra-y/m, always-y/m, hostprogs, userprogs, Kbuild
-	automatically adds it to $(targets). Otherwise, the target must be
-	explicitly added to $(targets).
+If the target is already listed in the recognized syntax such as
+obj-y/m, lib-y/m, extra-y/m, always-y/m, hostprogs, userprogs, Kbuild
+automatically adds it to $(targets). Otherwise, the target must be
+explicitly added to $(targets).
 
-	Assignments to $(targets) are without $(obj)/ prefix. if_changed may be
-	used in conjunction with custom rules as defined in `Custom Rules`_.
+Assignments to $(targets) are without $(obj)/ prefix. if_changed may be
+used in conjunction with custom rules as defined in `Custom Rules`_.
 
-	Note: It is a typical mistake to forget the FORCE prerequisite.
-	Another common pitfall is that whitespace is sometimes significant; for
-	instance, the below will fail (note the extra space after the comma)::
+Note: It is a typical mistake to forget the FORCE prerequisite.
+Another common pitfall is that whitespace is sometimes significant; for
+instance, the below will fail (note the extra space after the comma)::
 
-		target: source(s) FORCE
+  target: source(s) FORCE
 
-	**WRONG!**	$(call if_changed, objcopy)
+**WRONG!**	$(call if_changed, objcopy)
 
-	Note:
-		if_changed should not be used more than once per target.
-		It stores the executed command in a corresponding .cmd
-		file and multiple calls would result in overwrites and
-		unwanted results when the target is up to date and only the
-		tests on changed commands trigger execution of commands.
+Note:
+  if_changed should not be used more than once per target.
+  It stores the executed command in a corresponding .cmd
+  file and multiple calls would result in overwrites and
+  unwanted results when the target is up to date and only the
+  tests on changed commands trigger execution of commands.
 
 $(CC) support functions
 -----------------------
 
-	The kernel may be built with several different versions of
-	$(CC), each supporting a unique set of features and options.
-	kbuild provides basic support to check for valid options for $(CC).
-	$(CC) is usually the gcc compiler, but other alternatives are
-	available.
+The kernel may be built with several different versions of
+$(CC), each supporting a unique set of features and options.
+kbuild provides basic support to check for valid options for $(CC).
+$(CC) is usually the gcc compiler, but other alternatives are
+available.
+
+as-option
+  as-option is used to check if $(CC) -- when used to compile
+  assembler (`*.S`) files -- supports the given option. An optional
+  second option may be specified if the first option is not supported.
+
+  Example::
+
+    #arch/sh/Makefile
+    cflags-y += $(call as-option,-Wa$(comma)-isa=$(isa-y),)
 
-    as-option
-	as-option is used to check if $(CC) -- when used to compile
-	assembler (`*.S`) files -- supports the given option. An optional
-	second option may be specified if the first option is not supported.
+  In the above example, cflags-y will be assigned the option
+  -Wa$(comma)-isa=$(isa-y) if it is supported by $(CC).
+  The second argument is optional, and if supplied will be used
+  if first argument is not supported.
 
-	Example::
+as-instr
+  as-instr checks if the assembler reports a specific instruction
+  and then outputs either option1 or option2
+  C escapes are supported in the test instruction
+  Note: as-instr-option uses KBUILD_AFLAGS for assembler options
 
-		#arch/sh/Makefile
-		cflags-y += $(call as-option,-Wa$(comma)-isa=$(isa-y),)
+cc-option
+  cc-option is used to check if $(CC) supports a given option, and if
+  not supported to use an optional second option.
 
-	In the above example, cflags-y will be assigned the option
-	-Wa$(comma)-isa=$(isa-y) if it is supported by $(CC).
-	The second argument is optional, and if supplied will be used
-	if first argument is not supported.
+  Example::
 
-    as-instr
-	as-instr checks if the assembler reports a specific instruction
-	and then outputs either option1 or option2
-	C escapes are supported in the test instruction
-	Note: as-instr-option uses KBUILD_AFLAGS for assembler options
+    #arch/x86/Makefile
+    cflags-y += $(call cc-option,-march=pentium-mmx,-march=i586)
 
-    cc-option
-	cc-option is used to check if $(CC) supports a given option, and if
-	not supported to use an optional second option.
+  In the above example, cflags-y will be assigned the option
+  -march=pentium-mmx if supported by $(CC), otherwise -march=i586.
+  The second argument to cc-option is optional, and if omitted,
+  cflags-y will be assigned no value if first option is not supported.
+  Note: cc-option uses KBUILD_CFLAGS for $(CC) options
 
-	Example::
+cc-option-yn
+  cc-option-yn is used to check if gcc supports a given option
+  and return 'y' if supported, otherwise 'n'.
 
-		#arch/x86/Makefile
-		cflags-y += $(call cc-option,-march=pentium-mmx,-march=i586)
+  Example::
 
-	In the above example, cflags-y will be assigned the option
-	-march=pentium-mmx if supported by $(CC), otherwise -march=i586.
-	The second argument to cc-option is optional, and if omitted,
-	cflags-y will be assigned no value if first option is not supported.
-	Note: cc-option uses KBUILD_CFLAGS for $(CC) options
+    #arch/ppc/Makefile
+    biarch := $(call cc-option-yn, -m32)
+    aflags-$(biarch) += -a32
+    cflags-$(biarch) += -m32
 
-   cc-option-yn
-	cc-option-yn is used to check if gcc supports a given option
-	and return 'y' if supported, otherwise 'n'.
+  In the above example, $(biarch) is set to y if $(CC) supports the -m32
+  option. When $(biarch) equals 'y', the expanded variables $(aflags-y)
+  and $(cflags-y) will be assigned the values -a32 and -m32,
+  respectively.
 
-	Example::
+  Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
 
-		#arch/ppc/Makefile
-		biarch := $(call cc-option-yn, -m32)
-		aflags-$(biarch) += -a32
-		cflags-$(biarch) += -m32
+cc-disable-warning
+  cc-disable-warning checks if gcc supports a given warning and returns
+  the commandline switch to disable it. This special function is needed,
+  because gcc 4.4 and later accept any unknown -Wno-* option and only
+  warn about it if there is another warning in the source file.
 
-	In the above example, $(biarch) is set to y if $(CC) supports the -m32
-	option. When $(biarch) equals 'y', the expanded variables $(aflags-y)
-	and $(cflags-y) will be assigned the values -a32 and -m32,
-	respectively.
-	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
+  Example::
 
-    cc-disable-warning
-	cc-disable-warning checks if gcc supports a given warning and returns
-	the commandline switch to disable it. This special function is needed,
-	because gcc 4.4 and later accept any unknown -Wno-* option and only
-	warn about it if there is another warning in the source file.
+    KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 
-	Example::
+  In the above example, -Wno-unused-but-set-variable will be added to
+  KBUILD_CFLAGS only if gcc really accepts it.
 
-		KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
+gcc-min-version
+  gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than
+  or equal to the provided value and evaluates to y if so.
 
-	In the above example, -Wno-unused-but-set-variable will be added to
-	KBUILD_CFLAGS only if gcc really accepts it.
+  Example::
 
-    gcc-min-version
-	gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is greater than
-	or equal to the provided value and evaluates to y if so.
+    cflags-$(call gcc-min-version, 70100) := -foo
 
-	Example::
+  In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
+  $(CONFIG_GCC_VERSION) is >= 7.1.
 
-		cflags-$(call gcc-min-version, 70100) := -foo
+clang-min-version
+  clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater
+  than or equal to the provided value and evaluates to y if so.
 
-	In this example, cflags-y will be assigned the value -foo if $(CC) is gcc and
-	$(CONFIG_GCC_VERSION) is >= 7.1.
+  Example::
 
-    clang-min-version
-	clang-min-version tests if the value of $(CONFIG_CLANG_VERSION) is greater
-	than or equal to the provided value and evaluates to y if so.
+    cflags-$(call clang-min-version, 110000) := -foo
 
-	Example::
+  In this example, cflags-y will be assigned the value -foo if $(CC) is clang
+  and $(CONFIG_CLANG_VERSION) is >= 11.0.0.
 
-		cflags-$(call clang-min-version, 110000) := -foo
+cc-cross-prefix
+  cc-cross-prefix is used to check if there exists a $(CC) in path with
+  one of the listed prefixes. The first prefix where there exist a
+  prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found
+  then nothing is returned.
 
-	In this example, cflags-y will be assigned the value -foo if $(CC) is clang
-	and $(CONFIG_CLANG_VERSION) is >= 11.0.0.
+  Additional prefixes are separated by a single space in the
+  call of cc-cross-prefix.
 
-    cc-cross-prefix
-	cc-cross-prefix is used to check if there exists a $(CC) in path with
-	one of the listed prefixes. The first prefix where there exist a
-	prefix$(CC) in the PATH is returned - and if no prefix$(CC) is found
-	then nothing is returned.
-	Additional prefixes are separated by a single space in the
-	call of cc-cross-prefix.
-	This functionality is useful for architecture Makefiles that try
-	to set CROSS_COMPILE to well-known values but may have several
-	values to select between.
-	It is recommended only to try to set CROSS_COMPILE if it is a cross
-	build (host arch is different from target arch). And if CROSS_COMPILE
-	is already set then leave it with the old value.
+  This functionality is useful for architecture Makefiles that try
+  to set CROSS_COMPILE to well-known values but may have several
+  values to select between.
 
-	Example::
+  It is recommended only to try to set CROSS_COMPILE if it is a cross
+  build (host arch is different from target arch). And if CROSS_COMPILE
+  is already set then leave it with the old value.
 
-		#arch/m68k/Makefile
-		ifneq ($(SUBARCH),$(ARCH))
-		        ifeq ($(CROSS_COMPILE),)
-		               CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-)
-			endif
-		endif
+  Example::
+
+    #arch/m68k/Makefile
+    ifneq ($(SUBARCH),$(ARCH))
+            ifeq ($(CROSS_COMPILE),)
+                    CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu-)
+            endif
+    endif
 
 $(LD) support functions
 -----------------------
 
-    ld-option
-	ld-option is used to check if $(LD) supports the supplied option.
-	ld-option takes two options as arguments.
-	The second argument is an optional option that can be used if the
-	first option is not supported by $(LD).
+ld-option
+  ld-option is used to check if $(LD) supports the supplied option.
+  ld-option takes two options as arguments.
+
+  The second argument is an optional option that can be used if the
+  first option is not supported by $(LD).
 
-	Example::
+  Example::
 
-		#Makefile
-		LDFLAGS_vmlinux += $(call ld-option, -X)
+    #Makefile
+    LDFLAGS_vmlinux += $(call ld-option, -X)
 
 Script invocation
 -----------------
 
-	Make rules may invoke scripts to build the kernel. The rules shall
-	always provide the appropriate interpreter to execute the script. They
-	shall not rely on the execute bits being set, and shall not invoke the
-	script directly. For the convenience of manual script invocation, such
-	as invoking ./scripts/checkpatch.pl, it is recommended to set execute
-	bits on the scripts nonetheless.
+Make rules may invoke scripts to build the kernel. The rules shall
+always provide the appropriate interpreter to execute the script. They
+shall not rely on the execute bits being set, and shall not invoke the
+script directly. For the convenience of manual script invocation, such
+as invoking ./scripts/checkpatch.pl, it is recommended to set execute
+bits on the scripts nonetheless.
 
-	Kbuild provides variables $(CONFIG_SHELL), $(AWK), $(PERL),
-	and $(PYTHON3) to refer to interpreters for the respective
-	scripts.
+Kbuild provides variables $(CONFIG_SHELL), $(AWK), $(PERL),
+and $(PYTHON3) to refer to interpreters for the respective
+scripts.
 
-	Example::
+Example::
 
-		#Makefile
-		cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
-			     $(KERNELRELEASE)
+  #Makefile
+  cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
+          $(KERNELRELEASE)
 
 Host Program support
 ====================
 
 Kbuild supports building executables on the host for use during the
 compilation stage.
+
 Two steps are required in order to use a host executable.
 
 The first step is to tell kbuild that a host program exists. This is
@@ -703,154 +710,157 @@ Both possibilities are described in the following.
 Simple Host Program
 -------------------
 
-	In some cases there is a need to compile and run a program on the
-	computer where the build is running.
-	The following line tells kbuild that the program bin2hex shall be
-	built on the build host.
+In some cases there is a need to compile and run a program on the
+computer where the build is running.
+
+The following line tells kbuild that the program bin2hex shall be
+built on the build host.
 
-	Example::
+Example::
 
-		hostprogs := bin2hex
+  hostprogs := bin2hex
 
-	Kbuild assumes in the above example that bin2hex is made from a single
-	c-source file named bin2hex.c located in the same directory as
-	the Makefile.
+Kbuild assumes in the above example that bin2hex is made from a single
+c-source file named bin2hex.c located in the same directory as
+the Makefile.
 
 Composite Host Programs
 -----------------------
 
-	Host programs can be made up based on composite objects.
-	The syntax used to define composite objects for host programs is
-	similar to the syntax used for kernel objects.
-	$(<executable>-objs) lists all objects used to link the final
-	executable.
+Host programs can be made up based on composite objects.
+The syntax used to define composite objects for host programs is
+similar to the syntax used for kernel objects.
+$(<executable>-objs) lists all objects used to link the final
+executable.
 
-	Example::
+Example::
 
-		#scripts/lxdialog/Makefile
-		hostprogs     := lxdialog
-		lxdialog-objs := checklist.o lxdialog.o
+  #scripts/lxdialog/Makefile
+  hostprogs     := lxdialog
+  lxdialog-objs := checklist.o lxdialog.o
 
-	Objects with extension .o are compiled from the corresponding .c
-	files. In the above example, checklist.c is compiled to checklist.o
-	and lxdialog.c is compiled to lxdialog.o.
+Objects with extension .o are compiled from the corresponding .c
+files. In the above example, checklist.c is compiled to checklist.o
+and lxdialog.c is compiled to lxdialog.o.
 
-	Finally, the two .o files are linked to the executable, lxdialog.
-	Note: The syntax <executable>-y is not permitted for host-programs.
+Finally, the two .o files are linked to the executable, lxdialog.
+Note: The syntax <executable>-y is not permitted for host-programs.
 
 Using C++ for host programs
 ---------------------------
 
-	kbuild offers support for host programs written in C++. This was
-	introduced solely to support kconfig, and is not recommended
-	for general use.
+kbuild offers support for host programs written in C++. This was
+introduced solely to support kconfig, and is not recommended
+for general use.
 
-	Example::
+Example::
 
-		#scripts/kconfig/Makefile
-		hostprogs     := qconf
-		qconf-cxxobjs := qconf.o
+  #scripts/kconfig/Makefile
+  hostprogs     := qconf
+  qconf-cxxobjs := qconf.o
 
-	In the example above the executable is composed of the C++ file
-	qconf.cc - identified by $(qconf-cxxobjs).
+In the example above the executable is composed of the C++ file
+qconf.cc - identified by $(qconf-cxxobjs).
 
-	If qconf is composed of a mixture of .c and .cc files, then an
-	additional line can be used to identify this.
+If qconf is composed of a mixture of .c and .cc files, then an
+additional line can be used to identify this.
 
-	Example::
+Example::
 
-		#scripts/kconfig/Makefile
-		hostprogs     := qconf
-		qconf-cxxobjs := qconf.o
-		qconf-objs    := check.o
+  #scripts/kconfig/Makefile
+  hostprogs     := qconf
+  qconf-cxxobjs := qconf.o
+  qconf-objs    := check.o
 
 Using Rust for host programs
 ----------------------------
 
-	Kbuild offers support for host programs written in Rust. However,
-	since a Rust toolchain is not mandatory for kernel compilation,
-	it may only be used in scenarios where Rust is required to be
-	available (e.g. when  ``CONFIG_RUST`` is enabled).
+Kbuild offers support for host programs written in Rust. However,
+since a Rust toolchain is not mandatory for kernel compilation,
+it may only be used in scenarios where Rust is required to be
+available (e.g. when  ``CONFIG_RUST`` is enabled).
 
-	Example::
+Example::
 
-		hostprogs     := target
-		target-rust   := y
+  hostprogs     := target
+  target-rust   := y
 
-	Kbuild will compile ``target`` using ``target.rs`` as the crate root,
-	located in the same directory as the ``Makefile``. The crate may
-	consist of several source files (see ``samples/rust/hostprogs``).
+Kbuild will compile ``target`` using ``target.rs`` as the crate root,
+located in the same directory as the ``Makefile``. The crate may
+consist of several source files (see ``samples/rust/hostprogs``).
 
 Controlling compiler options for host programs
 ----------------------------------------------
 
-	When compiling host programs, it is possible to set specific flags.
-	The programs will always be compiled utilising $(HOSTCC) passed
-	the options specified in $(KBUILD_HOSTCFLAGS).
-	To set flags that will take effect for all host programs created
-	in that Makefile, use the variable HOST_EXTRACFLAGS.
+When compiling host programs, it is possible to set specific flags.
+The programs will always be compiled utilising $(HOSTCC) passed
+the options specified in $(KBUILD_HOSTCFLAGS).
 
-	Example::
+To set flags that will take effect for all host programs created
+in that Makefile, use the variable HOST_EXTRACFLAGS.
 
-		#scripts/lxdialog/Makefile
-		HOST_EXTRACFLAGS += -I/usr/include/ncurses
+Example::
 
-	To set specific flags for a single file the following construction
-	is used:
+  #scripts/lxdialog/Makefile
+  HOST_EXTRACFLAGS += -I/usr/include/ncurses
 
-	Example::
+To set specific flags for a single file the following construction
+is used:
 
-		#arch/ppc64/boot/Makefile
-		HOSTCFLAGS_piggyback.o := -DKERNELBASE=$(KERNELBASE)
+Example::
 
-	It is also possible to specify additional options to the linker.
+  #arch/ppc64/boot/Makefile
+  HOSTCFLAGS_piggyback.o := -DKERNELBASE=$(KERNELBASE)
 
-	Example::
+It is also possible to specify additional options to the linker.
 
-		#scripts/kconfig/Makefile
-		HOSTLDLIBS_qconf := -L$(QTDIR)/lib
+Example::
 
-	When linking qconf, it will be passed the extra option
-	"-L$(QTDIR)/lib".
+  #scripts/kconfig/Makefile
+  HOSTLDLIBS_qconf := -L$(QTDIR)/lib
+
+When linking qconf, it will be passed the extra option
+"-L$(QTDIR)/lib".
 
 When host programs are actually built
 -------------------------------------
 
-	Kbuild will only build host-programs when they are referenced
-	as a prerequisite.
-	This is possible in two ways:
+Kbuild will only build host-programs when they are referenced
+as a prerequisite.
+
+This is possible in two ways:
 
-	(1) List the prerequisite explicitly in a custom rule.
+(1) List the prerequisite explicitly in a custom rule.
 
-	Example::
+    Example::
 
-		#drivers/pci/Makefile
-		hostprogs := gen-devlist
-		$(obj)/devlist.h: $(src)/pci.ids $(obj)/gen-devlist
-			( cd $(obj); ./gen-devlist ) < $<
+      #drivers/pci/Makefile
+      hostprogs := gen-devlist
+      $(obj)/devlist.h: $(src)/pci.ids $(obj)/gen-devlist
+      ( cd $(obj); ./gen-devlist ) < $<
 
-	The target $(obj)/devlist.h will not be built before
-	$(obj)/gen-devlist is updated. Note that references to
-	the host programs in custom rules must be prefixed with $(obj).
+    The target $(obj)/devlist.h will not be built before
+    $(obj)/gen-devlist is updated. Note that references to
+    the host programs in custom rules must be prefixed with $(obj).
 
-	(2) Use always-y
+(2) Use always-y
 
-	When there is no suitable custom rule, and the host program
-	shall be built when a makefile is entered, the always-y
-	variable shall be used.
+    When there is no suitable custom rule, and the host program
+    shall be built when a makefile is entered, the always-y
+    variable shall be used.
 
-	Example::
+    Example::
 
-		#scripts/lxdialog/Makefile
-		hostprogs     := lxdialog
-		always-y      := $(hostprogs)
+      #scripts/lxdialog/Makefile
+      hostprogs     := lxdialog
+      always-y      := $(hostprogs)
 
-	Kbuild provides the following shorthand for this:
+    Kbuild provides the following shorthand for this::
 
-		hostprogs-always-y := lxdialog
+      hostprogs-always-y := lxdialog
 
-	This will tell kbuild to build lxdialog even if not referenced in
-	any rule.
+    This will tell kbuild to build lxdialog even if not referenced in
+    any rule.
 
 Userspace Program support
 =========================
@@ -865,100 +875,101 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
 Simple Userspace Program
 ------------------------
 
-	The following line tells kbuild that the program bpf-direct shall be
-	built for the target architecture.
+The following line tells kbuild that the program bpf-direct shall be
+built for the target architecture.
 
-	Example::
+Example::
 
-		userprogs := bpf-direct
+  userprogs := bpf-direct
 
-	Kbuild assumes in the above example that bpf-direct is made from a
-	single C source file named bpf-direct.c located in the same directory
-	as the Makefile.
+Kbuild assumes in the above example that bpf-direct is made from a
+single C source file named bpf-direct.c located in the same directory
+as the Makefile.
 
 Composite Userspace Programs
 ----------------------------
 
-	Userspace programs can be made up based on composite objects.
-	The syntax used to define composite objects for userspace programs is
-	similar to the syntax used for kernel objects.
-	$(<executable>-objs) lists all objects used to link the final
-	executable.
+Userspace programs can be made up based on composite objects.
+The syntax used to define composite objects for userspace programs is
+similar to the syntax used for kernel objects.
+$(<executable>-objs) lists all objects used to link the final
+executable.
 
-	Example::
+Example::
 
-		#samples/seccomp/Makefile
-		userprogs      := bpf-fancy
-		bpf-fancy-objs := bpf-fancy.o bpf-helper.o
+  #samples/seccomp/Makefile
+  userprogs      := bpf-fancy
+  bpf-fancy-objs := bpf-fancy.o bpf-helper.o
 
-	Objects with extension .o are compiled from the corresponding .c
-	files. In the above example, bpf-fancy.c is compiled to bpf-fancy.o
-	and bpf-helper.c is compiled to bpf-helper.o.
+Objects with extension .o are compiled from the corresponding .c
+files. In the above example, bpf-fancy.c is compiled to bpf-fancy.o
+and bpf-helper.c is compiled to bpf-helper.o.
 
-	Finally, the two .o files are linked to the executable, bpf-fancy.
-	Note: The syntax <executable>-y is not permitted for userspace programs.
+Finally, the two .o files are linked to the executable, bpf-fancy.
+Note: The syntax <executable>-y is not permitted for userspace programs.
 
 Controlling compiler options for userspace programs
 ---------------------------------------------------
 
-	When compiling userspace programs, it is possible to set specific flags.
-	The programs will always be compiled utilising $(CC) passed
-	the options specified in $(KBUILD_USERCFLAGS).
-	To set flags that will take effect for all userspace programs created
-	in that Makefile, use the variable userccflags.
+When compiling userspace programs, it is possible to set specific flags.
+The programs will always be compiled utilising $(CC) passed
+the options specified in $(KBUILD_USERCFLAGS).
+
+To set flags that will take effect for all userspace programs created
+in that Makefile, use the variable userccflags.
 
-	Example::
+Example::
 
-		# samples/seccomp/Makefile
-		userccflags += -I usr/include
+  # samples/seccomp/Makefile
+  userccflags += -I usr/include
 
-	To set specific flags for a single file the following construction
-	is used:
+To set specific flags for a single file the following construction
+is used:
 
-	Example::
+Example::
 
-		bpf-helper-userccflags += -I user/include
+  bpf-helper-userccflags += -I user/include
 
-	It is also possible to specify additional options to the linker.
+It is also possible to specify additional options to the linker.
 
-	Example::
+Example::
 
-		# net/bpfilter/Makefile
-		bpfilter_umh-userldflags += -static
+  # net/bpfilter/Makefile
+  bpfilter_umh-userldflags += -static
 
-	When linking bpfilter_umh, it will be passed the extra option -static.
+When linking bpfilter_umh, it will be passed the extra option -static.
 
-	From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
+From command line, :ref:`USERCFLAGS and USERLDFLAGS <userkbuildflags>` will also be used.
 
 When userspace programs are actually built
 ------------------------------------------
 
-	Kbuild builds userspace programs only when told to do so.
-	There are two ways to do this.
+Kbuild builds userspace programs only when told to do so.
+There are two ways to do this.
 
-	(1) Add it as the prerequisite of another file
+(1) Add it as the prerequisite of another file
 
-	Example::
+    Example::
 
-		#net/bpfilter/Makefile
-		userprogs := bpfilter_umh
-		$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+      #net/bpfilter/Makefile
+      userprogs := bpfilter_umh
+      $(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
 
-	$(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
+    $(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
 
-	(2) Use always-y
+(2) Use always-y
 
-	Example::
+    Example::
 
-		userprogs := binderfs_example
-		always-y := $(userprogs)
+      userprogs := binderfs_example
+      always-y := $(userprogs)
 
-	Kbuild provides the following shorthand for this:
+    Kbuild provides the following shorthand for this::
 
-		userprogs-always-y := binderfs_example
+      userprogs-always-y := binderfs_example
 
-	This will tell Kbuild to build binderfs_example when it visits this
-	Makefile.
+    This will tell Kbuild to build binderfs_example when it visits this
+    Makefile.
 
 Kbuild clean infrastructure
 ===========================
@@ -974,10 +985,10 @@ source tree when "make clean" is executed.
 Additional files or directories can be specified in kbuild makefiles by use of
 $(clean-files).
 
-	Example::
+Example::
 
-		#lib/Makefile
-		clean-files := crc32table.h
+  #lib/Makefile
+  clean-files := crc32table.h
 
 When executing "make clean", the file "crc32table.h" will be deleted.
 Kbuild will assume files to be in the same relative directory as the
@@ -990,10 +1001,10 @@ Usually kbuild descends down in subdirectories due to "obj-* := dir/",
 but in the architecture makefiles where the kbuild infrastructure
 is not sufficient this sometimes needs to be explicit.
 
-	Example::
+Example::
 
-		#arch/x86/boot/Makefile
-		subdir- := compressed
+  #arch/x86/boot/Makefile
+  subdir- := compressed
 
 The above assignment instructs kbuild to descend down in the
 directory compressed/ when "make clean" is executed.
@@ -1010,442 +1021,461 @@ Architecture Makefiles
 
 The top level Makefile sets up the environment and does the preparation,
 before starting to descend down in the individual directories.
+
 The top level makefile contains the generic part, whereas
 arch/$(SRCARCH)/Makefile contains what is required to set up kbuild
 for said architecture.
+
 To do so, arch/$(SRCARCH)/Makefile sets up a number of variables and defines
 a few targets.
 
 When kbuild executes, the following steps are followed (roughly):
 
 1) Configuration of the kernel => produce .config
+
 2) Store kernel version in include/linux/version.h
+
 3) Updating all other prerequisites to the target prepare:
+
    - Additional prerequisites are specified in arch/$(SRCARCH)/Makefile
+
 4) Recursively descend down in all directories listed in
    init-* core* drivers-* net-* libs-* and build all targets.
+
    - The values of the above variables are expanded in arch/$(SRCARCH)/Makefile.
+
 5) All object files are then linked and the resulting file vmlinux is
    located at the root of the obj tree.
    The very first objects linked are listed in scripts/head-object-list.txt.
+
 6) Finally, the architecture-specific part does any required post processing
    and builds the final bootimage.
+
    - This includes building boot records
    - Preparing initrd images and the like
 
-
 Set variables to tweak the build to the architecture
 ----------------------------------------------------
 
-    KBUILD_LDFLAGS
-	Generic $(LD) options
+KBUILD_LDFLAGS
+  Generic $(LD) options
 
-	Flags used for all invocations of the linker.
-	Often specifying the emulation is sufficient.
+  Flags used for all invocations of the linker.
+  Often specifying the emulation is sufficient.
 
-	Example::
+  Example::
 
-		#arch/s390/Makefile
-		KBUILD_LDFLAGS         := -m elf_s390
+    #arch/s390/Makefile
+    KBUILD_LDFLAGS         := -m elf_s390
 
-	Note: ldflags-y can be used to further customise
-	the flags used. See `Non-builtin vmlinux targets - extra-y`_.
+  Note: ldflags-y can be used to further customise
+  the flags used. See `Non-builtin vmlinux targets - extra-y`_.
 
-    LDFLAGS_vmlinux
-	Options for $(LD) when linking vmlinux
+LDFLAGS_vmlinux
+  Options for $(LD) when linking vmlinux
 
-	LDFLAGS_vmlinux is used to specify additional flags to pass to
-	the linker when linking the final vmlinux image.
-	LDFLAGS_vmlinux uses the LDFLAGS_$@ support.
+  LDFLAGS_vmlinux is used to specify additional flags to pass to
+  the linker when linking the final vmlinux image.
 
-	Example::
+  LDFLAGS_vmlinux uses the LDFLAGS_$@ support.
 
-		#arch/x86/Makefile
-		LDFLAGS_vmlinux := -e stext
+  Example::
 
-    OBJCOPYFLAGS
-	objcopy flags
+    #arch/x86/Makefile
+    LDFLAGS_vmlinux := -e stext
 
-	When $(call if_changed,objcopy) is used to translate a .o file,
-	the flags specified in OBJCOPYFLAGS will be used.
-	$(call if_changed,objcopy) is often used to generate raw binaries on
-	vmlinux.
+OBJCOPYFLAGS
+  objcopy flags
 
-	Example::
+  When $(call if_changed,objcopy) is used to translate a .o file,
+  the flags specified in OBJCOPYFLAGS will be used.
 
-		#arch/s390/Makefile
-		OBJCOPYFLAGS := -O binary
+  $(call if_changed,objcopy) is often used to generate raw binaries on
+  vmlinux.
 
-		#arch/s390/boot/Makefile
-		$(obj)/image: vmlinux FORCE
-			$(call if_changed,objcopy)
+  Example::
 
-	In this example, the binary $(obj)/image is a binary version of
-	vmlinux. The usage of $(call if_changed,xxx) will be described later.
+    #arch/s390/Makefile
+    OBJCOPYFLAGS := -O binary
 
-    KBUILD_AFLAGS
-	Assembler flags
+    #arch/s390/boot/Makefile
+    $(obj)/image: vmlinux FORCE
+            $(call if_changed,objcopy)
 
-	Default value - see top level Makefile
-	Append or modify as required per architecture.
+  In this example, the binary $(obj)/image is a binary version of
+  vmlinux. The usage of $(call if_changed,xxx) will be described later.
 
-	Example::
+KBUILD_AFLAGS
+  Assembler flags
 
-		#arch/sparc64/Makefile
-		KBUILD_AFLAGS += -m64 -mcpu=ultrasparc
+  Default value - see top level Makefile.
 
-    KBUILD_CFLAGS
-	$(CC) compiler flags
+  Append or modify as required per architecture.
 
-	Default value - see top level Makefile
-	Append or modify as required per architecture.
+  Example::
 
-	Often, the KBUILD_CFLAGS variable depends on the configuration.
+    #arch/sparc64/Makefile
+    KBUILD_AFLAGS += -m64 -mcpu=ultrasparc
 
-	Example::
+KBUILD_CFLAGS
+  $(CC) compiler flags
 
-		#arch/x86/boot/compressed/Makefile
-		cflags-$(CONFIG_X86_32) := -march=i386
-		cflags-$(CONFIG_X86_64) := -mcmodel=small
-		KBUILD_CFLAGS += $(cflags-y)
+  Default value - see top level Makefile.
 
-	Many arch Makefiles dynamically run the target C compiler to
-	probe supported options::
+  Append or modify as required per architecture.
 
-		#arch/x86/Makefile
+  Often, the KBUILD_CFLAGS variable depends on the configuration.
 
-		...
-		cflags-$(CONFIG_MPENTIUMII)     += $(call cc-option,\
-						-march=pentium2,-march=i686)
-		...
-		# Disable unit-at-a-time mode ...
-		KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time)
-		...
+  Example::
+
+    #arch/x86/boot/compressed/Makefile
+    cflags-$(CONFIG_X86_32) := -march=i386
+    cflags-$(CONFIG_X86_64) := -mcmodel=small
+    KBUILD_CFLAGS += $(cflags-y)
+
+  Many arch Makefiles dynamically run the target C compiler to
+  probe supported options::
+
+    #arch/x86/Makefile
 
+    ...
+    cflags-$(CONFIG_MPENTIUMII)     += $(call cc-option,\
+						-march=pentium2,-march=i686)
+    ...
+    # Disable unit-at-a-time mode ...
+    KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time)
+    ...
 
-	The first example utilises the trick that a config option expands
-	to 'y' when selected.
 
-    KBUILD_RUSTFLAGS
-	$(RUSTC) compiler flags
+  The first example utilises the trick that a config option expands
+  to 'y' when selected.
 
-	Default value - see top level Makefile
-	Append or modify as required per architecture.
+KBUILD_RUSTFLAGS
+  $(RUSTC) compiler flags
 
-	Often, the KBUILD_RUSTFLAGS variable depends on the configuration.
+  Default value - see top level Makefile.
 
-	Note that target specification file generation (for ``--target``)
-	is handled in ``scripts/generate_rust_target.rs``.
+  Append or modify as required per architecture.
 
-    KBUILD_AFLAGS_KERNEL
-	Assembler options specific for built-in
+  Often, the KBUILD_RUSTFLAGS variable depends on the configuration.
 
-	$(KBUILD_AFLAGS_KERNEL) contains extra C compiler flags used to compile
-	resident kernel code.
+  Note that target specification file generation (for ``--target``)
+  is handled in ``scripts/generate_rust_target.rs``.
 
-    KBUILD_AFLAGS_MODULE
-	Assembler options specific for modules
+KBUILD_AFLAGS_KERNEL
+  Assembler options specific for built-in
 
-	$(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that
-	are used for assembler.
+  $(KBUILD_AFLAGS_KERNEL) contains extra C compiler flags used to compile
+  resident kernel code.
 
-	From commandline AFLAGS_MODULE shall be used (see kbuild.rst).
+KBUILD_AFLAGS_MODULE
+  Assembler options specific for modules
 
-    KBUILD_CFLAGS_KERNEL
-	$(CC) options specific for built-in
+  $(KBUILD_AFLAGS_MODULE) is used to add arch-specific options that
+  are used for assembler.
 
-	$(KBUILD_CFLAGS_KERNEL) contains extra C compiler flags used to compile
-	resident kernel code.
+  From commandline AFLAGS_MODULE shall be used (see kbuild.rst).
 
-    KBUILD_CFLAGS_MODULE
-	Options for $(CC) when building modules
+KBUILD_CFLAGS_KERNEL
+  $(CC) options specific for built-in
 
-	$(KBUILD_CFLAGS_MODULE) is used to add arch-specific options that
-	are used for $(CC).
-	From commandline CFLAGS_MODULE shall be used (see kbuild.rst).
+  $(KBUILD_CFLAGS_KERNEL) contains extra C compiler flags used to compile
+  resident kernel code.
 
-    KBUILD_RUSTFLAGS_KERNEL
-	$(RUSTC) options specific for built-in
+KBUILD_CFLAGS_MODULE
+  Options for $(CC) when building modules
 
-	$(KBUILD_RUSTFLAGS_KERNEL) contains extra Rust compiler flags used to
-	compile resident kernel code.
+  $(KBUILD_CFLAGS_MODULE) is used to add arch-specific options that
+  are used for $(CC).
 
-    KBUILD_RUSTFLAGS_MODULE
-	Options for $(RUSTC) when building modules
+  From commandline CFLAGS_MODULE shall be used (see kbuild.rst).
 
-	$(KBUILD_RUSTFLAGS_MODULE) is used to add arch-specific options that
-	are used for $(RUSTC).
-	From commandline RUSTFLAGS_MODULE shall be used (see kbuild.rst).
+KBUILD_RUSTFLAGS_KERNEL
+  $(RUSTC) options specific for built-in
 
-    KBUILD_LDFLAGS_MODULE
-	Options for $(LD) when linking modules
+  $(KBUILD_RUSTFLAGS_KERNEL) contains extra Rust compiler flags used to
+  compile resident kernel code.
 
-	$(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options
-	used when linking modules. This is often a linker script.
+KBUILD_RUSTFLAGS_MODULE
+  Options for $(RUSTC) when building modules
 
-	From commandline LDFLAGS_MODULE shall be used (see kbuild.rst).
+  $(KBUILD_RUSTFLAGS_MODULE) is used to add arch-specific options that
+  are used for $(RUSTC).
 
-    KBUILD_LDS
+  From commandline RUSTFLAGS_MODULE shall be used (see kbuild.rst).
 
-	The linker script with full path. Assigned by the top-level Makefile.
+KBUILD_LDFLAGS_MODULE
+  Options for $(LD) when linking modules
 
-    KBUILD_LDS_MODULE
+  $(KBUILD_LDFLAGS_MODULE) is used to add arch-specific options
+  used when linking modules. This is often a linker script.
 
-	The module linker script with full path. Assigned by the top-level
-	Makefile and additionally by the arch Makefile.
+  From commandline LDFLAGS_MODULE shall be used (see kbuild.rst).
 
-    KBUILD_VMLINUX_OBJS
+KBUILD_LDS
+  The linker script with full path. Assigned by the top-level Makefile.
 
-	All object files for vmlinux. They are linked to vmlinux in the same
-	order as listed in KBUILD_VMLINUX_OBJS.
+KBUILD_LDS_MODULE
+  The module linker script with full path. Assigned by the top-level
+  Makefile and additionally by the arch Makefile.
 
-	The objects listed in scripts/head-object-list.txt are exceptions;
-	they are placed before the other objects.
+KBUILD_VMLINUX_OBJS
+  All object files for vmlinux. They are linked to vmlinux in the same
+  order as listed in KBUILD_VMLINUX_OBJS.
 
-    KBUILD_VMLINUX_LIBS
+  The objects listed in scripts/head-object-list.txt are exceptions;
+  they are placed before the other objects.
 
-	All .a "lib" files for vmlinux. KBUILD_VMLINUX_OBJS and
-	KBUILD_VMLINUX_LIBS together specify all the object files used to
-	link vmlinux.
+KBUILD_VMLINUX_LIBS
+  All .a "lib" files for vmlinux. KBUILD_VMLINUX_OBJS and
+  KBUILD_VMLINUX_LIBS together specify all the object files used to
+  link vmlinux.
 
 Add prerequisites to archheaders
 --------------------------------
 
-	The archheaders: rule is used to generate header files that
-	may be installed into user space by "make header_install".
-
-	It is run before "make archprepare" when run on the
-	architecture itself.
+The archheaders: rule is used to generate header files that
+may be installed into user space by "make header_install".
 
+It is run before "make archprepare" when run on the
+architecture itself.
 
 Add prerequisites to archprepare
 --------------------------------
 
-	The archprepare: rule is used to list prerequisites that need to be
-	built before starting to descend down in the subdirectories.
-	This is usually used for header files containing assembler constants.
+The archprepare: rule is used to list prerequisites that need to be
+built before starting to descend down in the subdirectories.
 
-	Example::
+This is usually used for header files containing assembler constants.
 
-		#arch/arm/Makefile
-		archprepare: maketools
+Example::
 
-	In this example, the file target maketools will be processed
-	before descending down in the subdirectories.
-	See also chapter XXX-TODO that describes how kbuild supports
-	generating offset header files.
+  #arch/arm/Makefile
+  archprepare: maketools
 
+In this example, the file target maketools will be processed
+before descending down in the subdirectories.
+
+See also chapter XXX-TODO that describes how kbuild supports
+generating offset header files.
 
 List directories to visit when descending
 -----------------------------------------
 
-	An arch Makefile cooperates with the top Makefile to define variables
-	which specify how to build the vmlinux file.  Note that there is no
-	corresponding arch-specific section for modules; the module-building
-	machinery is all architecture-independent.
-
+An arch Makefile cooperates with the top Makefile to define variables
+which specify how to build the vmlinux file.  Note that there is no
+corresponding arch-specific section for modules; the module-building
+machinery is all architecture-independent.
 
-	core-y, libs-y, drivers-y
+core-y, libs-y, drivers-y
+  $(libs-y) lists directories where a lib.a archive can be located.
 
-	    $(libs-y) lists directories where a lib.a archive can be located.
+  The rest list directories where a built-in.a object file can be
+  located.
 
-	    The rest list directories where a built-in.a object file can be
-	    located.
+  Then the rest follows in this order:
 
-	    Then the rest follows in this order:
+    $(core-y), $(libs-y), $(drivers-y)
 
-		$(core-y), $(libs-y), $(drivers-y)
+  The top level Makefile defines values for all generic directories,
+  and arch/$(SRCARCH)/Makefile only adds architecture-specific
+  directories.
 
-	    The top level Makefile defines values for all generic directories,
-	    and arch/$(SRCARCH)/Makefile only adds architecture-specific
-	    directories.
+  Example::
 
-	    Example::
+    # arch/sparc/Makefile
+    core-y                 += arch/sparc/
 
-		# arch/sparc/Makefile
-		core-y                 += arch/sparc/
+    libs-y                 += arch/sparc/prom/
+    libs-y                 += arch/sparc/lib/
 
-		libs-y                 += arch/sparc/prom/
-		libs-y                 += arch/sparc/lib/
-
-		drivers-$(CONFIG_PM) += arch/sparc/power/
+    drivers-$(CONFIG_PM) += arch/sparc/power/
 
 Architecture-specific boot images
 ---------------------------------
 
-	An arch Makefile specifies goals that take the vmlinux file, compress
-	it, wrap it in bootstrapping code, and copy the resulting files
-	somewhere. This includes various kinds of installation commands.
-	The actual goals are not standardized across architectures.
+An arch Makefile specifies goals that take the vmlinux file, compress
+it, wrap it in bootstrapping code, and copy the resulting files
+somewhere. This includes various kinds of installation commands.
+The actual goals are not standardized across architectures.
+
+It is common to locate any additional processing in a boot/
+directory below arch/$(SRCARCH)/.
 
-	It is common to locate any additional processing in a boot/
-	directory below arch/$(SRCARCH)/.
+Kbuild does not provide any smart way to support building a
+target specified in boot/. Therefore arch/$(SRCARCH)/Makefile shall
+call make manually to build a target in boot/.
 
-	Kbuild does not provide any smart way to support building a
-	target specified in boot/. Therefore arch/$(SRCARCH)/Makefile shall
-	call make manually to build a target in boot/.
+The recommended approach is to include shortcuts in
+arch/$(SRCARCH)/Makefile, and use the full path when calling down
+into the arch/$(SRCARCH)/boot/Makefile.
 
-	The recommended approach is to include shortcuts in
-	arch/$(SRCARCH)/Makefile, and use the full path when calling down
-	into the arch/$(SRCARCH)/boot/Makefile.
+Example::
 
-	Example::
+  #arch/x86/Makefile
+  boot := arch/x86/boot
+  bzImage: vmlinux
+          $(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
 
-		#arch/x86/Makefile
-		boot := arch/x86/boot
-		bzImage: vmlinux
-			$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+"$(Q)$(MAKE) $(build)=<dir>" is the recommended way to invoke
+make in a subdirectory.
 
-	"$(Q)$(MAKE) $(build)=<dir>" is the recommended way to invoke
-	make in a subdirectory.
+There are no rules for naming architecture-specific targets,
+but executing "make help" will list all relevant targets.
+To support this, $(archhelp) must be defined.
 
-	There are no rules for naming architecture-specific targets,
-	but executing "make help" will list all relevant targets.
-	To support this, $(archhelp) must be defined.
+Example::
 
-	Example::
+  #arch/x86/Makefile
+  define archhelp
+    echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
+  endif
 
-		#arch/x86/Makefile
-		define archhelp
-		  echo  '* bzImage      - Compressed kernel image (arch/x86/boot/bzImage)'
-		endif
+When make is executed without arguments, the first goal encountered
+will be built. In the top level Makefile the first goal present
+is all:.
 
-	When make is executed without arguments, the first goal encountered
-	will be built. In the top level Makefile the first goal present
-	is all:.
-	An architecture shall always, per default, build a bootable image.
-	In "make help", the default goal is highlighted with a '*'.
-	Add a new prerequisite to all: to select a default goal different
-	from vmlinux.
+An architecture shall always, per default, build a bootable image.
+In "make help", the default goal is highlighted with a '*'.
 
-	Example::
+Add a new prerequisite to all: to select a default goal different
+from vmlinux.
 
-		#arch/x86/Makefile
-		all: bzImage
+Example::
 
-	When "make" is executed without arguments, bzImage will be built.
+  #arch/x86/Makefile
+  all: bzImage
+
+When "make" is executed without arguments, bzImage will be built.
 
 Commands useful for building a boot image
 -----------------------------------------
 
-    Kbuild provides a few macros that are useful when building a
-    boot image.
+Kbuild provides a few macros that are useful when building a
+boot image.
+
+ld
+  Link target. Often, LDFLAGS_$@ is used to set specific options to ld.
 
-    ld
-	Link target. Often, LDFLAGS_$@ is used to set specific options to ld.
+  Example::
 
-	Example::
+    #arch/x86/boot/Makefile
+    LDFLAGS_bootsect := -Ttext 0x0 -s --oformat binary
+    LDFLAGS_setup    := -Ttext 0x0 -s --oformat binary -e begtext
 
-		#arch/x86/boot/Makefile
-		LDFLAGS_bootsect := -Ttext 0x0 -s --oformat binary
-		LDFLAGS_setup    := -Ttext 0x0 -s --oformat binary -e begtext
+    targets += setup setup.o bootsect bootsect.o
+    $(obj)/setup $(obj)/bootsect: %: %.o FORCE
+            $(call if_changed,ld)
 
-		targets += setup setup.o bootsect bootsect.o
-		$(obj)/setup $(obj)/bootsect: %: %.o FORCE
-			$(call if_changed,ld)
+  In this example, there are two possible targets, requiring different
+  options to the linker. The linker options are specified using the
+  LDFLAGS_$@ syntax - one for each potential target.
 
-	In this example, there are two possible targets, requiring different
-	options to the linker. The linker options are specified using the
-	LDFLAGS_$@ syntax - one for each potential target.
-	$(targets) are assigned all potential targets, by which kbuild knows
-	the targets and will:
+  $(targets) are assigned all potential targets, by which kbuild knows
+  the targets and will:
 
-		1) check for commandline changes
-		2) delete target during make clean
+  1) check for commandline changes
+  2) delete target during make clean
 
-	The ": %: %.o" part of the prerequisite is a shorthand that
-	frees us from listing the setup.o and bootsect.o files.
+  The ": %: %.o" part of the prerequisite is a shorthand that
+  frees us from listing the setup.o and bootsect.o files.
 
-	Note:
-	      It is a common mistake to forget the "targets :=" assignment,
-	      resulting in the target file being recompiled for no
-	      obvious reason.
+  Note:
+  It is a common mistake to forget the "targets :=" assignment,
+  resulting in the target file being recompiled for no
+  obvious reason.
 
-    objcopy
-	Copy binary. Uses OBJCOPYFLAGS usually specified in
-	arch/$(SRCARCH)/Makefile.
-	OBJCOPYFLAGS_$@ may be used to set additional options.
+objcopy
+  Copy binary. Uses OBJCOPYFLAGS usually specified in
+  arch/$(SRCARCH)/Makefile.
 
-    gzip
-	Compress target. Use maximum compression to compress target.
+  OBJCOPYFLAGS_$@ may be used to set additional options.
 
-	Example::
+gzip
+  Compress target. Use maximum compression to compress target.
 
-		#arch/x86/boot/compressed/Makefile
-		$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
-			$(call if_changed,gzip)
+  Example::
 
-    dtc
-	Create flattened device tree blob object suitable for linking
-	into vmlinux. Device tree blobs linked into vmlinux are placed
-	in an init section in the image. Platform code *must* copy the
-	blob to non-init memory prior to calling unflatten_device_tree().
+    #arch/x86/boot/compressed/Makefile
+    $(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE
+            $(call if_changed,gzip)
 
-	To use this command, simply add `*.dtb` into obj-y or targets, or make
-	some other target depend on `%.dtb`
+dtc
+  Create flattened device tree blob object suitable for linking
+  into vmlinux. Device tree blobs linked into vmlinux are placed
+  in an init section in the image. Platform code *must* copy the
+  blob to non-init memory prior to calling unflatten_device_tree().
 
-	A central rule exists to create `$(obj)/%.dtb` from `$(src)/%.dts`;
-	architecture Makefiles do no need to explicitly write out that rule.
+  To use this command, simply add `*.dtb` into obj-y or targets, or make
+  some other target depend on `%.dtb`
 
-	Example::
+  A central rule exists to create `$(obj)/%.dtb` from `$(src)/%.dts`;
+  architecture Makefiles do no need to explicitly write out that rule.
 
-		targets += $(dtb-y)
-		DTC_FLAGS ?= -p 1024
+  Example::
+
+    targets += $(dtb-y)
+    DTC_FLAGS ?= -p 1024
 
 Preprocessing linker scripts
 ----------------------------
 
-	When the vmlinux image is built, the linker script
-	arch/$(SRCARCH)/kernel/vmlinux.lds is used.
-	The script is a preprocessed variant of the file vmlinux.lds.S
-	located in the same directory.
-	kbuild knows .lds files and includes a rule `*lds.S` -> `*lds`.
+When the vmlinux image is built, the linker script
+arch/$(SRCARCH)/kernel/vmlinux.lds is used.
+
+The script is a preprocessed variant of the file vmlinux.lds.S
+located in the same directory.
+
+kbuild knows .lds files and includes a rule `*lds.S` -> `*lds`.
+
+Example::
 
-	Example::
+  #arch/x86/kernel/Makefile
+  extra-y := vmlinux.lds
 
-		#arch/x86/kernel/Makefile
-		extra-y := vmlinux.lds
+The assignment to extra-y is used to tell kbuild to build the
+target vmlinux.lds.
 
-	The assignment to extra-y is used to tell kbuild to build the
-	target vmlinux.lds.
-	The assignment to $(CPPFLAGS_vmlinux.lds) tells kbuild to use the
-	specified options when building the target vmlinux.lds.
+The assignment to $(CPPFLAGS_vmlinux.lds) tells kbuild to use the
+specified options when building the target vmlinux.lds.
 
-	When building the `*.lds` target, kbuild uses the variables::
+When building the `*.lds` target, kbuild uses the variables::
 
-		KBUILD_CPPFLAGS	: Set in top-level Makefile
-		cppflags-y	: May be set in the kbuild makefile
-		CPPFLAGS_$(@F)  : Target-specific flags.
-				Note that the full filename is used in this
-				assignment.
+  KBUILD_CPPFLAGS      : Set in top-level Makefile
+  cppflags-y           : May be set in the kbuild makefile
+  CPPFLAGS_$(@F)       : Target-specific flags.
+                         Note that the full filename is used in this
+                         assignment.
 
-	The kbuild infrastructure for `*lds` files is used in several
-	architecture-specific files.
+The kbuild infrastructure for `*lds` files is used in several
+architecture-specific files.
 
 Generic header files
 --------------------
 
-	The directory include/asm-generic contains the header files
-	that may be shared between individual architectures.
-	The recommended approach how to use a generic header file is
-	to list the file in the Kbuild file.
-	See `generic-y`_ for further info on syntax etc.
+The directory include/asm-generic contains the header files
+that may be shared between individual architectures.
+
+The recommended approach how to use a generic header file is
+to list the file in the Kbuild file.
+
+See `generic-y`_ for further info on syntax etc.
 
 Post-link pass
 --------------
 
-	If the file arch/xxx/Makefile.postlink exists, this makefile
-	will be invoked for post-link objects (vmlinux and modules.ko)
-	for architectures to run post-link passes on. Must also handle
-	the clean target.
+If the file arch/xxx/Makefile.postlink exists, this makefile
+will be invoked for post-link objects (vmlinux and modules.ko)
+for architectures to run post-link passes on. Must also handle
+the clean target.
 
-	This pass runs after kallsyms generation. If the architecture
-	needs to modify symbol locations, rather than manipulate the
-	kallsyms, it may be easier to add another postlink target for
-	.tmp_vmlinux? targets to be called from link-vmlinux.sh.
+This pass runs after kallsyms generation. If the architecture
+needs to modify symbol locations, rather than manipulate the
+kallsyms, it may be easier to add another postlink target for
+.tmp_vmlinux? targets to be called from link-vmlinux.sh.
 
-	For example, powerpc uses this to check relocation sanity of
-	the linked vmlinux file.
+For example, powerpc uses this to check relocation sanity of
+the linked vmlinux file.
 
 Kbuild syntax for exported headers
 ==================================
@@ -1453,6 +1483,7 @@ Kbuild syntax for exported headers
 The kernel includes a set of headers that is exported to userspace.
 Many headers can be exported as-is but other headers require a
 minimal pre-processing before they are ready for user-space.
+
 The pre-processing does:
 
 - drop kernel-specific annotations
@@ -1465,136 +1496,136 @@ are exported.
 
 A Kbuild file may be defined under arch/<arch>/include/uapi/asm/ and
 arch/<arch>/include/asm/ to list asm files coming from asm-generic.
+
 See subsequent chapter for the syntax of the Kbuild file.
 
 no-export-headers
 -----------------
 
-	no-export-headers is essentially used by include/uapi/linux/Kbuild to
-	avoid exporting specific headers (e.g. kvm.h) on architectures that do
-	not support it. It should be avoided as much as possible.
+no-export-headers is essentially used by include/uapi/linux/Kbuild to
+avoid exporting specific headers (e.g. kvm.h) on architectures that do
+not support it. It should be avoided as much as possible.
 
 generic-y
 ---------
 
-	If an architecture uses a verbatim copy of a header from
-	include/asm-generic then this is listed in the file
-	arch/$(SRCARCH)/include/asm/Kbuild like this:
+If an architecture uses a verbatim copy of a header from
+include/asm-generic then this is listed in the file
+arch/$(SRCARCH)/include/asm/Kbuild like this:
 
-		Example::
+Example::
 
-			#arch/x86/include/asm/Kbuild
-			generic-y += termios.h
-			generic-y += rtc.h
+  #arch/x86/include/asm/Kbuild
+  generic-y += termios.h
+  generic-y += rtc.h
 
-	During the prepare phase of the build a wrapper include
-	file is generated in the directory::
+During the prepare phase of the build a wrapper include
+file is generated in the directory::
 
-		arch/$(SRCARCH)/include/generated/asm
+  arch/$(SRCARCH)/include/generated/asm
 
-	When a header is exported where the architecture uses
-	the generic header a similar wrapper is generated as part
-	of the set of exported headers in the directory::
+When a header is exported where the architecture uses
+the generic header a similar wrapper is generated as part
+of the set of exported headers in the directory::
 
-		usr/include/asm
+  usr/include/asm
 
-	The generated wrapper will in both cases look like the following:
+The generated wrapper will in both cases look like the following:
 
-		Example: termios.h::
+Example: termios.h::
 
-			#include <asm-generic/termios.h>
+  #include <asm-generic/termios.h>
 
 generated-y
 -----------
 
-	If an architecture generates other header files alongside generic-y
-	wrappers, generated-y specifies them.
+If an architecture generates other header files alongside generic-y
+wrappers, generated-y specifies them.
 
-	This prevents them being treated as stale asm-generic wrappers and
-	removed.
+This prevents them being treated as stale asm-generic wrappers and
+removed.
 
-		Example::
+Example::
 
-			#arch/x86/include/asm/Kbuild
-			generated-y += syscalls_32.h
+  #arch/x86/include/asm/Kbuild
+  generated-y += syscalls_32.h
 
 mandatory-y
 -----------
 
-	mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild
-	to define the minimum set of ASM headers that all architectures must have.
+mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild
+to define the minimum set of ASM headers that all architectures must have.
 
-	This works like optional generic-y. If a mandatory header is missing
-	in arch/$(SRCARCH)/include/(uapi/)/asm, Kbuild will automatically
-	generate a wrapper of the asm-generic one.
+This works like optional generic-y. If a mandatory header is missing
+in arch/$(SRCARCH)/include/(uapi/)/asm, Kbuild will automatically
+generate a wrapper of the asm-generic one.
 
 Kbuild Variables
 ================
 
 The top Makefile exports the following variables:
 
-    VERSION, PATCHLEVEL, SUBLEVEL, EXTRAVERSION
-	These variables define the current kernel version.  A few arch
-	Makefiles actually use these values directly; they should use
-	$(KERNELRELEASE) instead.
-
-	$(VERSION), $(PATCHLEVEL), and $(SUBLEVEL) define the basic
-	three-part version number, such as "2", "4", and "0".  These three
-	values are always numeric.
-
-	$(EXTRAVERSION) defines an even tinier sublevel for pre-patches
-	or additional patches.	It is usually some non-numeric string
-	such as "-pre4", and is often blank.
-
-    KERNELRELEASE
-	$(KERNELRELEASE) is a single string such as "2.4.0-pre4", suitable
-	for constructing installation directory names or showing in
-	version strings.  Some arch Makefiles use it for this purpose.
-
-    ARCH
-	This variable defines the target architecture, such as "i386",
-	"arm", or "sparc". Some kbuild Makefiles test $(ARCH) to
-	determine which files to compile.
-
-	By default, the top Makefile sets $(ARCH) to be the same as the
-	host system architecture.  For a cross build, a user may
-	override the value of $(ARCH) on the command line::
-
-	    make ARCH=m68k ...
-
-    SRCARCH
-	This variable specifies the directory in arch/ to build.
-
-	ARCH and SRCARCH may not necessarily match. A couple of arch
-	directories are biarch, that is, a single `arch/*/` directory supports
-	both 32-bit and 64-bit.
-
-	For example, you can pass in ARCH=i386, ARCH=x86_64, or ARCH=x86.
-	For all of them, SRCARCH=x86 because arch/x86/ supports	both i386 and
-	x86_64.
-
-    INSTALL_PATH
-	This variable defines a place for the arch Makefiles to install
-	the resident kernel image and System.map file.
-	Use this for architecture-specific install targets.
-
-    INSTALL_MOD_PATH, MODLIB
-	$(INSTALL_MOD_PATH) specifies a prefix to $(MODLIB) for module
-	installation.  This variable is not defined in the Makefile but
-	may be passed in by the user if desired.
-
-	$(MODLIB) specifies the directory for module installation.
-	The top Makefile defines $(MODLIB) to
-	$(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE).  The user may
-	override this value on the command line if desired.
-
-    INSTALL_MOD_STRIP
-	If this variable is specified, it will cause modules to be stripped
-	after they are installed.  If INSTALL_MOD_STRIP is '1', then the
-	default option --strip-debug will be used.  Otherwise, the
-	INSTALL_MOD_STRIP value will be used as the option(s) to the strip
-	command.
-
+VERSION, PATCHLEVEL, SUBLEVEL, EXTRAVERSION
+  These variables define the current kernel version.  A few arch
+  Makefiles actually use these values directly; they should use
+  $(KERNELRELEASE) instead.
+
+  $(VERSION), $(PATCHLEVEL), and $(SUBLEVEL) define the basic
+  three-part version number, such as "2", "4", and "0".  These three
+  values are always numeric.
+
+  $(EXTRAVERSION) defines an even tinier sublevel for pre-patches
+  or additional patches.	It is usually some non-numeric string
+  such as "-pre4", and is often blank.
+
+KERNELRELEASE
+  $(KERNELRELEASE) is a single string such as "2.4.0-pre4", suitable
+  for constructing installation directory names or showing in
+  version strings.  Some arch Makefiles use it for this purpose.
+
+ARCH
+  This variable defines the target architecture, such as "i386",
+  "arm", or "sparc". Some kbuild Makefiles test $(ARCH) to
+  determine which files to compile.
+
+  By default, the top Makefile sets $(ARCH) to be the same as the
+  host system architecture.  For a cross build, a user may
+  override the value of $(ARCH) on the command line::
+
+    make ARCH=m68k ...
+
+SRCARCH
+  This variable specifies the directory in arch/ to build.
+
+  ARCH and SRCARCH may not necessarily match. A couple of arch
+  directories are biarch, that is, a single `arch/*/` directory supports
+  both 32-bit and 64-bit.
+
+  For example, you can pass in ARCH=i386, ARCH=x86_64, or ARCH=x86.
+  For all of them, SRCARCH=x86 because arch/x86/ supports both i386 and
+  x86_64.
+
+INSTALL_PATH
+  This variable defines a place for the arch Makefiles to install
+  the resident kernel image and System.map file.
+  Use this for architecture-specific install targets.
+
+INSTALL_MOD_PATH, MODLIB
+  $(INSTALL_MOD_PATH) specifies a prefix to $(MODLIB) for module
+  installation.  This variable is not defined in the Makefile but
+  may be passed in by the user if desired.
+
+  $(MODLIB) specifies the directory for module installation.
+  The top Makefile defines $(MODLIB) to
+  $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE).  The user may
+  override this value on the command line if desired.
+
+INSTALL_MOD_STRIP
+  If this variable is specified, it will cause modules to be stripped
+  after they are installed.  If INSTALL_MOD_STRIP is '1', then the
+  default option --strip-debug will be used.  Otherwise, the
+  INSTALL_MOD_STRIP value will be used as the option(s) to the strip
+  command.
 
 Makefile language
 =================
-- 
2.34.1




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