kbuild: Add support for an "archheaders" target

Add support for an "archheaders" target.  This target can generate
files that need to be installed for user space by "make
headers_install" or "make headers_install_all".

In order to support "make headers_install_all", it must be able to run
without the tree having to be configured first.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index f47cdefb4d1efc17d4e515df31996f134674649e..ab0a984530d87848435571d857b201484591f73c 100644 (file)
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -33,14 +33,15 @@ This document describes the Linux kernel Makefiles.
 
        === 6 Architecture Makefiles
           --- 6.1 Set variables to tweak the build to the architecture
 
        === 6 Architecture Makefiles
           --- 6.1 Set variables to tweak the build to the architecture

-          --- 6.2 Add prerequisites to archprepare:
-          --- 6.3 List directories to visit when descending
-          --- 6.4 Architecture-specific boot images
-          --- 6.5 Building non-kbuild targets
-          --- 6.6 Commands useful for building a boot image
-          --- 6.7 Custom kbuild commands
-          --- 6.8 Preprocessing linker scripts
-          --- 6.9 Generic header files
+          --- 6.2 Add prerequisites to archheaders:
+          --- 6.3 Add prerequisites to archprepare:
+          --- 6.4 List directories to visit when descending
+          --- 6.5 Architecture-specific boot images
+          --- 6.6 Building non-kbuild targets
+          --- 6.7 Commands useful for building a boot image
+          --- 6.8 Custom kbuild commands
+          --- 6.9 Preprocessing linker scripts
+          --- 6.10 Generic header files

 
        === 7 Kbuild syntax for exported headers
                --- 7.1 header-y
 
        === 7 Kbuild syntax for exported headers
                --- 7.1 header-y


@@ -252,7 +253,7 @@ more details, with real examples.
        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 "6.3 List directories to visit when descending".
+       See also "6.4 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.
 


@@ -974,7 +975,20 @@ When kbuild executes, the following steps are followed (roughly):
        $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic
        mode) if this option is supported by $(AR).
 
        $(KBUILD_ARFLAGS) set by the top level Makefile to "D" (deterministic
        mode) if this option is supported by $(AR).
 

---- 6.2 Add prerequisites to archprepare:
+--- 6.2 Add prerequisites to archheaders:
+
+       The archheaders: rule is used to generate header files that
+       may be installed into user space by "make header_install" or
+       "make headers_install_all".  In order to support
+       "make headers_install_all", this target has to be able to run
+       on an unconfigured tree, or a tree configured for another
+       architecture.
+
+       It is run before "make archprepare" when run on the
+       architecture itself.
+
+
+--- 6.3 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.
 
        The archprepare: rule is used to list prerequisites that need to be
        built before starting to descend down in the subdirectories.


@@ -990,7 +1004,7 @@ When kbuild executes, the following steps are followed (roughly):
        generating offset header files.
 
 
        generating offset header files.
 
 

---- 6.3 List directories to visit when descending
+--- 6.4 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
 
        An arch Makefile cooperates with the top Makefile to define variables
        which specify how to build the vmlinux file.  Note that there is no


@@ -1019,7 +1033,7 @@ When kbuild executes, the following steps are followed (roughly):
                drivers-$(CONFIG_OPROFILE)  += arch/sparc64/oprofile/
 
 
                drivers-$(CONFIG_OPROFILE)  += arch/sparc64/oprofile/
 
 

---- 6.4 Architecture-specific boot images
+--- 6.5 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
 
        An arch Makefile specifies goals that take the vmlinux file, compress
        it, wrap it in bootstrapping code, and copy the resulting files


@@ -1070,7 +1084,7 @@ When kbuild executes, the following steps are followed (roughly):
 
        When "make" is executed without arguments, bzImage will be built.
 
 
        When "make" is executed without arguments, bzImage will be built.
 

---- 6.5 Building non-kbuild targets
+--- 6.6 Building non-kbuild targets

 
     extra-y
 
 
     extra-y
 


@@ -1090,7 +1104,7 @@ When kbuild executes, the following steps are followed (roughly):
        shall be built, but shall not be linked as part of built-in.o.
 
 
        shall be built, but shall not be linked as part of built-in.o.
 
 

---- 6.6 Commands useful for building a boot image
+--- 6.7 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.


@@ -1112,7 +1126,7 @@ When kbuild executes, the following steps are followed (roughly):
        always be built.
        Assignments to $(targets) are without $(obj)/ prefix.
        if_changed may be used in conjunction with custom commands as
        always be built.
        Assignments to $(targets) are without $(obj)/ prefix.
        if_changed may be used in conjunction with custom commands as

-       defined in 6.7 "Custom kbuild commands".
+       defined in 6.8 "Custom kbuild commands".

 
        Note: It is a typical mistake to forget the FORCE prerequisite.
        Another common pitfall is that whitespace is sometimes
 
        Note: It is a typical mistake to forget the FORCE prerequisite.
        Another common pitfall is that whitespace is sometimes


@@ -1171,7 +1185,7 @@ When kbuild executes, the following steps are followed (roughly):
                $(obj)/%.dtb: $(src)/%.dts
                        $(call cmd,dtc)
 
                $(obj)/%.dtb: $(src)/%.dts
                        $(call cmd,dtc)
 

---- 6.7 Custom kbuild commands
+--- 6.8 Custom kbuild commands

 
        When kbuild is executing with KBUILD_VERBOSE=0, then only a shorthand
        of a command is normally displayed.
 
        When kbuild is executing with KBUILD_VERBOSE=0, then only a shorthand
        of a command is normally displayed.


@@ -1198,7 +1212,7 @@ When kbuild executes, the following steps are followed (roughly):
        will be displayed with "make KBUILD_VERBOSE=0".
 
 
        will be displayed with "make KBUILD_VERBOSE=0".
 
 

---- 6.8 Preprocessing linker scripts
+--- 6.9 Preprocessing linker scripts

 
        When the vmlinux image is built, the linker script
        arch/$(ARCH)/kernel/vmlinux.lds is used.
 
        When the vmlinux image is built, the linker script
        arch/$(ARCH)/kernel/vmlinux.lds is used.


@@ -1228,7 +1242,7 @@ When kbuild executes, the following steps are followed (roughly):
        The kbuild infrastructure for *lds file are used in several
        architecture-specific files.
 
        The kbuild infrastructure for *lds file are used in several
        architecture-specific files.
 

---- 6.9 Generic header files
+--- 6.10 Generic header files

 
        The directory include/asm-generic contains the header files
        that may be shared between individual architectures.
 
        The directory include/asm-generic contains the header files
        that may be shared between individual architectures.

diff --git a/Makefile b/Makefile
index dab8610c4d6f63a2cc589764596e07229dd7c761..e5e0e075fa1b7bbff1057bc9224f51fb759051cd 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -442,7 +442,7 @@ asm-generic:
 
 no-dot-config-targets := clean mrproper distclean \
                         cscope gtags TAGS tags help %docs check% coccicheck \
 
 no-dot-config-targets := clean mrproper distclean \
                         cscope gtags TAGS tags help %docs check% coccicheck \

-                        include/linux/version.h headers_% \
+                        include/linux/version.h headers_% archheaders \

                         kernelversion %src-pkg
 
 config-targets := 0
                         kernelversion %src-pkg
 
 config-targets := 0


@@ -979,7 +979,7 @@ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
                    include/config/auto.conf
        $(cmd_crmodverdir)
 
                    include/config/auto.conf
        $(cmd_crmodverdir)
 

-archprepare: prepare1 scripts_basic
+archprepare: archheaders prepare1 scripts_basic

 
 prepare0: archprepare FORCE
        $(Q)$(MAKE) $(build)=.
 
 prepare0: archprepare FORCE
        $(Q)$(MAKE) $(build)=.


@@ -1046,8 +1046,11 @@ hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
 # If we do an all arch process set dst to asm-$(hdr-arch)
 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
 
 # If we do an all arch process set dst to asm-$(hdr-arch)
 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
 

+PHONY += archheaders
+archheaders:
+

 PHONY += __headers
 PHONY += __headers

-__headers: include/linux/version.h scripts_basic asm-generic FORCE
+__headers: include/linux/version.h scripts_basic asm-generic archheaders FORCE

        $(Q)$(MAKE) $(build)=scripts build_unifdef
 
 PHONY += headers_install_all
        $(Q)$(MAKE) $(build)=scripts build_unifdef
 
 PHONY += headers_install_all

diff --git a/scripts/headers.sh b/scripts/headers.sh
index 978b42b3acd7e59519bdc74540a180da25e8c607..af1ed881008727ad01dca92a6e13c00d8ba110aa 100755 (executable)
--- a/scripts/headers.sh
+++ b/scripts/headers.sh
@@ -7,6 +7,7 @@ set -e
 do_command()
 {
        if [ -f ${srctree}/arch/$2/include/asm/Kbuild ]; then
 do_command()
 {
        if [ -f ${srctree}/arch/$2/include/asm/Kbuild ]; then

+               make ARCH=$2 KBUILD_HEADERS=$1 archheaders

                make ARCH=$2 KBUILD_HEADERS=$1 headers_$1
        else
                printf "Ignoring arch: %s\n" ${arch}
                make ARCH=$2 KBUILD_HEADERS=$1 headers_$1
        else
                printf "Ignoring arch: %s\n" ${arch}