Basic implementation of 'make headers_install'

This adds a make target which exports a subset of headers which contain
definitions which are useful for system libraries and tools. It uses the
BSD 'unifdef' tool to remove instances of #ifdef __KERNEL__, and uses
sed to remove markers like __user.

Based on an original implementation by Arnd Bergmann <arnd@arndb.de>
Hacked about by David Woodhouse <dwmw2@infradead.org>
Reviewed and cleaned up by Sam Ravnborg <sam@ravnborg.org>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 3494c17c9fb9..98e5af72983f 100644
--- a/Makefile
+++ b/Makefile
@@ -856,6 +856,17 @@ depend dep:
         @echo '*** Warning: make $@ is unnecessary now.'
 
 # ---------------------------------------------------------------------------
+# Kernel headers
+INSTALL_HDR_PATH=$(MODLIB)/abi
+export INSTALL_HDR_PATH
+
+PHONY += headers_install
+headers_install: include/linux/version.h
+        $(Q)unifdef -Ux /dev/null
+        $(Q)rm -rf $(INSTALL_HDR_PATH)/include
+        $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.headersinst obj=include
+
+# ---------------------------------------------------------------------------
 # Modules
 
 ifdef CONFIG_MODULES
@@ -1027,6 +1038,8 @@ help:
         @echo  '  cscope          - Generate cscope index'
         @echo  '  kernelrelease   - Output the release version string'
         @echo  '  kernelversion   - Output the version stored in Makefile'
+        @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'
+        @echo  '                    (default: /lib/modules/$$VERSION/abi)'
         @echo  ''
         @echo  'Static analysers'
         @echo  '  checkstack      - Generate a list of stack hogs'